Easter is almost here, so appropriately I have chosen today to shoot eggs – well actually one egg as an experiment to see how aperture and shutter speeds effect light – a learning exercise, partly inspired by Emma’s Challenge for #Remarkable2015 – but partly so I could compare for myself the different settings of Aperture priority and Shutter priority on my canon camera.
Today set up:
- Camera – 100 mm lens
- Off camera flash
Aperture is my comfort zone – the default mode on my camera and the one I choose to go to – I know it effects the depth of field of objects particularly those closer to the lens – but have not really thought about how the amount of light entering the camera changes when I change the aperture – so this was my challenge. I set the camera with an ISO 100, and a fixed shutter speed on 1/250 sec – ideal for using my flash and then I just changed the aperture in manual mode to see that happen.
The results were more obvious than I imagined, with F32 – the aperture hole was the smallest which meant that the least amount of light was let into the camera, you can see the detail in the background where the flash light spills onto the cloth, but you can’t see the focal object – the flash was directly slightly behind. As the aperture increased in size – you can see the shadows arrive, then the foreground exposed correctly – I think somewhere between F5.6 and F8 in this case, and then you can see how on the widest aperture the amount of light over powers the egg, the depth of field is shallow to the extent the egg looses its outline.
I then wondered what happened if I was brave and kept the aperture the same and experimented with shutter speed. Nothing ventured, nothing gained – so I dialled in ISO 100, choose F8 and then experimented again, using the same set up, although I did move the off camera flash slightly to get a more defined shadow on the egg.
This really does highlight that with a static object, increasing the time the shutter is open increases the amount of Light that enters the lens – 1/250 works well with the flash… but as you increase the amount of light you loose the shadows – so useful to know if you can control the ambient light and want to create a flat image with little definition, but too much and you over expose the details and almost loose sight of the object all together.
Finally I grabbed a tea pot … I got bored of eggs … and tried one more experiment – what happens if I move the light… so I set the aperture to F5.6, the shutter speed to 1/250 sec, the ISO100 and then with an off camera flash I moved the light in different directions on a similar plane – I was not surprised how this effected the shadows, but is has encouraged me to think more about where I want to position myself in relation to the light available.
This was really an eye opening exercise… and makes me aware:
- that the aperture is not only important for the depth of field, but it controls the available light
- that the shutter speeds are not only important for freezing moments, but also for making use of available light, which can effect the shadows and definition of the image.
- that the angle of the light makes a difference too to the shadows, the feeling of depth and the quality of the light reaching the aperture.
I was surprised at the different results, and the challenge now is to put some of this into action.