Histogram question...

[gardener]

I've been studying up on what the histogram on my camera means (Rebel XT) and how to "adjust" the camera image settings for the best final result straight out of the camera yet before any post processing. In the items I've read, it would seem that most if not all information pertains to where the graph is placed within the grid, ie: left, middle, or center, but not much is noted about the height of the picture graph within the grid and if there is some theoretical "perfect" point to which you strive.
Is in fact the height or in some cases, the lack of height of the graph something to tweak/adjust for also or is that just a factor of the individual shot and you get what you get?
Thanks for any advice...
Steve W

[LoungeLizard]

There is no "right" histogram - only right for THAT photo.

The histogram can be read from left to right as "darkest" to "brightest" pixel and the height is a count of how many pixels fall in that light range. As such, I always warn people, that a photo of a black car should have just about all parts of the graph bunched up on the left side while a photo of a snowy landscape should have most of the pixes bunched to the right.

So, with that in mind, use it wisely since there is no "bell curve" for every photo!

[johnastovall]

As the Saurian noted there is no, "Right" histogram.

You might want to read this:

http://www.luminous-landscape.com/tu...stograms.shtml

Explains why there are no "Right" histograms.

[brad]

Right.. it is a rule of thumb... left and right showing you what's dark and what's light on the image you exposed...

Its also good to note the height.. you don't want a lot of lines (some would say you don't want any, but that's not really true for every photo, either) that run off the top of the graph.. too many and it indicates a color cast to the image.

[huxley]

also be aware IF you are shooting RAW, the histogram you see is for the jpeg file not for the RAW file.

[beetleman]

Try here:

http://www.photozone.de/7Digital/histogram.htm

[gardener]

Thanks guys... Good links but I think Brad may have actually hit on what I was looking for and that was the height of the display, ie. proximity to the top of the graph.
I hadn't seen the photozone site before but find that every time I've go back to luminous landscape, I find something else to learn that I hadn't seen before.
Steve W

[brad]

Originally Posted by huxley

also be aware IF you are shooting RAW, the histogram you see is for the jpeg file not for the RAW file.

Indeed.. same goes for the image that the camera displays. That's the JPG file, not the RAW file.... it may indicate blown highlights that the RAW capture managed just fine.

(Look for verification on what I said about the heights of the lines.. I'm not 100% sure of that now that I've read what I said again.)