[UncleVanya]

A quick survey of the web yielded consensus on one point: The normal use of the term 100% crop means "shown at 100% resolution and cropped" (to fit the screen)

The other use of cropping 50% etc is more unclear. The problem appears to be that some people use the ratio of what is left, and some use the ratio of what they removed.

So a 25% reduction in total image size could be a 75% crop (what's left) or a 25% crop (what's gone). Part of the confusion appears to be verb (... cropped away 25%) vs noun, (... We are left with a 75% crop).

Just might be best to clarify precisely by stating intended meaning.

[Scintilla]

Note to self: use the phrase "crop at 100%" just to avoid having to deal with questions like these.

Because then it ought to be clear enough that what's implied is "crop (of arbitrary degree) at 100% (magnification)".

[fwcetus]

Rupert, despite what Otis is whispering in your ears -

1. I believe we all agree what the generic terms "cropping" and "resizing" mean.

2. The disagreement seems to be with what terms such as "100% crop", as commonly used on the internet, actually mean.

3. As is commonly used on the internet (in forums, etc.), the two parts of the expression are not directly related -- that is, the percentage does not refer to the amount of cropping, but to the amount of resolution (or magnification).

4a. ~IF~ you were correct, and ~IF~ the "lovely aqua colored shot" that originally included Otis before you rudely cropped him out of it were a "50% crop" simply because you cropped it in half, ~THEN~

4b. one would almost ~never~ see the commonly used term "100% crop" on the internet, ~BECAUSE~

4c. "cropping" means taking a ~portion~ of an image, as opposed to leaving the entire image, and

4d. the "100%" [to ~you~] would mean using a full-size image, ~THEN~

4e. it would be an ~oxymoron~ to use the term "100% crop", rather than to just say 'UN-cropped", or "full size", etc., so ~THEREFORE~,

4f. the percentage does ~NOT~ likely refer to the amount of "croppage" (so to speak).

[bertwert]

@fwcetus
4g. or a 100% crop would be useless as cropping the whole image (100%) would leaving nothing

[Rupert]

4e. it would be an ~oxymoron~ to use the term "100% crop", rather than to just say 'UN-cropped", or "full size", etc., so ~THEREFORE~

4f. the percentage does ~NOT~ likely refer to the amount of "croppage" (so to speak).

I agree that there is no such thing as a 100% crop.....if it is 100% it is a full image, not reduced in size...an original (in size) straight from the sensor and not a crop of anything. Well, maybe a crop of what was in your viewfinder...if you want to push the limits of reason!

However, the % DOES refer to the size of the portion cropped out of the original for whatever reasons it might have been cropped.....in my case to eliminate that damn squirrel! So if I cut the image in exactly half, it has been cropped....with the Cropping Tool...which eliminates the question of whether or not it was cropped. I didn't crop it with the re-sizing tool, the color adjustment tool, the sharpness tool....I used the Cropping Tool! How much was cropped? 50%!!! So even by squirrel logic, we can see it is a 50% crop!

Just as a side note.....after reading in this thread, Otis has declared that squirrels taking over the world is going to be a lot easier than he imagined! He is wondering how many humans will confuse a shotgun with a hair trimming tool and blow off their heads...I guess we could call it a flattop...if we could agree, which is doubtful!

Regards!

I will add one thing, since there is clearly a big difference in what a person calls a crop...and along with Dewman, the OP, ( Bless your heart Dewman, you didn't ask for this to go squirrely! ) I think it would be wise and responsible if a poster mentions crop in his photo post he/she should explain what they are referring to as a "crop". Almost 100% of my shots are cropped...then re-sized. The % varies wildly, so I seldom even mention that the image is cropped.

I shot this earlier today......it is cropped like almost all my shots......



According to Otis' math, which is better than mine, it is a 23.58% crop from the original. I keep in mind that although I am often wrong...anyhow according to both Otis and Mrs Rupert.....Otis is seldom if ever wrong...so that's my story and I'm stickin' to it!

Regards!

[D1N0]

A 100% crop is simply any crop without resizing the output, so that the pixel size is 1:1 when viewing the image unresized in the browser. so if you don't crop at all you can still have a 100% crop when you output the file with the same pixel dimensions it came of the sensor. If you crop a file to only 1 pixel from the sensor that is also 1 pixel on a screen it is also a 100% crop.

[dakight]

So what would a 100% crop be then???

It is either a misnomer in that a 100% image is not cropped at all or it wouldn't be a "crop" or it is an empty file with no data. Either 100% remains or 100% is gone and nothing remains. Either way it is an incorrect term. When I say that an image is cropped 20% (for example) I mean that I have removed approximately 20% and the remaining 80% is what you see. I believe that is the most straightforward interpretation but I certainly allow for the possibility that someone else may interpret it differently.


