What does 100% crop mean

Hi,
I constantly see reference's to a picture being a 100% crop of the original and I don't understand why the 100% is important. Does it mean that the image was enlarged to 100% on the screen and then the wanted portion cut and saved as a new file, would there be any difference to the quality of the crop if it was selected from a 50% or 200% enlargement.

Please educate me

Does it mean that the image was enlarged to 100% on the screen and then the wanted portion cut and saved as a new file?

Yes it does.

A 200% crop would cause pixelation. Anything less than 100% is fine. over caused pixelation as you go above the native full size.

Regards

Thanks, I'll do some experiments to demonstrate the effect to myself.
Rgds
Greg

Now I'm confused, if I cut exactly the same area of a picture it does not make any difference to the file size, pixilation or quality of the new file regardless of the screen magnification I use.

So I still do not understand the relevance of a 100% crop, I'm a slow thinker

Rgds
Greg

OK, I think I'm on-board with what your doing.

When they refer to a 100% crop they don't mean the whole image. They mean a much smaller crop to show detail, often in the smaller image areas of the main picture.

e.g. You have a portrait of a model, maybe head & shoulders (without the dandruff comments). You put it up for the gallery as is, full image but sized to suit the page etc. Now you enlarge the original file to 100% or actual image size and crop just the eye or eyes and if your crop is 800 pixels x 600 pixels or so, you now put that image on the gallery to show how much actual detail was actually recorded by the camera-lens combination. Since the image was actual size before you cropped the eyes, it's classed as a 100% crop. Simplified, I suppose it's any crop selection from an actual size image less than the original size, in pixel terms....

Does this make sense....:

Regards

Thanks,

So the statement "100% Crop" is wrong.

A crop of say 400 by 300 pixels of the original picture is a "crop"

A crop of 400 by 300 resized to 800 by 600 pixels for posting to the web should be described as a "Resized Crop"

Do I now understand correctly?

Regards
Greg

More

Or is the statement 100% crop shorthand for an un-resized crop of the original picture.

Greg

Technically, a crop is any thing less than full size taken from a full size image. If you make a 400x300 up to 800x600 you will loose detail as that is now enlargment over and above original size.



Lets say that crop means; an area from an image which is smaller than original size. Therefore, if you make a crop from an image which on screen is 100% (full size from camera and bigger than the screen size)you are making a 100% crop.

If you re-size an image to 50% of original size and then make a crop as that crop would be a 50% crop.

It's ambiguous to say the least!!

Any clearer?

Best regards

Thanks,

I understand what you are telling me but I still feel that the wording 100% Crop is ambiguous but we will let it be.

Regards
Greg

I do agree that it's a confusing term!

'Crop' isn't the part that's ambiguous - it just means that you've chosen some part of the original image, chopped that out and saved it as an image in its own right.

It's the '100%' that's troublesome.

The point is, it's 100% of the pixels, not of the size.

Take this image, for instance. It is not a crop, and had to be reduced substantially from its original 3872 pixels wide, since it would have been far too large for display. The whole frame looks like this:

[IMG]http://i162.photobucket.com/albums/t244/chris5gd/Aviation/Farnborough%202008/IMGP0652.jpg[/IMG]

An example of a 100% crop is this one:

[IMG]http://i162.photobucket.com/albums/t244/chris5gd/Aviation/Farnborough%202008/IMGP0652-cr1.jpg[/IMG]

It's a portion of the image, but it contains 100% of the pixels in that section of the original photograph.

It's the usual way of displaying the maximum amount of available detail in the original image, since in the absence of any browser-resizing, one pixel on the sensor ends up corresponding to one pixel on the screen.

They're very easy to do - just crop out a small enough piece of the original for it to fit comfortably in the browser without resizing - a max 800 pixels on the longest side is the convention here. It will display at full size (ie, one image pixel to one screen pixel) in an [IMG] tag without you needing to do anything special at all.

Hi,

Thanks that's how I understand it but you have clarified why the term 100% is used.

Regards
Greg

I just heard a penny drop.......it needed a second input....

Best regards

No problems whilst discussions are active....

You are correct, it hurt.

Greg

No problem Greg, first case of beer on me if we ever meet.

Boerewors is your task. Not too spicy though...

Best regards