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Pentax 6mm f/1.2 tested on the GH2 by Seb Farges (with Panasonic 14mm comparison)


The fantastic 1:1 video crop mode of the Panasonic GH2 allows you to use C-mount lenses without having that huge vignetting. Seb Farges tested the Pentax 6mm f/1.2 lens: “AT LEAST I’ve found the PERFECT WIDE SHARP and CHEAP lens for the GH2 !!! It’s a C-mount Pentax/Cosmicar 6mm 1:1.2 lens I’ve bought 9.99€ (12.50$) on Ebay!
The rear barrel had to be modified for 20€ (watch pictures below) to fit on the C-mount to micro 4/3 adapter (Kipon).
This 6mm focal lenght on the GH2 gives a huge vignetting on micro 4/3 sensor, but thanks to the new crop 1:1 GH2 function, the vignetting is disappearing completely !
This 6mm lens with the crop function gives nearly the same frame (same width but less height) than on the Lumix 14mm 1:2.5, but much much more faster.
It’s a sharp lens, even with the crop. In 24X36 eq. it’s a 30mm.
This lens is incredible for GH2, there is no other competition for such a fast lens !

In this movie you will watch daylight tests (always @ 1:1.2, 1/50 shutter speed, 160 asa) with a 22€ Polaroid 43mm variable ND filter and a 40.5 to 43mm step-up ring, there’s my girlfriend preparing her new collection for children “Pitchoovintage”.
Then you will watch night test, from 160 to 3200 asa, always @ 1:1.2 and 1/50 shutter speed.

Seb tested many C-mount lenses and is one of our daily 43rumors readers. Feel free to make him any question you want and he will answer you! Thanks SEB!

: This is the original place where Seb got the lens on eBay (Click here).

– C-mount Pentax/Cosmicar 6mm 1:1.2 at eBay (Click here).
– Kipon C-mount to micro 4/3 adapter at eBay (Click here).
– Panasonic GH2 at Amazon, B&H, Adorama, Olympus US store, FocusCamera, eBay.
– Panasonic 14mm f/2.5 lens at Amazon, B&H, Adorama, Olympus US store, FocusCamera, eBay.

  • JM

    Why the rear barrel had to be modified?

  • Here’s a link for a longer movie I’ve made with this Pentax 6mm 1:1.2 :

  • I tried this crop video mode on GH2. It magnifies any small shaking of the camera greatly. Good IOS or a very stable tripod is necessay to avoid shaking when using crop video mode. Handheld (even on a monopod) stable video is very difficult.

    • It depends of the lens. Here you have a wide lens a 15mm/30mm eq., so it’s less shaky than using a 25mm for example.

      • I tried 20mm (40mm eq) lens and it was pretty difficult to stabilize the video using handheld.

  • great, bot lens and footage!
    too bad olympus doesn’t have such crop modes :-(

  • frank

    What is special about the crop mode? My GF1 also has it if I only write JPG and do a digital zoom. Or is it that the GH2 has it in video mode?

  • unlike digital zoom it should have no loos in quality, in this case its perfect for getting rid of the 6 mm c-mount lens heavy vignetting -)

  • in video recording mode yes, using the central area of the sensor only, using a 1920×1080 area, so 1:1

  • disco

    how is 1920×1080 = 1:1?

    • i never thought i would gettin into technical stuff (because i know very little), but as you prob know, shooting video normally uses the whole sensor which is bigger then the 1920×1080 in this case, the conversion to 1920/1080 can involve some side effects. so the crop 1:1 mode doesn’t need to do this….i hope i am right about this.

  • ZDP-189

    Maybe I should buy a bunch of these and stick them on the lathe. They would make great Crimbo pressies and trade items.

  • mpgxsvcd

    That lens is cool but it isn’t cheap. I can’t find it for less than $100.

    If you want REALLY Wide, Fast, and cheap(if you already have the 14mm F2.5) then try the .45x wide angle converters from Amazon.

    Here is a video shot at just over 6mm F2.5.

    • Well I found it for 9.99 new one (see links below :)
      Your example is good and obviously wide but the Pentax is 4 times faster, without counting maybe the one stop lost with the converter.

    • Dsn

      The video looks great! Which wide angle converter did you use? Is there a link a name I can search with?

    • mpgxsvcd

      Awesome, Thanks for the links. I will have to try that lens out. Bummer that it needs to be modified for infinity focus though.

      Have you tried the wide angle adapter on the 14mm F2.5 yet? For about $30 it at least gives you an option for shooting very wide angle. None of these are replacements for the 7-14mm though. That is the lens to get if you can afford it.

    • Badfully the 14.5 mm is not mine :(
      I’ve tried the 9-14mm from olympus, it’s a great lens, but like the Panasonic7-14mm, it’s not very fast.

  • gl

    Thanks for posting the comparison. It seems decent, certainly great for the price, but it doesn’t match the Panny 14mm in terms of sharpness and detail, and it’s a little less wide.

    The sharpness difference is the killer for me, no point wasting the image quality of this body. Also with the Panny you can get another longer (zoomed) focal length with 1:1 crop, so it’s more versatile.

  • Leon

    I fail to see how this is a true wide angle lens after converting it to a 1:1 ratio. None of the images (still or video) appear to be what I normally associate with wide angle photography. If the cropping needs to be so severe, I wonder why go to 6mm at all? For instance, why not stay at 35mm with an ultra fast lens (where cropping is not necessary)? I ask out of genuine curiosity because I am interested in an affordable wide angle lens for my epl-1.

  • Valon

    Hello there !
    My first time here so hello everybody!
    Ia have two Cosmicar C mount lenses which I am using with my panasonic af 101. One of them is 75mm and the other one 50mm, Both are very fast and sharp. I also have a Nokton 25mm, which is designed for micro 4/3 sensor. I love the Nokton very much but is not that wide when need it for those tight spaces.
    At the moment I am using a Tokina 17mm,which on micro 4/3 is 34mm. This lens gives me a bit more room but not that much.
    I have seen few Cosmicar 16mm lenses on ebay for cheep but not sure if it covers the micro 4/3 sensor. I don’t want to crop because as Leon mention it looses the purpose of having a wide lens.

    Any suggestion as to what sort of lens I can look for the wide angle lens a apart from Lumix lenses?
    Best regards

  • David


    I have the Kipon adapter, 6mm pentax lens, and Dremel electric filing tool.

    I read this blog of yours along with this:

    which usefully utilizes detailed pictures to explain the process.
    however, i believe this guy is using a different adapter.

    could you please explain how to modify the lens?

    i know this is detailed work and i don’t want to do this blindly.

    i appreciate the work you do. thank you

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