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50mm ... not hitting focal reducer ...
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PostPosted: Tue Jun 18, 2019 11:57 pm    Post subject: 50mm ... not hitting focal reducer ... Reply with quote

Hi !

I use a VILTROX EF-E II (EOS to Sony E) focal reducer, with an additional M42 to EOS adapter.
Focal reducer is set to infinity the right way.

My few 50mm (or so) M42 lenses always hit the focal reducer element near infinity.
Takumar 50mm 1.4, Helios...

First question :
-does this happens to you ?
-what good 50mm will not hit the focal reducer element near infinity ?

Thanks !


PostPosted: Wed Jun 19, 2019 12:28 am    Post subject: Reply with quote

Not exactly. Canon FF mirror hits those same lenses near infinity focus. Lucky for me the lenses aren't usually focused to infinity. The Takumar focuses beyond infinity with the M42 EOS adapter; mirror will not hit if infinity is in focus, not beyond; in warm weather but not cold, go figure. Laughing

An M42 to E focal reducer might not have the problem; maybe somebody here knows...


PostPosted: Wed Jun 19, 2019 1:46 am    Post subject: Reply with quote

This wont help you, but just as an extra bit of information: there is no REC with Helios and FD-E Lens Turbo II as well as EF-E LT II.


PostPosted: Thu Jun 20, 2019 10:16 pm    Post subject: Re: 50mm ... not hitting focal reducer ... Reply with quote

gLOW-x wrote:
I use a VILTROX EF-E II (EOS to Sony E) focal reducer, with an additional M42 to EOS adapter.

So I actually tried this same setup word for word with Helios 44M-6.
While yes, Viltrox vII seem to have less room than Lens Turbo II, there was no REC.

I should probably do a separate recheck for both pieces of glass for 100% correct adjustment, but just from looking at Helios (lack of) back protrusion at infinity, it looks safe to me.

If every lens without internal focusing causes REC, booster might not be correctly adjusted after all.

Have you by chance used IF lenses to reach a conclusion about booster being set correctly?
A lot of AF lenses are IF and IF is sensitive/finicky: IF lenses won't focus the same way on film and on digital, even if the adapter of the correct thickness is used.
It's not hard to imagine how the correct adjustment for IF lens screws up focusing for every other piece of glass out there.