Scan sharpening

[Meekyman]

Hi Folks,

I am relatively new to scanning 4x5 and use an Epson V700 along with Vuescan. For editing I have adobe photoshop elements 6, capture NX2 and have purchased "colorperfect" for colour negative inversion. I'm happy with these choices and really like the output of colorperfect on negatives.

I have been reading around about sharpening lately and get the impression that the best strategy is "capture sharpening to combat digitisation - creative sharpening as you wish (e.g selectively sharpen foliage, rocks etc. but not sky) - output sharpening to combat printing reality" and have a few questions.

With regard to capture sharpening:

1) Should it be image content independent? So, for a given scanner should always be the same? Is it film dependant? How do I know when I have gone too far?

2) If my assumptions above are correct, can someone put me in the right ball park area for settings using USM for 4x5 on an Epson V700?

Thanks

Graham

[bob carnie]

I would not sharpen at the scan stage, but rather leave it for post scanning in PS or Lightroom.


I agree that sharpening is image dependent and use multiple types base on subject matter...

[Meekyman]

Hi Bob,

Thanks for your reply. I don't use the scanning software to sharpen, but am considering how best to go about capture sharpening/creative sharpening/output sharpening.

Cheers

Graham

[paulr]

I sharpen at the scan stage, with a different intent than sharpening for output. I'm trying to recover sharpness lost in the scanning, and to start with as high an apparent signal-to-noise ratio as possible. The amount of sharpening really isn't image-dependent. It may be somewhat film-dependent, but I didn't change up the films that I used very much.

I came up with a standard sharpening algorithm based on results that looked best (naturally sharp detail without artifacts) at 100% pixel view. This is an extreme degree of magnification relative to any print—a sharpness level that looks good here will look very soft in a print. But it gives you solid edge contrast that can survive other image manipulations with minimal degradation. It also makes it easy to see what you're doing.

Output sharpening is entirely different. I calculate this individually for a given print size and estimated viewing distance. The calculation usually gets me close; I may adjust after making a test print or two. This kind of sharpening is a pretty broad topic, so I won't go into detail on it here.

Occasionally an image will warrant some corrective sharpening. Like, if there's something in the frame that looks to soft relative to everything else. This should be done at an intermediate stage. It could be considered retouching, while the other kinds of sharpening are just quality management.

I do all sharpening non-destructively, on a layer. Blatner and Frasier's Real World Photoshop books have excellent chapters on sharpening strategies. A lot of my workflow is adapted from them.

[Ari]

You can use this method for selective sharpening, it works very well and doesn't leave the image looking over-sharpened:
https://www.youtube.com/watch?v=r7JqcC2h5zk&feature=related

[SergeiR]

Scan 4x5s at like 2400/4800 dpi as DNG or TIFF.

cleanup and such, then copy layer, UMS it to slightly exceed what you need. Do NOT do pixel sharpness ever. Then this is your first pass. Join layers.

Downsize to whatever your printing size is, then run either USM or Smart Sharpen. This is your pre-print sharpening, adjust tones if needed for paper/media. Don't save it like this, unless you save in separate file.

Your typical radius of sharpening is going to be pretty big on first step. Almost to point where you start seeing halos (you can dial it down using opacity of that layer and/or do mask and do selective sharpening)

[Michael Rosenberg]

I agree with Paul and Bob. Do not sharpen at the scan stage as it is indiscriminate, and will likely increase noise in skies. I use PhotoKit sharpening tools (converting to color and then back after sharpening a b/w image). I also use ACR to sharpen and to reduce noise. However, Noise Ninja does a better job of reducing noise. When I first started sharpening digital images I fell into the trap of over sharpen for appearance on the screen, which for the majority of the cases resulted in an overly sharpened print. Now I judge the type of image and decide how much is needed. PhotoKit has good options for doing local sharpening/contrast control by introducing a mask on the layer and painint in the degree of sharpness.

Mike

[Andrew O'Neill]

You can use this method for selective sharpening, it works very well and doesn't leave the image looking over-sharpened:
https://www.youtube.com/watch?v=r7Jq...eature=related

I have used this method as well and find it very useful. I also never sharpen when scanning.

[fishbulb]

Scan 4x5s at like 2400/4800 dpi as DNG or TIFF.

cleanup and such, then copy layer, UMS it to slightly exceed what you need. Do NOT do pixel sharpness ever. Then this is your first pass. Join layers.

Downsize to whatever your printing size is, then run either USM or Smart Sharpen. This is your pre-print sharpening, adjust tones if needed for paper/media. Don't save it like this, unless you save in separate file.

Your typical radius of sharpening is going to be pretty big on first step. Almost to point where you start seeing halos (you can dial it down using opacity of that layer and/or do mask and do selective sharpening)

This is good advice.

I recommend using the Smart Sharpen tool in Photoshop. It's very flexible and produces great results once you learn to use it.

Here's the menu for it:

128163

[jp]

I don't sharpen a thing with LF. Flickr sharpens it a little. It's a personal choice. I like LF for being smooth yet detailed.

[Ken Lee]

What Bob said.