Levels Question

[Robert Boire]

Hello,

Can someone explain (or send me a link or something) to explain what the "output levels" are for in the PS levels adjustment. It seem to me it just reduces the range of reproducible tones.

Thanks

Robert

[Joseph Yeung]

Yes, it takes the full range of levels in your image (0-255) and compresses them into the range you specify (black point >0 and white point <0).  This usually isn't something you want to do to your image for printing or viewing, but can be useful in some image manipulation steps (eg you have a layer mask and want to reduce the effect of that layer evenly, you can pull down the white output level of the layer mask)

[Guillermo Luijk]

This interpretation as curve may help to understand (both are 100% equivalent adjustments):



EVERYthing that can be done with a given Levels adjustment, can be done using a single curve. The opposite is usually not true.

Regards

[AlanPezzulich]

Hello,

Can someone explain (or send me a link or something) to explain what the "output levels" are for in the PS levels adjustment. It seem to me it just reduces the range of reproducible tones.

Thanks

Robert

This is usefull if you are trying to change the color of something from a light color to a dark color (or the other way around). If you have a yellow dress and you try to color it dark blue using a brush and a layer with the blending mode set to color the dress will retain the luminosity of the yellow



Alan

[Lightsmith]

A RAW file will have a dynamic range in excess of what you can print. Levels in effect compresses the DR of the image to match the expected output - different for Web where the image will be viewed on a monitor or when printed on an inkjet printer or with a RA printer.