You know your blowing the whites when.......

[elaine marie]

You know your blowing the whites when.......The histogram is peaking

to the very top or touching all the way to the right side? Thanks

for any histogram lessons or sites that I can study.<P> Elaine Marie

[mikestryinagain]

Elaine,

Here is a good start for you. Most helpful.

 

http://www.luminous-landscape.com/tutorials/understanding-series/understanding-histograms.shtml

[ellis_vener_photography]

Histograms are pretty easy: tthe horizontal scale measures the intensity of exposure and the vertical scale measures the amount of tonality at a given exposure exposure level.

 

So to answer your question, exposures are being clipped in the highlights when the mountain range touches (or slams against) the right end of the histogram. Some points in a photograph -- a light source or a specular reflection of a light sourcewill almost always be blown out in at least one channel. By "blown out " what is meant is that you have no discernable detail at that point in the R, G or B channel. Remember "difference is detail"

[lovcom_photo]

Splitting hairs, but when the curve touches the right wall of the historgram, that's not necessarily a blown highlight....that last value is 255 (8-bit) or 4,095 (12 bit).

 

When the mountain slops down so that a point of the curve (not a wall of the curve) touches the right wall, you're okay, and highlights are not necessarily blown. Same for shadows against the left wall of the historgram.

 

There are times when one has to blow some highlights, in order to expose the "subject" of the composition. sometimes one has to sacrifice the highlights, or shadows, for that matter, to get the "subject" exposed properly.

 

And while we're on the subject, it would be wrong to judge exposure from the LCD on the back of the camera....these things often lie. Better to judge exposure from the histogram on the back LCD...this is going to be much more accurate. Better to use the LCD display of the image just for composition reasons.

[kiva]

Realizing I'm at risk to say this but what the heck ... sometimes, sometimes, sometimes blown out highlights Enhance a photo and take it to a very nice "place".

 

Just like dark shadows are sometimes preferable.

 

Take a look at the top fashion photographers and magazines; you'll recongnize blown highlights as a "style".

 

My point is to learn to reduce and eliminate blown hightlights, that's good, it's not only Interesting but also Important.

 

Then, decide when to Use blown highlights as a form of your Art. The use of blown highlights is a well hidden and denied "style".

[jmichaelc]

Past the right side......

 

JPEG: Yes, more than likely you've blown.

 

RAW: No

 

If your shooting RAW, the histogram that you view, is from the JPEG file embeded into your RAW file.

 

However, i've found that your RAW file has about 10-15% more leverage with the highlights, especially at higher ISO's. If your camera previews the clipping, a good safe zone is when you see < 10-15% clipping on your intended subject of exposure. Anything less than this, your subject will be somewhat underexposed when you bring the image up in the RAW developer.

[jmichaelc]

I couldn't agree with you more William :)

[bruce_rubenstein___nyc]

Depending on what is in the picture the histogram may not be indicating that "whites are blown out". It may be specular highlights or a light source in the frame. The only quick reliable way to see what is actually clipping is to enable "flashing highlights" on the screen. Then you can see if it's the bride's dress or just some small reflection that's clipping.

[mikestryinagain]

Jammey,

When you say < 10-15% clipping of your intended subject, I assume you are talking about say 10-15% of the brides dress flashing on the display? Or are you referencing the actual histogram in some way?

[jmichaelc]

Michael,

When you have fairly even lighting (exception to this: Harsh sunlight outside or a direct spotlit subject), you have lots of leverage into what i would call "Putting exposure into the midtones or shadows". How do you judge this exposure? When shooting RAW, certainly not the JPEG histogram reading. As Bruice and i suggested above, the best way is (if your camera supports it) is by viewing the clippings or "Flashing Highlights" on the image preview itself. Lets say for instance your intended subject is standing in front of a harsh lit window and you wanted to expose the actual subject properly. If using flash, you would attempt to balance out the window lighting and fill the subject. I've found that a good indicator that your subject has been properly filled (RAW), is when you see about 10-15% clipping on your subject (the person). Sure, the clippings around the window will probably be more, but the subject is our No.1 concern in this example. If you have enough flash power, you possibly can balance both scenes...but this isn't the case all the time. This is when i would say that it's good to blow the highlights of the window in order to properly expose the subject.

[mikestryinagain]

Jammey, thanks. Thats what I thought you were talking about, but just wanted to make sure. You never know what trick someone may have discovered.

[lex_jenkins]

Depends on the camera. If I'm recalling correctly my D2H histogram is only shows what's happening with the green channel on JPEGs. Sometimes it indicates clipping but there's still detail in highlights. Some dSLRs offer more sophisticated histogram displays.

[lovcom_photo]

Does anyone know how much more DR a raw image has versus a jpg? And if so, how do you know?

 

I think just because there are blown highlights in the displayed jpg on the back of the camera does not mean a corresponding raw will not have blown highlights too, even if perhaps less given the wider DR.

 

Once pixels reach a value of 255, pixels blown are set to a constant 255...so that if 10 or 15% are blown highlights, there is no way to "recover" them in post, and perhaps often this is okay. So if you have pixels that are imaginary "260" or "278" or whatever, how is post processing supposed to know what their real values are? Of course there is no way, therefore no recover available...details lost forever.

 

I guess what I'm trying to say is that one should not blow highlights even with the small jpg used to display on the back of the camera, and even though the corresponding raw may not necessarily experience blown HL's. The exception would be having to "sacrifice" some highlights or shadows to expose properly the subject of the composition.

 

Perhaps this issue is camera-specific? Then there's the issue of noise...one may have to blow some highligts to keep the noise away from the shadows and/or mid tones.

[jmichaelc]

I couldn't disagree with you more Dan. But... to each their own.

 

All i can say is "Try it", look at it and come to your own conclusions. Some things are only defineable by the eye, even though it doesn't make mathmatical sense.

 

However, i would morgage my house in defense that there is a certain percentage (Considerable amount) more leverage in the highlights of a RAW file than there are from the processed JPEG. Systems that i know this to the case: D30, 10D and 1DMII.

[eric merrill]

Dan:

 

"Once pixels reach a value of 255, pixels blown are set to a constant 255...so that if 10 or 15% are blown highlights, there is no way to "recover" them in post, and perhaps often this is okay. So if you have pixels that are imaginary "260" or "278" or whatever, how is post processing supposed to know what their real values are?"

 

When you shoot raw, you get more than 8 bits of data per channel. You get 12. With 8 bits, you can represent 0-255. With 12 bits, you can represent 0-4095. So that will help out to some degree.

 

Your question is still valid, though. Instead of imaginary values of "260", maybe we'll have imaginary values of "4100."

 

If only one of the color channels is blown, you can bring it back fairly easily within Adobe Raw Converter. If two are blown, the results aren't so good. If all three are blown? Well, white contrasts nicely and makes the shadows stick out, right? :)

 

That said, if you want a nice, blue sky you need to be very careful. Blow your sky, and it's white forever. Or until you select it, feather it, and color it artificially. :)

 

There are times to "expose to the right". And there are times to err on the side of slight underexposure. The key is to experiment and see how your own equipment responds.

 

 

Eric

[cjogo]

... When your subject is in partial bright sun--and your camera is set @ 250 /f10 but your flash does not cover the necessary power required to bring the highlight under control..(film example)

 

A.) higher output flash (Metz ~Quantum~ Norman)

 

B.) higher sync ( Hassy , etc)

 

C.) Slower speed film

 

D.) Move closer to subject