These days I do most of my colour adjustments using Nik filters. I guess these will automatically use the right blending mode but I'll try to remember your advice when I'm making alterations "by hand", as it were.
I'd have saved myself a lot of pain down the years if I had actually read, and understood, the gazillion-page Photoshop instruction manual that I bought donkey's years ago (and made a lot more money, too).
Generally speaking, in determining middle grey you should take the middle values for RGB, i.e, R=G=B=128, or 256/2. In your image the jacket might be a good starting point, or the sack by the burro's rear side. I think the street payment might be a bit too light for middle grey. Hover the eye dropper over what you perceive middle grey to be and read the RGB values on the "info" tab.
Keep in mind, though, that by drastically changing the colour in RGB you're also affecting contrast. The way to avoid this is by changing the blending mode of any colour corrections layer to "colour." This will process the colour portions of the layer only and not affect contrast. If you want to affect contrast only (and not disturb colour,) change the blending mode layer to "luminosity."
Jeffrey, how can you identify what is meant to be middle grey on the picture? Is there an objective test or is it a judgement based on experience?
Rich, I never made the connection with Don Quixote but Cervantes must have seen dozens of people just like this every day (and this IS Sancho, the Don had a horse!). There were quite a lot of old guys still using donkeys every day when we first went to Crete 15 years ago. Today they are almost all gone and with them a way of life that stretches back probably thousands of years. This guy is one of the last, unless the economic crisis does end up pushing the Greeks back to the 1950s, the way the prime minister warned, in which case maybe donkeys will start to make a comeback.
Here's one, Rich. The road in the bottom right corner looks like a medium to light grey and the guy's coat, around the shoulder area, a medium dark grey. Overall, the image looks just about perfectly exposed on my monitor.
Yes I do see the white blob that's blown out in the corner. And I think it has a tiny cast of cyan overall, as does your "woodpill" image. My image may also be a third under exposed.
I wasn't suggesting this is a perfect color corrected image, just that you should post something with a neutral gray in it, get it perfect on your laptop and then post it and I and others can look and see if we see any color in the grays.
If my color chart looks a little cyanish and a bit underexposed, I think your monitor is very close. I didn't color correct the color chart, just copied it and then used this as an example for my "How to Copy Artwork" instructions.
Thanks Johnny. I think you are right about the eyedropper in PS. If the channels match in things that are meant to be grey then I should be OK for everything except, possibly, brightness. It's no good PMing me anything because I would just look at it on this screen and see what I saw to start with.
It could just be my eyes messing the colours. I'm on a laptop at the moment because my tower died and the colours it comes up with often look bizarre, that's why I broke out the old Spyder. I'll put up a common or garden (or agricultural) landscape I'm working on to see if that looks more normal.
Driving myself ever so slightly beresk trying to work out some empirical way to convey what we're seeing. Ie - if we took a screen grab (with your permission) and PMd it back to you through FAA (if that's possible) would that help? Alternatively what about taking a screen grab and using the Photoshop eyedropper for RGB values on selected points?
Amy, do you think my picture is over-exposed? The reflections on the apples are just out in some channels, I think, but the rest doesn't look too bright to me and I see detail in it, so I'm inclined to think the calibration is probably OK.
Rich, are you seeing the blob of sunlight on the top left side of your card, with the rest of the white parts of the card looking grey, or do you see the card as having a white background without a sunlit blob?
I made this before the latest colour calibration. Now it looks to me as if it has a greenish cast to it...
The colour card looks OK to me, maybe a slight blue tinge to the grey at the bottom right, but it's hard to say (just checked the card with the PS colour picker and it is 211 229 243 in the RGB channels, so I guess I am seeing it right.
It's a bit too bright and may have a warm/yellow tone to it. But can't tell with this image. Do you have another image that has grey in it and we can look at it. It's almost impossible to judge color without a standard grey.
Thanks. So the colour balance looks all right then? That's my biggest concern. I can check whether the whites are blown easily enough, though I was able to see all the blocks on a 16 level greyscale chart. The front of the stall should be a natural colour while there is a slight warmth to the stuff at the back from light reflecting from a red awning.
Paul... Not sure if this is helpful. Viewing on iMac with default calibration and there is a slight over-exposed look to me. The whites and specular highlights on the apples are blown out on my screen.