interpolarization+USM

CarlPedersen · #1 01-20-2003, 10:18 AM

I¥m a proff with a Nikon D1X for one and a half year now. Satisfied with the digital camera.
I just shot a picture which should end up as a transparency in the airport - approx. one meter wide/150 dpi (=6000 px wide/150 dpi ). Vertical picture.
It looks pretty good after resizing in Photoshop (yes, I¥ve heard about special programs doing this type of things). But - what¥ll be the right amount of USM?
Is there a kind of a formula for USM (size/dpi/media/etc) ?
A brief discription of the picture: a close-up of a hand with a kind of a creditcard - Raw/16 bit through MacBibble 2.99 which gives a 315 MB file/16 bit ! (...and a 60 mm Micro-Nikkor)
Thanks for any advice.

Adam Wade · #2 01-20-2003, 10:26 PM

I would either contact the house making the actual transparency, or let them take care of it. They know how much USM is necessary without overdoing it for each type of media they output on, so they can take care of it.

Being in contact with your printer is, IMHO, one of the most important steps in getting decent output.

Chuck_Kimmerle · #3 01-21-2003, 10:05 AM

Carl,

If you are not making the CMYK output file yourself then you should not do much, if any, sharpening. It's okay to do a small amount to regain the sharpness lost through digital processing, but don't over do it.

If you are doing the output file, then here's my rule of thumb for duratrans-type products: Open the file in Photoshop with a view of 100%. Using whatever sharpening method you prefer (USM, high pass, find edges, etc), sharpen so that the image looks a little over sharpened (if using USM, be sure not to use too much radius or you'll get halos). The thing to remember with duratrans displays is that they are usually viewed from a distance, so you can get away with a little over sharpening.

One last thought.....These types of displays tend to fade after only a few months, so make your shadows, especially blacks, rather strong since they're the first areas to show any degradation.

Chuck

Dixon_Zalit · #4 01-22-2003, 12:16 AM

Over time you will develop and eye for sharpening with a good feel for how the print will look.

Here is my approach to sharpening. After resizing to 300 dpi or so for printing, a 50% view will give me a good idea how the print will look in hand. If you are sizing to 150 dpi, a 100% view should simulate nicely the print look.