ISO - Digital vs Film

[peter868]

Would a fast ISO (800+) affect the quality of enlarged prints in Digital photography as in Film (that result in grainy prints)?

[Paradox]

Yes - In digital photography, rather than grain, you get 'Noise' in your image. It's basically the digital equivalent. Some cameras exhibit it less than others - DSLR's tend to have very useable images at high ISO, whereas compacts tend to have much more noise.

[DonSchap]

Typically, in the newer SLRs ... ISO-800 will provide a nice looking image. Some have even gotten good quality out to ISO-1600, but you have to be very careful, at that point, and a tuned to examining your shot for degradation. There are also software programs that can massage the noise out of an image quite successfully, should it become an issue. Extra costs, for sure, time and money per shot.

Your best solution, as usual, is to try and provide as much light as possible to your camera's sensor ... be it through longer exposure (if possible) or wider aperture (if affordable). Anything above ISO-400 should, typically, be considered last ... unless you have already proven the reliability of making such a choice.

The beauty of the digital ISO over the Film-ISO is that you are not stuck with any setting for an entire roll of film (usually 24 or 36 frames) ... you can change it from shot to shot, therefore allowing you to take a myriad of manual setting changes for the same image (while the image lasts - nothing lasts forever - light changes -clouds creep in - people move - that kind of thing.).

Say you initially snap the image at 300mm - f/5.6 - 1/60 - ISO-400 and it is still too dark. You are at your widest, available aperture. You are pushing your image, even at this point, because you really need to be up at 1/250th for a stable looking shot (unless you have an IS-equipped device), but hey, you've got steady hands. Obviously, your choices are few ...

Either:

get a tripod, prop your camera on something stable and take a longer exposure ramp up the ISO.


Moving up to ISO-800 will double the amount of light the sensor will take in during those above settings. Go to ISO-1600 and you quadruple it ... but, now the sensor is cookin' and electronic noise will creep into your solid areas, both dark and light.

Once again, anti-noise software can mitigate this ... and you can also get cute with Photoshop's tools and try to "touch-up" deeply affected areas. What it boils down to is ... more work per shot ... so be judicious in using this otherwise it will be a long day of clean-up.


Of course, you could always just whip out the fixed 300mm f/2.8 lens (going from a $500 solution to a $4000 one) and get that two-stop wider aperture. But, you'd still have that ISO-400 quality shot.

What's in your camera bag?