!00% Crop.

[martycon]

I finally sought the meaning of "100% crop". I understand it to be a crop made with the monitor set at !00% zoom. My reaction was 100% of what? Then I noticed the 1:1 view option in my editing software, and read further that this is where image size equals screen size. This in it's self takes a bit of comprehending.
I realise that most specialists use jargon as shorthand, but believe there could be a better, more descriptive title than "100% crop". Ideally it would make the reader readily aware that it was made with image and screen size equal.
As it must be short, the best I can think of is "crop from view 1:1"
The only good thing about "100% crop" is that it caused me to find out what it meant.
What do you think?

[Lance B]

Yes, a 100% crop is a crop where the number of pixels equals the size at which it will be displayed on a monitor. A photo from a camera may be 6000x4000 pixels for a 24Mp camera for example but will not fit onto a conventional screen as most are about 1920x1080 or 2560x1440 or whatever. So, we reduce the photo for display purposes to suit these screen resolutions, otherwise we would not see the photo in full without needing to navigate over the photo. However, we would be seeing the photo at 100% and any part of that photo that we see on the screen could be seen as being a 100% crop. I generally make mine 1800x1200 as it fits my monitor which has a resolution of 2560x1440. However, if we looked at any part of that original sized photo on the screen, then we would be looking at any part of that photo at 100%. So, to get a 100% crop of a full photo, I crop a portion of the original photo so that the cropped amount ends up being 1800x1200 and thus fits onto my monitor.

As for a name

An example:
D810 + 400mm f2.8E FL VR + 2x TCIII (800mm). Full resolution from the D810 would be 7360x4912.

http://www.pbase.com/lance_b/image/160057295/original.jpg

100% crop 1800x1200

http://www.pbase.com/lance_b/image/160057297/original.jpg

[ameerat42]

What I think. (Arguably, mostly rubbish, but...)

It's good you asked here.

What you have quoted in your first response to the Q - sorry and apologies beforehand - is wrong.

It has NOthing, zero, zot, and the NULL set to do with ANY screen magnification. It is simply...

Do NOT resample your image.
INSTEAD, open up your full size image;
then take a selection from it;
then make a a new file. This new file will be the exact size of the selection you made - say 400 x 300 pixels...;
now paste that selection (sitting in Clipboard typically) into the new document;
Now that's the 100% crop.

After getting it, you can flatten the image and save as jpeg/tiff/...etc.

Recap: It's NOT what screen magnification you use; it's JUST copying out a section FROM a full size file WITHOUT re-sampling.

OK, now that that's over, what is re-sampling?

Re-sampling means CHANGING the (BASIC/NATIVE) image size. Say your camera produces 6000 x 4000 pixel files (Wow! A 24 MPx camera!!)
Now, if you use some program - like Photoshop - to change the image to, say, 1500 x 1000 pixels, then that is re-sampling. This does not mean
you are changing the display size - you can do that by scrolling the mouse wheel. It is instead making the image as if it came out of a 1.5 Mpx
camera instead of a 24 MPx camera.

Martycon. Thanks for raising the Q again. It is one that's often confusing/confused/bewildering... etc.

(Cripes! I hope I haven't muddled it!!:o:o)

[jjphoto]

'100% crop' is a very commonly used term in forums or places where people are regularly illustrating or comparing lens resolution. There's not much point trying to illustrate a lenses resolution if an image has been resized and sharpened because this can mask the real resolution of a lens (or system). 100% crops are typically unsharpened when used to show a lenses resolution, that is aside from any standard sharpening applied during the RAW conversion stage to compensate for anti aliasing filters on sensors.

[Lance B]

What I think. (Arguably, mostly rubbish, but...)

It's good you asked here.

What you have quoted in your first response to the Q - sorry and apologies beforehand - is wrong.

It has NOthing, zero, zot, and the NULL set to do with ANY screen magnification. It is simply...

Do NOT resample your image.
INSTEAD, open up your full size image;
then take a selection from it;
then make a a new file. This new file will be the exact size of the selection you made - say 400 x 300 pixels...;
now paste that selection (sitting in Clipboard typically) into the new document;
Now that's the 100% crop.

After getting it, you can flatten the image and save as jpeg/tiff/...etc.

Recap: It's NOT what screen magnification you use; it's JUST copying out a section FROM a full size file WITHOUT re-sampling.

OK, now that that's over, what is re-sampling?

