Cropping image to precise dimension in Lightroom

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  • Updated 6 years ago
Looking for a means to crop to a specific dimension in Lightroom. For example, I was cropping an image last night and realized that I was real close to my iPad native resolution of 2048 on the long side. To maximize image quality, I decided to make it exactly 2048, but couldn't. I'm not changing the aspect ratio, just the length of the long side.
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Ross Dillon

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Posted 6 years ago

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Gary Peterson

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Since cropping in LR doesn't actually change the original, you must eventually export the image to be used on other devices. So... set the crop so the photo is pleasing to you, then when you export, set the long side to be exactly 2048. LR will then up or down rez as needed to give you what you want. Of course, the exported version is the one you pass over to your iPad. Hope this helps.
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Ross Dillon

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But letting LR (or any software) resize an image impacts its quality. If my desired crop is really close to 2048, then by God I should be able to actually crop it exactly to that...and LR won't let me.
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Gary Peterson

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Well, LR must resize upon export, because it can not, by design, change the original image that you are viewing within LR. If you are starting with a 2100 pixel image in LR, then export a 2048 derivative out, at a high quality setting (assuming jpg), then it will be nearly impossible to see any impact on quality.
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Ross Dillon

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I respectfully disagree. Most times you're right, but like some music doesn't like mp3 compression, some images don't resize well, especially when they are small amounts. I just don't see the reason why I should when I can make it exactly the way I want.

By the way, I finally found a way. I caught a break and actually caught a crop at exactly 2048...so I save in in a collection and when I feel the need I copy the crop over from that one. Have to check all the boxes but it works...
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Rob Cole

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Another trick for precise crop values:

Crop to any ol' thing, then save in xmp. Edit the crop values in xmp with a text editor then read it back in. Save dummy cropped images as you are doing in lieu of a cropping preset...

If your xmp is in DNG, you'll need a hex editor, and then it may only work if number of digits is same. Or, use ExifTool to extract the xmp, and then re-insert after editing. Or, use the xEmP Lightroom plugin which allows you to have xmp sidecars for DNG too.

R