Histogram versus the Zebra

[Arty]

As someone who's migrated across from camcorders. I'm struggling to get to grips with the 'histogram'. I'm ploughing through the excellent Luminous-landscape tutorial at the moment. On the face of it, the histogram looks pretty complicated to master. So why not a simple zebra pattern? Any half decent camcorder sports one of these. I can't believe it'd be too complicated to display a zebra on the LCD of a DSLR. Biggest advantage is that it's quick and very easy to understand. Thoughts?

[lcoleman]

I think that when you get used to the histogram you will like it better than the zebra patterns. The good news of the zebra is that it is live and gives instant feedback (although on a DSLR you don't get a live preview on the current models anyway). The bad news is that it doesn't give nearly as much or accurate info as the histogram. With a zebra pattern you only know which areas are at or above your set point (80%, 90%, 100%, etc.) If you have it set for 90% you still wouldn't know which areas have detail and which are totally lost. With a histogram you can see relative amounts across the whole spectrum and not just the highlights. The shadows are as important as the highlights. My 20D does flash on the screen the areas that are totally blown out, much like a zebra pattern. I assume the other Canon models do this as well.

Good luck with the histograms. I think you will find they are the best way to judge your overall exposure when you get used to them.

[tim]

I've no idea what a zebra pattern is, but a histogram's a very simple tool, once you plough through that article it should be simple. All it is is black on the left, white on the right, and shades of grey between, representing the brightness of the photo you've taken.

[Jon]

If you're set to view the histogram, you'll get "blinkies" in the image preview where you'd see your "zebra pattern" in a camcorder. But the histogram also tells you if you're underexposing an area, or not using the full dynamic range of the sensor, which a zebra pattern won't.

[PhotosGuy]

If you're set to view the histogram, you'll get "blinkies" in the image preview where you'd see your "zebra pattern" in a camcorder. But the histogram also tells you if you're underexposing an area, or not using the full dynamic range of the sensor, which a zebra pattern won't.
PLus, 50% of the info in the pic file is at the top 20% of the histogram, so if you underexpose, you lose a LOT of pic data + gain a LOT of noise.

[PacAce]

PLus, 50% of the info in the pic file is at the top 20% of the histogram, so if you underexpose, you lose a LOT of pic data + gain a LOT of noise.
I'm not sure I understand what this is trying to say? ??? Maybe I'm just having a bad day. :confused:

[PhotosGuy]

:D:D Having one of "those days"? You know it, you're just not "connecting" due to my abbreviated comment. ;)
From, "Expose (to the) Right"
http://www.luminous-landscape.com/tutorials/expose-right.shtml

Quote: "A 12 bit image is capable of recording 4,096 (2^12) discrete tonal values. One would think that therefore each F/Stop of the 5 stop range would be able to record some 850 (4096 / 5) of these steps. But, alas, this is not the case. The way that it really works is that the first (brightest) stop's worth of data contains 2048 of these steps — fully half of those available."

OK?

[PacAce]

:D:D Having one of "those days"? You know it, you're just not "connecting" due to my abbreviated comment. ;)
From, "Expose (to the) Right"
http://www.luminous-landscape.com/tutorials/expose-right.shtml

Quote: "A 12 bit image is capable of recording 4,096 (2^12) discrete tonal values. One would think that therefore each F/Stop of the 5 stop range would be able to record some 850 (4096 / 5) of these steps. But, alas, this is not the case. The way that it really works is that the first (brightest) stop's worth of data contains 2048 of these steps — fully half of those available."

OK?
Thanks, Frank. That's what I thought you were implying but the "50% of the info in the pic file" part kind of threw me. I think what you meant to say was that 50% of the possilble data values for each pixel lies in the right 20% of the histogram (assuming a 5-stop dynamic range sensor). ;)

[Arty]

I don't doubt that the histo is far more detailed than a zebra. But as a quick 'guide' the zeb is invaluble. 'Snapshot' digital stills pass what the cam is seeing through to the LCD, so why not have that facility (if you want to use it) on an expensive DSLR? Anyways....back to "Understanding histograms". ;)

[juneappal]

Snapshot' digital stills pass what the cam is seeing through to the LCD, so why not have that facility (if you want to use it) on an expensive DSLR

Maybe because the slr by definition does not have an image to pass through until you release the shutter. The chip is all covered up behind it's SL waiting for the R.

-Adam

[PhotosGuy]

That's IT, Leo! As usual, trying to save time & I wound up wasting twice as much! ;-)