The medium format digital back market is a small niche but one of intense competition. There are currently just four companies producing these backs –Phase One,Leaf,Sinar / EyelikeandHasselblad / Imacon. Between them they likely sell less than 10,000 backs annually. By way of comparison, Canon makes far more than that many digital cameras in a single day.
And because these backs sell for between $15,000 and $30,000, and are purchased by astute and knowledgeable pros, as well as occasionally those with Platinum Amex cards, the purchase cycle is never quick or easy. Most pros request that a dealer visit their studio and provide an in-depth demonstration, allowing the photographer to take a controlled test drive as well.
Andtest driveis an apt description, because no one would buy a car without one, and these backs cost considerably more than most people’s vehicles.
But, even with the ability to test these backs out for oneself by those that actually are able to buy them, there is always a general desire by a wider range of photographers to know how they perform and compare. To this end, over the past several years I have tested and reported onmost of the medium format backsto come to market.
My own first medium format back was a 16MPKodak DCS Proback, followed by the 22MPPhase One P25. Recently, this was upgraded to the 39MP Phase One P45. I have also tested and used various backs from Imacon and Leaf over the past few years.
With that as background, here is a report on my experience testing and shooting briefly with an Aptus 75.
Murphy Was An Optimist
© 2006Yair Shahar. British Columbia, Canada
Mamiya AFD with 35mm lens and Leaf Aptus 75. ISO 100
I had planned to do a shoot in the coastal mountains of British Columbia with photographer and colour science engineerRay Maxwell. Ray also acts as a technical support rep for Leaf on Canada’s west coast, and had arranged for the loan of an Aptus 75 back for this occasion. We were joined as well byYair Shahar, a European country manager for Leaf. Our host wasDaryl Spenser, an executive with Leaf’s parent company, Kodak, who kindly loaned us the use of his family’s ski chalet in Whistler, BC. Photographer, and the publisher ofLensworkmagazine,Brooks Jensen, and Video Journal directorChris Sandersonrounded out the group.
Since an Aptus 75 in Hasselblad H mount was unfortunately unavailable for testing I had brought along myLinhof 617cswith a spare adaptor plate for Hasselblad V mount. As soon as we began to do our first comparisons though we discovered that while my Phase One P45 focused perfectly on the groundglass, the Aptus did not. Something to do with needing shims for the back.
As he often is, Murphy was at work, but in the end it turned out not to be such a bad thing. I got to shoot with an Aptus 75 on a Mamiya AFD, and we did a lot of side by side shooting with myHasselblad H2and P45. Because we couldn’t use the two backs on the same camera with the same lenses I am unable to share with you the type of pixel peeping that would have resulted. I don’t necessarily find that to be a bad thing though, for the following reason.
Based on everything that I’ve seen, the Aptus 75 and the P45 are both such capable imaging backs that the small difference in performance between them simply are not of a big enough magnitude to warrant a snap decision in favour of one or the other. To be sure though, each has its strengths and weaknesses, as we will soon see.
So rather that regard this as a comprehensive review, or product shoot-out, think of it instead as a friendly comparison test drive.
The Aptus 75
This new back, which started shipping in early 2006, is Leaf’s current flagship model. It features a 33 Megapixel Dalsa sensor, and is completely self-contained, with attached battery and internal CF card. It features a large and bright rear panel LCD. Its primary competitor is the Phase One P45, a 39 Megapixel back. The Aptus 75 lists for about $30,000, though discounts are available through local dealers and VARS.
Cosmetics and Controls
Though both backs are designed to attached to a range of medium format and technical view cameras, they are quite different in terms of cosmetics and user interface. The Aptus has a very large LCD screen filling almost the entire rear of the back. It is a touch screen, which may be activated with either a finger nail or the included stylus, which tucks away inside the top panel of the back, just as with a PDA, which indeed the screen resembles in operation.
Phase One P series backs, on the other hand, have a much smaller screen, which is navigated through the use of four metal soft-keys, whose functions change based on on-screen menu choices.
Which is found preferable is very much a matter of personal style and choice. After more than two years of using Phase One backs I have become very comfortable with that company’s approach. It is simple. Almost minimalist. The Aptus, on the other hand, offers a much broader range of controls and settings via its touch screen. Are they all necessary? Probably not for all photographers.
