Can someone explain what a 50 or 100% crop is?

[HDNitehawk]

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The reason for the exact 100% crop size is to compare lenses, or show camera noise levels. That sort of thing. It can show lens sharpness, contrast, amount of chromatic aberations on high contrast edges. For comparisons, it's a wealth of information, which is why the reviews and ISO charts are all filled with 100% crops. For actual final useful results, yeah, you aren't usually going to use a 100% crop, but the information from the crop is useful. If a lens isn't sharp at 100%, you aren't going to use that lens for large prints, for cropped wildlife shots, etc.


It's also neat to show off how much detail your camera captures. I have a portrait shot of my wife carrying our daughter on her shoulders through a forest. It goes from my wife's waist, past her head, to include the head of our daughter up top, holding a lilypad she found. I can zoom in to 100% and clearly read the brand name on her jacket's zipper. It's completely inconsequential to the image, but amazing what gets captured unintentionally.
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David


I like to do big prints. And the way I judge how well my lens and camera perform together is by the 100%, 200%, 300% to 500% full views on the computer screen. The ones that can only make it to 100% are usualy marginal. and can't take much croping at all for a big print. At least for my use.


Actually when I read the OP, I was thinking finished product and not comparison


I can releate to the story about the zooming in on the brand name of the zipper. I don't know how many times I have had my 5D IIwith the 35mm lens on and someone ask me to "Zoom" in with my camera to see some detail or what somthing says. At least a dozen times I have had to explain the diffrence in a wide lens, telephoto lens and zoom lens to someone asking. ...But I still take the picture and zoom in on the viewer to see if I can see it. The most memorable time someone asked was at Mt Rushmore. I had the 500mm with 1.4x on and we took a head shot of George Washington, zoomed in on his eye lid. There is a steel spike sticking out of the eye lid on George Washington.





Rick

[wickerprints]

An x% crop is simply a portion of the original image that has been resized to x% of its original pixel dimensions.


Let

[bob williams]

I enoy reading how others have different approaches or methods of achiveing the same ends. So, I will throw my two cents worth in:


I normally use lightroom and since lightroom doesn

[tkerr]

I think where some people get confused about the term 50% or 100% crop is because the term is kind of misleading in the way it is often said.
After all if it is 100% crop then did you really crop it? if you crop 100% of the picture you're left with nothing aren't you? [] Those are Rhetorical questions!
Actually it's the difference between showing a 100% crop or cropping 100% of the image. Obviously it's not cropped 100%


As described already, by viewing the original image at 100% on your screen, setting your crop size to the desired dimensions so that when you crop the image it shows that portion at the same size you see it in the full image without having to re-sample(re-size) it when viewed at 100%. The idea is to show the cropped portion of the image without any interpolation. That is what is referred to as a 100% crop and has nothing to do with the actually percentage of the image you cropped it down to. If that were the case then if I were to crop one of my pictures (4752 x 3168) down to 800 x 640 for example, then I am only cropping about 17 to 20% from the original picture. That's the percentage of the original image size/dimensions, and then a 50% crop would be half the pixel height and width of the original. Understandably, this is why I think some people get confused about the term, and programs such as Photoshop don't make it any less confusing. Photoshop for example has the ruler guides that can be set to show inches, mm, cm, picas, pixels and percentage which is a great tool to aid when cropping photos down to certain sizes for whatever reasons. If you use Photoshop or something similar and want to show a true 100% crop use Pixels rather than Percentage on the ruler guides, Size your crop box to the desired pixel dimensions then move it over the portion you want to keep. Or use the rectangular marque tool and set the fixed size then slide it over the portion of the image you want. Either way works.



When photo editing / image processing, working on an image when viewed at 100% vs whatever size to fit your screen has advantages and will have better end results.

[Tom Wertman]

Here are 2 examples using the PS fixed marquee tool.


[img]/resized-image.ashx/__size/800x0/__key/CommunityServer-Discussions-Components-Files/13/2046._5F00_002-copy.jpg[/img]


[img]/resized-image.ashx/__size/800x0/__key/CommunityServer-Discussions-Components-Files/13/2402.cats-eye2.jpg[/img]


[img]/resized-image.ashx/__size/800x0/__key/CommunityServer-Discussions-Components-Files/13/0284.Cats-eye-copy.jpg[/img]

[bouwy]

Wow What a shot Tom. LUV It


Nicely Cropped too


Wally

[Sheiky]

Haha this thread is genius!! I thought I had a clear view on a 100% crop, but after reading some replies I got confused nonetheless []


The point where it goes wrong is in the name. It's not a 100% crop...(yes we call it this way)


It's actually very simply said a crop of an image that is shown full/100% scale..


Actually when you are looking at the 100% view of your image, you're not zooming in, nor are you zooming out. (to make it even more confusing)


Actually most people view their photo's zoomed out [:|] How's that might you be asking...


Say you have a full HD screen. That would mean you have 1920 horizontal pixels * 1080 vertical pixels. A total of 1920*1080=2073600 pixels = 2 Megapixel. At a 16:9 ratio.


If you were to have a camera that shoots 2MP photos at a 16:9 ratio. You could view your photos at full scale all the time, since the monitor isn't a limitation.


With modern day camera's we often have much bigger photos than the monitor can handle at once. If I have an image of 6MP: 3000*2000p. All you can see is 1920*1080p at a time. Since that's what my monitor can handle. This means that if you want to view your image at full scale, you aren't able to see it entirely. You'd miss 1080 pixels horizontally (3000-1920) and 920pixels vertically (2000-1080)


That's not what we want in general and therefor pretty much every photo viewer scales your image down to view the entire photo. So it's actually zoomed out to fit your screen [A]





Anyway, to make a "100% crop" as we use it here, is easy. The photos on the forums are limited to 800p wide. If you have photoshop, use the rectangle selection tool with a fixed size of 800p wide and use the crop tool to make your "100% crop" .


If you don't have photoshop or a program where you can select your selection wideness, there's another option. See which screen resolution you are using. In windows it's a simple right click on the background and go to options or something.


I for instance use a 1920*1080 resolution. If I need to make a 800p "100% crop" I could also " guess" how wide I need to go. 800p is approximately 1/2.5 width of the screen. (1920/800)


Crop for that part and you are very close to a "100% crop" without the need of photoshop or another difficult program. Close enough to use here for to show your "100% crop".





That's my 2 cents,


Jan