Why are my whites glowing?

I have something that I need to figure out. I don't know if it because of the cold temperatures or if I am doing something wrong with my exposure, but I am checking my histogram and not blowing my whites. However, when I download my files and start checking them, things like a bald eagle's head and common goldeneyes' bodies have this glow around all the whites, like a haze. I have to then go back when I am all done editing and use a small, hard brush to clone the sky or whatever background a few pixels along the edge of the whites to make them look sharp again. I am shooting with a 1D Mark3 and my 600mm f/4 and 1.4x TC. If someone could explain what I am doing incorrectly or how to fix this I would much appreciate it. Thanks.

-Bryan

Does this happen before or after post-processing? The way you decribe it kinda suggests aggressive shadows/highlights tool that tends to do that to blue skies around subjects' edges. Hard to say...do you have an example to show?

This is a large crop too so that might have something to do with it. Also, it's ISO 1000, so could just be noise too. So, it could be as simple as the limitations of that ISO setting too? This is a zoomed in shot of the raw file in LR3.3 before I did anything to it. Didn't use a tool of any kind.

After cloning. I went along the edges around the whole head to get rid of the haze which in turn made it look sharper. Again this is just a zoomed in part of the whole photo, so once I zoom back out, it looks pretty good.

Anyone have a comment or advice???

Hey Bryn,
Since you are looking at it w/o any adjustment layers.....the whites do appear toasted. On my Mark lll......if I keep the histogram pushed to the right and it looks good on my LCD.......they are blown when I pull them in to Breezebrowser. I need to keep the histogram a bit more to the left......just my Mark lll so perhaps even though it originally looks good on the LCD......you may need to tweak where your histogram is actually toast. Do a test with some white paper or snow.......it may be simple as that.

Bryan,
At ISO 1000, what exposure and f/stop were you using?

Roger

I used f/6.3, 0 comp, Eval meter. Here is the histogram below.

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Originally Posted by Roman Kurywczak

Hey Bryn,
Since you are looking at it w/o any adjustment layers.....the whites do appear toasted. On my Mark lll......if I keep the histogram pushed to the right and it looks good on my LCD.......they are blown when I pull them in to Breezebrowser. I need to keep the histogram a bit more to the left......just my Mark lll so perhaps even though it originally looks good on the LCD......you may need to tweak where your histogram is actually toast. Do a test with some white paper or snow.......it may be simple as that.

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So, are you saying that on your camera histogram even if you keep it pushed to the right, but not over it still comes out blown in your BB? If so, why do you think that happens? I guess the easy thing to do is not push it so far to the right, but I guess I also want to understand could the "haze" be caused by a cold day too or the ISO setting? It was about 20 degrees that day. By the way, here is the finished photo.

Bryan,

Several things can cause the effect you are observing. Some of it is diffraction, and some from lens flare. The diffraction will spread light from a bright source (the eagle's white head) by 2 to 3 pixels at f/6.3, the blur filter spreads it a little more, and flare, due to microscopic imperfections in the polish and any dust on the lenses will spread light out more. You will see this on any high contrast boundary, but will be especially prominent if you saturate any portion of the scene.

In the histogram you posted, the red, green and blue peaks near the right side are due to the sky (the blue being brighter is a giveaway for the blue sky). The white in the eagle is a smaller peak closest to the right edge and will have the red, green and blue on top of each other (thus white). It is hard to tell with that peak, but you may have saturated some pixels.

On the full eagle image you posted, you can see blue sky leaking into the bird's dark feathers, especially in the lower wing, forward feathers that turn up.

There is not much you can do about the diffraction except open the aperture. On the lens flare, keep your optics clean, but even if perfectly clean, there is still flare. To show it, take some images of distant lights from under to over exposed. Note on the overexposed images, how the lights grow in size. That is flare.

In the end, fixing by hand is probably the only solution.

Roger

Thanks Roger for the explanation. I have noticed this on high contrast subjects like black and white Goldeneye ducks as well. Yet in the same scene I can take a perfectly exposed and sharp photo of a female mallard.

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Originally Posted by Bryan Hix

So, are you saying that on your camera histogram even if you keep it pushed to the right, but not over it still comes out blown in your BB? If so, why do you think that happens? ................

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That is exactly what I am saying......the why gets a bit harder although I do feel Roger gives a pretty good explanation for one possible source. When I lead my tours......and I give my settings(all manual BTW)......many times depending on the camera bodies I have seen variations as high as 1 stop between bodies. On my Mark lll I have to always pull back 1/3 to 2/3 from the right.....just my camera I guess but would be interesting if Roger has an idea there.

Quote:

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Originally Posted by Roman Kurywczak

That is exactly what I am saying......the why gets a bit harder although I do feel Roger gives a pretty good explanation for one possible source. When I lead my tours......and I give my settings(all manual BTW)......many times depending on the camera bodies I have seen variations as high as 1 stop between bodies. On my Mark lll I have to always pull back 1/3 to 2/3 from the right.....just my camera I guess but would be interesting if Roger has an idea there.

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Roman,
This does not surprise me. Back in film days, photo books would recommend that when you get a new camera or new film to go out, take pictures, and calibrate your meter. It is very difficult to have perfectly calibrated meters mass produced. While solid state electronics today are much better, there are still variables, and "everything is a thermometer" meaning the components will vary with temperature. A 1/3 stop variation is pretty good in general.

Then manufacturers set the metering system to be more or less aggressive from model to model. For example, after complaints about saturation in a digital camera, they might pull back a little on the next model to reduce saturation. The ISO spec gives leeway for such interpretation, so there is no one "perfect" ISO calibration, and no perfect metering.

Roger

Great explanation Roger and confirms my suspicions! As I like to say......know your camera!!!

Thanks for the information.
Below is a link for a detailed discussion of diffraction and photography. which is interesting but complicated
Probably 'old hat' to Roger

Ray Rozema

http://www.cambridgeincolour.com/tut...hotography.htm

Bryan,

Just curious...when was the last time you pulled out the drop in filter and checked it for dust, haze, etc? Many do not know this is necessary. A slight hazy film on any of the glass surfaces can often cause the effect shown. Make sure the glass surface of lens, filters, and converters are free of fingerprints, dust, and haze.

Improper cleaning of the anti-alias filter surface can also be a culprit.

Best,

Chas

Thanks for those suggestions Chas. Good points

Ray

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Originally Posted by Charles Glatzer

Bryan,

Just curious...when was the last time you pulled out the drop in filter and checked it for dust, haze, etc? Many do not know this is necessary. A slight hazy film on any of the glass surfaces can often cause the effect shown. Make sure the glass surface of lens, filters, and converters are free of fingerprints, dust, and haze.

Improper cleaning of the anti-alias filter surface can also be a culprit.

Best,

Chas

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Well, it's been quite a while. I will give it a good cleaning before I head out tomorrow and see if it helps. Thanks for the suggestions.