Sharpening for large prints

[arash_hazeghi]

I want to make a few large prints (24" and wider) with 5DMKII files, I have not done this before so I wanted to get some feedback before I submit my files for printing (online printing service). What method and amount of sharpening yields the best results after you upsample the TIFF file to the desired size? I tried smart sharpen with amount 100 , radius 1 and looks good on monitor but I have no idea how the print will come out.

Thanks

[Lance Peters]

Hi - I only use Genuine fractals when I sharpen to print - I use Noel Carboni's actions and find the light to med max texture actions work very nicely, I am using Nikon though but assume they will be much the same on the canon files.
I think they general rule of thumb is to view them at 50% onscreen and to sharpen so that they just start to look like they have too much sharpening and then back it off a tad.

If you are upsampling the files - Genuine fractals is definitely the way to go. Just what works for me :)

[Jeff Donald]

What paper surface are you printing on? I sharpen much more for matte paper than I do glossy, for example. Subject matter also factors into my decisions. In general, I apply much greater sharpening to a landscape than to a portrait.

I agree with Lance that the image should look over sharpened on the screen. You often hear the term "crunchy" used when describing how an overly sharp file looks on the screen.

[arash_hazeghi]

Thanks Jeff, I will be printing on matte with luster coating, here is the image I will be printing I want it to look appealing to an average viewer

http://ari1982.smugmug.com/Architecture/Wideangle/Clark-Center/746260314_HqUR8-XL.jpg

[Jeff Donald]

Is this a true matte surface (dull, flat tones) such as Epson Enhanced Matte or is it the consumer matte surface that has a slight pebble type texture to it and a lustre finish?

True matte surface has a ceramic coating on top. When a drop of ink is placed on the surface, the ceramic coating is porous and the drop diffuses slightly, hence the need for greater sharpening.

What are you using to sharpen, Lightroom or PS? Are you using any of the PS plugins for sharpening? I have seen good results from several different plugins, including Noel Carboni's method, that Lance recommends. If you don't have Genuine Fractals you'll need to purchase that from OnOne Software. I also like Nik Sharpener Pro from Nik Software. Both are easy to use and Nik offers some easy to use presets that simply the process greatly, with excellent results.

If you using the built in sharpening tools in PS, such as Unsharp Mask and Smart Sharpen with a true matte paper, I would start with settings like Amount 100% /Radius 1.5 Pixels / Threshold 1~3 and look at the edges for artifacts. I would apply the sharpening on a separate layer with a mask, so I don't sharpen the shadows/sky and make any noise present in the image more visible.

[Roger Clark]

Arash,
You have a very difficult scene to enlarge and print. The many curved lines make it easy for our eyes to see artifacts from upsizing and sharpening. If you have the opportunity to re-image this scene, you might try a multi-frame mosaic, large enough so you don't have to upsize the final print.

When I "sharpen" images with curved edges, I mask out those edges, e.g. the moon. But you have many edges. There are a number of BPN threads on "sharpening." The discussion above, which I agree with regarding "over sharpening" for the print is changing edge contrast. True sharpening needs algorithms like Richardson-Lucy image deconvolution (RL). I use RL when making large prints, followed by some unsharp masking. The amount of unsharp mask to be applied depends on the printer, paper and inks, so you might try making a small test print with different amounts of unsharp mask applied to tune for the best results. If you are interested in pursuing RL, I can give you more information.

Roger

[arash_hazeghi]

Thanks guys,
The print paper is true matte surface, for now I have only CS4, I did try to download Genuine Fractals but the demo will watermark the image and since I don't do this more than a few times a year I am not very inclined to pay $600 to buy the plugin. So please let me know if there are any free/inexpensive solutions that are better than USM or smart sharpen.The company that I use for printing is http://www.mpix.com/Products.aspx and I have had good results with 8X10 but never done large prints.

Thanks

[Nancy A Elwood]

Arash I use Niksoftware, Nik sharpener 3.0 for all my output sharpening needs. http://www.niksoftware.com/sharpenerpro/usa/entry.php . I have been using it for quite awhile with excellent results.

[Alan Lillich]

Arash,

Eric Chan, one of the main Lightroom developers, wrote a great article for Naturescapes:

http://www.naturescapes.net/Joomla1.5/index.php/category-image-editing/37-image-editing/168-ten-tips-for-better-prints

Tip 4 is about print sharpening.

Alan

[Jeff Donald]

I would also look at PhotoKit sharpener (http://www.pixelgenius.com/sharpener/index.html). It is priced much more reasonably, and it used by many of the big names in printing. It is a PS plugin. But, as I mentioned earlier I'm a big fan of Nik Sharpener Pro. But if you don't do much printing, any of these plugins may seem expensive.

[Roger Clark]

Arash,
You might check out IRIS:
http://astrosurf.com/buil/us/iris/iris.htm
It is free, designed for astronomical images, but has tools like RL deconvolution as well as others.
I haven't used it; it appears command line driven.

Roger

[arash_hazeghi]

Thanks Jeff and Roger,

The photo from Saturn is remarkable indeed, I will try it out hope it is not too much complicated to setup.

[Alfred Forns]

I rely on PhotoKit Sharpener, seems to do a very good job !!! .. don't trust myself for the sharpening amount, when is just right usually looks overdone.