Hi all,

Although I have been aware of optical illusions that can be caused by putting two different colors or grey patches next to each other, I recently experimented a bit with different background colors in Irfanview, where it is very easy to set a background color, varying it from white, via grey to pure black.

Now I noticed that there is a very marked, and quite shocking, appearance in the photos, especially concerning the shadows / blacks. If the background is set to pure black, shadows "open up", showing lots of detail, but in a certain way, even to much, appearing washed out and indicating I may not have set my blackpoints right.

However, assuming the images are being displayed on a webpage with a non-pure black background (light grey), is it wise to set the PS background to pure-black?

What do you do while editing in Photoshop?

- Have you set a white / 18% grey / pure black background?
- And how does this all effect how you edit your images, and especially set your black points or adjust overall contrast?

Something that may look right with a light grey background, may look washed out and lacking contrast on a pure black background. While an image adjusted for a pure black background, my look like having blocked up shadows on a lighter background...

How do you deal with these issues of apparent changes in the overall contrast of an image depending on what type of (website) background you have???

What is your ultimate "reference" for adjusting the overall contrast and black and white points...??? And how does this also relate to printing???

Marco

I don't have the answer to them all, but here's what I know:
To set the background color in PS:
1. Press F to go to full screen mode.
2. Select background color. Default value for PS gray is R=204, G=204 and B=204.
3. Select Paint Bucket Tool
4. Shift and click on the background.
5. The color you select in step 2 is now the background color.

In terms of background color, I make the background of PS the same color as the background of both my website and the PDF files where I display my work. It makes no sense to me to have a different color for the PS background and the background of your primary display media.

Any adjustments I make to the black and white points are made with the histogram, not by eyeball. This helps me avoid the optical illusion of what is gray and what is white.

I use a deep gray. Your choice of gray is up to you by using the above technique to customize the background color. I've never used PS preset background color choice.

I use a nuetral grey .. Lab numbers reading = L-80 A- 0 b-0
I do not like using the white or black background .
For my workflow this setting seems to work real well.

OK, thanks guys, the general consensus is clear. I am probably going to set a slightly darker neutral grey background than the default setting of photoshop, just to get a bit clearer view of the total tonal range in the images, but not a pure black background, as that will be overdone.