histogram help

scooter2044 · May 22, 2015

I haven't had my camera very long and am trying to learn more about the histogram. When I open the raw file the blue is clipped in every single one of my photos. It doesn't matter what mode I'm, even auto. The blue is always clipped. Can anyone tell me what is causing this, or what am I doing wrong?

unpopular · May 22, 2015

Single channel clipping is not ideal, however, it may also be unavoidable in some situations provided that exposure is correct. Mustard flowers for example will always clip the blue channel at the low end for me on my Sony DSLRs. They simply absorb so much blue light that my sensor cannot detect it.

But the issue may very well be in processing, and not in exposure - are you shooting raw or jpeg? In the situations where this is problematic and unavoidable, there are ways to build up detail from the other channels in Photoshop, but this is a bit more of an advanced topic.

However, my guess is that your sky is blowing out - which again isn't ideal - but without any detail there it's not necessarily a bad thing either.

Can you post some examples?

scooter2044 · May 22, 2015

unpopular said:
Single channel clipping is not ideal, however, it may also be unavoidable in some situations provided that exposure is correct. Mustard flowers for example will always clip the blue channel at the low end for me on my Sony DSLRs. They simply absorb so much blue light that my sensor cannot detect it.

But the issue may very well be in processing, and not in exposure - are you shooting raw or jpeg? In the situations where this is problematic and unavoidable, there are ways to build up detail from the other channels in Photoshop, but this is a bit more of an advanced topic.

However, my guess is that your sky is blowing out - which again isn't ideal - but without any detail there it's not necessarily a bad thing either.

Can you post some examples?

I didn't do any processing at all to this one in the raw file or in Elements.

IMG_2066_0741
by Sheila Swindell, on Flickr

unpopular · May 22, 2015

In this particular photograph, the issue appears to be that the green leaves are absorbing all the blue light. This makes sense, as the leaves use ultraviolet light in photosynthesis. By the time the back-side of the leaf is illuminated there is insufficient blue light left to record. You have good detail in the leaves and they look natural. I wouldn't worry about it too much.

The image is a little dark (not under exposed). Consider looking into ETTR if the issue remains problematic, though even then you might not really get anything useful from the blue channel in the backlit leaves.

But in this example, the bottom of the blue channel is clipping naturally.

scooter2044 · May 22, 2015

unpopular said:
In this particular photograph, the issue appears to be that the green leaves are absorbing all the blue light. This makes sense, as the leaves use ultraviolet light in photosynthesis. By the time the back-side of the leaf is illuminated there is insufficient blue light left to record. You have good detail in the leaves and they look natural. I wouldn't worry about it too much.

The image is a little dark (not under exposed). Consider looking into ETTR if the issue remains problematic, though even then you might not really get anything useful from the blue channel in the backlit leaves.

But in this example, the bottom of the blue channel is clipping naturally.

Not sure what ETTR is. So if it doesn't look like I'm losing detail, I should be ok?

unpopular · May 22, 2015

Oh and by the way, this is a jpeg, not a raw file. The raw data may very well contain data on the blue channel, though you're only going to access that if you process the file accordingly - rather than simply pushing it through a preset.

unpopular · May 22, 2015

scooter2044 said:
Not sure what ETTR is. So if it doesn't look like I'm losing detail, I should be ok?

You're loosing detail, sure. But not in a way that is problematic. It may very well be that our eyes cannot detect the blue light in these leaves either.

So, yeah, it might look bad to a bee. But for humans, this is acceptable. There might be some editing situations that it could be problematic (in particular in certain greyscale conversions), but as it is, no. This kind of clipping is to be expected.

As for ETTR, look it up - but put it in your mental storage. Right now it's more beneficial to understand the basics.

scooter2044 · May 22, 2015

unpopular said:
Oh and by the way, this is a jpeg, not a raw file. The raw data may very well contain data on the blue channel, though you're only going to access that if you process the file accordingly - rather than simply pushing it through a preset.

I didn't think you could upload a raw file to Flicker, so I did the jpeg. I don't know how to set any presets in Elements so whatever the settings were when I got it are what got used when I saved it to jpeg. Would there be something I need to change?

unpopular · May 22, 2015

I haven't used elements in like 10 years. So I don't know specifically.

I wouldn't worry about it yet. Like I said, until you get pretty deep into the channel mixer, it's not something you'll need to think about.

And for what it's worth, I just avoid mustard entirely

scooter2044 · May 22, 2015

unpopular said:
I haven't used elements in like 10 years. So I don't know specifically.

I wouldn't worry about it yet. Like I said, until you get pretty deep into the channel mixer, it's not something you'll need to think about.

And for what it's worth, I just avoid mustard entirely

But it's soo pretty. I'm also allergic. By the way, once I looked up ETTR I knew what it was. I keep forgetting all the abbreviations. I still don't know what the OP stands for, lol.
By the way, thanks for all your help.

unpopular · May 22, 2015

ETTR might pull enough data from the back side of the leaves. I don't really know - this isn;t a subject I do much of.

Mustard though is hell. I'd LOVE to photograph it, but every time I try I get nothing but blobs of yellow with NO DETAIL. Maybe a blue filter for b/w? For color though, it just never works out for me.

Haven't tried it on my Fuji yet...

scooter2044 · May 22, 2015

unpopular said:
ETTR might pull enough data from the back side of the leaves. I don't really know - this isn;t a subject I do much of.

Mustard though is hell. I'd LOVE to photograph it, but every time I try I get nothing but blobs of yellow with NO DETAIL. Maybe a blue filter for b/w? For color though, it just never works out for me.

Haven't tried it on my Fuji yet...

I havn't got into using filters yet. Maybe that's why everyone else's photos are so much more bright and colorful. Mine just seem so drab. I've tried adjusting the contrast but usually end up clipping something in the histogram so I don't go very high. I have an especially hard time with getting good contrast in b/w. Thanks for the answers. I've got so much more to learn...

unpopular · May 22, 2015

Most people do not use optical filters with digital. I've proposed using them, but only in as far as theory. In practice, I have no idea how useful they are. Derrel knows more on that topic.