I still have my old film based SLR which I bought when AF wasn't an option. Somewhere between then and now I let my interest take a back row seat, and have since used quite a few digital cameras, but mostly not for serious use. Mostly Minolta Dimage7. Now I'm getting back into this hobby again, and it's time to update my knowledge a little. I'm itching to get back into it when I get my new camera!

1. Reciprocity - is there an equivalent with digital sensors or is this now completely irrelevant? Or is it compensated for by technology?

2. Filters - is there any difference in how a digital camera responds to filters? I'm not a big filter user, I just have a polarizer (wish it would fit my new digital!) which I use to control reflections and give the sky a bit more oomph.

3. Dynamic range - is there more or less with digital? Is it worth getting a graduated ND filter? I know you can just take 2 photos exposed for different parts and then stitch them together but for handheld ... Your thoughts? ... Maybe I'm just getting over zealous here.

4. Flashes - I've heard someone say that an external flash can fry a digital camera, but I'm suspicious that this isn't true. Can anyone confirm either way?

5. Flash use - are there any differences with digital with using a flash? I used to use a flash with a GN around 25 but somehow with the Dimage I found myself never needing the full power of the flash. But then I used to bounce my flash a lot.

6. Speed - does digital handle low light better than film? I know film goes grainy and digital gets noisy, but how do they compare for low light hand held use?

7. Does digital outresolve film? According to one article on this site - yes. But what about at around 6 - 9 megapixels?

Lots of questions I know. If anyone can help me get up to speed on any of these points, I'd be grateful.

There is no reciprocity with digital



Warming and cooling filters that change the colors only slightly are not usually needed with digital, since the adjustment can be made digitally, especially with raw. White balancing can be done digitally with raw, but an 80A filter will give slightly better results with digital, but at a loss of two stops of speed. Digital cameras require a circular polarizer as do most newer film cameras.



Digital has more DR than transparency color film and more DR than color negative film according to tests done by Roger Clark. Some disagree with the latter.



Most electronic cameras can be damaged by a flash that uses a high sync voltage, such as the Vivitar 283. Check with a volt meter if you are not sure.



IMHO there is no difference, but the results of the exposure are immediately apparent with digital.



Digital SLRs are considerably better than film at high ISO, especially the Canons. P&S cameras will have high noise.



8MP or more will out resolve film.

These are my opinions, but I'm sure some will differ.

I believe colour negative film more easily retains finer tonal gradation in the bottom quarter of the luminosity scale - intrinsically better than both positive film and DSLR, but with good digital exposure technique and creative post-capture processing digital can replicate much of this performance without the grain.

Here's Clark's article on the digital/film resolution. If you look down the page a bit you will see a technicolor graph which presents his findings.

http://www.clarkvision.com/imagedetail/fil...l.summary1.html

But, I think, a more reasonable way to approach the issue is asking how many pixels does one need to produce the size prints that are desired.

Coming from your previous Fuji S9500 post, I'd suggest you go to www.dpreview.com and download some sample shots from the S9100/S9600 (I think the S9500 has been discontinued) and any other camera that interests you and get some nice big prints made.

Worry less about how film equates to digital and concentrate on whether the camera in question will do the work you want to do.

Thanks for the response.

Regarding voltage, I had a look at my existing flash, which is an old generic cheapie - Achiever TZ 250. GN based on the dial is around 22.

I measured DC voltage to the pins from centre pin to all others (I think being multi dedicated, it has different pins for each camera). The max voltage I measure when it's charged up ready to flash is 8.7V DC.

Is this the correct way to measure? Does anyone know what would be a safe voltage limit?

Another question. PC sync. My old Ricoh film SLR Camera has a connection for a lead going to an external flash. It fires off the flash without any intelligence attached - the flash has to control its own output. Is this a PC sync? Are all PC syncs compatible?

One thing that I haven't seen yet in the other answers.

Besides raising the ISO, the traditional method for dealing with low lights is long exposures.

Digital does indeed not suffer from reciprocity failures, but many cameras have noise appearing with long exposures (long being as short as 15 seconds).

This is the result of the dark current of the sensor that becomes visible together with actual image information if incoming light is very weak. This is integrated over time. Most DSLR deal with this by exposing a second frame the same lenght as the actual exposure and then substract the result electronically.

The facto, this doubles the actual exposure time of images, which can from a user standpoint been seen like a kind of digital reciprocity failure. It shows up in a stepwise matter for exposures as short as 2 seconds, and always doubles the exposure time.

