Crop Transformation

[Marpel]

I start with a 6048 X 4032 pixel image, in Landscape format and the Shape = Rectangle, Proportions = Arbitrary, the Width/Height is 1.000 X .667.

If I change the Proportions to "Custom", the crop changes to 5161 X 4032 and the Width/Height changes to 64.000 X 50.000. Regardless of how I cursor the crop borders, the proportions remain the same. Although the rectangle will get smaller if I move the border inwards, I can't change the proportions and it stops at 5161 X 4032 if I try to move it outwards.

My questions - What is the significance of the 64.000 X 50.000 proportions? 6048 X 4032 is also a rectangle and I wonder why the crop lines immediately go to 5161 X 4032? And, what is the purpose of changing 1.000 X .667 to 64.000 X 50.000? If I wish the proportions to remain as they were at 6048 X 4032, is the only way that can be controlled is through changing the Width/Height percentages, or how is that done?

Marv

[jsachs]

When you select Custom, the proportions are restricted to the ratio you enter just below as Width/Height (which are normally grayed out). This lets you constrain the proportions to a ratio of your choosing rather than using one of the built-in values. If you want unconstrained proportions, select Arbitrary.

[Marpel]

Jonathan,

Thanks for the reply.

I think I understand the general idea of the "Custom" setting, however, what puzzles me is (1) why the program automatically chooses a crop of 5161 X 4032 pixels (and 64 X 50 proportions) for the 6048 X 4032 image (rather than any other size) and (2) what 64.00 and 50.00 represent. I understand that I can change those two numbers (64 and 50) however, without knowing what they mean, I wouldn't know what numbers to enter if I wished to change the crop to a specific size. Are they percentages of something or??

Marv

[Dieter Mayr]

Marv

You should see the Width/Hight as a quotient, not as a product, as you wrote (64 x 50).
It's simply the quotient from Width/Hight and this does not change if you mulitpy or divde both by the same factor.
So 64/50 is the same W/H-ratio as 32/25 or 640/500 or 5161/4032, or even 1/0.78125 or 1.28/1 .
So the 2 numbers have no real meaning for the size, they just describe the ratio between the Width and Hight.

The cropping rectangle is initially set that it covers most of the image at the given ratio, so if the cropping rectangle had a higher ratio then the input image (e.g. a 2:1 cropping Rectangle on a 1.5/1 image) will set initially the Width as it is from the original image and adjust the Hight as needed from the ratio (the original may be 1500 x 1000 pixel (ratio 1.5/1), the cropping rectange will be 1500 x 750 (ratio 2/1)).
The same image cropped with a ratio of 1.2/1 gives a cropping rectangle of 1200x1000.

Hope it helps!

[jsachs]

The custom crop proportions are restored to those used in the previous session, so they depend on what you did the last time you used custom proportions. If you never used them, they are initialized to 1:1.

[Marpel]

Jonathan and Dieter,

Thanks for the replies. I think I got it now.

Marv