Of The Complexities of Image Quality – Part I – the sensor itself.

Camera & Technology

November 13, 2022 ·

Dan Wells

Sensor Generations

A Nikon D1 – arguably the first successful digital SLR

There are roughly four generations of ancient sensors from the Nikon D1, which many would call the first true DSLR, to what I’m calling the first generation of modern sensors. The first generation around 1999 (let’s use geologic names and call it Cambrian) was represented by the D1, D1x, D1h and many of the old Kodak DSLRs. Dynamic range was less than seven stops by most measures and color was charitably defined as “interesting” – meaning “missing large chunks of sRGB and somewhat unpredictable”. Resolutions were generally 3 mp and below (the D1x was higher, although it used oddly shaped pixels to get there). These were all CCD sensors, and they were at their best at ISOs around 100, with even ISO 400 showing clear noise and artifacts. The second generation, Permian sensors like Canon’s EOS-D30 of the very early 2000s had a couple of important advances over their Cambrian forebears – they had much more standard colors, generally being able to do a credible version of sRGB. Permian sensors were a mixture of CCD and CMOS technologies, and the CMOS sensors in particular could handle substantially higher ISOs than their predecessors. Resolutions ranged from 3 to 6 mp, and like Cambrian sensors, essentially all of them were APS-C.

And a Canon EOS-1Ds with a full-frame CMOS sensor – we still see a lot of full-frame CMOS today.

The Jurassic generation included the 6 to 8 mp CMOS sensors that became standard for several years in the mid-2000s. The earliest full-frame sensors, like the original Canon 1Ds, also fall in the Jurassic generation. They produced a credible image as high as ISO 1600 and even 3200, and there was a real advantage to using an Adobe RGB colorspace at low ISOs. There were a few Jurassic (and even Cretaceous) CCDs, but it was clear that CMOS was the wave of the future, and the CCDs had major disadvantages in high ISO performance. Their dynamic range at low ISOs was as good as most color print films, and they no longer needed the kid-gloves handling of their predecessors to avoid blowing highlights and crushing shadows. Graduated neutral density filters were still needed, but mostly in special situations, rather than in every shot with a sky.

The final generation before the first modern sensors was the Cretaceous – from roughly 2006 to 2010, CCDs were effectively gone, color reached well beyond sRGB to the point that Adobe RGB was a very valuable colorspace for raw editing, not only at low ISOs, but in the midrange as well, and dynamic range was rising. This was the era of low double-digit megapixel counts in APS-C, and it was also the era when full-frame sensors went from one very expensive Canon model to a number of choices from several manufacturers. Cameras like the Canon EOS 5D and 5D mk II and the Nikon D700 made full-frame a mainstream option. High ISO performance was good enough that previously unthinkable ISOs like 6400 and even 12800 were becoming routine. At the end of this generation, we began to see the truly absurd high ISO values around 51200 and above – there were (and are) huge noise penalties, but they allowed shots that could never be captured before.

There are three (or so – the generation lines aren’t neat) technological generations of image sensors that we might still see in everyday photography – and each generation is worth a half to a full stop in overall image quality performance. These are sensor generations that are still sold new, and they are sensors that many of us have in our camera bags.

The X-Pro 1 used one of the first sensors I’d really call modern – the 16 mp Sony APS-C unit that was in everything for a while…

What I would call a first generation modern sensor is rapidly fading even from the used market, although there is actually a first generation sensor sold new. The classic example of a first generation modern sensor is the 16 MP Sony APS-C sensor that appeared in everything from the Nikon D7000 to the first generation of Fujifilm mirrorless cameras (and a lot of other cameras from Sony themselves, Fujifilm, Nikon, Pentax and perhaps others). It was a really good sensor for its day, and I chose to start the generation count with it due not only to its long life (it debuted around 2010, and Fujifilm released their last 16 mp camera in 2018), but because it made important advances in image quality. The earliest 24 mp full-frame sensors (the Nikon D3x and Sony A900) are also first generation, but those are confusing, because there are actually 24 mp Sony full-frame sensors in all three generations, and Nikon for one has managed to use them all over the years (D3x, D750, Z6).The only clearly first generation sensor still on the market (that I know of) is the Even Older Sensor, the 16 mp Micro 4/3 sensor that still appears in a few low-end models like Olympus’ E-PL10 and Panasonic’s GX85.

The 24 mp APS-C sensor in the Sony a6000 is a very common second-generation sensor. Not only have second-generation sensors been around for nine years or so, this particular camera model has as well. The a6000 was released in February of 2014, and still listed as a current model on Sony’s website and at B&H as of Halloween 2022. That has to be some sort of record for any consumer electronics product – it was released before the iPhone 6.

The second generation sensors are very familiar to many of us, because they include most of the ubiquitous 24 MP sensors (both full-frame and APS-C), until the backside-illuminated versions showed up a few years ago. Second-generation sensors don’t have a single defining technology that separates them from the first generation, nor are they always 24 mp. The 36 mp full-frame sensor in various Sonys, Nikons and Pentaxes is second generation in my view. So are the 20 mp Same Old Sensor in Micro 4/3 (that’s arguably first generation) and the 50 mp medium format sensor that has shown up in cameras from Fujifilm, Hasselblad, Phase One, Leaf and Pentax. All but the most recent Canon sensors are second generation or older, with their reduced dynamic range.

