anselwannab
Well-known
Getting close to pulling the trigger on a NEX. I'm interested in using M-mount lenses on it. I came across the Luminous Landscape article about NEX and M lenses and how most V-lenses are not retro-focus and there for can cause issues due to light incident angle on the senor.
I looked all over cameraquest and google, but I couldn't find a list of rerto vs non-retro focus lenses. Is this a tru go/no-go (or OK vs great) performance attribute?
What Voigtländer lenses are retrofocus and to performers on the CEVIL cameras
I looked all over cameraquest and google, but I couldn't find a list of rerto vs non-retro focus lenses. Is this a tru go/no-go (or OK vs great) performance attribute?
What Voigtländer lenses are retrofocus and to performers on the CEVIL cameras
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sevo
Fokutorendaburando
It's "Voigtländer". And as far as I can make out, none of their M, LTM and Contrax mount wides are retrofocus. Their SLR lenses are - but their SLR lenses generally are notr up to their rangefinder standard, the latter are the prestige/boutique series from a maker that is otherwise catering for the lower end of the market...
Their ultrawides might be to some degree retrofocal from a strictly technical point of view, as it is hard to build a symmetric lens whose rear half fits into the less than 10mm space between lens centre and focal plane shutter, but as the CV 12/15mm's are tiny (compared to SLR lenses), they obviously are not offset to a degree where they can be expected to behave even remotely like like the sensor friendly telecentric designs used on SLRs.
Their ultrawides might be to some degree retrofocal from a strictly technical point of view, as it is hard to build a symmetric lens whose rear half fits into the less than 10mm space between lens centre and focal plane shutter, but as the CV 12/15mm's are tiny (compared to SLR lenses), they obviously are not offset to a degree where they can be expected to behave even remotely like like the sensor friendly telecentric designs used on SLRs.
Adanac
Well-known
Instead of dealing with cherry picking lenses, significantly reducing choice and likely increasing cost, I'm happy as a clam[1] shooting almost any M or adapted LTM lens on the GXR with its Mount A12 module.
Biogons, ultra-wides, happy, happy, happy.
[1] Never having met an unhappy or happy clam, take this under advisement.
Biogons, ultra-wides, happy, happy, happy.
[1] Never having met an unhappy or happy clam, take this under advisement.
V
varjag
Guest
Most CV wides ARE retrofocus. 50mm and teles aren't.
That said, they can still be seated too deep so it causes problems for NEX sensor. There is obviously less working distance in M mount than with SLRs, so the reverse-telephoto trick doesn't have to be employed to same extent.
That said, they can still be seated too deep so it causes problems for NEX sensor. There is obviously less working distance in M mount than with SLRs, so the reverse-telephoto trick doesn't have to be employed to same extent.
sevo
Fokutorendaburando
Most CV wides ARE retrofocus.
That is rather debatable - they certainly do not seem to have been specially designed for a increased register distance. Indeed they ride pretty low over the shutter.
There is no doubt that they are asymmetric, but so is just about every small format lens - asymmetry is an advantage at the enlargement factors common there. But we can hardly define that asymmetry and the moderate plane offsets it usually implies to be already retrofocus, or we'd have a hard time finding any normal or wide that isn't.
Roger Hicks
Veteran
But we can hardly define that asymmetry and the moderate plane offsets it usually implies to be already retrofocus, or we'd have a hard time finding any normal or wide that isn't.
Not really. Topogons? Super-Angulons? And weren't Slussarev's WAs designed for non-reflexes? That's before you look at the vast majority of 50mm lenses at f/2 or slower.
Cheers,
R.
sevo
Fokutorendaburando
Not really. Topogons? Super-Angulons?
The Topogon (and similar designs) are strictly symmetric. Modern versions of the Super Angulon have grown even more asymmetric than the initial ones. Neither are that relevant in small format either, the bulk of wider than 35mm non-SLR wides are Biogon types.
And weren't Slussarev's WAs designed for non-reflexes? That's before you look at the vast majority of 50mm lenses at f/2 or slower.
50mm f/2 Double Gauss types are perhaps the only widespread strictly symmetrical small format lenses. Even the Tessar and Cooke triplet have primary planes that aren't coincident with their geometric mean - so no, there is more to being retrofocus than merely being asymmetric...
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