Find a strong definitive colour and choose a viewpoint so that the colour fills the viewfinder frame. Find the average exposure setting – the one your camera’s meter or your own meter recommends. Then take a sequence of pictures; all composed exactly the same, but differently exposed from bright to dark. Start at one stop brighter than the original metered setting, then stop down the aperture by half a stop each time.
Upon reading the guide notes in the OCA handbook i was pretty confused. The exercise is dealing with varying the exposure, yet it requires the exposure to be kept at the same setting, altering the aperture instead. While at first I thought this was a very long winded way to get the same result as if you were to simply alter the exposure settings – I did learn quite a bit about the effect different settings have in relation to one another. I haven’t shot too much using the manual setting either – which gives the photographer 100% control of all settings.
I found that my camera gave me a shutter speed of 1/4th (this may have been to do with the fact that I was shooting indoors) so I applied this shutter speed to the following apertures: f5.6, f7.1, f10, f16. Any setting beyong this was completely black. These settings demonstrated the objective.
My main observation is that the brightness of the pink is reduced through each photo. It’s clear and vivid in the first image, standing out from the surroundings, but as it gets darker it is less noticable. Altering exposure shouldn’t alter the hue of the colour itself, but the pink could be mistaken for red in the last picture. This may be because pink is not a primary colour. Had i done this exercise with, say, a red subject it may have appeared to have stayed red throughout. This is something i will experiment with later.
In conclusion altering the aperture has affected the brightness of the colour with hue and saturation remaining the same.