50%, 100%, 75% crop

TeamSpeed wrote in post #18572980
Your resulting size is nothing more than an indicator of what you cropped out of the image, it is not any kind of metric for others to use. I could crop out a 20x20 grid of pixels from my image and then post it.

Its a crop from the center of my picture that matches the 1/1 image size in pixals as the 100% view does meaning its a 100% crop simple.

P.

Pagman wrote in post #18572959
to about 100%

This type of statement is exactly what confuses the issue.

There is only one thing that qualifies as "a 100 percent crop" ... posting an image to the web, to be hosted on a server in such a way that the viewer will see the same pixels that were captured by the camera. None of the pixels WITHIN THE BOUNDARY OF THE POSTED IMAGE can be deleted, neither can any be added.

The term did not exist before online discussions of raster images and has no relevance elsewhere.

Cropping as Tom R mentions above should be discussed in terms of percentage of the frame that was eliminated.

"I cropped half the width and bald the height, so it is 50 percent of the frame"

It is quite literally two different means to two different ends. If in the 50 percent example, the original was 6000 x 4000, and the resulting crop yielded an image 3000 x 4000, the image uploaded would be resized (pixels within the boundaries of the posted image thrown out!!!?!?!??!!! ) by the POTN server before being stored and hosted.

The exact same could happen in Pagman's method.

The only way to post a 100 percent crop is to insure there is no pixels dropped from the image at any point in the saving, uploading, and hosting of the image.

TeamSpeed wrote in post #18572977
A 3600x2400 where section is cut out that is now 1800x1200 isn't a 50% crop, you have 1/4th the total image, not 1/2 the total image. If you take roughly 71% of the width and 71% of the height (if you want to keep the same aspect ratio), then the final 50% crop out of the image would give you a 2550 x 1700 final result.

Since a crop factor is a product of height and width, you need the square root.

A crop is a crop zooming in on any portion of any image then saving it regardless of the size of the frame that was cropped - hence why its called a crop - its easy and vert straitforward.

P.

Pagman wrote in post #18572989
Its a crop from the center of my picture that matches the 1/1 image size in pixals as the 100% view does meaning its a 100% crop simple.

P.

Ugh. The size the image is on your screen has zero to do with the resulting image pixel dimentions.

ZERO.

So to make it clear to all - in my pictures above I zoomed in on a portion of the image starting from a 6000 pixal image and zoomed in till it became a 1054 pixal long side image.

Is that not making a selective crop?

P.

Left Handed Brisket wrote in post #18572990
The only way to post a 100 percent crop is to insure there is no pixels dropped from the image at any point in the saving, uploading, and hosting of the image.

"...and fits within ANY person's display matrix dimensions."

When we were dealing with 1024x768 4:3 monitors only. an image of 900x600 we knew would fit on anyone's monitor.

Now in 16:9 monitors there are 1024×576, 1152×648, 1280×720, 1600×900, 1920×1080, 2560×1440 and 3840×2160, and even 1366×768. So even outputting 1024x768 pixel crop may not work on a 1024 16:9 monitor to be displayed at 100%. Today, not even a 900x600 is guaranteed to fit at 100%.

Pagman wrote in post #18572993
A crop is a crop zooming in on any portion of any image then saving it regardless of the size of the frame that was cropped - hence why its called a crop - its easy and vert straitforward.

P.

A crop has nothing to do with zooming at all. A crop is simply taking a portion of the pixels from your image file and discarding the rest. It does not imply anything about zoom factor or viewing factor at all. That is purely the responsibility of each individual involved in viewing the image with their monitor, their viewing tool, and their enlargement/zoom factor.

3 people could look at a crop of my image, and each could see it at 50%, 100% or 200% depending on these factors, but my crop doesn't change.

Pagman wrote in post #18572998
So to make it clear to all - in my pictures above I zoomed in on a portion of the image starting from a 6000 pixal image and zoomed in till it became a 1054 pixal long side image.

Is that not making a selective crop?

P.

You don't even have to zoom in. Just take your crop tool, make sure it isn't resizing for you (some editors do that), and then crop the image and save as a new file without resizing. That is a crop.

Now view that crop at 100% with your monitor and software. That is a 100% view of your crop. Change your zoom level to 50% and now you are looking at the image shrunken down to that parameter. The crop and the viewing parameters are mutually exclusive.