I’m cheating a bit – there is no third-generation sensor in this picture. The Pentax K-3 mark III does use one (the 26 mp standard pixel APS-C sensor) when assembled, though – and I thought its rugged frame was a more interesting image than yet another picture of an X-T4, A7r IV or GFX 100s (all more standard cameras that use third-generation sensors). Does Pentax only release one camera every few years because they put three cameras worth of buttons on every one – it has 30 controls, including 15 on the back panel alone – a record?

Most third generation sensors are backside illuminated (BSI), although Canon has achieved third generation performance in several recent sensors without it. Canon’s Dual Pixel sensors are mostly third generation, and all stacked sensors in interchangeable lens cameras are (although they deliberately trade off a bit of image quality for speed). The classic example of a third generation sensor is Sony’s “standard pixel” lineup which come in 26 mp APS-C, 61 mp full-frame, 102 mp medium format (GFX) and 151 mp medium format (Phase One). They all use the same 3.76 µm backside illuminated pixel, and they are all close to or at the present state of the art. They offer a lot of resolution and dynamic range for the sensor size, and they have excellent noise performance. None of them are especially fast sensors, and their modest readout speeds can be an issue for video and electronic shutter work. Other third generation sensors include the 45+ mp full-frame sensor Nikon uses in the D850 and Z7 line and the various stacked sensors found in high-performance cameras from Canon, Sony and Nikon. There are some third generation sensors of relatively modest resolution, even beyond the stacked units in the EOS-R3 and the Sony A9 line. The EOS-R6 mk II sensor is an example, as is the latest generation of the Sony 24 mp full-frame sensor.

There is one sensor just appearing on the market that might be half a generation or even a full generation ahead of the third generation crowd, although the only performance results we have seen from it are very preliminary. It is the 40 mp sensor in the Fujifilm X-H2, and it crams in extra pixels while seeming to maintain per-pixel performance very similar to the standard pixel sensors. Is this the 2022 standard pixel? It’s almost certainly a Sony sensor, since we haven’t known Fujifilm to use anything else in a long time. If it is the first of a line, a full-frame version would be about 93+ megapixels, about 11,800 pixels across (just big enough for 12k video, or for 1.5x oversampled 8k – although not for the cinema versions). A 33x44mm GFX-format version would be just shy of 158 mp, and a 54x40mm Phase One format version would be almost 235 mp (and print 60 inches on the long side at a native 300 dpi).

Will we see it? When will we see it? Do we need it? Assuming that the performance other than resolution is similar to the 3.76µm standard pixel (as it seems to be in preliminary tests), how often do we need the really high resolutions? The only application in which a 102 mp GFX file is superior to a 61 mp full-frame file or even a 26 mp APS-C file is in a substantial print (a high quality 16×24” print to see easily it over 61 mp, about 12×18” to see the advantage over 26 mp). The higher the resolution gets, the bigger the print it takes to see it, and the bigger the print, the bigger the printer and the bigger the wall. The 40 mp APS-C version does have a future-proofing advantage over other APS-C sensors – it captures not only 8k video, but stills large enough to fill an 8k display without resizing. 8k displays are vanishingly rare now, but they may become more common over the lifetime of this sensor generation. Other than APS-C, all the other sizes of the 3.76 µm standard pixel sensor are already 8k compatible.

Sensor Size

Given the same sensor technology generation, there are seven sensor size ranges that are each about a stop apart in overall image quality. Going from one sensor size to the next and holding all else the same – similar sensor “toppings”, a comparable lens and similar processing – is in the same ballpark as turning the ISO dial on your camera up or down a stop.

Common image sensor sizes, late 2022. The APS-C sensor is the Sony/Nikon/Fujifilm/Pentax standard (Canon uses a slightly smaller version). The two iPhone sensors are representative of “standard” and “oversize” phone sensors. The Phase One sensor is a little smaller than a 645 film frame, and full-frame is nearly identical to a 35mm film frame.

A standard-sized cell phone sensor (say an iPhone 12) is at the bottom of the heap, and it is similar to what’s in many cheap ($100) compact cameras, in many action cameras and inexpensive drones, and in cameras with very long built-in lenses. These tiny sensors vary in size, but they’re somewhere around half a centimeter on a side, with areas of around 25 mm2. They’re essentially the size of a frame of old Super 8mm home movie film.

One size up, we find the oversized cell phone sensors seen in a lot of flagship phones such as the iPhone 14 Pro. What stands out about the “high-resolution” phone sensors is not their resolution (that’s mostly a myth – they’re really 12 mp sensors with unusual color filters) ,but that they are physically larger than most other phone sensors. The best of them may have a stop more real information than a standard phone sensor (there are also some 12 mp phone sensors that are significantly larger than average). The iPhone 14 Pro sensor is typical of oversize phone sensors, measuring 9.8mmx7.3mm, with an area of 71.5 mm2, about 3x as large as many small phone sensors.

