What does a perfect histogram look like?

[MikeMcL]

please post a very good or "perfect" histogram... I have pleenty of good shots, and i have tweaked raws for hours trying to get the histograms to perfect levels, but the shot always look so jacked up.

-a link to another thread would be much appreciated as well.

I did an event this weekend, i shot in RAW+L. I nailed the exposure so well that i just ran a curve/USM action on the larges, and sent it to the press. I didnt even bother with doing raw conversions, because it was waaay more work to produce the same (almost identical) image. If this is way off, let me know, i might be dense.

basically, it was about 30-40 couples - holiday portraits, quick and dirty at a christmas party.

Setup is 3 AB's... 2 800's as main lights set at about -1.5f stops and a AB400 with shovel reflector at -2f in in the left of frame, lighting the muslin. shot the whole thing at f8 and 200, iso 100 with the 28-70L 2.8

[TMR Design]

Take a look at this:
http://www.luminous-landscape.com/tutorials/understanding-series/understanding-histograms.shtml
http://www.larry-bolch.com/histogram/

[redbutt]

That is a loaded question. A "perfect" histogram is one that shows you the information you expect to see from a shot. It changes depending on what your trying to do (I know I'm gonna catch hell from someone for saying that). I've attached two samples though to illustrate my point. In both of these images you see the histograms that represent the image. In both cases, you see exactly what I was attempting to capture. People would probably look at the second one and say that it was under exposed, while the first one was closer to ideal. I guess my point is that the histogram is a great tool, but there is no *one* perfect histogram.

In your case, you would want to see a histogram that does not clip off the left or right side. As far as the image goes, my only real complaint is that I would have composed that with a tighter crop...probably only go as low as the waist.

Oh yeah...28-70? I assume you meant the 24-70 f/2.8 L?

[Curtis N]

Redbutt, I don't think you'll find anyone disagreeing with your statement, which you illustrated quite well.

The histogram of a properly exposed polar bear on a snow-covered hill will look quite different from that of a black cat on a pile of coal.

The image posted by the OP represents a great challenge, typically seen by wedding shooters. Perfectly exposed, it would have a spike near the right side from the white shirt, a spike near the left side from the black dress, and a hill in the middle from the background. However, this shot might contain more dynamic range than today's digital cameras are capable of capturing.

[MikeMcL]

Thanks for the detailed and fast responses. i found this quote at luminous landscape, aand i think it sums it up "with the possible exception of showing badly blown out highlights there really is no such thing as a bad histogram. They just are"

i have the older version of the 24-70 L f/2.8 by the way, for redbutt... it is 28-70mm

TY!

[NickSimcheck]

If everything is still in the histogram, then it's technically perfect.

If starts out high on the left side, you are cutting dark detail.
If ends high on the right side, you are are cutting highlight.
If it shoots through the roof, you are loosing detail in that range.

*Edit* Before somebody gets all huffed & puffed about my statement...I also agree with everybody else that depending on what you want from the image, it can show lost darks or blown lights on the histogram while still being a good image.

[FlashZebra]

If it shoots through the roof, you are loosing detail in that range..
Not with you on this.

A grand height ("shoots through the roof") indicates there are a lot of pixels of that particular bit value (or bit values). But, I see no bad attribute associate with this?

Am I just misunderstanding your copy?

Enjoy! Lon

[DocFrankenstein]

I'm with Mr. Redbutt.

You have to use your head. A perfect histogram for a high key image is not the same as for a low key... and is not the same if you have a particular filter in mind for post processing.

I would just learn what the histogram tells you and go from there.

[YosemiteJunkie]

That is a loaded question. A "perfect" histogram is one that shows you the information you expect to see from a shot. It changes depending on what your trying to do (I know I'm gonna catch hell from someone for saying that). I've attached two samples though to illustrate my point. In both of these images you see the histograms that represent the image. In both cases, you see exactly what I was attempting to capture. People would probably look at the second one and say that it was under exposed, while the first one was closer to ideal. I guess my point is that the histogram is a great tool, but there is no *one* perfect histogram.

In your case, you would want to see a histogram that does not clip off the left or right side. As far as the image goes, my only real complaint is that I would have composed that with a tighter crop...probably only go as low as the waist.

Oh yeah...28-70? I assume you meant the 24-70 f/2.8 L?
Redbutt, could you pm me (don't want to hijack this thread) with a bit of info on how you got that second shot, please. I've been trying to do that with my limited means and just not getting there. Thanks for you help.

[PaulCee]

Can't really be a 'perfect' histogram - every scene is going to be different in some way, so a perfect histogram for one scene isn't going to be the perfect one for another scene.

The histogram is a wonderful tool, in it's own way, but trust your eyes - the end viewer of your picture is going to be looking at just that - the picture. They won't have the benefit of a histogram to tell them the picture is right, they'll just go by what they can see.

If in doubt get a second opinion on your pictures - sometimes others see things you may not have done - try it - it works!!!

[René Damkot]

An old thread (http://photography-on-the.net/forum/showthread.php?t=70397). Have a look at the ShootsSmarter link in post #11.

[TMR Design]

The perfect histogram does not always mean you have the correct exposure. Well, it does but as Bryan Peterson points out in 'Understanding Exposure' thre is something called a creatively correct exposure and quite often the histogram for one of these images doesn't look at all like what we would consider a perfect histogram. You have to use your head and some smarts when interpreting this and other technical specs.

[themirage]

You could always chimp :)
http://www.mikeweb.net/ebay/chimping.jpg

I'm no expert but I would also shoot in RAW. It will let you play around with settings after taking the shot. You then can watch the histogram change.

[TMR Design]

You can demonstrate this for yourself by bracketing, taking one shot that is technically correct and previewing the LCD to get a perfect histogram (or as close to it given the subject and contrast) and then under or overexposing to achieve the creatively correct exposure and then compare the histograms.

[NickSimcheck]

Not with you on this.

A grand height ("shoots through the roof") indicates there are a lot of pixels of that particular bit value (or bit values). But, I see no bad attribute associate with this?

Am I just misunderstanding your copy?

Enjoy! Lon

Yeah I didn't word it right, that's what happens what you don't proof read at midnight.

"So if it shoots through the roof at either end, you're loosing a lot of detail."

[redbutt]

Not with you on this.

A grand height ("shoots through the roof") indicates there are a lot of pixels of that particular bit value (or bit values). But, I see no bad attribute associate with this?

Am I just misunderstanding your copy?

Enjoy! Lon

Bingo...you only loose detail if the histogram is clipping to the left or right...not off the top.

[redbutt]

Yeah I didn't word it right, that's what happens what you don't proof read at midnight.

"So if it shoots through the roof at either end, you're loosing a lot of detail."

Even that is not entirely correct...but I get what you are trying to say...it's hard to describe. Shooting through the roof is fine...that just means lots of pixels are capturing that tonal range. What you don't want (technically) is for the histogram to show a spike that doesn't return to the floor BEFORE it goes off the end.