40D in camera histogram compared to photoshop

[vadtel]

Hi guys. Strange story. Checked exposure with flash meter (Hensel monolight was

in use). As per camera histogram - underexposed 1 stop. I thought that meter

needs to be calibrated for camera (find right ISO). Then I added 1 stop -

camera histogram was perfect. Opened files in Canon's Zoom browser - histogram

looked exact as it did in camera. Opened pictures in Photoshop - completely

different histogram! My meter reading was ok and first exposure too! Second

picture (adjusted to plus one stop, which was ok with camera histogram) in

Photoshop was overexposed at this added stop of light.

What is wrong here? I thought maybe camera needs calibration, but the Zoom

browser gave me the same histogram as camera did. Any ideas?

[zml]

Check your photoshop settings and/or Camera Raw presets (if you are using CR to convert RAW.)

[colinsouthern]

Is ACR on Auto-Adjust by any chance?

[chrisjb]

Are you viewing the same type of histogram in both? camera has rgb as well as luminous, likewise check PS :)

[PuppyDigs]

The important thing is, did the image look the same--good--when opened in Zoom

browser and PS? If so, who cares about the histogram. Histograms from different software

never match up any way.

[patrick.mason]

Puppy Face is right on. Different applications do produce different histograms. I believe this

happens because of differing algorithms from application to application. Bottom line: How's

it look? You might also want to be sure you are using the same color spec from camera to

processing application to final pic to browser.