The next step up is the 1” sensors that are popular in midrange drones and higher-end compact cameras. The name 1” sensor is misleading, because the sensor is not 1” wide (a sensor that is 1”wide is actually an APS-C sensor), it’s certainly not 1” tall (a 1” tall sensor is actually a full-frame sensor). It’s not even 1” on the diagonal (a Micro 4/3 sensor is almost, but not quite 1” on the diagonal). It’s actually 13.2mm by 8.8mm with an area of 116.2 mm2), quite close in size to a frame of Super 16 movie film. It’s a little over 1.5x the size of a large cell phone sensor (iPhone 14 Pro) and between four and five times the size of a small cell phone sensor, but it’s only about half the size of a Micro 4/3 sensor, and it’s only a little over 1/8 the size of a full-frame sensor.

The next size up is the 4/3 sensor used in Micro 4/3 cameras, measuring 17.3mm x 13mm, with an area of 225 mm2. It’s almost exactly the size of 110 film, and it’s right around ¼ the size of a full-frame sensor. 4/3 is the sensor size where we transition from mostly fixed-lens cameras to mostly interchangeable-lens cameras, and we find quite a few of both using this sensor size. High-end compact cameras from Panasonic and Leica use this sensor size, but where we really see it in fixed-lens cameras is in drones like DJI’s popular Mavic 3. The Micro 4/3 system uses this sensor size in a variety of interchangeable-lens cameras ranging from extremely compact low-end models up to the very fast OM System OM-1 and the video-centric Panasonic GH6. Until this year, the 4/3 sensors available on the market were older designs that performed less well than would be expected from their size, closer to 1.5-2 stops behind the best APS-C sensors than the expected 1 stop. Two new sensors debuted in the OM-1 and GH6, with high expectations – but have largely disappointed from the viewpoint of still image quality. The new sensors excel at speed and video, but continue to lag the best of APS-C and full-frame by more than expected if you are looking for a clean, detailed still image with good dynamic range.

Above 4/3, we have the first of the standard interchangeable-lens camera sensor sizes – APS-C. APS-C sensors usually measure just under 24x16mm , with an area of 384 mm2 (Canon and a few minor players use slightly smaller sensors that are also considered APS-C). The obscure APS-C film size the sensors are named after is slightly larger than any APS-C sensor, and the better known Super 35 cinema film size is also slightly larger, but in the same range. APC-C is a bit less than twice the area of Micro 4/3, and a bit less than half the area of full-frame. Unlike 4/3, some of the best performing sensors on the market are available in APS-C, including the Sony “standard pixel” sensors that use a 3.76 µm pixel size. The “standard pixel” sensor in an APS-C size works out to 26 megapixels, and is used in a variety of Fujifilm cameras and one Pentax DSLR (although, perhaps oddly, not in any Sony models except the new FX30, which is really video-only). Fujifilm has just begun to use a new, unprecedently dense, APS-C sensor with 40 megapixels, which seems to be an excellent overall performer in very preliminary results.

The next size up from APS-C (ignoring some odd-sized Canon sensors from more than a decade ago) is full-frame, measuring 24×36 mm with a sensor area of 864 mm2. Full-frame gets its name from sharing dimensions with the standard 35mm film frame used in still photography (both are much larger than most 35mm cinema film frames). For most LuLa readers, full-frame is the sensor size against which the others are measured, and it is the size with the most sensor options for higher-end cameras. Modern full-frame sensors come in resolutions ranging from 12 mp to 61 mp (the 61 mp models use the 3.76µm standard pixel we also find on both smaller and larger sensors) , and in every configuration imaginable. You can get a tiny full-frame camera that fits in a pocket or mounts on a drone (the smallest are the viewfinderless Sigma fp and fp L), or you can get a big dual-grip Nikon Z9 in the preferred body type for sports photographers and war correspondents.

Most full-frame sensors come with standard Bayer color filtration, but not all. They come with no color filter at all, for incredibly sharp monochrome images. They come with modified filters for astrophotography, and with the IR-cut filter removed altogether for infrared photography. Some full-frame sensors used stacked designs that offer incredibly fast readouts for action and video. Modern full-frame sensors offer among the best performance characteristics per sensor area of any sensor size, and they are among the first sensor sizes to benefit from any new technology that improves image quality or camera performance. For most serious amateur, artistic and professional photographers, the question to be answered about any OTHER sensor size is “why not full-frame?”

Until a few years ago, any sensor larger than full-frame was in an extreme niche market. Most of the options were incredibly expensive digital backs ($20,000+, sometimes $40,000-$50,000) for medium format cameras. Many medium format backs continued to use CCD sensors until around 2016 or 2017, even as essentially every smaller-format interchangeable lens camera introduced since 2010 (and most from about 2006 on) used CMOS sensors that offered much better performance at medium and high ISOs, and allowed features like live view. The results from CCD backs at base ISO, often as low as ISO 35, are absolutely gorgeous – but they begin to fall apart by ISO 400. The first medium format CMOS sensors, larger versions of the sensors found in other cameras (and much more flexible than CCDs), appeared in 2014, long after APS-C CMOS sensors were first released in 2000, followed by full-frame versions in 2002. Pentax’s 645Z was the first one-piece medium-format CMOS camera that was comparable in price to a top professional full-frame model, but it was still very heavy and had a primitive autofocus system.