The downside is that I found using the stylus in the field to be a somewhat finicky task, while using ones thumbnails to make selections didn’t always take the first time, requiring the occasional double or even sometimes triple press. I also found that there are quite a few settings which can be made on the Aptus that take a while to register, while one watches a spinning leaf logo on-screen until control is returned. This is akin to watching the Mac’s spinning beach ball. It only lasts for a few seconds at most, but when compared to a Phase back’s instantaneous settings it can be somewhat annoying.
It must be said though that the Aptus does allow a wide range of settings to be made directly on the back which Phase backs simply do not allow. Among these, for example, is the ability to create and name alternate directories for file storage, as well as annotate individual files with text, entered via an on-screen keyboard. Whether such abilities are of value to any given photographer will very much depend on ones workflow and needs. No generalized conclusion can be made.
One Aptus feature that I did appreciate is theUser Button, located at the top right of the back. This can be programmed to perform a number of different functions, and falls nicely to hand (or thumb) while hand-holding a camera.
Another is that when the back is rotated while reviewing images, so are the images. The P45 does this as well, but what I appreciated about the Aptus was that the label text on-screen is also rotated – something that the Phase back does not do.
In addition to the comments above about the Aptus’ screen, the following needs to be added. In anything except the brightest direct sunlight it is clear, readable and very useful for judging composition, and to some extent image quality. In direct sunlight though it is quite washed out.
The P45’s screen, on the other hand, is quite poor by comparison under most light conditions, though the brighter the direct light on it, the better it appears. In direct sunlight the P45 is the clear winner in the screen sweepstakes.
For photographers working tethered in a studio this point is moot, and for most photographers who simply use the screen to view the shot’s histogram or highlight warnings it isn’t that critical either. Some photographers though may find the bigger and brighter Aptus screen to be preferable for their needs.
It should be noted though that when shooting tethered the Aptus’ screen is unavailable for making settings. The Phase back allows settings to be made from either the LCD or the tethered computer.
Batteries and Battery Life
On one of the shooting days Yair and I started out shooting at 5am with fresh batteries on both the Aptus 75 and the P45. By early afternoon, some 7-8 hours later, each of us had taken about 100 frames, and each of our backs was showing a very low battery warning. Based on this very unscientific data I would judge battery consumption as being roughly comparable.
Incidentally, I have found that the P45 uses batteries much more rapidly than did my P25 back, though I can find no satisfactory explanation for this behaviour.
The P45 uses fixed sized Canon Lithium Ion video batteries, currently available in up to 2500 mA capacity. The Aptus uses a comparable Samsung video battery, but has the advantage of being able to take physically larger batteries, if needed, because the battery attaching point lies beneath the back. On the P series backs the battery lies internal to the back’s structure and therefore is limited to a single physical battery size.
But the downside of the Aptus mounting point is that when mounted the battery covers the access hole for the Firewire cable. This means that one can either be tethered, or running on battery, but not both simultaneously. On Phase backs the Firewire port is on the rear panel, and the back can be set to run on battery while tethered, if desired.
Heat and Fans
Heat is the enemy, at least when you’re a digital sensor. The hotter a sensor gets the noisier it becomes. Leaf’s approach to heat reduction is to use a small built-in fan inside the back to move warm air out. This fan is virtually silent, and is claimed to be vibration free. Itisessentially silent, except when one has ones eye to the viewfinder, at which time it is noticeable but not annoying. As for possible fan vibration, I have no knowledge of this, nor have I heard or read anything about it, so I can only assume that it’s a non-issue.
Phase One’s approach to heat is to power down the sensor along with all unneeded back circuitry, except when actually in use. No fan is used, or apparently needed. The rear panel LCD is also a low power design, which goes a long way toward explaining its lower brightness. Lower power means less heat.
According to Leaf, they use a similar power-down architecture, and the fan only really comes into play when doing Live Video preview. This may be the case, but I can hear the fan in operation during normal use.
The Aptus 75 is capable of shooting directly to a powered hard drive while the P45 is not. In some ways this is a hold-over from the days when Leaf backs did not have built-in CF cards. Today, with 8GB cards available, such bulky drives are not as needed or desirable as they once were, but for some photographers a 40GB powered drive may be worth the added bulk and weight.
Timing tests were performed on both backs using a4GB Sandisk Extreme IIIcard, one of the fastest currently available.
The turn-on time for the Aptus was nine seconds. For the P45 three seconds, making the P45 much faster to the first shot.
