Focusing Problem w/ Adaptors?

J

Jovin

Member
Hey Guys,

I have been using my AF102 with Nikon and Tamron lenses with a borrowed generic adaptor and realised that at infinity, the focus was still a little soft. I just received my Olympus 14-35 today with the Olympus adaptor and found that the focus distance stated on the screen is slightly different from the focus marks on the lens.

Sorry for sounding stupid, does this mean when using adaptors, the markings on the lens are no longer valid and I will need to remark them on a follow focus due to the extra distance caused by the adaptor? Does this mean I have to focus past infinity to get infinity?

Thanks for your help =)
Jovin
 
You should check into the marks discrepancies here on the forum-maybe do a search. I vaguely recall somebody mention this. The camera display overlay is tied to the lens so the marks on screen should always match the ones on the barrel- even if the image is soft. Don't the cameras have some kind of calibration in the menu?
Otherwise there are three options:
1. the lens backfocus is off-easy to verify- just try several lenses and see if the error is consistent.
2. The adapter is off- you can try a lens without adapter and see if the error is the same or just have the adapter properly measured- a local machine shop can do it well.
3. The camera flange distance is off- you can send the camera in for service to verify, you can get a hold of several M43 lenses and see how they come up...
As you can see this is a technical issue that requires a lot of steps and practice- I think there is going to be a lot of these issues coming up in the near future with thousands of cameras recently shipped.
Maybe a dedicated tech section tied to all interchangeable lens cameras? Barry?

Jacek Zakowicz, Optitek.org
 
Which ones are the good adapters, while still being in a range, obviously? For the Nikon manual focus lens and the zeiss contax/yashica mount? What do you guys think about the fotodiox?
 
SLR lenses aren't ever really accurately marked in the first place. If you want to be able to trust the distance marks and focus by tape measure, you'll need to either a) use properly-collimated cinema lenses on a perfectly-shimmed mount, or b) retape and mark all your lenses, and hope that they don't shift focus due to temperature issues etc...
 
Rayqual Adapter for the contax is probably the best bet. You can adjust infinity on a c/y lens itself pretty easily, but probably best to find a precise adapter if you can.


oh and I have the fotodiox. I don't like it. My 28mm c/y doesn't lock into place. Can slip off pretty easily.
 
Yeah remember the focus markings on still cameras are meant for the type of mount they're designed for. Once you throw an adapter into the mix- you've changed the flange distance completely and they are no longer going to be completely accurate. You can either recalibrate by adding your own markings to the lens or you simply focus using your monitor and set specific marks to hit for shots. For that you would need some extra matte box, follow focus etc. Or simply a good enough onboard monitor to allow you to eyeball it. Practice makes perfect.

Noah
 
I have several Nikon AIS lenses that I use with cheap adapters--I never expected a lens that wasn't intended for the AF100 to perform that way.

The marks? I've never really looked at 'em.

I just focus on the subject and press record . . .
 
NoahK said:
Yeah remember the focus markings on still cameras are meant for the type of mount they're designed for. Once you throw an adapter into the mix- you've changed the flange distance completely and they are no longer going to be completely accurate. You can either recalibrate by adding your own markings to the lens or you simply focus using your monitor and set specific marks to hit for shots. For that you would need some extra matte box, follow focus etc. Or simply a good enough onboard monitor to allow you to eyeball it. Practice makes perfect.

Noah
Click to expand...
This is absolutely not true.
Adapters just build the flange on the lens to the proper height (flange distance). On a properly built adapter the marks will be as accurate as on original. The lens doesn't "know" what camera it's on...
 
NoahK said:
For that you would need some extra matte box...
Click to expand...

What in God's name does a matte box have anything to do with focusing? LOL Sorry, didn't mean to sound harsh, but I think you're off the mark on that one. Correct me if I'm wrong, but with the AF100 (since it has built in ND filters) the only reason you would need a matte box is a) to use other filters b) to keep direct sunlight off of the lens (rather expensive accessory for that purpose) and of course c) to have your rig look more "professional"
 
I am buying the AF100. I am also buying the following lens:

Zeiss Contax/Yashica 24mm f2.8
Zeiss Contax/Yashica 35mm f1.4
Nikon Ai-S 18mm f3.5

Which adapters to buy for both of them staying under a $100 a piece? And what do you guys think about the lens. I am not too passionate about the zooms. I am more of a primes guy.
 
plwells42 said:
What in God's name does a matte box have anything to do with focusing?
Click to expand...