In 2017, Fujifilm and Hasselblad introduced mirrorless medium-format cameras. By eliminating the oversized swinging mirror, camera size and weight declined precipitously – to the point that medium-format mirrorless cameras are the size of midsized full-frame DSLRs, and not much bulkier than most full-frame mirrorless cameras. These cameras also use new lenses designed for digital from the ground up. The one fly in the ointment was that they were still using the 50 mp CMOS sensor from 2014, which was a significant step behind the best full-frame sensors of 2017 – until you account for the effects of sensor area. That sensor used older technology even by 2017 standards, let alone 2022 – and it didn’t share a pixel size with any other sensor, so it didn’t automatically get updated when some other sensor that sold in higher volume did. Since the sensor was 170% the size of a full-frame sensor, it gained back the image quality lost from its technology. This was still an extreme niche market, because 50 mp medium format with the older sensor is only a little better in overall image quality than a full-frame pixel monster with a much newer sensor, the cameras and lenses are more expensive, and it’s much slower.

Enter 2019 – Fujifilm introduces the GFX 100 with a brand-new 102 mp sensor using the 3.76 µm standard pixel, and the image quality is unique! Here’s the potential of (semi) affordable medium format! It’s a big, heavy, unergonomic camera, though – and it’s $10,000 (certainly not $40,000, but much more than $5000+ pro full-framers). In early 2021, they followed up with the GFX 100S – a D850-sized camera with the 102 mp sensor, for a price that’s extremely competitive with pro full-frame ($6000, priced exactly between the $5500 Nikon Z9 and the $6500 Sony A1). It’s a LOT slower than almost any full-frame camera, let alone the very fast models it competes with on price, but oh, those 102 mp GFX files! In late 2022, Hasselblad introduced the H2D 100C with that same 102 mp sensor. Not only is the overall image quality of that oversize sensor a full stop better than any full-frame camera, but it’s using exactly the same sensor technology as a bunch of smaller-format cameras. There’s no reason to think this sensor won’t get updated at the same pace as APS-C and full-frame, so it should maintain its one stop lead as technology improves.

Most of the time, when we talk about medium format digital, we mean 33×44 mm medium format – it’s about the same size as the very obscure 127 rollfilm format, which was usually exposed as a square image a little under 40x40mm. 127 was best known as a copy format, used for Superslides that were copied down from larger format film to provide the best possible image from a standard projector. Projecting even standard 120 medium format transparencies was frightfully expensive, requiring special projectors that often didn’t have the features of standard 35mm units. Projecting large-format film required even more exotic projectors that lacked such conveniences as automatic slide change. Many photographers had their work copied down to 127, the largest format that would project in a regular projector – and National Park gift shops and the like also sold Superslides of famous views (originally photographed on medium or large format film) in their gift shops, so visitors could take home professionally photographed slides that worked in their projector – toss a few in with your vacation memories to show how beautiful the place was. 33x44mm medium format is also close in image area to the smaller variants of 65mm/70mm cinema film! What it’s not close to is true 645 medium format (~40x56mm), let alone any of the larger formats found on 120 rollfilm. There is one final sensor size…

At the ultimate rarefied end of the image sensor market, Sony makes a single, frightfully expensive sensor (at least in the photo market – there may be other sensors of a similar size used for other purposes, at least some of which are classified spy secrets) with dimensions of 40x54mm. It uses the 3.76 µm standard pixel, so it should get updated with everything else when the next iteration of the standard pixel appears. It’s only available in backs from Phase One, at a cost of $40,000 or so. It’s the big brother of the 26 mp APS-C, 61 mp full-frame and 102 mp 33x44mm sensors, and should share a lot of characteristics with them (I’ve never shot one, although I know the other three standard pixel sensors very well).

Sensor Quality

How better to open a section on sensor quality than with an image of the highest quality sensor of all (assuming you don’t work for the CIA) – the business end of a Phase One IQ4 150

There are only two characteristics of the final image affected by the image sensor itself (as opposed to the toppings on the sensor, the lens and everything else that goes into the making of the image).The first is resolution, which is simply, but somewhat misleadingly, defined by the total number of pixels on the sensor. The oversimplification comes in because of the “toppings” filtering the sensor. There are only two cameras sold new today for which the theoretical sensor resolution is actually almost correct at the lens mount. In order to have the full resolution in the final image, you’d also need a near-perfect lens that significantly outresolved the sensor, and there are still sensor “toppings” that have a minor impact on resolution, although these two cameras eliminate the main culprits. Those cameras are the Leica M10 Monochrom (and predecessors) and the Phase One IQ4 150 Achromatic (and predecessors). Even the quickest glance at their spec sheets will reveal a feature (even beyond the price) that places them in a niche market. Neither camera makes color images.

