Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
04-06-2012, 01:28 PM   #16
Site Supporter
gofour3's Avatar

Join Date: Oct 2008
Location: Vancouver, Canada
Posts: 5,196
QuoteOriginally posted by lytrytyr Quote
Those tests are based on a perceived resolution,
which also factors in contrast to a large extent.
Thus a contrasty lens like the FA*24/2 is favored,
while a sharply resolving lens like the M100/2.8 looks poorer,
because it is less contrasty.

I have tried to set the record straight in my review of the M100/2.8:
SMC Pentax-M 100mm F2.8 Reviews - M Prime Lenses - Pentax Lens Reviews & Lens Database
Yoshihiko’s lens tests are straight resolution only, see the link below for his procedures. He’s also testing these FF lenses on a film camera.

http://www.takinami.com/yoshihiko/photo/lens_test/procedure.html

Phil.

04-06-2012, 04:38 PM   #17
Pentaxian




Join Date: Nov 2011
Photos: Gallery | Albums
Posts: 3,674
QuoteOriginally posted by gofour3 Quote
Yoshihiko’s lens tests are straight resolution only, see the link below for his procedures.
He refers in turn to
PDML Lens Testing Procedure
The critical part there is the visual perception in Step 16.
This is the step where contrast becomes relevant.

Compare Yoshihiko's results with modern Imatest results
obtained by Photozone, Optyczne/Lenstip, et al.

Note the Photozone discussion of the FA*24/2.8:
Pentax SMC-FA* 24mm f/2 AL [IF] - Review / Lab Test Report - Analysis

QuoteOriginally posted by gofour3 Quote
He’s also testing these FF lenses on a film camera.
Right. For APS-C, the only relevant targets are those out to "C."

Since digital images may have their contrast enhanced in PP,
the visual perceptions analyzed with analogue techniques
no longer have direct relevance (although some conclusions may still be drawn).

As I've mentioned, the most striking discrepancies seem to be
Yoshihiko's overestimate of the FA*24/2,
and his underestimate of the M100/2.8.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
k-mount, pentax, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Another which is sharper @ 300mm photolady95 Pentax SLR Lens Discussion 73 12-30-2010 01:41 PM
making silhouettes sharper? Reportage Troubleshooting and Beginner Help 6 10-05-2010 01:35 PM
[K-x]How can I get a sharper picture Pak Troubleshooting and Beginner Help 21 09-07-2010 03:58 PM
which lens is sharper? DA 18-55 al II or A 35-105mm f3.5 angelo9978 Pentax SLR Lens Discussion 8 04-09-2010 09:18 AM
Which lens is sharper at 50mm? lurchlarson Pentax SLR Lens Discussion 20 12-22-2009 02:11 PM



All times are GMT -7. The time now is 03:48 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top