Timing shooting rates is more problematic because some backs are faster on an initial shot-to-shot basis, but slow down when they run into their buffer limit. For this reason we agreed on timing the number of shots that could be made in one minute as well as the shot-to-shot rate.
The Aptus 75 was able to shoot 25 frames in 60 seconds, or 2.5 SPF, with no slow down at any time. The P45 was able to shoot an initial 7 frames at about 1.5 seconds per frame, but then slowed down, leading to a total of 21 frames in 60 seconds, or an average of 2.85 SPF. So the Aptus 75 is a bit faster over the long run, but the P45 is faster on shorter bursts.
Another way of looking at it is that the Aptus on a Mamiya 645 AF could shoot 5 frames in 9.5 seconds, while the P45 on a Hasselblad H2 could shoot 5 frames in 7.2 seconds.
It should be noted as well that the Aptus was timed on a Mamiya 645, while the P45 was timed on a Hasselblad H2. Since these cameras have different shooting rates inContinuousframe mode these timing tests should be taken with a grain of salt. The Mamiya is somewhat slower shot to shot than the Hasselblad, notwithstanding the back used.
Aptus 75 @ ISO 400
The photograph above of Ray Maxwell (sorry Ray), was taken at ISO 400. On the right is seen a 100% crop.
Phase One P45 @ ISO 400
I find the noise to be noticeable at this speed on both backs, and roughly comparable. (At ISO 50 and 100 there is no noise visible whatsoever with either back). Clearly medium format backs have a way to go before they can compete with the lowest noise DSLRs on the market, which typically use CMOS technology. Such backs are essentially noiseless at ISO 400.
Though taken roughly at the same time, difference between the cameras, lenses and exposure produced noticeably different results. For those that are curious, the Aptus 75 exposure was 1/230 sec at f/8, while the P45 exposure was 1/200 sec at f/6.8, less than a half stop difference. Each was correctly exposed according to its camera’s metering system.
Each image was gray balanced, and sharpened equally. No other adjustments were made in post processing other than ultimate conversion to sRGB for web display.
The Aptus 75 is capable of ISO 800, which the P45 is not.
Aptus 75 @ ISO 400
Aptus 75 @ ISO 800
Noise increases fairly strongly at ISO 800, and while some may find it useful in a pinch, I regard it as unusable for most quality applications where an MF system would typically be used.
No test of the Aptus 75’s long exposure capability was performed. The back is limited to 30 seconds, in any event. The P45 has no such limit, and indeed produces very fine, almost noise free images at up to20-30 minute exposures.
Live Video Preview
The Aptus 75 is capable of live video preview in tethered mode using their new Capture 10 software. This software is in some ways still a work in progress, and is only available for Macs, and not yet for Macs using Intel chips, though this should be ready before too long.
Live preview can be a very handy tool for focus confirmation as well as in some scientific applications. It is a B&W image, with a somewhat slow refresh rate, but sufficient for its task.
There are rumours that Phase One will be introducing Live Preview as a firmware update for the P45, but whether true, or when, remains to be seen.
Like its Valeo model predecessors the Aptus line has Bluetooth built in. This is to allow wireless connectivity to an IPaq PDA, which can be used for reviewing images and controlling the back’s settings. According to Leaf this capability is currently vestigial. It is there, but not working appropriately. This is not an issue though since the larger, brighter screen of the Aptus line makes it somewhat redundant.
Phase One backs do not currently have wireless connectivity.
Leaf supplies two software products for handling raw files from its backs;LeafCapture 8.4.2and the newCapture 10. V8 is the older product, obviously, and though competent, in my view doesn’t hold up well against some contemporary offerings. Capture 10 is a much more contemporary offering, but it is still rather new, and there are some reports of instability.
Leaf back users also have the ability to process their files usingAdobe Camera RaworAdobe Lightroom(which uses Camera Raw as its raw file processing base). Neither Camera Raw nor Lightroom can handle P45 files at the moment, though support is likely to be added prior to the next release of both programs.
Capture One, from Phase One, has become something of an industry standard, with support for many major DSLRs as well as Phase One backs, and it has developed a stellar reputation not only for its quality of Image processing but also workflow.
In the final analysis both backs offer very competent software alternatives for Mac users, but Microsoft OS based Leaf back owners are ill served. because though promised for the past several years there still is no Windows software available from that company. The best solution for them at the moment is the use of Camera Raw. But, for tethered shooting, with an Aptus 75, there is no current alternative other than to use a Mac.
