How much sharpening should I be doing on my large sized film scans?

[jimbobuk]

I've been putting my various results of 35mm, medium format, and home developed pictures of both online at my flickr site

http://www.flickr.com/photos/jimbobuk/

Originally I was doing 4800dpi scans but flickrs struggled with 3200 and i kind of liked the lower resolution scans when viewed at 100% more than the 4800dpi ones, obviously both are above the resolution of the scanner (epson 4490) so perhaps i should start scanning at even lower resolution.

Anyways today i received back the first pictures (from photobox) from my home developing and various medium format films, and to be honest I was a little dissapointed. The shots were pretty much as they are on the flickr site, three such shots that i got printed were

http://www.flickr.com/photos/jimbobuk/148446068/in/set-72057594137853867/
http://www.flickr.com/photos/jimbobuk/148460490/in/set-72057594137853867/
http://www.flickr.com/photos/jimbobuk/148470516/in/set-72057594137853867/

As I thought they were some of the sharper ones I'd gotten so far. To be honest though they didn't jump of the page in the prints, basically from the point of view of sharpness mainly. The sizes of the prints were only 10x7 so relatively small for the size files I uploaded.

Related to my preferering 3200dpi to 4800dpi scans I've also been avoiding doing any significant USM sharpening of my shots, this is clearly the problem in my lack of sharpness so i thought i'd ask the experts what I should roughly be doing with typically soft flat bed film scans.

I use photo-i as my first reference, namely this page of the V750 review

http://www.photo-i.co.uk/Reviews/interactive/Epson V750/page_5.htm

which shows some comparisons with medium format film.. with an example of

"USM applied - A-200, R-2.0, T-0.0 and A-100, R-1.0"

on the last shot of the comparison. Not sure why its listing two sets of amount and radius, I think i need to really practice my photoshopping skills.. the radius of 2 seems to help stop you sharpening the actual artefacts of the scan when viewed at 100%, I had a go with the "A-200, R-2.0, T-0.0" on the 1st linked image above and I guess I was quite impressed by the improvement of sharpness, whilst the actual sharpening artefacts weren't too bad and were very hard to see as you got down to smaller viewing levels than 100%.

Obviously this amount of sharpening is quite severe, if I scanned at a lower resolution (closer to screen resolutions) so that i actually got more real detail from the original scan then I guess I could lower this sharpening and the artefacts whilst still achieving similar improvements to the POP of the image.

Your advice is appreciated, I may send off for some more once I've found a sharpening amount that pleases.. I'm keen for the medium format scans to better my EOS 350D's shots as on todays photos that arrived the 350D shots are looking much sharper and I guess impressive.

Cheers

 

[photodog]

Try scanning medium format at 1200 dpi. I believe that Flicker resizes high resolution files. Sharpening is required because of scanning error and Photoshop resampling error. Try these settings for USM: Amount 100, Radius 3(for 300dpi file), and Threshold 10. As a general rule set the radius for the file resolution divided by 100. Set at 2 for 200 dpi file.

I set my Flicker files for 72 dpi. Good luck.

 

[sf]

On my 35mm scans at 4800 dpi on the Multi Pro, I give 1.5 pixels of sharpening at 100%.

On 120, I do the same at 3200dpi. But only rarely because the scanner produces very sharp scans. I find it helps most when I'm posting on the net because JPG conversion softens the images.

 

[Nick R.]

When it comes to sharpening, I always try to err on the side of less rather than more. To me, oversharpening an image distracts attention from the gist of any photo while softness might not even be noticeable if the composition is strong. If I sharpen at all, I try to never go beyond 1px r and to sharpen to a percent that is just noticeable and then back off.

 

[jano]

Nick has good advice on sharpening for web use.

For printing, you're just going to have to experiment. I've found that for some printers, I need to do the amount of sharpening to the point where I just get a 1 px halo around small, sharp details, then back it off just a touch. It's never the same, but find yourself a starting point (it's all good so long as you can ID where to go from the starting point).

Also, you may want to try working with "local contrast", meaning use a low sharpening %, but a high pixel radius (e.g. 20% 30). This creates a different kind of perceived sharpness, and can often add a subtle "pop" to the image.

Often times, I will create a copy of the image, sharpen just to the point of too much, then go through and mask out what I don't like (typically enhanced grain in areas not needed). You can vary opacity with masks as well, thus having more control over what's sharp and what's not. Sometimes it may take more than one round of USM.

There are some other advanced techniques, but for now, I'd recommend to get yourself a dozen photos or so (good or bad), give yourself a starting point for USM (e.g. 100%, 1, 0), apply various settings, and have them printed.

Bottom line, it's just going to take some practice. I didn't like being told this a couple years ago, either, but just be patient and you'll gradually get an eye for what works and what doesn't.

Jano

PS: not to muddy the waters, but the techniques and settings will also be different for various sizes, depending on whether you are printing 4x6, 8x12, or 20x30.

 

[Nick R.]

Yes, Jano is correct. My numbers really apply to web posting. Printing is another matter.

 

[jimbobuk]

Thanks a lot guys for all the advice... I will definitely be having another go sometime soon.. either again with an online print service or perhaps i'll plump for my own printer to get a quicker turn around.

Your advice here is a great starting point to run with.. cheers 🙂