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Why, when and how do you crop an image?
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Jan 23, 2019 17:44:28   #
brucewells Loc: Central Kentucky
 
minniev wrote:
No expert here but I will chime in with an opinion. I think it is simple.

For me the histogram is not a goal but a reference - a dataset that can provide some feedback about distribution of tones. But it does not drive how I edit.

When I first started with editing and first met the histogram, I thought of it as more of a goal than I do now. But considering it as such led me to make many mistakes. A “good” histogram would produce pictures that didn’t look the way I wanted them to. Yes, the uncropped turkey has more lights in the histogram because there’s a larger proportion of lights in the uncroppped than the cropped version. But if you edit according to how you want the image to look, it shouldn’t matter what the crop does to the histogram. Unless there is something else afoot that I’m not understanding.
No expert here but I will chime in with an opinion... (show quote)


You did a great job of vocalizing (writing) how I feel about the histogram. I think you're spot on.

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Jan 23, 2019 19:45:59   #
Blenheim Orange Loc: Michigan
 
srt101fan wrote:
You all are probably right. If you don't rely on the histogram the effect of cropping shouldn't matter. I'll go back to the course (actually I haven't finished it yet!) to see if there is further info on how he uses the histogram.


I know how to "read" the histogram from a certain type of image that I take, just from experience. It was one of the first things I learned about digital imaging back 20 years ago. Adjusting the histogram can assign the 256 possible tonal values, or brightness values to different parts of the image. (I may not be describing that well.) 0 represents pure black, and 255 represents pure white. Adjusting the histogram lets you determine upon what part of the image those 256 different gradations fall.

Pretty good article here:

https://www.cambridgeincolour.com/tutorials/histograms1.htm

Mike

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Jan 23, 2019 20:11:55   #
srt101fan
 
Blenheim Orange wrote:
I know how to "read" the histogram from a certain type of image that I take, just from experience. It was one of the first things I learned about digital imaging back 20 years ago. Adjusting the histogram can assign the 256 possible tonal values, or brightness values to different parts of the image. (I may not be describing that well.) 0 represents pure black, and 255 represents pure white. Adjusting the histogram lets you determine upon what part of the image those 256 different gradations fall.

Pretty good article here:

https://www.cambridgeincolour.com/tutorials/histograms1.htm

Mike
I know how to "read" the histogram from ... (show quote)


Thanks for the link. I'll check it out.

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Jan 23, 2019 21:48:56   #
Pysanka Artist Loc: Rochester, NY
 
This thread is great . . . I'm pretty green to photo editing. Been doing very basic editing with (now don't laugh) Photoshop Elements 2.0 for a couple of years with photos from my Canon Powershot. Bought a Canon Rebel T6 in August . . . upgrading to a Canon7D Mark II (it's in the mail!!!!). I've been learning how to use the Canon DPP4 system and seem to be getting the hang of it.

Anyway I crop to fit to a certain size (usually 4 x 6) or to recompose a poorly composed photo. I usually crop at the end, but sometimes would think (especially when I would manually select a subject to invert selection to blur the background) I should crop first to save myself this time-consuming selection process with the magnetic lasso and refinements. I definitely understand and see how this "before editing" crop would affect the histrogram.

I still have a TON of learning to do with the in's and out's of post processing editing/histogram and am looking for anything free to get my hands on to learn more.

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Jan 23, 2019 21:52:04   #
Pysanka Artist Loc: Rochester, NY
 
Blenheim Orange wrote:
I know how to "read" the histogram from a certain type of image that I take, just from experience. It was one of the first things I learned about digital imaging back 20 years ago. Adjusting the histogram can assign the 256 possible tonal values, or brightness values to different parts of the image. (I may not be describing that well.) 0 represents pure black, and 255 represents pure white. Adjusting the histogram lets you determine upon what part of the image those 256 different gradations fall.

Pretty good article here:

https://www.cambridgeincolour.com/tutorials/histograms1.htm

Mike
I know how to "read" the histogram from ... (show quote)


Understand exactly what you're saying -- but it's all hit and miss for me -- seems the more you practice, the more you understand. Thanks for the article -- I'm sure it will enrich me!

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Jan 23, 2019 21:58:43   #
Pysanka Artist Loc: Rochester, NY
 
minniev wrote:
No expert here but I will chime in with an opinion. I think it is simple.

For me the histogram is not a goal but a reference - a dataset that can provide some feedback about distribution of tones. But it does not drive how I edit.

When I first started with editing and first met the histogram, I thought of it as more of a goal than I do now. But considering it as such led me to make many mistakes. A “good” histogram would produce pictures that didn’t look the way I wanted them to. Yes, the uncropped turkey has more lights in the histogram because there’s a larger proportion of lights in the uncroppped than the cropped version. But if you edit according to how you want the image to look, it shouldn’t matter what the crop does to the histogram. Unless there is something else afoot that I’m not understanding.
No expert here but I will chime in with an opinion... (show quote)


I concur the histogram is a reference/tool. A great photo should be based on what it looks like --not what the histogram looks like.

I don't know if cropping a photo first to adjust the histogram has any advantage.

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Jan 24, 2019 07:12:16   #
Linda From Maine Loc: Yakima, Washington
 
Pysanka Artist wrote:
I still have a TON of learning to do with the in's and out's of post processing editing/histogram and am looking for anything free to get my hands on to learn more.
See if your local library system offers lynda.com via its e-resources. I have free access and I've heard of several other folks around the U.S., even Canada and Ireland!

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Jan 24, 2019 13:16:11   #
Pysanka Artist Loc: Rochester, NY
 
Linda From Maine wrote:
See if your local library system offers lynda.com via its e-resources. I have free access and I've heard of several other folks around the U.S., even Canada and Ireland!


Thanks Linda I'll have to check that out -- is it something to be accessed only in the library?

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Jan 24, 2019 13:24:52   #
Linda From Maine Loc: Yakima, Washington
 
Pysanka Artist wrote:
Thanks Linda I'll have to check that out -- is it something to be accessed only in the library?
I stumbled onto the feature when on my library's website (while at home). All I had to do was click the link, and then enter some initial information, which included my library card number, and then I had access to lynda.com right from home. I like the site very much!

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