Digital BW, The Print

Paul, Sharpness in the digital landscape has always been an issue for me.
Aside from the mechanics of focusing the light on the senor, we also have to
deal with processing of the image; USM in Photoshop, Clarity Slider in LR,
Nik Sharp, etc.  There are many ways to improve or screw up an image. IS any
one aware of a good comprehensive test or series of test that have been done
to take the myth and marketing out of it and get down to the brass tacks? 

 

Eric

 

Eric Neilsen Photo

4101 Commerce Street, Suite 9

Dallas, TX 75226

214 827-8301

 

http://ericneilsenphotography.com

SKype ejprinter

 

  _____  

From: DigitalBlackandWhiteThePrint@yahoogroups.com
[mailto:DigitalBlackandWhiteThePrint@yahoogroups.com] On Behalf Of pr_roark
Sent: Saturday, September 27, 2008 4:28 PM
To: DigitalBlackandWhiteThePrint@yahoogroups.com
Subject: [Digital BW] DSLR sharp? -- was How tiny dots determine real
resolution in a B&W ink print

 

Hi Clayton,

>... I'd like to see the same subject taken with a 12mp 
> or greater modern DSLR with equivalent lens. 

I'm interested in DSLR sharpness or resolution also -- not 
necessarily directly comparing to the test Tyler ran, but to the 
issues of how to get the most out of the DSLR systems, as it relates 
to the type of B&W I do. From my large display landscape 
perspective, resolution was always a significant factor for me.

I've tried for years to have at least some objective criteria. The 
bottom line for resolution has been 5 pl/mm at display size -- where 
I use 16x20 as the main target. 5 lp/mm is what many believe is the 
approximate limit of our eyes at "normal" viewing distance, but with 
the caveat that edge detection visual systems can distinquish higher 
frequencies. (The 5D2 is close on paper, so that is part of why I'm 
going there.)

Optics are an obvious variable I've tried to learn something about. 
Most lens reviews are, however, almost useless in predicting the 
level of performance I want. I've found the MTF curves to be more 
useful, particularly the high resolution (40 lp/mm) tests at 
http://www.photodo. <http://www.photodo.com/products.html> com/products.html
(but they're aging). 

See also http://www.ocf.
<http://www.ocf.berkeley.edu/~ashon/photo/comparo6.htm>
berkeley.edu/~ashon/photo/comparo6.htm for a 
convenient colection of Canon lens MTF charts. These look like what 
Canon publishes on its site, but arranged conveniently. 

Note the definitions of the terms.

Right now, I'm inclined to think that the meridonial MTF performance 
at f8 and at the edge of the frame (18 mm out) may be very 
significant for the performance I'm looking for.

See http://www.paulroar <http://www.paulroark.com/BW-Info/MTF-Canon35f2.jpg>
k.com/BW-Info/MTF-Canon35f2.jpg and look at 
the meridonial MTF measures. 

So, right now, while I expect film to take my serious wide angle 
business for a while longer, the Canon 35mm f2 is going to be my 
first attempt at getting the most out of the 5D2 on the wide-normal 
side (with 2-fram shots taking me wider). With the 90 TS, I think 
I'll have my best shot at what I'm looking for. 

I'll let you know if the MTF meridonial measure correlation to 
performance continues to hold.

Paul
www.PaulRoark.com 

 



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