Having said that, I found this exercise interesting not least because of the comparisons between low and high contrast lighting and the way that this is demonstrated on the histogram both on the camera and also in Photoshop.
I took three sets of three images over a number of days, all outside and all weather dependent. The first set was on a bright sunny day, the second set on a day when the light was reasonably diffused by cloud but still felt brighter ( I suppose what we would consider is a typical English day) and the third set was taken on a wet overcast day when the sky was very flat and washed out.
The impact on the lighting was obvious in terms of the histograms and what they showed.
One thing I realised when I uploaded the images was that I should have taken the photographs in Raw - that way, I would have automatically got the histogram when I first looked at the image on Photoshop. Fortunately, all was not lost and there is a histogram menu as well as the histogram also appearing on the right hand side of the screen under Levels. It was the latter that I used to take my screen shots and which are below.
The first set of images were taken in an average contrast situation - plenty of light but no deep shadows . As set out in the instructions, one image was taken at normal exposure, one that was one f-stop darker and another that was one f-stop brighter. The screen shots together with the histograms are below:
Average contrast - one f-stop brighter
The highlighting and the way that the histogram swings from the left on the under-exposed to the right on the over-exposed is very noticable. I also observed how 'flat' the average exposure was on the histogram. In terms of personal preference, I much preferred the image that was one f stop darker.
The second set of shots were taken in a very high contrast situation - lots of bright sunlight and deep shadows. I deliberately shot into a dark area but with the foreground lit up by the sun. These are below:
High contrast - one f-stop brighter
The difference in histograms at each stage was not so noticeable - in each case, the pixel brightness recording is highest on the left each time with only a slight variance particularly for the image that was one f-stop brighter.. This was not what I was expecting as I had imagined that with a high contrast image, it would be spread right across the histogram (and I suppose that to some extent it still is although the bulk of the reading is more emphasised on the left). I'm not sure if this means that I have misinterpreted what I thought constituted a 'high contrast' image but will look on this further as I go through the course.
The final set of images were taken on a what I considered to be a low contrast situation where the day was very overcast and there was virtually no colour in the sky (other than a milky grey). The images are as follows:
Low contrast - average exposure
Low contrast - one f-stop darker
Low contrast - one f-stop brighter
Similar to the 'high contrast' images above, there was little to show in the histograms with mostof the values squeezed together to the right this time. With the exposure one f stop darker, there is some recording on the left side which is what I would have expected.
This has been an interesting exercise and has led me to ask more questions rather than actually answer them - as well as encourage me to have a look at the histogram a little more closely (which I guess was the intention all along). I'll come back to this again as I continue through the course.
Anyway, I'm writing this on a bright sunny day - I really should be outside with my camera!
Mark
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