Lightroom Export — Image Size

There are times when you would like to get a picture out of Lightroom.  You do this with the Export option; right click on the picture and select Export>Export… Or, to export a group of pictures first select them (in the filmstrip for example) then do the right click.  This will bring up a new window something like this:

Lightroom Export

At the top of the window (shown by the red arrow) it will tell you how many files will be exported.  If you want to export 20 files and it only shows one, then you will have to cancel and redo the selection.

Open the Image Sizing sub-menu by left click on the arrow.  It will expand to show:

Screen Shot 2017-07-12 at 10.56.17 AM

There is lots here to consider.  If you want full size files, then leave this unchecked; with today’s large image files, however, expect the file to to be large.  If you want to resize the file(s), then check the box.  You then need to consider the next pull down box which controls the resize:

Screen Shot 2017-07-12 at 11.01.30 AM

Width & Height

Resizes the photo to fit within the specified width and height, while retaining the original aspect ratio. The box order is Height x Width (just opposite of what the name is).  Suppose the original photo is a 5x7 (HxW) landscape.  Specifying 400 x 600 requires the output to fit in a box 400 pixels high and 600 wide, for example, and produces a 400 x 560 landscape photo.


Applies the higher value to the longer edge of the photo and the lower value to the shorter edge regardless of the photo’s original aspect ratio.  I find this easier to remember.  Specifying either 400 x 600 or 600 x 400, for example to the 5x7 (HxW) landscape, still produces a 400 x 560 landscape photo  .

Long Edge and Short Edge

Applies the value to the long or short edge of the photo and uses the original aspect ratio of the photo to calculate the other edge. This is easier to apply when you have an “in-between” output.  For example, if the image is a 5x7 aspect ratio and you want 15” on the long side it is easier to enter 15 inches in the box like this:

Screen Shot 2017-07-12 at 11.35.19 AM

If you use this, however, you MUST enter a print resolution (e.g., 300 pixels per inch.)


Sets the number of megapixels of the exported photo.  This is useful if the recipient has given you a maximum file size, for example.


This is a confusing setting.  It specifies what the resolution should be, but sometimes it can be ignored; other times it is essential.  If you have chosen a print measure, such as inches or centimeters, then it is essential and will be used by Lightroom to calculate the pixel dimensions.  If you choose an absolute measure in pixels or megabytes, however, then it makes no difference in the output file.

More details about this can be found at the Adobe website, linked here.

--© Robert Rose 2018