Is clipping in only individual channel necessarily a problem?

[peter_berger2]

<p>When editing image in Camera Raw... is clipping in only individual channel necessarily a problem or should I be concerned only about overall clipping (in all channels)? Sometimes I see that one of the channels have reached its max or min values, but the image looks ok... So should I correct it or not? Will be such image printable?</p>

[Spearhead]

<p>If you're happy with how the image looks, you shouldn't worry about the technical analysis. </p>

[craigd]

<p>I'm with Jeff on this. Nothing in photography is "necessarily" a problem. The only thing that matters is whether the final image is what you want it to be. If it looks good on the screen, try printing it and see how it comes out.</p>

[steve_dunn2]

<p>Before I go into a bit more detail, let me first say that I agree with the first two responses. You ask if it's <em>necessarily</em> a problem, and the answer is no, it's not necessarily a problem. Certainly, in some cases, it's a problem. But in others, it's not. The bottom line in most cases* is this: do you like the way the image looks? If so, then whether there's clipping is pretty much a non-issue. Nobody except weenies and the editors at stock photography sites (and the two groups probably overlap somewhat :-) is going to check the histogram of your image before deciding if they like it.</p>

 

<p>On a technical level, if a channel clips, it's going to throw off the colour balance of those pixels where clipping occurs. For instance, imagine that part of your scene is an area that's all the same colour but some parts are lit more brightly than others. Let's say the colour is such that its blue component is exactly twice its red and green components (i.e. a moderately saturated blue). In areas where there's no clipping, every pixel has this relationship, which is correct for the item you're photographing. In areas that are brightly lit, though, maybe the blue channel in your image starts clipping: it's stuck at 255 (on the traditional 0-255 scale), yet the green and blue components keep rising. As they rise, it fades from blue towards white, even though the actual item you're photographing is all blue, not white.</p>

 

<p>An example of this type of effect in the real world is the sky. Ever taken a picture in which the the sky, which was various shades of blue in real life when you took the picture, ends up as much lighter shades of blue and heads towards white in some areas? Yeah, we all have at one time or another. That's because the blue channel is clipping before the others.</p>

 

<p>But what if it's only slightly clipped? If it's stuck at 255 when the real number should have been 260, then for almost all practical purposes, it's not a problem. You'll end up with a very slightly different shade of that colour, but it's close enough that nobody's going to notice.</p>

 

<p>And since you ask if the image will be "printable," that brings up another point: your monitor, whatever device you're thinking of using to print the images, and the colour space you're working in probably all have different gamuts (the range of all colours the device/space can represent) anyway. Just because a channel isn't clipped in your image file doesn't mean your monitor and/or printing device won't clip it. Again, backing off from a technical answer into a more practical one, if it <em>looks</em> good, then it <em>is</em> good, regardless of whether there's some clipping going on somewhere in there.</p>

 

<p>*: There are some technical types of photography in which maintaining precise colour accuracy is crucial, and clipping is going to be a no-no there. But these are the exception rather than the rule.</p>

[franklin_white]

<p>If you're shooting a red rose, the red channel is often going to overload long before the other channels. If you don't watch this on an RGB historgram, you will never get the color of the flower to look right. You can also often mess up fine distinctions in skin color by letting the red channel clip. </p>