Re-sampling means CHANGING the (BASIC/NATIVE) image size. Say your camera produces 6000 x 4000 pixel files (Wow! A 24 MPx camera!!)
Now, if you use some program - like Photoshop - to change the image to, say, 1500 x 1000 pixels, then that is re-sampling. This does not mean
you are changing the display size - you can do that by scrolling the mouse wheel. It is instead making the image as if it came out of a 1.5 Mpx
camera instead of a 24 MPx camera.

Martycon. Thanks for raising the Q again. It is one that's often confusing/confused/bewildering... etc.

(Cripes! I hope I haven't muddled it!!:o:o)

Exactly what I said:
'"However, if we looked at any part of that original sized photo on the screen, then we would be looking at any part of that photo at 100%. So, to get a 100% crop of a full photo, I crop a portion of the original photo so that the cropped amount ends up being 1800x1200 and thus fits onto my monitor. " :)

[Mark L]

(Cripes! I hope I haven't muddled it!!:o:o)
As usual you have.:p

Apart from that I'll be interested in further responses to the question.
Pretty impressive Lance. Do I need better lens or PPing skills?;)

[Lance B]

Pretty impressive Lance. Do I need better lens or PPing skills?;)

The lens must take most of the credit, it's quite amazing how good it is. There was little PPing done. :)

[ameerat42]

Lance. Yes, we do agree about what it is. I usually leave mentions of screen sizes out.
Am.

[swifty]

The way I understand 100% for anything is actual size.
Whether 100% crop, 100% view, 1:1 view, 1:1 magnification ratio they all have similar relative meaning in that whatever it is describing equals the actual size.

In the case of 100% crop, we are specifically talking about a 'crop' made from an original image at its actual original resolution without any resizing.

Now if we look at 100% view (same as 1:1 view) then your monitor size and resolution will determine how that would actually look on your screen.
On your editing software, you can view an image at any ratio or percentage - fit to screeen, 1:1 (100%) etc. But it doesn't mean you've resized the actual file. You're just viewing it at various magnification on your screen which is controlled by the algorithm of your editing software. It will display your actual non-resized file at various magnifications of the original file.

You can crop a smaller image from that actual original file whilst viewing at 25% or 'fit to screen' or whatever viewing size and it would still be an 100% crop. Because you haven't resized the actual file.

If you now resized the original file to 50% for example, you've taken the original file and halved the resolution both horizontally and vertically. Now you have an altered file with less resolution and any crop from this new file will be viewed as a '50% crop' of the original file.

The reason people post these 100% crops is to illustrate a portion of the original unresized file as it is not always practical to post the entire image, especially with today's extremely high resolution cameras.
In practice it is often less useful to post 50% crops and 25% crops hence you don't see these terms pop up very often.

[ameerat42]

Yes, yep, and ah-ha:D

[swifty]

Sorry I had to fix up an error in my bottom example in post #9.
When you half both horizontal and vertical pixels, you get the 50% image (but 25% of the original total pixel count hence my original confusion and mistake in my post). I've edited my post to fix this error but in case ppl read the original and got confused.

[martycon]

Thanks swifty and all others. After much discussion, all seem to agree, which probably means that a more precise and generally agreed definition is desirable. As I understand it, a crop which comprises say 95% of the original image is still a 100% crop, provided the file has not been resized. Or am I still going around in a "circle of confusion"?

[ameerat42]

Yes. No, you're on the right track...
ANY part of the full size image is a 100% crop, even the whole image.

- - - Updated - - -

:Doh:Oh!! Just think of it as:

"100%" means the full size image. (Screen magnification is optional.)

"Crop" means a crop of THAT image.

[martycon]

Thanks Am, in this case the farmers get it easy, as the crop is good, poor or a failure. Nice simple easily understood words.

[Circled By Confusion]

What I think. (Arguably, mostly rubbish, but...)

It's good you asked here.

What you have quoted in your first response to the Q - sorry and apologies beforehand - is wrong.

It has NOthing, zero, zot, and the NULL set to do with ANY screen magnification. It is simply...

Do NOT resample your image.
INSTEAD, open up your full size image;
then take a selection from it;
then make a a new file. This new file will be the exact size of the selection you made - say 400 x 300 pixels...;
now paste that selection (sitting in Clipboard typically) into the new document;
Now that's the 100% crop.

After getting it, you can flatten the image and save as jpeg/tiff/...etc.

