My suggestion to Greg and Mike:
develop a quick cheat sheet with numbers and ranges of values.
I.e. sky should have a hue clock at the 7 to 8 with length equal to xxx
and the lab values should range ....
skin
lawn, tree greenery, water
Only guide lines. Water can be white, brown, green, even blue.
There are guidelines of "impossible" colors, green hair, rocks etc.
julie dog
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Julie,
"Question time. There seems to be a lot of discussion about numbers this time course. Numbers just don't mean anything to me. I know they are numbers, but I have trouble assigning meanings to them. I love the hue clock and the visual representation of the curves but I just cant seem to make the numbers represent things. I also tend to make judgements around my aesthetic values, I know what I do won't please everyone but it should please me. Is this going to create problems for me."
I too am in exactly this same place, and I was so glad to hear that I am not the only one struggling with these issues. Thank you!
I thought I'd post my thoughts on this, even though I said in my last post that I wouldn't post anymore.(I never thought about posting to see if I could help someone. :))
First, the numbers DON"T mean anything. Don't try to relate the numbers to the hue clocks. All the numbers are there for is as a reference point. If you see a hue clock set on a white area (a highlight point) and it has the numbers R=235.......G=245.....B=255, then all you can derive from the numbers is that you have the correct amount of blue, since it's reading 255, which is the amount of blue you need to obtain pure white, but you need to increase the red from 235 to 255, and increase the green from 245 to 255, because pure white is R=255.....G=255.....B=255. The actual value of Red being 235 means nothing, it's just a numerical representation of the amount of red in the area where you placed the sample point, which to us is an abstract, since we don't know how 235 relates to how much red we see.
The same applies to the black point. If you set a hue clock to a black area and it reads R=0.....G=8.....B=6, then you know that pure black is R=0.....G=0.....B=0, so from the numbers you can see that you have red already at 0, but you need to decrease the green from 8 down to 0, and decrease the blue down from 6 to 0. That is all the numbers tell you.....whether or not you need to increase or decrease a color in order to get the hue clock colors to become aligned.
It's kinda like your stereo in your car or in your home. If you set your volume control to 4 and it is the correct volume, then you know you need to set it to 4 without the volume being too loud or too soft. The number 4 means nothing, it's just an arbitrary setting that you use as a reference to set the volume. There is no such thing as hearing a "4" volume in real life, it's just a reference number that you use to set the volume at. The "4" has no real world value....it's just a number.
And you only got 1% of the information... ;D
Great answer art...
The thing to remember is this....The highlight value need not be all the way up to 254. If you threshold an image for highlight and for shadow and the RGB values are 240, 225, 230 You really only wan to raise them up to the 240 level. You need not hit 255 unless you want that region to be completely white with no details. On the other side you would not drive the darkest shadow you find all the way down to zero. If the shadows are 10, 5, 15 you want to drive them down to 5...Again you are keeping details in the image...
Greg
Great answer art...
The thing to remember is this....The highlight value need not be all the way up to 254. If you threshold an image for highlight and for shadow and the RGB values are 240, 225, 230 You really only wan to raise them up to the 240 level. You need not hit 255 unless you want that region to be completely white with no details. On the other side you would not drive the darkest shadow you find all the way down to zero. If the shadows are 10, 5, 15 you want to drive them down to 5...Again you are keeping details in the image...
Greg
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I agree Greg. That's what I was doing when I adjusted the curves. In my post above, I just used the 255 number for pure white, and the 0 number for pure black, to keep from making things complicated, since we are taught that 255 for all three colors is white, and all three colors equal 0 to be black. :)
If I placed a hue clock in a white area and it said R=230.....G=235.....B=240, I know that the blue value of 240 is the highest number I can get, so I'll use that as my highest number, and adjust the R and G values to equal 240.
I'd do the same to adjust the black point (the shadow area). If I set a hue clock in a dark area and it showed R=10.....G=8.....B=6, then I'd use the blue value of 6 as my point, since it's the lowest number. I'd adjust the red and green curves so that they both showed a 6, not 0, since 6 was the lowest number that I got from my sample points.
To be honest, I actually used CM to help me with a picture this week. My uncle passed away this week, and at the funeral home, they had a black and white picture of him placed at the back of the room where you signed in. I asked if I could borrow this picture to scan and make prints of. His daughter (my cousin) said it was okay, so I picked up the picture after the service, took it home, scanned it, then used CM to make the necessary adjustments, then used Photoshop to repair the damaged areas of the picture. I then sent it to an online developer (Kodak) and had a bunch of prints made from it.(I haven't gotten them yet, but I'm sure they will be fine).
This was the first picture where I knew how to use CM on my own to make adjustments. The results were satisfying..... :)
Even though I don't know a lot about CM, what I do know has been useful for me. I can thank Greg for that knowledge. :)
If I placed a hue clock in a white area and it said R=230.....G=235.....B=240, I know that the blue value of 240 is the highest number I can get, so I'll use that as my highest number, and adjust the R and G values to equal 240.
I'd do the same to adjust the black point (the shadow area). If I set a hue clock in a dark area and it showed R=10.....G=8.....B=6, then I'd use the blue value of 6 as my point, since it's the lowest number. I'd adjust the red and green curves so that they both showed a 6, not 0, since 6 was the lowest number that I got from my sample points.
To be honest, I actually used CM to help me with a picture this week. My uncle passed away this week, and at the funeral home, they had a black and white picture of him placed at the back of the room where you signed in. I asked if I could borrow this picture to scan and make prints of. His daughter (my cousin) said it was okay, so I picked up the picture after the service, took it home, scanned it, then used CM to make the necessary adjustments, then used Photoshop to repair the damaged areas of the picture. I then sent it to an online developer (Kodak) and had a bunch of prints made from it.(I haven't gotten them yet, but I'm sure they will be fine).
This was the first picture where I knew how to use CM on my own to make adjustments. The results were satisfying..... :)
Even though I don't know a lot about CM, what I do know has been useful for me. I can thank Greg for that knowledge. :)
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