Newsgroup: it.arti.fotografia.digitale
Titolo: sharpest lens...

da una mailing list dove c'e' anche chi ne capisce qualcosa (inutile
chiedere, non vi diro' quale sia :P).
+++
Hi,
  With all the talk of which lens is sharper etc. I thought I'd share 
an experiment of mine with you. 
  I collect cameras and have over 50 "normal" lenses of all makes and 
many of them are adaptable to DSLR's. I wanted to compare a few.
  Most of my testing was done with a Canon XT (8mp) and a Nikon D200 
and focusing by using software on my laptop that allowed me to focus
at 
40x magification, thus eliminating any error from my eyes.
I set up NBS Test charts in a typical testing pattern placing charts
at 
the corners, center edge, 1/3 out from center and center. The targets 
were illuminated by diffused strobes at 45 degrees apart. Tripod, 
everything as standard as possible, all based on the DX format.
 I tested Nikkors (AF & AIS & S) as well as Takumar, Leica, Zeiss, 
Canon, and Olympus. f1.2 - f2 normals. But only at their widest 
aperture and f8. (too much work for all the stops).
 Ok...now the results.
 I was very dissapointed! All of the lenses peaked out at ~68
lines/mm, 
I couldn't tell one from the other. It was the limit of my Canon & 
Nikon CCD chip that limited it. At wide open I could see differences, 
the best being the Leica and Zeiss.
 But my point is here, most lenses at their optimum aperture can 
achieve 68 l/mm, so it does not matter if your using a $2000 lens or a
$300 aftermarket lens. Although some aftermarket lenses (and even 
Nikkors) I've tested couldn't reach 40 in the corners. You won't see a
difference between a 35mm f2 & a 35mm f1.4 on a CCD image. What will 
matter is contrast, so keep your optics clean and sharpness can be
lost 
do to vibration.
  BTW, for fun I tested some choice lenses on film bodies using Delta 
400 and scanning with a Nikon Coolscan V ED, but all focusing was done
by eye. The film was able to reach 96 l/mm before the grain became too
large.
+++
saluti.
-- 
Gianni Rondinini (32, tanti, RA)
Nikon user - Bmw driver
http://www.giannirondinini.com
http://bugbarbeq.deviantart.com
http://xkcd.com/387

 grain became too large.
è bene che l'amico cambi pellicola per fare i test!
Fabio/che se mi scrivi in pvt ti mando un'interessantissima 
dispensa al riguardo (.rtf da qualche Mb)
-- 
Postato da Alice Newsgroup: lo usi da web ma con le funzioni del newsreader 
http://newsgroup.alice.it
Gerarchie it, italia, it-alt, tin, it.binari. Unico!

 dispensa al riguardo (.rtf da qualche Mb)
una dispensa sulla nitidezza in italiano...la mandi anche a me? ;)
Ciao ;)
Daniele
http://www.flickr.com/photos/danpa_76/

 dispensa al riguardo (.rtf da qualche Mb)
Mettila da qualche parte che ce la scarichiamo, se puoi.
Storyteller.

StoryTeller ha scritto:

le dimensioni sono ancora nei limiti di un normale allegato, ma 
per "poggiarla" da qualche parte mi dovrete aiutare, non ho 
nessuna repository a disposizione... oppure la giro a qualcuno 
che poi provvede (grazie comunque)
ci penso domani o lunedì
Fabio


 che poi provvede (grazie comunque)
E se la mettessi su rapidshare?
gratuito e possono accedervi tutti
Saluti!
Gippe 

che poi provvede (grazie comunque)
mandamela a 
no...@nomecognome.com


 mandamela a 
no...@nomecognome.com
OK, ci leggiamo stasera sul tardi
grazie


grazie
bene.
ti rispondo domattina, perche' da casa non leggo email.
