Histogram: Camera vs PSE3

[ExpertNovice]

I am trying to figure out what the differences are between the Canon 5D RGB histogram and what I see in PSE3.

The 5D histogram shows all three colors on different lines. Red at top, Blue at bottom. Each color is displayed across 5 zones.

Each of the colors being displayed are spanning from the middle of zone 1 (to the left) and ending just over the beginning of the fifth zone. Blue stops at the 4th zone. red and green look like a flat mountain with very slight dips in the middle. The blue is more like a peaked mountain with the peak at the start of zone 2.

Thus, all looks reasonably well.

The image Raw and JPG are both loaded into PSE3. The RAW image in the PSE3 raw image "editor" appears similar to that of the camera. The raw image is opened with all settings to 0 and As Shot, which forces the tint to a +19.

The raw and jpg histogram look radically different than what is displayed in the 5D. Actually, the blue has the same basic shape except that it never drops to 0 so the channel appears over exposed. Green runs off the right edge fairly high up. (The picture is primarily green landscape.) Red runs off the right edge also fairly high.

It almost appears as if the 5D is showing 5 zones and PSE3 is only representing the first three zones.

If this matters, the images in the 5D are being saved using the Adobe RGB color space.

If this is normal, then no problem. If it is something that I'm doing wrong, then someone come and slap me! ;)

[MikeH]

Hi,

How do the RAW and RGB histograms look in DPP?

Mike

[ExpertNovice]

DPP (Digital Photo Professional) was not installed since I was using PSE3. It was just installed in order to answer your question. The color space was changed from sRGB to Adobe RGB. Color Matching was changed from sRGB to the most recent saved icc for this monitor. Reloading the picture the status bar still reads RAW / sRGB. I will look into that later.

I'm now comparing the histogram between the 5D, PSE3, and DPP.

The differences between DPP and the 5D are due to differences in space available for the height of the histogram. For example, on the 5d the green, in the current picture, rises about 10-15 degrees from the end of zone 1 to the middle of zone 4 then the slope changes to about 30 degrees for a short bit then drops off. Finally it runs on and spikes where small portions of the scene were blown out.

On the DPP the slopes are about 60 degrees, then 45, then 80, then drops 80 degrees until it, again runs on to the end spike.

In otherwords, they are the same.

in PSE3 the histogram is close but there are differences that are not explained by space alloted.

Thanks for helping. From my novice mentality it appears that either the PSE3 histogram is not quite as accurate in interpreting the picture or that the picture is being modified when loaded.