Project 39: Using higher sensitivity

This project is something I did not find challenging as I have already done similar exercises for my Open University course, and am also very aware of high ISO impact on image quality. It is also affected by the camera used, as more expensive, newer cameras can perform well at high iso whereas entry level DSLRs, including my Canon EOS 450D, produce less usable images at higher ISO. In my experience, all compacts, no matter how expensive they are and how much fancy technology they incorporate, produce "noisier" images. My first digital camera was a 3.1 MP camera, and it tended to produce good quality images outdoors with much less "noise" than many of the newer cameras. It seems to be side effect of cramming more pixels into a smaller sensor. I hope that one day those clever people in Japan can sort out the "noise" issue, so we can look back and laugh at those grainy photos.

I use noise reduction sliders in Adobe Lightroom, which is helpful to make higher ISO images more usable. Bright scenes also enable higher ISOs to be used. However I try to use the lowest ISO possible, and therefore a tripod wherever practical. This provides the sharpest, highest quality images.

I tend to use higher ISOs when photographing children or pets. This is because they are such mobile subjects that much higher shutter speeds are required to catch them (more than 1/125s). This point is shown in the results from my project below.

For this project I used my compact, as I believe "noise" is much greater in a compact camera. I chose the extreme settings of ISO 80 and ISO 1600 and my chosen location was conifer woodland, which does not allow much light through to the forest floor. As a result of using those extreme ISO settings, the principles laid out in the project are clearly demonstrated even on a pc screen, however none of the images are usable and won't be staying on my hard drive. The night after doing the project, I went to see "The Dog Whisperer" on tour. Stage events are one situations were high ISO settings are required, as the alternative is no pictures at all. I've included a high ISO picture at ISO 800, also taken with the same compact camera, of the stage set. Because the stage is bright and lit, the image of the higher ISO setting is less obvious.

Key learning points from this project:

1. Film grain is a result of bigger light sensitive crystals in the film emulsion. I never knew that!
2. Higher ISO is essential when photographing fast moving subjects in low light (children & pets). In those circumstances, best to capture them against a light background to lose the noise.
3. Digital noise is most evident in images containing a blocks of medium to dark tones. The solid colour of my dog displays this quite clearly.
4. Digital noise can be lost in busy images containing lots of different light coloured tones.
5. Cropping (equivalent to digital zoom) results in noise being more evident, as it's equivalent to making a large scale print. This explains why so many pictures of garden birds look noisy as they are often cropped to make the bird appear bigger in the frame. The solution - a bird hide, a long focal length lens and bright sunlight. Garden birds are a good example of a subject that looks so much better when photographed in the middle of the day in bright sunlight, as opposed to portraits and landscapes which clearly should be avoided in those conditions.