Recently I have been wondering about the aesthetics of film grain. I see some images that look ok with film grain, or even look more real with film grain, and others that look horrible with it. Also I keep thinking that the professional opinion on the film grain effect in digital photography caused by a higher ISO is ALWAYS a bad thing.
On this image, the only really telling sign of the ISO and grain is in the top corners and dark places, where I feel that it detracts from the image. On the flower itself it is barely noticeable and where it is noticeable, I feel that it adds a bit of warmth to the image and makes the flower feel less plastic than a perfect ISO 100 image would. The image is also tack sharp, which is something that would have not been possible at a lower ISO value (modest light, slight breeze, 200mm, 1/400 or faster is best). What do you think? (view full size to see all the details)
This image, on the other hand, is a sunny ISO-100 image, absolutely minimum grain. It feels overly reflective, a little more plastic and not quite as attractive. The intense clarity makes me feel the warmth of the day, an almost too uncomfortable warmth from the sun (perhaps from too many days picking strawberries with my mother and grandmother and feeling very sick afterwards). The image above does not cause that discomfort, it feels more pleasant and almost zen.
This image was shot at ISO-400. It has a nice balance of softness from the ISO, but is not as distracting with the amount of grain, although, in the full size version, it is quite obviously present.
I am still completely undecided on what I really think. I suppose it has its advantages and disadvantages. ISO-1600 is a very extreme ISO value, but it allows me to stop motion easily in most lighting conditions. ISO-100 is grain-free, but rarely produces a very sharp images, unless you have a lot of light. I kind of like the grain of an ISO-400, it has the feeling and depth without the harsh bits of unusable pixels.
Funny, this whole damn thing started because I was searching for something to use as a desktop background and I was inspecting each image for its usefulness at a large size, and now I am even more undecided about what I want to use, since I went diving for exemplars of the other ISO values. I still may use the first one I picked at ISO-1600, since its grain is not that distracting.
BTW, Anyone notice the low file number of the ISO-100 sample? On May 2nd my camera rolled over from 9999 to 0001, I have taken over 10,000 images on the D60 since December 
