Lightroom and re-sizing for printing

[Yazz]

In Photoshop, when printing, I've learned that one should re-size the image to the intended print size. When printing in LR, what is going on "behind the scenes" when I change the print size to either much smaller or much larger than the "image size"? I have been "expanding" the dimensions of the image to match the paper size in the print panel when enlarging, and if I choose a smaller paper size, LR reduces the image to fit the paper in the print panel, adjusting to allow for the specified margins. Just curious......

 

[Denis Pagé]

Welcome to Lightroom Forums Yazz!

Depends on what you call Size!...

In Lightroom you have image size in pixels. On print, you have image size in inches. So, when printing, it is better to talk about dimension rather than size.

Lightroom may or may not have to resample (resize) your original depending on the number of pixels you start with. For example, if you have an image 8'' x 6'' pixels that you fit on a 1'" x 7½" paper, you will get 8'ppi (pixels per inches). To print this same sheet at 3''ppi without interpolating, you need an image at least 3''' x 225' pixels.

 

[Yazz]

Thank you for the "welcome", Denis.

So, LR does re-sample (automatically, in the background) when it may be necessary? I have been used to the re-sizing window in PS (bicubic sharper, bicubic smoother, etc) and was just wondering what LR was doing since this choice was not "visibly" available.

 

[Brad Snyder]

Only if you choose 'Resize to Fit' in the Image Sizing panel of the Export Dialog

Our guru Mark Sirota describes the method in this post, which I believe is direct from one of the principal authors/engineers of the program.

 

[Yazz]

Thanks, Brad, for the additional clarification. I have not had any problems when printing from LR, even when varying the print size from 4x6 to 13x19 for the same image.