histogram in raw converter vs levels

[jann1033]

after i convert from raw, the histogram that shows in levels is often different than the one from the raw converter...the general shape is the same but roomier on the edges...any idea why( pse5)?
if i tweak it in the editor after the raw converter via levels is there a chance i could blow out the highlights or something in that step?
i guess i just wonder do the two work together or if i am just undoing what i did in the raw converter if i change the levels in the pse5 editor

 

[seashoreCM]

I would not worry about the histogram unless it is high up the extreme left side or the extreme right side. If it was high up on either side on the raw image, shadows may already have been buried or highlights may already have been washed out.

If the histogram is high up at one or both extremes only after conversion, then you may have buried more shadows or blown out more highlights.

In either case inspect selected very dark and very bright parts of both the RAW image and converted image (picture material, not histogram content) to see whether you made shadows and/or highlights better or worse.

Camera hints:
http://members.aol.com/ajaynejr/digicam.htm

 

[tinksdad]

Just a guess, but it's probably just a display issue and not a major problem. As you know the histogram shows the distribution of light across the five stop dynamic range of the CCD chip. If the shape was changing then some changes would have to be made in the light values of the image. Maybe the the difference is the dynamic range of the "displayed" histogram between your RAW converter and Elements.

If you make changes to the image in the RAW converter it sends those changes to your editing program and then you save or change the image further there. The original RAW image is not affected and the program (at least PS-CS2) wants the edited version to be saved as another file after that.

Try using the same RAW file and changing the levels or saturation (or whatever) separately and then displaying the two different files on your monitor. You can get some interesting difference from the same basic image that way. You can adjust for background and foreground differently and combine the two for a well rounded exposure with more range than you could get from the camera with one image.


Does any of that make sense??

 

[gruZ]

Jann, what RAW converter are you using? If I remember from previous posts you have a Canon DSLR??

I believe if you are using any of the picture styles, then Canon's RAW converter captures these picture styles in the conversion, which might impact what the histogram looks like. The previous comments are right,though - after you convert and export to another file format, such as jpg or tif the histogram shouldn't change until you change it through levels or curves.

Even after conversion to jpg or tif, I would at least look at the histogram to see if you need to increase contrast through levels. Unless you change the levels so the histogram is bumping to the right, overall highlights won't be blown out.

 

[jann1033]

i've been using the pse5 converter...i might check out the canon one though as i thinkj the elements one is not all that detailed( read in the missing manual the big photoshop is much better for raw conversion)
i like the idea about the 2 photos combined...i might give that a try

Thanks all!