I was referring to an entire mechanical follow focus rig, of which rods and a matte box are typical components. If you spend five seconds googling me you'll find out I know what it is I'm talking about. So sorry if I was being too brief for your liking. :)

-Noah
 
sharry said:
I am buying the AF100. I am also buying the following lens:

Zeiss Contax/Yashica 24mm f2.8
Zeiss Contax/Yashica 35mm f1.4
Nikon Ai-S 18mm f3.5

Which adapters to buy for both of them staying under a $100 a piece? And what do you guys think about the lens. I am not too passionate about the zooms. I am more of a primes guy.
Click to expand...

I believe you'll find Fotodiox adapters for both mounts for under $100- try Amazon.com for starters.

Noah
 
I would say it is your adapter. I have the generic Kipon one, which is apparently guaranteed to hit infinity, and guess what, it does not. Really, unless you are using a good adapter, I would guaranteed that is the reason you are not hitting infinity.

P.s. Ignore the distance marks on your still lenses for focusing... they are a rough guide at best. Use your other focus aids to judge focus.
 
sharry said:
I am buying the AF100. I am also buying the following lens:

Zeiss Contax/Yashica 24mm f2.8
Zeiss Contax/Yashica 35mm f1.4
Nikon Ai-S 18mm f3.5

Which adapters to buy for both of them staying under a $100 a piece? And what do you guys think about the lens. I am not too passionate about the zooms. I am more of a primes guy.
Click to expand...

I would dare say there are no good nikon adapters for under $100. For the Nikon I would go with the Voigtlander, Novoflex, or Adaptimax ones and spend the extra money, it is worth it.... Yes, really, it is.
I have used a few cheaper ones, and hate them all. All the cheaper ones are good for is playing around with the glass and to show you why you need to spend the money... if you want to seriously shoot with those lenses, get a good adapter. My biggest regret was skimping on mine.
 
Oliver Rush said:
I would say it is your adapter. I have the generic Kipon one, which is apparently guaranteed to hit infinity, and guess what, it does not. Really, unless you are using a good adapter, I would guaranteed that is the reason you are not hitting infinity.

P.s. Ignore the distance marks on your still lenses for focusing... they are a rough guide at best. Use your other focus aids to judge focus.
Click to expand...
When you buy adapters claiming "Hit infinity" that only means that it will allow the lens to focus an infinity shot, not that infinity markings will be in fact infinity.
 
dustylense said:
When you buy adapters claiming "Hit infinity" that only means that it will allow the lens to focus an infinity shot, not that infinity markings will be in fact infinity.
Click to expand...

Exactly... My glass hits the hard stop before it hits infinity focus. I dont use the marks on my still glass to focus. Hence why I said ignore distance marks on your still lenses for focusing.
 
Jovin, the focus should be pin sharp at infinity. Cheap adapters are probably the cause. You get what you pay for. Spend extra on a top of the range adapter and get something that is reliable and works.

Steve Shovlar
 
NoahK said:
I was referring to an entire mechanical follow focus rig, of which rods and a matte box are typical components. If you spend five seconds googling me you'll find out I know what it is I'm talking about. So sorry if I was being too brief for your liking. :)

-Noah
Click to expand...

Noah, lighten up, I was joking. Your bio is impressive............ for me to poop on! I KEED, I KEED. Seriously, though, for a moment I thought I was missing something important about the matte box. I'm planning to do a feature here soon and wasn't going to worry about a matte box. I scour all the threads here trying to pick up as much from what you experienced folk are putting out there to verify that how I plan on doing this shoot is going to get me the results I'm aiming for. So believe me, I'm very grateful for you sharing your knowledge.
 
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