Strange Histogram

[polymoog]

Well strange to me anyway I have read articles from sites such as Luminous Landscape and Cambridge in Colour about understanding histograms, but so far I haven't seen an example that looks like mine, not that wasn't a composition of several images anyway ... so I was wondering if I could post it here and see what people think :



So if I understand correctly, the image has no highlight or shadow clipping b/c none of the data is pushed off the left/right hand edges. However, what does it mean when a lot of data is pushed off the top of the display? To my mind/eye, the image is both dark and the snow is lacking in detail/contrast, so I would be very grateful if there is a way to improve this image, because basically the whole set came out like this ...

This is only the second set of snow pics I have taken with this camera, and I am still learning about all the settings, the ones from last weekend (in if anything slightly darker conditions) seemed to come out better. The only changes between the 2 occasions are shutter speed, aperture and ISO. Was aiming to avoid loss of detail in the snow, to help convey the sense of speed, but it doesn't seem to have happened

If I alter Levels after opening, (making no changes in Camera Raw), pulling the right slider over till it gets to the edge of the Histogram, the light cleans up nicely, but all hint of detail in the snow is gone. I can get it back, technically, by drastically increasing the amount of Highlights, but then the whole image ends up with a strange, dark tint.

Any advice much appreciated

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[analog.universe]

I prefer a curves tool for this type of thing. Draw in a curve so that the brightest highlight is just about to clip (but doesn't quite), and then quickly bring the curve down. You have a bunch of different types of white that are all close to each other, so you want to spread them out. Then you can draw the midtones and the shadows to make the snowmobilers look right. Make sure the blacks are black, etc.

Those slider controls give you some control, but not much. If you can really get an understanding of the curves tool, you'll have control over anything you need.

[polymoog]

Thanks analog, I'll have a try and see what I can do. Have limited knowledge/experience with Curves, so time to do something about that

[ann]

The histogram is pushing out at the top to show you have a huge amount of information within those points.

On my monitor it appears to be underexposed.

[Dao]

Take a look at this link

Juza Nature Photography - Exposure and histogram

Scroll down to the section where there is a photo of a duck with a fish in it's mouth.

[480sparky]

Take a photo of just a plain white sheet of paper, or a gray card. Your histo will look even stranger...... the 3 or 4 channels will be 99.9% identical.

And the reason it looks underexposed is because it is. Your camera's meter doesn' know snow is white, so it underexposed it to make it gray.

[polymoog]

Ann : thanks, yes I would have said it was underexposed as well
Dao : thanks for the link, some great examples there
480sparky : Yes I probably should have done a manual WB setting as you suggest ...

Thanks everyone for your replies, I will now try to learn more about Curves, because half the time my pics turn out like an Andy Warhol exihibtion, if I do anything with Curves

[480sparky]

.........480sparky : Yes I probably should have done a manual WB setting as you suggest ...
.......

Histograms aren't for white balance.... they're for judging exposure.

[polymoog]

sparky : I know, but judging from the results, I should have set the WB manually anyway

[Garbz]

Why bother. You shot RAW, you lose nothing at all by adjusting the white balance now. Yet out in the field you may have missed the shot because you were fuffing around with it.

Your photo has a plain background. It's hard to convey a sense of speed with a plain background as it really helps to have something you can blur with camera movement. As for your exposure, yes it's underexposed, but that is far better than the alternative of overexposing. Right now you can bump up the brightness to the point where the snow is almost white (major points are nearly at the top of the histogram), but if you are over the top of the histogram then you can't do anything to recover the lost data.

[polymoog]

Garbz : thanks for your comments This was my main concern, that I lost texture in the snow, which would otherwise have emphasised the movement of the sled. Also, my WB adjustments are not always that successful afterwards, and if the lighting doesn't change much during the shoot, then I have to alter all of them. When it's off by a long way, eg as it was with some of the hockey pics where it went really red, it was actually easier to clean up, but these pics were a bit harder to deal with. But I would always rather get a shot with poor colour or WB, than not at all, as you say I did manage to clean the images up with Brightness and Levels, and put some texture back into the snow with Highlights/Shadows, but that was a quick fix, so I am as said going to look into Curves, and see if I can learn more about that.