Ressing up 5D images

[brucepercy1]

Hi,

I've been experimenting with the 5D since I got it this summer.

I have been an avid Mamiya 7 user for the past six years and tend to print images up to 24 inches wide by pro.

I was wondering if anyone has experience, tips or can point me in the direction of articles regarding ressing up 5D images.

I would be interested to see what the comparible difference is between the M7 shots at 24 inches wide compared to a ressed up 5D file.... and this is a test I mean to do myself.

But I'd like some info on which is the best approach for ressing up digital files.

Thanks.

[Jonathan Wienke]

If you use QImage to print (which I highly recommend, it is an inexpensive but very powerful print program), you really don't need to bother with upsizing images; QImage will take care of all that internally on the fly and do an excellent job without you needing to have 5 different sized files  of an image for different sized prints. The only reason to have alternate versions is for different aspect ratios, if auto-cropping isn't appropriate.

[Tim Gray]

If you use QImage to print (which I highly recommend, it is an inexpensive but very powerful print program), you really don't need to bother with upsizing images; QImage will take care of all that internally on the fly and do an excellent job without you needing to have 5 different sized files  of an image for different sized prints. The only reason to have alternate versions is for different aspect ratios, if auto-cropping isn't appropriate.
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I'm a big fan of Qimage as well.  But...  for large prints (in my world, thats anything over 13x19) I prefer Photokit Sharpener over the built in sharpening options in Qimage.  You can still use QI to uprez, then just print to a file, sharpen, then print.  I think the uprezzing in QI is pretty well state of the art.

[Jonathan Wienke]

I sharpen in PS with a combination of Focus Magic and my own midtone sharpening actions, and disable the sharpening in QImage as well.

[bjanes]

I'm a big fan of Qimage as well.  But...  for large prints (in my world, thats anything over 13x19) I prefer Photokit Sharpener over the built in sharpening options in Qimage.  You can still use QI to uprez, then just print to a file, sharpen, then print.  I think the uprezzing in QI is pretty well state of the art.
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I use PK also, but it merely increases perceived sharpness. The Richardson-Lucy algorithm can actually restore image detail. It was used in the Hubble telescope images before the instrument was fixed. This algorithm is discussed on Roger Clark's web site. He says that the print size can be doubled with this technique. Beware, the method is quite slow.

[a href=\"http://www.clarkvision.com/imagedetail/image-restoration1/index.html]http://www.clarkvision.com/imagedetail/ima...ion1/index.html[/url]

The RL algorithm is available in the freeware astronomy image processing program
IRIS. I think that smart sharpening in PS also uses a deconvolution method and can be useful if you use the right parameters. However, Bruce Fraser reports that it is of limited value in his sharpening book. I have not used either method and would be interested in hearing from those who have.

Bill