I'm rather surprised by how poorly the FA 1.7 does at wider apertures. Similarly surprised that the Ricoh 50mm f2.0 did so poorly.
I'm trying to put these numbers into perspective with the *ist-D....
Let's see - 23.5mm x a5.7 mm sensor with 3008 x 2008 pixels works out to about 128 pixels per mm. With LPM being a factor of on half pixels per mm (it takes one pixel for the line, one for the background) then the theoretical maximum resolution of the *ist-D / DS is only 64 lpm.... ????
Is my math wrong on that, or are most of these lenses equal on the *ist-D / DS? And for that matter, more or less equal with most films except the highest performing slide films (I seem to recall that Velvia could resolve something like 160 lpm? Or maybe that was DPI... My memory is about as good as my math.)
- MCC
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Mark Cassino Photography
Kalamazoo, MI
www.markcassino.com
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----- Original Message ----- From: "Fred" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, April 13, 2005 11:57 AM
Subject: Re: 50mm lenses test pages: help with japanese translation
Below is a link to an interesting page with test charts for all major 50mm lenses out there.
Just for simplicity (to make it easier to compare the K-mount 50's), I put the Pentax and Ricoh lens charts on a page at
http://www.cetussoft.com/pentax/xitek50/
If anyone can come up with English translations for the Chinese comments below each chart (on the original site), I'll add them, too.
I think that the charts pretty much confirm my own experiences, although I'm comparing all A lenses (substituting my A models for the FA 50/1.4 and FA 50/1.7 lenses). That is to say, I ~still~ think that -
1. My favorite 50 is the A 50/1.4.
2. The A 50/1.2 is a better lens than some people give it credit for.
3. The A 50/2 has a high "bang for the buck ratio".
4. And then there's the A 50/1.7...
Fred
