Originally shared by Scott Horwath

Sharpening and enlarging with Lightroom (and Photoshop, but mostly Lightroom)

I’ve started this post from a question by Sandra Parlow on one of Karin Nelson posts. We went way off topic!

Sandra had some questions about when/how to sharpen, as well as in conjunction with printing enlargements.

First off, the sharpening…there are as many opinions on this as there are photographers, and while there are grey areas here, I’ll present my workflow and I think it’ll make sense…

I subscribe to 3 pass sharpening, and this is not something I’ve made up, it comes from some very high level PS and sharpening gurus, Bruce Fraser and Jeff Schewe. In a nutshell sharpening should be done in 3 stages: capture, creative, and output.

Capture sharpening corrects for the softening of the image inherent in digital media, there is no way around this. The light that travels through your lens must travel through a low pass filter (meant to soften the edges!), and then be translated by a grid of photocells. What once was an edge is no longer, it’s just a fact of digital life. Capture sharpening should be done first in the sharpening order. If you use Photoshop exclusively the sharpening box in ACR is identical.

For capture sharpening I use Lightroom exclusively. Why? Because it works so good! (The sharpening used by Lightroom and ACR is most similar to Unsharp Mask in PS) One of the images I’ve added to the post is the Detail pane in Lightroom. If you are using LR you probably have some default sharpening turned on here… most likely 25, 1, 25, and 0 for the Amount, Radius, Detail, and Masking respectively. You should spend some time playing with these sliders, what may be great capture sharpening for a distant landscape can be horrible for a frame filling portrait. Below sharpening is Noise Reduction. Often you are looking to strike a balance between sharpening and noise. (please ask questions in the comments if you want to delve into individual sliders 🙂

The second pass of sharpening is Creative. I don’t do this much because of the kind of photography I do. Most often I may soften (negative sharpen) other areas of my image here if I want the subject to stand out more. If you are working in PS there are all kinds of options for creative sharpening: high pass, unsharp mask, smart sharpen, blur, radial blur etc. etc.

The third pass of sharpening is Output. If possible I think this pass is the least understood! Output sharpening should occur ONLY when you have reached your final output size! Output sharpening has everything to do with output size, intended viewing distance, and assumptions on average human vision. If you resize your 3000×2000 pixel photo for web viewing at 300×200, it is going to go very soft! This is why the image needs to be sharpened after downres. The output sharpening on a web image resized to 300×200 will be different than the same image resized to 1500×1000.

The same holds true for enlargements (for screen or print). When you enlarge an image beyond your actual pixel data whatever enlarging software you are using is making up data. Again, this made up data is going to soften your image somewhat. Proper sharpening after enlargement will correct for this softening. What about if you are exporting an image to print at the exact same pixel dimensions as is contained in the file? You still need to do output sharpening! This will counteract any softness to the image imparted by the actual printing process, as well as take into account the estimated viewing distance and average human eyesight.

Again I use Lightroom for output sharpening exclusively. It is just so easy! Attached are 2 images of some export settings I use, one for web and the other for photographic prints. On the one for the Lightjet Photographic prints you will see that I’ve instructed Lightroom to output an 11″ by 16″ file at 300ppi. If I don’t have enough image data to get to 300ppi, Lightroom will make it up. How? It uses the exact same process as ‘Bicubic smoother’ in Photoshops image resize window. After extrapolating the extra data if needed Lightroom will apply a certain amount of sharpening. While it is a bit ambiguous as to what ‘Low’, ‘Standard’, and ‘High’ mean rest assured that once you figure out that your image printed on glossy inkjet printer looks best with ‘Standard’ sharpening at normal viewing distances, all of your other images will look similar (assuming you do not change the paper, printer, printing process, or viewing distance ;), so this just takes some testing to see what your preferences are.

Likewise Lightroom will downres the file if needed (as in my web export option) using the same process as PS ‘Bicubic sharper’ routine. It will then apply the appropriate amount of sharpening.

Alright Sandra Parlow I know you must have some questions after this 😉 I also invite Jay Patel  or Mike Spinak or anyone else on the original thread to join the conversation…