When this is done, the noise issue disappears almost completely with top of the notch DSLR like the Nikon D2x and Canon 1ds2, but it is still very present with some of the medium format digital backs (Leaf, Mamiya ZD to some extend).

Even with DSLR, there is a bit of smearing that shows in very long exposures, but it is often not really a problem.

One problem that can occur with really long exposures is the appearance of an ugly green cast, but that also shows up with film.

Finally, even a D2x that probably has the best battery around will not be able to do an 8 hours star trails with one fresh battery. The technique used by most people doing these things with digital is to supposed 30 sec exposures taken one after the other. This has less effect on battery, and does also not induce green casts.

Regards,
Bernard

Bob, I had a look at the article and it's very interesting.

I've printed some images from both the Fuji S9500 and the Canon EOS 400D - the difference isn't worty worrying about on 4x6" but with enlargements 10 x 15" viewed from 1m the difference is definately there. I compared the two because the Fuji is what I'm almost decided on getting now, and the Canon is what I'll probably get in the future, if not something similar.

Noise is another compelling reason for DSLR - I really like night photography.

I also like doing night photography of cityscapes - the atmospherics are wonderful. I'm using a Canon 1Ds (not the Mark ll). Just last night I was printing the last of a bunch I made in London in Soho and Leicester Sq. Exposures were about 1/50th of a second more or less at f/4 with my Canon 24~105 L. Noting this is sensor and processor technology in its 6th year, the results are really good. I analyzed each image with Noiseware and on a good number of them noise reduction simply wasn't necessary, while some of them did benefit from a modest pass of noise reduction with settings maximized to preserve image detail. As of now these prints are about 9 by six inches, but from experience I know they can be enlarged at least to A3 very satisfactorily. Bottom line: newer digital technology in a high quality DSLR will do even better and there is nothing to worry about.

1/50 sec is not long enough to require dark frame subtraction, but it may be done. Due to their on chip noise reductions Canon SLRs are particularly good at high ISO, but the Nikon D200 or D2x with smaller pixels and less photon gathering ability can also produce good results at ISO 1600 if you avoid underexposure. P&S digitals usually have more noise, since they use small pixels. ISO 1600 with 35 mm film is quite grainy.

I forgot to mention the key point - I was shooting at ISO 640.

I made 8"x12" prints from the S9000, Panasonic FZ30, and Canon 350D (XT). Side by side they lined up in that order in terms of image quality.

But try something. Have someone place the S9500 and 400D prints in separate rooms (so that you won't know which is which) and then see how much difference there is.

Not trying to push you toward the Pentax - but take a look at this K100D test using Imatest.

http://www.imaging-resource.com/PRODS/K100D/K100DIMATEST.HTM

Look down the page a bit and you can see how several (affordable) dSLRs stack up in terms of noise at higher ISO settings. The Nikon D50 is the best.

The K100D might be a better choice if you shoot mainly off tripod as the in-body IS would let you use a slower shutter speed.

Here's a review using Imatest for the S9000/S9500. You can directly compare low light noise against the dSLRs.

http://www.imaging-resource.com/PRODS/S9000/S9KIMATEST.HTM

Another thing to consider is that apparently Canon has dropped the price on the 350D and it's now available in the US for under $500. Don't know if those prices have drifted south from here.

(1Ds-type folks: The OP is working from a tight budget.)

Doing it, however, may create more noise than it eliminates. Random pixel and line noises increase by 41% with dark frame subtraction.

Subtracting random noise is exactly the same thing as adding it.

It is within the realm of possibility, of course, that a particular camera can benefit from black frame subtraction at short exposures, because of non-dark current noises that repeat in successive frames.

I agree that subtraction of random noise is not useful, but thermal noise is not random, and is concentrated on a small number of hot pixels. In short exposures, read noise is predominant in a dark frame exposure, but as the exposure time increases, thermal noise becomes more prominent. For the Nikon D200 (which has relatively high thermal noise), Thom Hogan recommends dark frame subtraction for exposures over 8 seconds.

... and he is already jealous!

I think when I do go for DSLR I will be a bit more picky than I can afford to be right now. I've been out of it for some time as far as photography goes, so I'm not well placed to choose a DSLR - I doubt I'd make a good decision. There are a lot of decisions to make and I don't think they can be made until you are "in the game" more than I have been.

I think when I do take the DSLR plunge, I'll be looking for as much resolution as I can get, image stabilised lens and very fast AF and shooting.

I think if I bought an entry level DSLR, it would bother me that it was big, heavy and inconventient enough for me to think twice about bringing it with me, but not good enough to keep me happy with the quality and performance.