One of the two filters that reduces resolution is present on every other camera on the market, and it is responsible for the fact that cameras take pictures in color. It is the color filter that allows a monochrome image sensor to record a color image. Because it records the color image by filtering each pixel to either red, green or blue, then interpolating the other two colors at each location, the real resolution of a senser with a color filter is somewhere over half of the stated resolution. Half of the pixels in a standard Bayer pattern sensor are filtered to green, the part of the spectrum where human eyes have the greatest sensitivity. The effective resolution is at least the number of green pixels, and the red and blue pixels also contribute something – is the actual effective resolution somewhere around 2/3 or ¾ of the total pixel count?

The second filter that sometimes reduces total resolution is the anti-aliasing or optical low-pass filter. This filter actually reduces resolution on purpose – its job is to blur the image slightly to prevent moiré patterns from repeating detail in the subject interacting with the repeating pattern of the color filter. You can see the effect by holding up two pieces of window screen, one in front of the other. If the two pieces of screen are aligned, everything’s fine. Now rotate one screen by 45 degrees – an odd pattern appears. The low-pass filter combats this by blurring the image slightly so there won’t be sharp repeating lines that could produce moiré – but it also reduces resolution. The higher the sensor’s resolution, the less likely moiré is to be visible (both because it would require a finer and finer pattern in the subject, and because, if it did appear, it might be too small to be visible), so sensors with a higher resolution to begin with often eliminate the low-pass filter.

While both color filters and low-pass filters reduce resolution from what the base sensor can deliver, there are also a couple of factors that can increase apparent resolution. One is that the best sharpening algorithms are quite good at recovering the detail that was lost to the filters, and the other is that resizing has improved greatly, and the final print size and pixel density can be the product of some resizing. Good resizing algorithms are a far cry from the simple nearest-neighbor interpolation that many print drivers perform, and resizing with a good algorithm should be one of the last steps before making a print. Do most of the editing for color, contrast and the like on the image data as it came from the camera, then do the final resize and sharpen in the editing software, a plug-in or the RIP if you are using one right before printing.

There is rarely if ever any harm in having too much resolution going into the process, assuming that the quality per pixel is excellent. If having a lot of pixels means having a lot of lousy pixels (the most glaring example is smartphones’ high-resolution modes), more pixels can be a disadvantage – but, all else being equal, they’re not. If you’re preparing an image for Instagram (where the output size is only about 1 million pixels), you won’t gain anything by starting with a file from a GFX 100S (102 million pixels) rather than an X-T4 (26 million of the same pixels), but you won’t lose anything either. I chose the two Fujifilm cameras for this example because the quality of each individual pixel is so close (the sensor pixels are the same, and the color is very close despite the XTrans/Bayer difference)). More pixels are useful for larger and higher-resolution output.

For screen display (almost no matter what the screen is – 8K displays are the rare exception), resolution doesn’t matter among interchangeable lens cameras. Anything from an inexpensive APS-C camera with a decent lens on up to a Phase One back will have enough resolution that you’re scaling down by quite a bit, and the other aspects of image quality are also likely to be better than the display. Technically, that’s also true of Micro 4/3, but other aspects of image quality can matter, especially with 4K displays, and Micro 4/3 has enough differences in dynamic range and noise to be noticeable on screen, especially at higher ISOs or high dynamic range scenes. A 12 mp smartphone image has more sensor resolution than a 4K display (which is around 8 mp), but it’s close enough that you might wish you had more pixels to deal with quality issues (downsizing an image can reduce noise, for example). Even a 12 mp smartphone has more than enough resolution for the ~1 mp images typical of social media – and the compression social media sites use tends to obscure differences in other aspects of image quality. If the goal is Instagram and friends, use any camera that can get the shot.

For printing, you want a resolution of 600 or 720 dpi at print size for prints that will be viewed closely in hand, or 300 or 360 dpi at print size for large wall prints. Whether you are aiming for 300/600 or 360/720 dpi depends on your printer – all Canons and some Epsons, especially larger models, take 300/600 dpi input. Smaller Epsons tend to be 360/720. Ideally, you’d have that resolution on the sensor, relying on sharpening and resizing only to counteract the effects of the two resolution-stealing filters. By these exacting standards, a good 24 mp camera will print about 7×10” at 600 dpi, or 14×20” at 300 dpi. A 61 mp camera (the highest resolution available outside of medium format) will print almost 12×18” at 600 dpi and above 20×30” at 300 dpi. A 102 mp camera will print about 16×20” at 600 dpi or 30×40” at 300 dpi. Note that the 102 mp medium format camera has a different aspect ratio, and that all print sizes are approximated to the nearest standard size (good resizing will easily take care of those differences).

