Histogram Question

Bill Ravens wrote on 8/9/2004, 8:10 PM

I've imported a still image that comes from Adobe Photoshop. I saved the image with sRGB color mapping so it will import into Vegas5 with a known map. When I compare the histogram from V5 with the histogram generated in Photoshop, they bear only a faint resemblance, with a lot of apparent clipping at both ends of the histogram scale. What gives? I checked to make sure I didn't have any video FX applied, This is the raw import file.

Comments

SonyEPM wrote on 8/10/2004, 10:09 AM

Vegas uses a log scale for histograms and it appears that PS uses a linear scale, so the histograms between the two apps won't match. Neither app is "doing it wrong", we're just using different methods to plot.

mhbstevens wrote on 8/10/2004, 10:52 AM

Note the end clipping shown by both programs shows the original shot was wrongly exposed.

Bill Ravens wrote on 8/10/2004, 12:58 PM

SonyEPM..

thanx, that's a relief to understand. Part of my problem was that the black bars generated within the frame but in the background (from having an undersized image) were showing on the histogram as a bottom end clipping. That misled me to beleive the original image was causing the clipping indication. The log scale must be on the ordinate? The abcissa is not a log scale, but, 0 RGB-255 RGB linear.

mhbstevens..

thanx for your input. the original image was not being clipped in PS.