karlukov
белый ру
hi everyone
i have a very strange and very annoying problem with my cv 35/1.4.
when shooting wide open focus is where it should be, from 1m to infinity.
but starting from f/1,7-2 to f/8 lens shows awful back-focus at close and middle distances - oof spot at center and blurred corners (dissapears at f/5.6 and smaller)
far objects is okay though
a couple of months ago i noticed this problem so i gave a lens to repairman, he said that infinity was off like at 5m or something
so he adjusted a lens to my camera using collimator.
last week when i got developed two rolls of across i saw that nothing's changed - wide open is okay; stopped down it has back focus; at f/11 and f/16 - sharp enough, but can't beat even my olympus xa2
yeah yeah, i know about 35/1.4 focus shift and stuff
it just didn't seems like a shift - focusing at 2-3m using rangefinder in range f/2-f/8 i get oof image at 2-3m at the center and sharp infinity.
oh forgot to say
i'm shooting with this lens on bessa r2 and bought it used without box and papers from epson rd-1 user
judging by his shots he didn't suffer from this problem.
it's my only leica-m lens - all other lens are ltm via leica-m adapters (soviet Jupiter-3 50/1.5, Jupiter-8 50/2 and Orion-15 28/6), they're fine though - no problems with focus even with J-3 wide open.
i love this lens - it gives me a nice glowing images wide open.
but mainly i'm shooting street and genre photography using scale and small apertures and honestly, i'm sick of guessing if there was a right focus or not.
so, what should i do?
it needs to re-adjust or i should just sell it and get another one?
i have a very strange and very annoying problem with my cv 35/1.4.
when shooting wide open focus is where it should be, from 1m to infinity.
but starting from f/1,7-2 to f/8 lens shows awful back-focus at close and middle distances - oof spot at center and blurred corners (dissapears at f/5.6 and smaller)
far objects is okay though
a couple of months ago i noticed this problem so i gave a lens to repairman, he said that infinity was off like at 5m or something
so he adjusted a lens to my camera using collimator.
last week when i got developed two rolls of across i saw that nothing's changed - wide open is okay; stopped down it has back focus; at f/11 and f/16 - sharp enough, but can't beat even my olympus xa2
yeah yeah, i know about 35/1.4 focus shift and stuff
it just didn't seems like a shift - focusing at 2-3m using rangefinder in range f/2-f/8 i get oof image at 2-3m at the center and sharp infinity.
oh forgot to say
i'm shooting with this lens on bessa r2 and bought it used without box and papers from epson rd-1 user
judging by his shots he didn't suffer from this problem.
it's my only leica-m lens - all other lens are ltm via leica-m adapters (soviet Jupiter-3 50/1.5, Jupiter-8 50/2 and Orion-15 28/6), they're fine though - no problems with focus even with J-3 wide open.
i love this lens - it gives me a nice glowing images wide open.
but mainly i'm shooting street and genre photography using scale and small apertures and honestly, i'm sick of guessing if there was a right focus or not.
so, what should i do?
it needs to re-adjust or i should just sell it and get another one?
rscheffler
Well-known
It does sound like focus shift.
My understanding is focus shift is worse at near distances than when approaching infinity. That lens also has a lot of field curvature, which might complicate matters when the subject is placed off center.
You could try having the lens optimized for correct focus at f/2 or f/2.8, which will balance the focus shift somewhat, but will cause front focus when shot wide open.
It might be a hassle, but I would almost consider using the Nokton for wide open shooting and get a 35/2.5 for everything else (assuming it doesn't also have focus shift problems). It's small enough, but yes, it's one more thing to carry.
My understanding is focus shift is worse at near distances than when approaching infinity. That lens also has a lot of field curvature, which might complicate matters when the subject is placed off center.
You could try having the lens optimized for correct focus at f/2 or f/2.8, which will balance the focus shift somewhat, but will cause front focus when shot wide open.
It might be a hassle, but I would almost consider using the Nokton for wide open shooting and get a 35/2.5 for everything else (assuming it doesn't also have focus shift problems). It's small enough, but yes, it's one more thing to carry.
ferider
Veteran
Agree.
I optimized mine for f2 on my m240. That makes 1.4 front focus in the center a bit, but when you focus using rule of thirds, the cosine error compensates perfectly wide open. For critical focus, I avoid f2.8, 4, and 5.6, if possible.
Roland.
karlukov
белый ру
thank you guys!
i'll try to tighten up the span ring - my lens gets a little bit wobbly
maybe sharpness problem is connected with it somehow
i'll try to tighten up the span ring - my lens gets a little bit wobbly
maybe sharpness problem is connected with it somehow