ISO vs. Image Quality

Started Feb 21, 2014 | Discussions thread
Dr Bob
Dr Bob Senior Member • Posts: 1,319
Re: Fact & Perceptions

michaeladawson wrote:

BartyLobethal wrote:

The fact is that every increase in ISO above base for your camera model will result in a measurable decrease in parameters such as dynamic range and colour sensitivity, and an attendant increase in noise.

How far you go before you cross a line where those things are no longer acceptable to you is a matter of perception - personal taste. Another consideration is output - what is acceptable for a small downscaled image used for web display might not be acceptable for a large high-gloss print.

I'm happy with images out of my FX camera all the way up to ISO6400 provided I get the exposure correct in-camera. But coming from 35mm film I find the luma noise acceptable as is, and don't think the small amount of chroma correction required is problematic. But my typical output is pretty undemanding and allows a much greater latitude for error than a commercial landscape or architecture photographer.

Lastly, how important is the shot to you? Is it better to get that image of the Lesser-Crested Knuckle Farter albeit with some noise and additional post-processing ahead of you, or to go home and try again another day?

-- hide signature --


In general I agree with what you said. I think one factor you didn't give enough attention to is subject matter. Noise impacts detail. You can often clean up the noise such that it is not objectionable at all in a printed photo at 8x10 (or even larger). But you lose detail as you go up the ISO range.

Someone in a response above had a photo of a baby. I can imagine that you could go quite high in ISO and the photo will clean up nicely with noise reduction software. But a bird photo is a different matter if you are trying to bring out feather detail.

-- hide signature --

Mike Dawson

I agree with BartyL. A lot will depend on what the OP is doing with the images. If it is just for the web then high isos can be usable as in the following

This was taken at Iso 6400 (but on an 800E) and gives sufficient feather detail for the web as I managed to expose it well enough (not always easy in low light). I missed my shot of the Lesser-Crested Knuckle Farter 'cause I left the lens cap on.

 Dr Bob's gear list:Dr Bob's gear list
Nikon D800E Nikon D600 Nikon AF-S Nikkor 500mm f/4G ED VR Nikon AF-S Nikkor 24-120mm f/4G ED VR Nikon AF-S Nikkor 28mm f/1.8G +1 more
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow