Other/Uncategorized Lovely Pentax 43/1.9 Special in LTM mount

Other Screw mount bodies/lenses
Hacker said:
Does anyone know the filter size of the Pentax 43mm LTM lens?
49mm, a common and traditional Pentax size. You're going to love it... :)

Edit: 49mm for the SLR version, 40.5mm for the LTM version.
 
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ChrisN said:
Doug - I wonder about the extra blade in the iris. I suspect that has more to do with pandering to the perceived desires of the specialist Japanese market than any practical effect on image quality.
Back to Chris's comment... It's been my observation that good SLR lenses tend to have fewer diaphragm blades than good RF lenses. And I believe this due to weight/inertia reasons. The SLR blades are spring-loaded to snap back when released, as of course they close down and reopen each exposure. Total weight of the blades would slow response and more blades also add friction. This of course is not an issue for RF lenses.
 
Hacker said:
I'm confused: 40.5mm or 49mm for the filter diameter for LTM?
Sorry, misread your question! Threaded for 40.5mm filters for the Leica-mount L Special, and 49mm for the FA mount Limited.
 
40.5 is correct I believe. It is not 49mm. I had this lens for a while, and interestingly the Rollei 80/2.8 Hacker, they are both wonderful.
 
Bob allowed me to try out his Pentax 43mm lens. I took two rolls of film with it, and I took another roll with the Summicron-c 40mm/2 for comparison purposes. Both lenses did extremely well. There was no clear superiority of the Pentax lens over the less expensive Summicron-C. Bob may have commented once about it.
 
raid said:
Bob allowed me to try out his Pentax 43mm lens. I took two rolls of film with it, and I took another roll with the Summicron-c 40mm/2 for comparison purposes. Both lenses did extremely well. There was no clear superiority of the Pentax lens over the less expensive Summicron-C. Bob may have commented once about it.

Raid, what about flare? Isn't the Cron 40mm uncoated?
 
My 40/2.0 was coated if I'm remembering correctly. We're talking 70's, so some coating must have been on there by then.

I didn't see surprising flare with either the 43 or the 40, and I shot the Pentax a lot in late day light.
 
Sorry to ask another stupid question. Is the 40 Cron single coated then vs the Pentax multicoating?
 
Someone dig out a lens diagram of the Pentax 43/1.9?
7/6 reads like a Gaussian type, but could be a retrofocus too because of its length!

have fun, Frank
 
Sonnar2 said:
Someone dig out a lens diagram of the Pentax 43/1.9?
7/6 reads like a Gaussian type, but could be a retrofocus too because of its length!

have fun, Frank

We'd need someone from Japan, Pentax USA had zero idea what I was talking about when I tried to get anything about this lens. I was told that Pentax had never made such a lens.:bang:
 
Sonnar2 said:
Someone dig out a lens diagram of the Pentax 43/1.9?
7/6 reads like a Gaussian type, but could be a retrofocus too because of its length!
Looks like a Planar (SLR type) relative to me...

I believe the L Special in the ltm mount was not marketed in the US; not so surprising then that Pentax USA didn't know about it. :)
 

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