Anders Uschold's DCTau Lens Tests.

[Dave Rosser]

Today's (Wed 4th May) issue of British Journal of Photography carries a test of 4 Nikon zooms on a D2X by Anders Uschold using the DCTau lens test methodology. The explanation of this methodology in BJP is gibberish probably due to poor translation from the original German (I suspect these test have or will appear in a German magazine). Can anyone explain, in words that a retired aerospace engineer who managed research programmes in control system engineering can understand, exactly what the parameters coefficient of resolution and net file size are?

 

[Iliah]

Dave, can you give some context?

 

[MontyDog]

#1064 - You have an error in your SQL syntax;

 

[Iliah]

Currently I would suggest that net size is another name for Shannon capacity, or similar measure. I think I will get my copy of the nagazine, and probably e-mail the author for futher explanations of the methodics he used. Meanwhile, you can have a look at methodics used by Norman Koren in his Imatest

 

[Chris101]

I'm a technical guy, and enjoy testing my own lenses when the mood strikes, but isn't the picture really the final arbiter of quality? I think a great many of the important photographs taken over the last 150 years or so have been made using less than optimal optics. This test seems so esoteric that a Rocket Scientist and a couple of our most learned gurus don't get it.

I'll be watching this thread to see if anything amazing comes of this, but probably won't get the magazine because it's been a zehr lange zeit since I've had to read German. Thanks for bringing it up Dave!

 

[Dave Rosser]

Thanks for all the replys - I did find a technical paper on the methodology but it was in German and though I worked off and on in Munich for many years my German is very weak to non existant. Here is the link if anyone is interested:
http://www.uschold.com/pdf/Test.pdf

 

[MontyDog]

#1064 - You have an error in your SQL syntax;