Realistically, you can certainly resize with care if you’re starting with somewhat less resolution than this, especially if you have a low-ISO file taken with a very good lens. Use a good resizing algorithm, rather than letting the print driver resize. Lightroom Classic, QImage and ImagePrint all have very good algorithms built into their printing functions – but if you’re printing from DxO or Capture One, which don’t have dedicated print modules, or if you’re sending the print to a lab, make sure that you resize and sharpen to the correct size. Going up one print size is easy – don’t worry about resizing a 24 mp APS-C image, or especially the newer 26 mp APS-C image (which is a somewhat better sensor overall, although the resolution is nearly identical) to 12×18” for a very finely detailed image to view in hand. 20×30” is about as far as I’d go for a top-end wall print. A big print like that from 24 mp can look quite good, but the differences are clear next to a print that size from a higher resolution sensor. With a 45-60 mp full-frame pixel monster, a 16×24” print in hand and up to a 30×45” wall print will look quite good. If you’re starting with a 102 mp (or 151 mp) medium format file, the sky’s the limit – your print size is limited by the size of your printer (I’ve tried to run out of resolution and always run out of printer instead)…

All of this is assuming art prints to hang on the wall and look at closely (or, in smaller sizes, to see in hand). For more casual display, more resizing is acceptable – at the absolute extreme, billboards and video walls are often under 10 dpi, because they’re huge, seen from a distance and seen in passing. With larger prints, there is an issue of the resolution of the human eye – as the print gets larger, the viewer needs to be farther from it to see it all at once. This is why a 30×40” print from a 45 mp sensor will look somewhat better than a 20×30” from a ~24 mp sensor of equal quality per pixel – the print resolution is very similar, but a 30×40” print is big enough that you take a step back. This is also why double-resolution (600/720 dpi)print modes are most useful for prints viewed in hand – the difference is still there on a wall print, but the viewer is less likely to be close enough to notice. I’ve seen a variety of numbers for the maximum useful resolution the eye can take in (if the print takes up your central field of view, how much detail can someone with excellent vision see?), and they aren’t that far from the resolution of the highest-resolution sensors – the numbers I’ve encountered are in the range of 120-500 mp. Today’s best sensors, especially medium format, will resize and sharpen right into that range.

The second factor affected directly by the image sensor (color is NOT actually affected by the image sensor, but by the color filter on top of the sensor) is dynamic range, which again has a relatively simple but misleading definition. The simple definition of dynamic range (expressed in bits or stops, they are equivalent in the absence of compression) is expressed mathematically as log2(full well capacity/noise floor). Full well capacity is the number of photons that can strike a single pixel before it simply reports maximum white while noise floor is the point (also expressed as a number of photons) where an incoming photon can no longer be detected reliably because there will be electrical noise obscuring the signal.

A sensor’s analog to digital converter (again, simplistically) counts one electron for each photon it sees at a given pixel, and outputs that count as the brightness value for the pixel – but noise (regardless of the source) causes the converter to count extra electrons. If there are two electrons per pixel of noise on average on a given sensor at a given ISO, there will usually be somewhere between zero and four at any given pixel due to random and patterned variations. If a lone photon provides one count of real signal to the pixel, the reported value will be somewhere between one and five electrons – the signal is completely lost in the noise. If there are sixteen photons of real signal, the value will be between sixteen and twenty electrons – the signal predominates, but there’s significant noise. If the real signal is 256 photons, the value will be between 256 and 260 – the difference is tiny, and the signal overwhelms the noise. If the real signal is 16,380 photons, the noise means the value will be between 16,380 and 16,384 (the maximum value a 14-bit readout can handle) – but 16,380 is just as pure white as 16,384 – the noise makes no difference at all.

Real photographic dynamic range is somewhat less than the simple definition, which is sometimes called engineering dynamic range. How big the difference is depends on the precise definition of photographic dynamic range you are using. They are different because a signal right at the noise floor, where you can first distinguish the signal from the noise, is not terribly photographically useful. It is defined in the Zone System as Zone I, the place where the dark grays are distinguishable from the deepest black the print can contain, but too dark to distinguish detail. In a color print, it is likely to be a very dark, muddy brown. Photographic dynamic range begins in Zone II, the darkest shades with detail (and in color, where different colors become distinguishable). While the Zone System places Zone I exactly a stop of exposure from Zone II, the difference between engineering and photographic dynamic range is often more than that – somewhere around two stops, sometimes more with especially picky ways of measuring photographic dynamic range. The best engineering dynamic range scores given by DxOMark are in the range of 14.7 or 14.8 stops, while the same cameras tested by Photons to Photos show photographic dynamic ranges from 11.6 to 11.85 stops. Photons to Photos is one of the most conservative (lowest dynamic range) sets of measurements around, accounting for the ~3 stop differences..

The list of top cameras is reassuringly very similar, although Photons to Photos also has a number of cameras with dynamic ranges over 12 stops by their measurements that DxOMark didn’t test. All of the 12 stop plus cameras (except for one Sony tested in multi-shot mode and gaining 1.2 stops over a single exposure from the same camera) are medium format, and all except one 50 mp Hasselblad (at 12.01 stops) are using the newest 100 and 150 mp medium format sensors. My opinion from looking at a lot of images (but not doing a lot of measurements myself) is that the ordering of cameras by dynamic range that Photons to Photos and DxOMark mostly agree on is pretty much what I see when working with images from those cameras. The real dynamic range I have to work with is more than Photons to Photos reports, but less than DxOMark reports (some of DxOMark’s numbers are impossible to get into a photograph – more than 14 stops of dynamic range from a 14-bit converter).