Recap: It's NOT what screen magnification you use; it's JUST copying out a section FROM a full size file WITHOUT re-sampling.

OK, now that that's over, what is re-sampling?

Re-sampling means CHANGING the (BASIC/NATIVE) image size. Say your camera produces 6000 x 4000 pixel files (Wow! A 24 MPx camera!!)
Now, if you use some program - like Photoshop - to change the image to, say, 1500 x 1000 pixels, then that is re-sampling. This does not mean
you are changing the display size - you can do that by scrolling the mouse wheel. It is instead making the image as if it came out of a 1.5 Mpx
camera instead of a 24 MPx camera.

Martycon. Thanks for raising the Q again. It is one that's often confusing/confused/bewildering... etc.

(Cripes! I hope I haven't muddled it!!:o:o)

Far from muddled imho.

That's how I've always presumed the meaning of the term.

I think the first time I saw it was at the website "DP Review". They crop a little chunk out of
a sample photo; it's then a reasonably small file so it's quick to download, it doesn't flood
your display, and you get to see it at full rezzo giving you a good idea of
what the lens/camera (/Photographer) combo can do.

Don't worry about it though Marty, you well and truly know how to use a camera, and that's the main thing.

[martycon]

Thanks for your comments, CbC. I still recon it needs a better more self descriptive name. For me and the uneducated, a !00% crop must refer to the size of the crop, and resolution is not mentioned. Further, that if it is a 100% crop nothing has been cropped out. I now know that it means a crop done at original resolution. For me a better term would be, for example, "50% crop at original resolution" which abbreviates to "crop50 OR", where 50 obviously refers to half the original area of the image, unfortunately the reader would still have to ask what OR meant.
Thanks to you and all other respondents I have finally got that off my chest, and will in future use "crop ___OR" whether or not it is understood.

[Circled By Confusion]

Thanks for your comments, CbC. I still recon it needs a better more self descriptive name. For me and the uneducated, a !00% crop must refer to the size of the crop, and resolution is not mentioned. Further, that if it is a 100% crop nothing has been cropped out. I now know that it means a crop done at original resolution. For me a better term would be, for example, "50% crop at original resolution" which abbreviates to "crop50 OR", where 50 obviously refers to half the original area of the image, unfortunately the reader would still have to ask what OR meant.
Thanks to you and all other respondents I have finally got that off my chest, and will in future use "crop ___OR" whether or not it is understood.

Yeah Marty, it is a misleading term... and so is "hardwood" such as balsa, "softwood" such as yew, and a "space frame" of welded steel tubes.

Having said that our minds are exact opposites. ie you reckon "Further, that if it is a 100% crop nothing has been cropped out. "
The way I think, a 100% crop; everything is cropped out.... come to think of it Ive got a shipload of
shots that would benefit from a 100% crop... save some space on my hard drive that's for sure.

[arthurking83]

It never made sense to me at first either! .. but the way I view it:

100% crop = 100% view, then crop.

To not crop anything out would then constitute a 100% view(ie. of the image).

So a 50% crop would then be, view at 50%, then crop.
the percentage value is obviously how you the pixels are presented(at what magnification).

I'm thinking that the reason it came into existence is due to the way most(if not all) editors are set up to view images at various scaling factors.
In your editor, you should have a 'zoom' or magnification tool.
Depending on your screen resolution, at first the image is presented in it's entirety, so the magnification, or zoom factor will be probably low, such as 10%, or 20% .. or whatever .. it obviously depends on the digital imaging device used too.
So to view each pixel at it's largest native size(ie. without scaling it up any more), you set the view ratio, or magnification, to 100%. The you would crop out a sample.

.. ie. 100% crop.
We could finesse with terminology and more correctly call it 100%, crop(note the comma!), or 100% then crop .. but in the end it's not worth the effort to change such a trivial subject.

[martycon]

Thanks CbC, your point about woods is well made. It is great to ba able to get a smiling chuckle out of a partial disagreement.

[Circled By Confusion]

In the 80s I worked for a few IBM dealers; during that time personal computing
gained traction. At one of those dealers we had a big poster, well away from the retail facility,
of a chimpanzee at a keyboard with the caption
"Keep computers confusing"...

Does "100% crop" fit into that syndrome, or is it just an unfortunate choice of words that stuck?

Just for the record; "Keep computers confusing" was spawned by Prime, not IBM... obviously
however some IBMers surreptitiously jumped onto that part of Primes bandwagon.