Leaf assures me that notwishstanding years of delay, therereally, really, reallyis a Windows version of Capture 10 coming, and sent me a screen shot to prove it.
Shooting with a View Camera
One of the side benefits of working with a digital back is that as well as the camera that they were designed to fit, they can be attached to technical and large format view cameras as well. This allows for the use of movements and specialty lenses.
One downside though is that when lens plane movements are invoked something calledlens castalso rears its ugly head. This is caused when oblique light rays from the lens strike the photosites, especially when retrofocus design wide angles are used. The effect is seen as a magenta / green shift across the image.
This is seen most on higher resolution chips, and particularly on Kodak chips over those from Dalsa, the reason being that the wells are apparently deeper on Kodak’s design. But now that Dalsa chips are higher resolution as well, they are also subject to this problem. All back makers now offer software solutions to the problem.
There are basic design differences between Leaf and Phase One backs that play a role in how they work when used with a view camera. Phase One uses what it calls a "sleeping architecture". This means that they power down the sensor and other parts of the backs circuitry when not in use. On a medium format camera, when the shutter cycle begins, these circuits are fired up in a fraction of a second, just before the shutter opens and the photosites are exposed to light. This is not the case with Leaf backs. Apparently the Kodak chip takes 0.4 seconds to wake up, while the Dalsa chip takes 0.004 seconds, thus obviating the need for special wake up cables.
Consequently, when a Leaf back is attached to a view camera no special cables or techniques are needed other than to sync the back and the shutter. With a Phase One back though one needs to adopt a two-shot approach, taking two shots in quick succession – one to wake up the back and the second to expose the sensor, or use a special single shot cable from theKapture Groupthat does the same trick as the sync circuits in a medium format camera. A somewhat pricey option though.
© 2006Yair Shahar. British Columbia, Canada
Mamiya AFD with 210mm lens and Leaf Aptus 75. ISO 100
A Question of Colour
I have read a great many comments online about preferences in how various backs reproduce colour, with proponents of one brand or another claiming superiority for their particular champion. This is like saying that one prefers Ektachrome over Fujichrome, or Velvia over Astia. Such preferences are inherent in human nature, and are simply a matter of personal taste. It’s not terribly meaningful though to regard one as inherently superior to another, except insofar as a particular back running a particular profile may appeal to ones own taste.
Each back maker has scientists and engineers who sweat over creating profiles for their cameras when used in different lighting conditions. They even provide a choice of profiles for some lighting conditions, as well as various "looks". Add to this the ability of each photographer to create their own custom profiles using any of the major raw processing programs, and the whole point is moot.
This is especially true with medium format backs, where one assumes that the photographer is someone more likely to have a high level of concern about colour accuracy and reproduction than the typical DSLR shooter. It’s the nature of demanding high-end commercial assignments. This implies that each image, or group of similar images, will be worked on to such an extent that the minor differences imposed by the tastes or biases of the engineers at one company or another will not end up being significant factors in the end result.
The Bottom Line
Hopefully this report has provided you with some insights into the pros and cons, features and foibles of the Leaf Aptus 75, and a comparison with its prime competitor, the Phase One P45. I have avoided too much pixel peeping, partially because we ran into some technical hitches while attempting to set up some rigorous tests, but also because to do so is to lose sight of the fact that such high end products need to be evaluated in their entirety, not just on their ability to show up the competition in one particular aspect or another of their behavior.
It should go without saying that anyone considering spending this amount of money should insist on a demo by a dealer. If you don’t live in a city that has a dealer for the brand that you’re interested in I would suggest that it’s likely worth your while to drive or fly to the nearest city that does, and spend a day doing your own hands-on tests and evaluation.
Frankly. articles such as this one serve more as camera porn for the casually interested, than they do as useful buying guides. No one ever bought a Ferrari based on a test report inCar and Driver, and nether should they on anything that appears in a net review, or a magazine review for that matter.
But, just asrust never sleeps, curiosity about competitive products always remains unsatisfied, I have therefore arranged to borrow an Aptus 75 for a week in early August, when I have an intensive shoot planned in Iceland. It will be in Hasselblad H mount and I will have my P45 on one Hasselblad body and the Aptus on another. Hopefully this will generate some appropriate side-by-side comparisons, along with a bit of obligatory pixel peeping. Certainly it will provide a further opportunity for hands-on impressions and sample images.
Part Two of this report will therefore appear in the second half of August, 2006.