Panasonic GH2 + Pentax 6mm f1.2 lens

Seb Fargas encouraged me to toy with c-mount lenses on my GH2. The first lens i tackled was the Pentax 6mm f1.2 CCTV lens. This lens will not fit on c-mount adapters without further modification from the user or via professional modification of the lens. I personally decided to do the work my self rather then send it out, more fun that way right? I had to grind down the rear of the lens to get it to screw in further into the adapter’s thread allowing me to achieve infinity focus. Granted you should not do this at home without the proper equipment this is precision work and needs to be done professionally but none the less i did my own grinding with a power drill and a grinding rock. I eventually broke the rear of the lens and had to reassemble it using crazy & tape creating a new permanently adapted lens. It was still drying but I was eager to test it out so i mounted it on my camera as i ran around the city running some errands, here is the result. I will do a proper test for the lens sooner or later but for now i have included Sebastian’s Video under mine so you can get a better idea of what to expect but keep in mind you are viewing my home made performance vs a professionally treated lens =).

My Candid Impressions:

Seb Fargas’ Test

Below are some c-mount Adapters and Adapters lens combinations. Keep in mind what i said in the post some lenses will fit prefectly together with your adapter and some lenses will need adjusting to be able to reach infinity focus.[amzn_product_inline asin=’B004WIMB9E’][amzn_product_inline asin=’B00601CU1K’][amzn_product_inline asin=’B002XDHZNM’][amzn_product_inline asin=’B003EAS5SM’]

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Comments 25

  1. I have a Pentax 6mm f/1.2 TV lens.

    It fit fine with a fotodiox c-mount to m43 adaptor.

    But it’s essentially a macro lens, and will only focus on that which is right right in front of it, like almost touching the lens.

    How did you manage otherwise? Racking the focus…well, it has no effect. Only when at a nearly closed aperture do I get some focus…dark focus.

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  2. I had a camera repair shop down the street grind my 6mm for me and after 2 attempts nailed it. Now to go super wide – get a Pixco .45x wide converter. It’s almost as wide as my new 12mm Olympus f2. 12mm though, doesn’t require crop mode obviously.

    1. Hello, my name is Ed and was wondering what your machine shop would charge me
      to modify my adapter to allow the 6mm f1.2 togive me infinity focus on my GH2?
      Thank you.

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        I did not have a machine shop do it. i did it myself … with a drill and rock, it was quite the adventure. I have no idea how much a machine shop would charge you because i did it myself.

        1. I am pretty sure he was talking to the guy he replied to, who DID in fact get it done at a camera shop..and it worked on the second attempt. perhaps you should read things before commenting. or understand how someone could comment on someone elses comment.

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            WordPress back end doesn’t reflect comment hierarchy =/ so when replying its impossible to tell if its a thread or not. Its just a long list of comments to reply to all from different posts. Sorry about that, was having a long day.

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      1. Cincinnati, Ohio. I’ve tried sanding it down with a rounded file, but this would take forever with sore joints!!! Thanks OSGondar

  3. Hello again Orlando, took the 6mm Pentax to the machine shop and they modified the barrel and the c-mount as far as they could without breaking either part. Its almost there but he was afraid to shave off anymore. He was using a $60,000 computerized lathe. Just bought a Kipon C-mount adapter and will try again. Any ideas. Thanks ed

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      there seems to be a few versions of this lens around but all have a similar modification to be done you should be able to get the right amount shaved off the back to get infinity focus on all of then. I use the kopon c mount adapter with mine btw.

  4. Hello Orlando, success at last. Took the back of the detachable lens and the c-mount adapter to a machine shop. After two tries he almost nailed it. He said that he was afraid to shave off anymore for fear of breaking either parts. Thought I had a 100.00 paper weight. Took the lens back home and decided to shave some of the lens that the detachable rear fits on and whala. It worked! Great fast lens.

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  5. Hi, sorry to bother you with such a question, but I really have no idea whom to turn to. Long story short: I’ve seen sebs video and got myself an 8mm lens with a c mount adapter. (Although, rather than owning a gh2, I got a canon 550d myself) Anyways, the lens mounts perfectly, but everything is out of focus, to the point, that the whole image i get would look exactly like the one I’d take without a lens on the camera. I’m really confused, as the lens looks to be in perfect shape, and have no idea how to fix this issue. What might be the problem?

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      In this article i could not get far objects in focus, so in order to get infinity focus the lens had to be closer to the sensor. I fixed the lack of infinity focus by getting it closer to the sensor. In my case i did some grinding on the back of the lens to have the lens sit closer to the sensor in the adapter, problem solved.

      For the exact same reason if it was just too far from the sensor NOTHING, not just infinity focus, nothing would be in focus or achievable. For a lens like this to function correctly as stated above it has to be the right distance from the sensor. On the GH2 this was not hard to remedy because Micro Four Thirds lets you go right up to the sensor with the right adapter like it would on the original camera system. I imagine you are way too far or way too close to the sensor if absolutely nothing is in focus or you cant get focus turning that ring. That’s all it is, unless its the lens…

      TEST TO SEE IF IT IS THE LENS:
      1. Take the lens off the mounts and adapters
      2. Focus the lens just a few feet ahead assuming there is something to focus on a few feet in front of you and and assuming its not a fixed focus lens. Either way step 3 applies.
      3. Hold it with your hands in front of the sensor and start with the lens right in front of the sensor or as close as you can. Getting an image? no? ok so start to move the lens away from the sensor slowly. See where you have to hold it from the sensor to get an image, start too close and move away…got an image?! that is where it should be sitting. Your adapter may just keeping it in the wrong place and thus impossible to focus and everything is blurry. That or you have the lens way out of focus and its as simple as that, turn that focus ring!

  6. wow Dominik Kulas
    nice for the first try, the moon and us move this may affecting to get a good focus?
    Try any filter normally you have green filter with telescope.

    Interesting the 6mm But Bolex got lens made in c mount for the 16mm camera and some are made by zeiss. You have 2 kind of lens the one call AR and some RX thr RX it’s for the Bolex reflex and the AR for the Bolex no reflex those 2 type do not have the same flange distance for the infinity focus.The 26mm RX is very sharp.

    Later when i get my GH 2 i will try a 10mm RX.

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