In order to get a feel for manipulating Aperture, ISO, and Shutter Speed in order to capture a large range of colours I decided to shoot photos of 2D art. The idea is to get a feel of how to manipulate the three variables to obtain a decent exposure and in what order it makes sense to do so.
Since shooting photos of a relatively small area with little distance variation the effects of Depth of Field (DOF) will be minimized. That is, any depth of field is probably suitable, and the effects of ISO and Shutter Speed and of course ambient lighting come into play. This photo of my Zelda Breath of the Wild canvas was shot in a very low light setting using a Tripod.
Here are my thoughts when trying to take this photo:
- Since depth of field does not matter much, I increased the aperture to 4.0 (the largest on my lens)
- I reduced the ISO down to 200 in order to get the noise to be as low as possible
- I used Av to automatically select the shutter speed to see what the camera thought was suitable
If aperture doesn't matter since we want a 2D completely clear image, we simply want the maximum light. ISO which is simply sensor gain should always be as low as is practical. However, what ended up happening in this situation was that the shutter speed was far too slow for my hands to take a very crisp image.
I found through some experimentation that my hands are not very still. In the very best scenario, holding the camera close to my chest I could get a clear image at 0.3s. Basically, anything slower than that I would definitely need a tripod, but my hands just shooting comfortably were good to roughly 1/6s. This posed a problem in this scenario as there was so little light that I needed to use a tripod as I was not willing to bring the ISO up. In practice I've seen ISO 800 produce reasonably good results in terms of clarity without noise.
So assuming that I want a still, low depth image to be clear without a tripod these would be my steps:
- Shutter speed priority 1/6
- ISO drop down to something low to start
- Check exposure
- Raise ISO as necessary and let Aperture automatically adjust into proper range
The shutter speed being the slowest I can use allows the most like to come in. If the ISO is too low, then exposure will on the low side and I can simply adjust. This has worked well in practice to produce some good results on paintings and Canvas Frames. Below are the actual pictures using this method the left side is slightly brighter since 1/6 shutter speed was used, while 1/8 shutter speed was used on the right.