Photons to Photos numbers are more comprehensive, in that they report not only maximum dynamic range at base ISO but also dynamic range at other ISOs (you lose about a stop of DR for each stop you raise ISO – sometimes less (or more), depending on how the amplifiers and readouts in a particular camera are structured). Photons to Photos also has quite a few cameras in their database that DxOMark doesn’t, on both ends of the range (plus XTrans cameras DxOMark can’t test with their equipment). From this point on, I’ll be using Photons to Photos numbers throughout – remember that comparisons between cameras, formats and ISOs are good (everything’s in the right order), but the actual numbers are probably too low.

Several factors make a difference in dynamic range, and the comparison charts below try to make at least a little sense of it. Theoretically, ISO should make a one-stop difference per stop of ISO – when you amplify the signal by a stop, you also amplify the noise by a stop. It’s not always that linear in practice, but a stop per stop is a good rule of thumb. A sensor that behaves linearly will show a 45 degree line on the charts below, and most are pretty close to that. The many sensors that show jumps have two (or more) base ISOs, and use different signal paths, one optimized for high dynamic range at low ISO, and the other for lower noise at higher ISO. I’m not sure exactly what the extremely expensive Phase One with the stairstep pattern is doing – it might have signal paths optimized for each whole stop (but why are the intermediate settings completely flat)?

Theory versus practice – the ideal dynamic range line as ISO increases for a full-frame sensor (black) versus a real-life full-frame camera with pronounced dual gain (Nikon Z9, green), and a medium format camera with an unusual stairstep pattern (Phase One IQ4 150, blue)

Sensor size also makes a difference – roughly a stop per sensor size, before taking differences in sensor design and technology into account. Newer sensors tend to do better than older sensors, with the exception that stacked sensors do slightly worse than comparable non-stacked sensors. The stacked sensor is much faster, with advantages in frames per second, video, flash sync, etc. but it loses some dynamic range (and ultimate image quality potential). Different designs and manufacturing techniques can make a tremendous difference – older Canon sensors were routinely as much as a couple of stops worse than contemporary Sony-based sensors, although Canon has caught up more recently.

The effect of sensor size on dynamic range in theory. The upper (black) line is an ideal full-frame sensor, the middle (green) line is APS-C, and the lower (blue) line is Micro 4/3. Photons to Photos didn’t have any calculated values for larger sensors.

The effect of sensor size on dynamic range in practice. The upper (black) line is the medium
format GFX 100S, the middle line is the full frame A7r IV, and the lower line is the APS C X
-T4.
They all use exactly the same sensor technology, in different sizes
There’s no substitute for sensor size– the medium format GFX 100S traces the ideal line for a theoretical full-frame sensor very closely, and is actually above it from ISO 800 on up. The same is true at smaller sizes – a good real-world full-frame camera in 2022 can exceed the theoretical maximum performance of APS-C, and a good APS-C camera can exceed the theoretical performance of Micro 4/3.
The A7r IV against… The A7r IV (in APS-C crop mode). This is a pure example of sensor size
effects in the real world. It’s the same camera, so all other variables are the same.
Three modern full-frame pixel monsters (EOS-R5, A7r IV, Z7 II) – the differences are not worth worrying about. The curve shapes are slightly different due to amplification strategies, but everybody’s within 1/3 stop for the whole ISO range. If you want more, you need medium format
The effects of sensor generation (Sony edition). Two Sony 24 mp full-frame sensors. The upper line is the A7 III –using Sony’s most modern 24 mp sensor – while the lower line is the A900 DSLR that introduced the first 24 mp full-frame sensor. The difference is one to two stops, depending on ISO.
The effects of generation are even more pronounced when comparing Canons to Canons. There are nearly 4 stops of difference between the original EOS-5D and the current EOS-R5 at low ISO!
Here’s why I’m so hard on Micro 4/3. The GH6 is nearly four stops behind the state of the art (GFX 100S), and the OM-1 is nearly three stops behind at low ISO.
Medium format isn’t fair? Here are the $2000 2022 model Micro 4/3 flagships (GH6 in blue, OM-1 in green) against a humble APS-C X-T30 that was introduced in early 2019 and costs $900. The GH6 loses by 2 full stops at ISO 200.
This REALLY isn’t fair – an iPhone (XS Max – Photons to Photos didn’t have anything newer) against the GFX. Not only is there a 5+ stop difference (the markers that look like 4 stops are very low ISOs on the phone – like ISO 12…), the iPhone is using heavy noise reduction at every stop. A more modern iPhone might gain one stop of real DR, but the noise reduction would actually get heavier – most of the gains in modern iPhones come through computational photography.


Thank you to Photons to Photos https://www.photonstophotos.net/Charts/PDR.htm and Bill Clapp for a remarkable tool for exploring the effects of every conceivable factor on dynamic range.

How much dynamic range do we really need? Certainly no more than the scene holds. Reductio ad absurdum, if all we were doing was photographing gray cards all day long, a camera with 1/3 stop of dynamic range would be enough – nail the exposure, and the gray card will fall right in the middle of the range. The lowest contrast “real” scenes may have four or five stops of dynamic range (a foggy landscape or a flatly lit portrait of a light-skinned person in light clothes or a dark-skinned person in dark clothes) – even an iPhone can handle that scene without tricks. Most real-world scenes, though, will exceed the dynamic range of a phone sensor without resorting to stacking. You may not even be aware the phone is stacking – it does it quickly and seamlessly – but the risk of artifacts from processing is real, and there is a strong “processed” look about a lot of phone images.

