I was actually referring to shutter speed lens and ISO. It is helpful to use as a starting point when developing technique. IE it is very useful to know that a shutter speed of 4000 sec or more is needed when photographing small BIF. I know this would be discovered with experience but it is good to have a reference point when starting out.
I can see where you are coming from with this but they are just numbers if you don't know why they were selected and what the lighting conditions were. EXIF isn't really a 'how to guide' because you would be making assumptions why the settings were used. There are many reasons why some settings are chosen over others, most of those reasons can't be seen in the image or the EXIF. To really find out how an image is taken its best to ask on a photo thread to find out why they where used. I went to a few talks at bird fair and one photographer said whilst he puts up the exposure details only because some want that information it generally means nothing. He also said most of the numbers are just made up to sound about right, and that's it's too time consuming to actually find the actual settings.
As an example here are a couple of images I took on Skomer this year, they were taken 8 minutes apart:
Skomer Puffin Portrait by -Rob'81-
1/2000, f5.6, ISO500 taken at 19:35
Puffin Straight On by -Rob'81-
1/800, f8, ISO200 taken at 19:43
So what do the numbers mean? The images are quite similar in the way they are head on portraits taken close up. So why did I choose these settings? Well, the aperture was increased from f5.6 to f8 because of the reduction in depth of field due to the closer subject distance (2.6m to 1.68m). Why 1/2000 in the first yet 1/800 in the second? Was it to freeze the movement of the Puffin? No, it was a hang up from shooting Puffins in flight then acting quickly when I saw this nicely posing Puffin. At the time I could have used a lower shutter speed and a smaller aperture (f11) to get the end of the beak in focus whilst still keeping the ISO low.
Generally for wildlife:
- shutter speed high enough to freeze subject movement (unless you are trying to be creative) and stop hand holding induced blur.
- aperture wide enough for sufficient DOF for the subject to be sharp, taking into account subject distance and focal length (note with wildlife subject isolation has more to do with distance from photographer to subject and the distance from the subject to the background than using a wide aperture)
- ISO- set to the lighting conditions (the shutter speed and aperture) and the ISO performance of your camera.
The issue is the shutter speed-aperture-ISO relationship really depends on the lighting conditions on the day and other aspects you may not aware of from reading the exit data. I usually try to shoot with an idea of what the ideal settings (where the aperture gives sufficient depth of field and the shutter speed is sufficient to keep the subject sharp) and work from there as an exposure triangle compromise. As the light levels dropped I would raise ISO until it got to a point where I reach the ISO limit for my camera (this can be subjective between cameras and different photographers), then I would look at lowering the shutter speed, if more light gathering was needed I would open the aperture up. If I was then beyond mine and the cameras limit it would be time to watch or go home.
The problem with reading exif is it could easily send you down the wrong path, unless you know more information. It's much better to ask on here for help with 'ideals' if you are unsure, there are plenty of members willing to help guide other members.
and I think it can help and as people have brains and probably do know that the light can change second to second I can't see any harm in it. It's not as if people are going to think "Ah Ha! That picture was taken at ISO 3200, f2.8 and 1/2000. That's what I'll use from now on!"