This also means you could crop out a 2000x2000 from a larger image or a 100x100, both are crops, and both can be viewed at 100%. Your monitor AND your viewing tool of choice both play a part in how you view that image. Some browsers will resize images based on your preferences for viewing sizes. You can enlarge or shrink an image displayed using CTRL - and CTRL + (windows, firefox, chrome), and that is different than using photoshop to view the image. A photo editor is the best way to view at 1:1 (100%), I am leary about a browser saying it is viewing an image at 100%, because there is always more to a browser than meets the eye.

When I say (and I have a bunch of times) that "this is a 100% crop", I am saying that the submitted snippet of an image wasn't resized by me at all, just cropped from a larger image file, and I expect the recipient to view it at a 1:1 reproduction level on their monitor (ie. they need to view that image at 100%).

I can supply this "100% crop" in a post, but if the browser the person uses is showing content at 75%, they won't see the crop at 100%. If POTN uploads the snippet I supply in my post, and it resizes it to save space or meet sizing constraints, then nobody can see this at 100%.

So In my pictures above if someone said "How much have you cropped that photo you are so close to the plane" how would you describe it?

P.

Wilt wrote in post #18573000
"...and fits within ANY person's display matrix dimensions."

When we were dealing with 1024x768 4:3 monitors only. an image of 900x600 we knew would fit on anyone's monitor.

Now in 16:9 monitors there are 1024×576, 1152×648, 1280×720, 1600×900, 1920×1080, 2560×1440 and 3840×2160, and even 1366×768. So even outputting 1024x768 pixel crop may not work on a 1024 16:9 monitor to be displayed at 100%. Today, not even a 900x600 is guaranteed to fit at 100%.

That's why I included "hosting" in the sentence you quoted!

There are however ways to strip away any HTML that might shrink the image to one's screen and view only the image at 100 percent.

Most of the time.

Pagman wrote in post #18573008
So In my pictures above if someone said "How much have you cropped that photo you are so close to the plane" how would you describe it?

P.

If you crop out everything from your image and you just have 1100 pixels on the long side of the resulting crop, and you don't resize it up at all, and supply that crop as is, if somebody says "you are so close to that plane" that means:

a) they are viewing the image at a zoomed level in their browser
b) they have a low resolution monitor
c) they have their resolution set much lower than what the monitor allows

Somebody with a 4K monitor viewing a 1100 pixel image isn't going to see a large plane in the image, as somebody with a 1080p monitor.

To put this differently, you wouldn't have to crop anything from your image all. Host that image on a photo sharing site where it will allow you to store the full resolution, then just post a link. If the person views the image at 100%, and they move the image around to the plane, they will see the same thing as if you just crop that section out and post just that result.

TeamSpeed wrote in post #18572977
A 3600x2400 where section is cut out that is now 1800x1200 isn't a 50% crop, you have 1/4th the total image, not 1/2 the total image.

Right, of course - that is what I was saying. . Did you somehow not understand that I "got that" from my post????

.

So if the 50% crop 3000 pixals from an original 6000, is doubled 50 x 2 = 100 (percent crop?) yes - no?

P.

Tom Reichner wrote in post #18573014
Right, of course - that is what I was saying. . Did you somehow not understand that I "got that" from my post????

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Yes, I see that with the paragraph before, but we just need to correct anyone that says this is a 50% crop to make sure they really mean they cropped out 71% on each dimension, or the fiinal file has an area that is 50% of the original image at the sensor resolution. Never should they say 50% where they took 50% from each dimension.

I always try to post both the full size image (resized down to fit forum rules), then post a crop that also fits within forum rules (which means my crops are less than 1600 on the long end). Much less confusing this way!

If everyone uses 8K monitors and forums can host full size images from today's cameras, we probably wouldn't have these discussions.

Pagman wrote in post #18573008
So In my pictures above if someone said "How much have you cropped that photo you are so close to the plane" how would you describe it?

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The way I would answer that question would be to say something such as:

"The original, uncropped image was 4896 pixels by 3264 pixels, and the portion that I showed you is a 1200 by 800 pixel portion of that image."

This kind of answer is constant, and does not change depending on what one's display resolution or size is. . It will be an accurate, useful answer regardless of what device someone is viewing it on.


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