Moving up from phones, Micro 4/3 and older sensors require a lot of care in exposure, and there are quite a few scenes they just won’t capture without blowing highlights or crushing blacks. The original EOS-D30, arguably the first affordable DSLR, was severely dynamic range challenged (six to seven stops with ugly clipping in the highlights and crushed blacks) – and the rule was “handle it like slow slide film”. There are certain scenes you just don’t try, you might need to use a gradient filter in the sky, and you’d better nail the exposure (being especially careful not to blow an important highlight, because there wasn’t a lot of room for highlight recovery). By 2008 or 2009, there were cameras around with a lot more dynamic range.

The Nikon D3x was the first camera (apart from a few digital backs) with a 14-bit readout, necessary because there were some cases in which it might pick up a little bit of detail past the 12th stop that a 12-bit converter would cut off. The much cheaper Sony A900 used the same sensor, but didn’t have the 14-bit mode or the extremely sharp low-pass filter, and the Nikon had an image quality edge. By about 2013 or 2014, that level of dynamic range or greater was relatively standard in most full-frame cameras and the best of APS-C was coming close. Even in 2022, Micro 4/3 still can’t match the 14 year old D3x at low ISOs, and the GH6 is down two full stops. The D800 had legendary dynamic range for its time in the mid-2010s, a full stop better than the already good D3x, and that’s where most good full-frame cameras are today – somewhere between 11.5 and 12 stops according to Photons to Photos, close to 15 by DxOMark, with maybe 13-13.5 stops useful in the image. There’s about an extra stop available in semi-affordable medium format, and I run the GFX 100s in 16-bit mode, because there’s just that last little bit of possible detail in certain circumstances past the 14th stop, as the D3x had it past the 12th stop.

There was never any film capable of picking up 14 stops (in Zone System terms, going from Zone -II to Zone XII), although some later Zone System books do note the existence of Zone -I and Zone XI under limited circumstances. There is also no medium that can print 14 stops (and only OLED displays can display them) – the goal of contrast control in editing is to put those 14 stops into the 9.5 stops or so that Platine can handle on the best printers. I might raise a dark shadow that the camera captured detail in in Zone -I or even Zone -II to the edge between Zone I and Zone II, putting it in the print right at the edge of where the first detail occurs in a deep shadow. Conversely, a Zone XI or XII highlight might come down to the border between Zone IX and Zone X, where detail just begins to appear out of the brightest highlights. The advantage of having a camera with a dynamic range well beyond the tonal range of any printer and paper is that those decisions are left to be made in the editing process. The negative as score has an enormous amount of flexibility to be printed or performed in many different ways.

A composite image, because the night launch of the Space Shuttle would require much more dynamic range than any sensor could have. NASA photo by Louise Walker and J.T. Heineck

There are scenes where 14+ stops still aren’t enough. An extreme case is a night rocket launch, where the background is very dark, and the flames from the engines can be 20 or more stops brighter than the night sky. When NASA presents images that have detail everywhere, those are multi-camera stacks with as many as seven different cameras exposing at different ISOs (since the rocket is moving, all the exposures have to happen at once). A case landscape photographers run into is scenes containing the disc of the sun.

Dynamic range is deeply connected with the question of noise – there are two ways to make a sensor with greater dynamic range. The first is to reduce noise – an ideal image sensor (which doesn’t exist) would have no noise at all – a pixel that sees 0 photons will register as black. Every real-world sensor has some noise, and that noise increases as we turn the ISO up, because the noise gets amplified along with the signal.

This installment of a technical look at image quality sets the parameters and looks at the image sensor itself, alluding to, but not going into depth about, the various filters covering the image sensor, the rest of the camera body, and the lens. The next installment will work forward from the filter stack through the camera body, followed by one focusing on the lens, and it will intersect with our ongoing printing series to look at what happens through the processing and printing stages.

Dan Wells

November 2022

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Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

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Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Dan Wells, "Shuttterbug" on the trail, is a landscape photographer, long-distance hiker and student in the Master of Divinity program at Harvard Divinity School. He lives in Cambridge, MA when not in wild places photographing and contemplating our connection to the natural world. Dan's images try to capture the spirit he finds in places where, in the worlds of the Wilderness Act of 1964, "Man himself is but a visitor". He has hiked 230 miles of Vermont's Long Trail and 450 miles of the Pacific Crest Trail with his cameras, as well as photographing in numerous National Parks, Seashores and Forests over the years - often in the offseason when few people think to be there. In the summer of 2020, Dan plans to hike a stretch of hundreds of miles on the Pacific Crest Trail, focusing on his own and others' spiritual connection to these special places, and making images that document these connections. Over years of personal work and teaching photography, Dan has used a variety of equipment (presently Nikon Z7 and Fujifilm APS-C). He is looking for the perfect combination of light weight, ruggedness and superb image quality.

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