*edit* Let me add... I could just plain be mistaken too... it wouldn't be the first time.

[Edgar_in_Indy]

@fwcetus
4g. or a 100% crop would be useless as cropping the whole image (100%) would leaving nothing

Not entirely true, and this is kind of a pet peeve of mine:

Pentax DSLR's supposedly use a 2:3 shaped sensor. But the images are just a few pixels wider than 2:3. So if I do a 100% crop with the crop tool set to an aspect ratio of 2:3, it actually does crop a little bit off the edges. And I do this all the time because it annoys me to have oddball resolutions, such as 1998x3000, instead of a nice round 2000x3000.

[fwcetus]

[...] if you want to push the limits of reason!

Well, Rupert, ~I~ have been trying to stay within the bounds of reason. (YMMV)

[...] I used the Cropping Tool! [/B] How much was cropped? 50%!!! So by even squirrel logic, we can see it is a 50% crop!

[Note -- the following is intended as (vaguely) humorous, and is not intended as logic.]

Well, I most often use FastStone Image Viewer for my croppng, resizing, etc. I will point out that the resizing (or resampling) tool does allow setting for actual pixels (or dpi, or in, or cm) or for a percentage of the original. However, I will also point out that the cropping tool allows setting for actual pixels (or in, or cm) or for a ratio, but the ratio is the proportion of width to height (or for height to width), and not a percentage proportion of the original image. Therefore, ~I~ am never confused by cropping as a percentage.

[Rupert]

*edit* Let me add... I could just plain be mistaken too... it wouldn't be the first time.

Yep....you must have a wife too?

Regards!

Back to what I said just above....there are so many interpretations that posters should explain their "personal" view of what a crop is when they mention cropping their shot in a post. Heck, from what I see here it could mean damn near anything....

Here is a 50% crop of my 50% crop......Cropped the saturation 50%!



Without specific information, the word "crop" is basically meaningless as used in far too many cases.

Regards!

[paulh]

A 100% crop is simply any crop without resizing the output

Exactly.

[Scintilla]

Not entirely true, and this is kind of a pet peeve of mine:

Pentax DSLR's supposedly use a 2:3 shaped sensor. But the images are just a few pixels wider than 2:3. So if I do a 100% crop with the crop tool set to an aspect ratio of 2:3, it actually does crop a little bit off the edges. And I do this all the time because it annoys me to have oddball resolutions, such as 1998x3000, instead of a nice round 2000x3000.

If there's one good thing about the odd 4928x3264 aspect ratio of my K-30's sensor, it's that (assuming I need no cropping) resizing the image to width of 1280 (important to me because it's the native width of my monitors at work and I like making my photos into wallpapers for it; also the maximum width you can upload to Tumblr without them downsizing it) gives 1280x848, which is a lot more sensible than the 1280x853 that would result from an actual 3:2 image.

But for just about any other size, I'd rather have a true 3:2.

[Edgar_in_Indy]

If there's one good thing about the odd 4928x3264 aspect ratio of my K-30's sensor, it's that (assuming I need no cropping) resizing the image to width of 1280 (important to me because it's the native width of my monitors at work and I like making my photos into wallpapers for it; also the maximum width you can upload to Tumblr without them downsizing it) gives 1280x848, which is a lot more sensible than the 1280x853 that would result from an actual 3:2 image.

But for just about any other size, I'd rather have a true 3:2.

You're right, 1280x848 does have a better ring to it than 1280x853, but surely neither of those resolutions are the native resolution of your monitor? So you'll either end up with some blank edges, a distorted/stretched image, or an arbitrary crop and upsample to fill the screen.

When I make wallpapers from my photos, I resize AND crop to the exact resolution, such as 1280x768.

[Rupert]

Neat trick.....cropping without resizing the output!!! Ever look at the pixel dimensions of a crop and happened to notice they are not the same as the original? That is because the image was cropped!

How much was it cropped? What % of pixels were removed from the original...that's how much it was cropped! If you didn't crop it the sizes would be identical. That's why they call it "cropping"!

Regards!

[D1N0]

Neat trick.....cropping without resizing the output!!! Ever look at the pixel dimensions of a crop and happened to notice they are not the same as the original? That is because the image was cropped!

How much was it cropped? What % of pixels were removed from the original...that's how much it was cropped! If you didn't crop it the sizes would be identical. That's why they call it "cropping"!

Regards!

The number of or percentage of pixels that were cropped of is irrelevant. from 0 to all but 1. % in cropping is about the relation screenpixels/sensorpixels If it is 1 then it is a 100% crop, if it is 0.25 it is a 50% crop