# Cropping and Aspect Ratios



## 21tones (Jan 29, 2013)

When I've done a custom crop, rather than a fixed aspect ratio crop, is there anyway to know what the cropped aspect ratio is?
I'd like to know then I can decided what is the appropriate size print for the cropped photo.

Thanks


----------



## clee01l (Jan 29, 2013)

An Aspect ratio is the proportions of the image reduced to the lowest common denominator. A 4:5 aspect ratio  is the same as 8X10, 16X20 or 4256X5320. Most cameras shoot approximately 2:3 aspect ratio which could easily fit on 4"X6" or 8"X12" paper.  Knowing this in advance can help you in composition both in the camera and when cropping for a final print. 
In the example 4256X5320, begin by dividing 5320 by 4256 (5320 ÷ 4256).  This operation yields 1.25 or 1/1.25 (also expressed as 1:1.25) Next find the whole number that represents the lowest common denominator.  You can do this by multiplying both the top (1.0) and the bottom(1.25) by 4 to obtain a result of 4:5 which is the aspect ratio expressed as the lowest common denominator. It is also equally correct to say the aspect ratio is 1.25 which is 1/1.25 or the denominator when the numerator is 1.0.  Aspect ratios 4:5 and 5:4 are the same since the length and width are interchangeable and both fit on the same size paper.


----------



## 21tones (Jan 29, 2013)

Cletus
Thanks for your response. I know my Canon 600D has an aspect ratio of 3:2, and I take that into account when thinking of print sizes. But when I#ve cropped a picture using custom crop is there some way of finding out what the resulting aspect ratio is. Does Lightroom show it to me in pixels, or any other measurement somewhere?
thanks


----------



## clee01l (Jan 29, 2013)

21tones said:


> Cletus
> Thanks for your response. I know my Canon 600D has an aspect ratio of 3:2, and I take that into account when thinking of print sizes. But when I#ve cropped a picture using custom crop is there some way of finding out what the resulting aspect ratio is. Does Lightroom show it to me in pixels, or any other measurement somewhere?
> thanks


LR always shows the image in pixels.  If you follow the example that I gave earlier you can always resolve the pixels to an aspect ratio of the lowest common denominator.


----------



## Mark Sirota (Jan 29, 2013)

If the question is "where can I see the cropped pixel dimensions", you can see it in the Metadata panel on the right side of Library, or in a Loupe overlay, or in the expanded grid cells. In the latter two you may need to set it up to see that -- press Control-J to bring up the View Options menu.


----------



## 21tones (Jan 29, 2013)

Cletus
Sorry to be thick about this but where do I find the pixel size of the image once I've cropped it in the Develop module?My Canon camera (18mp) has a sensor of 
5184 x3456 pixels. If I don't crop the image as taken, presumably that is the size of the image in Lightroom? If I custom crop the image how do I find the pixel size? Once I know that I can follow your calculation to work out the resulting aspect ratio.
Thanks for your patience!


----------



## JimHess43 (Jan 29, 2013)

If you are using "expanded cells" in the library mode you will see the dimensions.  Or, you can make cropped dimensions one of your options in the develop module when you press "i" to get information.

I should clarify that cropped dimensions will show in the expanded cell in the library module if you choose to have it displayed.  It's all part of the view options (Ctrl/J) that are separate for the library module and the develop module.


----------



## clee01l (Jan 29, 2013)

21tones said:


> Cletus
> Sorry to be thick about this but where do I find the pixel size of the image once I've cropped it in the Develop module?My Canon camera (18mp) has a sensor of
> 5184 x3456 pixels. If I don't crop the image as taken, presumably that is the size of the image in Lightroom? If I custom crop the image how do I find the pixel size? Once I know that I can follow your calculation to work out the resulting aspect ratio.
> Thanks for your patience!


I think Mark Addressed this for you prior to your post.  Check back if you need additional clarification


----------



## 21tones (Jan 29, 2013)

Thank you for your helpful responses.
Mark - sorry, but I didn't see your reply before I posted my next query. Apologies.


----------



## MarkNicholas (Jan 30, 2013)

I really really wish there was a filter that identified different crop ratios ! I appreciate that there are potentially an infinite number of permutations but If I was able to filter photos with a crop of say 1.6:1 that would be perfect.


----------



## clee01l (Jan 30, 2013)

MarkNicholas said:


> I really really wish there was a filter that identified different crop ratios ! I appreciate that there are potentially an infinite number of permutations but If I was able to filter photos with a crop of say 1.6:1 that would be perfect.


1.6:1 is a common aspect ratio.  What do you do with the non standard crops?  Where does that 1.5734:1 image get filtered?


----------



## Mark Sirota (Jan 30, 2013)

Mark, see Jeffrey's Extended Search plug-in.


----------



## MarkNicholas (Feb 1, 2013)

clee01l said:


> 1.6:1 is a common aspect ratio.  What do you do with the non standard crops?  Where does that 1.5734:1 image get filtered?



Yes I am not suggesting a filter that "list" all the different crop ratios but one where you can search for a crop ratio of say exactly 1.6:1 or perhaps crop ratios between 1.6:1 and 3:2.


----------



## clee01l (Feb 1, 2013)

MarkNicholas said:


> Yes I am not suggesting a filter that "list" all the different crop ratios but one where you can search for a crop ratio of say exactly 1.6:1 or perhaps crop ratios between 1.6:1 and 3:2.


Until Mark Sirota brought it to my attention, I was not aware that Jeffrey's plug-in does exactly what you want. And rather elegantly too.


----------

