Posted by Don Mullaney on January 29, 2009 at 8:15 AM
I often read, in some post, about percentage of crop such as a 100 % crop etc. How do you arrive at that number?
Thanks
Posted by David Bostedo on January 29, 2009 at 9:19 AM
What "100% crop" means Don, is that the number of pixels on your screen are the same as the number of pixels in the original image. For instance, if the original image was 2000x1000 pixels, and I show you the whole thing shrunken to 1000x500, that's not a 100% crop, because each screen pixel represents more than one original image pixel. But if I crop out a section of the original that's 1000x500, and save that so it displays at 1000x500, then I have a 100% crop.
"100%" means that each pixel on your monitor equals 1 pixel of the image; "100% crop" is because usually these are created by cropping in PS at the 100% view.
It pretty much means you're seeing all the pixels of the image without any upsizing or downsizing...seeing it as the camera recorded it.
Posted by Don Mullaney on January 29, 2009 at 4:43 PM
Thanks, David!..... Continuing with that thought, will the 1000X500 crop of the original 2000X1000 image then be called a 50% crop?
Posted by David Bostedo on January 29, 2009 at 5:38 PM
...will the 1000X500 crop of the original 2000X1000 image then be called a 50% crop?
Well, I suppose it would, but there may be no cropping when you downsize, if the entire image doesn't fill the screen. I actually don't think I've seen the "xxx% crop" term used for anything other than 100% or larger. A 200% crop would use 4 screen pixels for one image pixel. A 400% crop would use 16 image pixels for each screen pixel. But "100% crop" is the most common usage as far as I can tell, since there's no interpolation up or down, and usually that's what people are going for.
Wouldn't a % crop simply refer to the amount of the image either cropped away or left behind?
PhotoPortfolios.net seems to definite it as what % is left after cropping.
From the PhotoPortfolios.net definition page
Image Crop
Full Frame (Full Frame) - Image displayed represents the entire image as originally captured. For 35mm slides, the entire area inside the slide mount.
Greater than 75% (>75%) - Greater than 75% of the image originally captured
Less than 75% (<75%) - Less than 75% of the image originally captured
Posted by Buck Ward on January 29, 2009 at 7:22 PM
I think there's a lot of confusion here. Meaning depends on context.
A 20% crop could mean that 20 percent of the image has been removed by cropping. In that sense, a 100% crop would mean that all of the image had been removed by cropping.
A 100% crop means that the image shown is a segment of the original image shown at 100% zoom. That is, each pixel you see is one pixel in the original image, e.g. a 600 pixel by 400 pixel excerpt from the full image, without reaizing. Much of the original image has been removed by cropping, so that you can see all of the excerpt on you monitor. It's usually used to show a particular area of detail.
Posted by Richard Ditch on January 29, 2009 at 7:37 PM
"100% crop" used to mean "actual pixels" is extremely confusing. It is far better to call this something like "1:1 crop" to indicate that you are seeing each pixel. "100%" means "all" everywhere else, so why use it in an entirely different way for single meaning?
I calculate the percentage of pixels remaining from the total original pixels as described in this article on my web site.
Note that cropping is completely independent of resizing.
So, Don's example (cropping a 2000x1000 original to 1000x500 is a crop of 75%, leaving 25% remaining).
Posted by David Bostedo on January 29, 2009 at 8:04 PM
Absolutely correct on the different usages, and I'm sorry I didn't mention it. I guess that's why you see it used more with the higher percentages, since with normal cropping, you can't have 100% or more of the image. Therefore the percentage must refer to ratio of image to screen pixels.
So a "25% crop" would leave 25% of the image remaining, and a "70% crop" would leave 70% of the original image. But a "100% crop" would be any crop from the image at a 100% view, and a "200% crop" would be any crop of an image blown up (resized) to a 200% view.
Nice and simple
...why use it in an entirely different way for single meaning?
I think it's simply because it refers to the way imaging programs (Photoshop being dominant) show "actual pixels". Usually that view is 100%, and a view of the whole image at half that linear size is 50% etc. For what it's worth, "actual pixels" makes the most sense to me (or twice actual pixels, 4 times actual pixels, etc), and 1:1 crop doesn't seem much better than 100% crop.
Posted by John Mumaw on January 30, 2009 at 9:38 PM
A 100% crop means that the image shown is a segment of the original image shown at 100% zoom.
This is the definition that I always assumed was meant when folks posted 100% crops to show image sharpness, etc.
Discussion
8 repliesThanks
"100%" means that each pixel on your monitor equals 1 pixel of the image; "100% crop" is because usually these are created by cropping in PS at the 100% view.
It pretty much means you're seeing all the pixels of the image without any upsizing or downsizing...seeing it as the camera recorded it.
Well, I suppose it would, but there may be no cropping when you downsize, if the entire image doesn't fill the screen. I actually don't think I've seen the "xxx% crop" term used for anything other than 100% or larger. A 200% crop would use 4 screen pixels for one image pixel. A 400% crop would use 16 image pixels for each screen pixel. But "100% crop" is the most common usage as far as I can tell, since there's no interpolation up or down, and usually that's what people are going for.
Wouldn't a % crop simply refer to the amount of the image either cropped away or left behind?
PhotoPortfolios.net seems to definite it as what % is left after cropping.
From the PhotoPortfolios.net definition page
A 20% crop could mean that 20 percent of the image has been removed by cropping. In that sense, a 100% crop would mean that all of the image had been removed by cropping.
A 100% crop means that the image shown is a segment of the original image shown at 100% zoom. That is, each pixel you see is one pixel in the original image, e.g. a 600 pixel by 400 pixel excerpt from the full image, without reaizing. Much of the original image has been removed by cropping, so that you can see all of the excerpt on you monitor. It's usually used to show a particular area of detail.
I calculate the percentage of pixels remaining from the total original pixels as described in this article on my web site.
Note that cropping is completely independent of resizing.
So, Don's example (cropping a 2000x1000 original to 1000x500 is a crop of 75%, leaving 25% remaining).
So a "25% crop" would leave 25% of the image remaining, and a "70% crop" would leave 70% of the original image. But a "100% crop" would be any crop from the image at a 100% view, and a "200% crop" would be any crop of an image blown up (resized) to a 200% view.
Nice and simple
I think it's simply because it refers to the way imaging programs (Photoshop being dominant) show "actual pixels". Usually that view is 100%, and a view of the whole image at half that linear size is 50% etc. For what it's worth, "actual pixels" makes the most sense to me (or twice actual pixels, 4 times actual pixels, etc), and 1:1 crop doesn't seem much better than 100% crop.
This is the definition that I always assumed was meant when folks posted 100% crops to show image sharpness, etc.