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  1. #31
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    Quote Originally Posted by Poisson Du Jour View Post
    I am presently considering the 105mm f2.4 as a go-between for the 55mm and 165mm. The extra speed is sought after as focusing can be a challenge in low light+ POL with 55 or 165.
    It is a wonderful lens and is certainly my most used lens when I had my 67 and still now with my 67ii. However, be careful which version you get if you'll be shooting color as I recently bought a back up copy of the lens from KEH just in time for a cross country tour with my friend's band. Well it was the version with the rare earth element in it that causes it to yellow and I didn't have to time to send it back so I took it along anyway. For my BW work it was fine, worked just like a K2 filter but all of my color shots needed some color correction. It can be UV'd out but it's much easier to just not get a yellow one in the first place
    Brett William - Flickr

    Minolta Autocord
    Zeiss Ikon ZM
    Pentax 67ii

  2. #32
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    A "rare earth element" !?
    By the Lord Harry, I have never heard of it (much less seen it!). Or maybe I have read about such things here on APUG affecting lenses here and there. But...Pentax??
    The lens I am scrutinising is listed as having "minor dust" but no quantification as to it, other than being told politely to "nick off and find a better one then".

  3. #33
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    Quote Originally Posted by Poisson Du Jour View Post
    A "rare earth element" !?
    By the Lord Harry, I have never heard of it (much less seen it!). Or maybe I have read about such things here on APUG affecting lenses here and there. But...Pentax??
    The lens I am scrutinising is listed as having "minor dust" but no quantification as to it, other than being told politely to "nick off and find a better one then".
    Yeah, I believe it's Thorium. As far as I know only the earliest example of the three versions of this lens utilized Thorium and it's readily noticable just looking through the lens wide open. If they noticed the dust they'd be blind to not notice the yellowing if present. I'll take a look at mine when I get home and check the SN and labeling of the lens to confirm which version it is. In any case, the lens is a great performer. Light with an equivalent view of around 55mm and surprisingly sharp as well. A couple more examples:
    Attached Thumbnails Attached Thumbnails Richmond John Shaving.jpg   Walker Shaine Richmond.jpg  
    Brett William - Flickr

    Minolta Autocord
    Zeiss Ikon ZM
    Pentax 67ii

  4. #34
    Poisson Du Jour's Avatar
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    Quote Originally Posted by RangerFinder View Post
    Yeah, I believe it's Thorium. As far as I know only the earliest example of the three versions of this lens utilized Thorium and it's readily noticable just looking through the lens wide open. If they noticed the dust they'd be blind to not notice the yellowing if present. I'll take a look at mine when I get home and check the SN and labeling of the lens to confirm which version it is. In any case, the lens is a great performer. Light with an equivalent view of around 55mm and surprisingly sharp as well. A couple more examples:

    Indeed, most helpful. You must be shooting wide open to get the extremely shallow depth of focus in your images. I'm imagining a different result if you were tripod-shooting.
    There is commentary the lens is best at f8 to infinity and that the Dof scale is off slightly.
    All of my photography is necessarily done on a tripod as I am hopeless handholding the big 67 and even need a haul-up strap just to dock it (mind you, once docked it is a sure-fire conversation starter!). That means, notwithstanding induced vibration when and where it occurs, either 55 or 165mm are performing at the best, around f8 to f11 for 55mm, f16++ for 165mm.

  5. #35
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    Quote Originally Posted by Poisson Du Jour View Post
    Indeed, most helpful. You must be shooting wide open to get the extremely shallow depth of focus in your images. I'm imagining a different result if you were tripod-shooting.
    There is commentary the lens is best at f8 to infinity and that the Dof scale is off slightly.
    All of my photography is necessarily done on a tripod as I am hopeless handholding the big 67 and even need a haul-up strap just to dock it (mind you, once docked it is a sure-fire conversation starter!). That means, notwithstanding induced vibration when and where it occurs, either 55 or 165mm are performing at the best, around f8 to f11 for 55mm, f16++ for 165mm.
    More than anything else it was probably the #1 tube that narrowed that DoF, it was used on the shot of my friend shaving and of the girl and yes the camera is indeed heavy!

    EDIT: Just got home and checked, my lens is labeled Super-Takumar/6x7 and the SN is 42XXXXX. Both the S-M-C Takumar 6X7 105mm f/2.4 and the SMC Pentax 67 105mm f2.4 should be free of the lens yellowing problem.
    Last edited by RangerFinder; 08-20-2012 at 10:34 PM. Click to view previous post history.
    Brett William - Flickr

    Minolta Autocord
    Zeiss Ikon ZM
    Pentax 67ii

  6. #36
    Poisson Du Jour's Avatar
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    Quote Originally Posted by RangerFinder View Post
    More than anything else it was probably the #1 tube that narrowed that DoF, it was used on the shot of my friend shaving and of the girl and yes the camera is indeed heavy!

    EDIT: Just got home and checked, my lens is labeled Super-Takumar/6x7 and the SN is 42XXXXX. Both the S-M-C Takumar 6X7 105mm f/2.4 and the SMC Pentax 67 105mm f2.4 should be free of the lens yellowing problem.


    Very good. I'm still surprised by the thorium/yellowing bit of the Takumars; I surmise there are potentially other Takumar lenses out there with this quirk?
    Meanwhile, the tens of interest I am tracking is serialised 855xxxx — no doubt a much later release.

  7. #37

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    Thorium Lens

    Quote Originally Posted by Poisson Du Jour View Post
    Very good. I'm still surprised by the thorium/yellowing bit of the Takumars; I surmise there are potentially other Takumar lenses out there with this quirk?
    Google for the words Thorium and Lens; you'll find a lot of interesting information.

  8. #38
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    Quote Originally Posted by sbjornda View Post
    Google for the words Thorium and Lens; you'll find a lot of interesting information.
    Yeah the camerapedia page has quite a bit of info on it. I know that when I was buying my SMC Pentax M 50 1.4 for my k1000 there was a generation of those lenses as well that used Thorium as well so I'm sure these more.
    Brett William - Flickr

    Minolta Autocord
    Zeiss Ikon ZM
    Pentax 67ii

  9. #39
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    The CameraPedia page is what is in view at the moment. Interesting: at one time in the early 1980s the Canon FD 35mm f2 was joined by the FD 35-105 and 28mm lenses on a T90. Never knew anything about thorium back then.
    Pentax is well represented in the list: Super Takumar 6x7 105mm f2.4 is one I have seen several times but never associated with thorium (lens of interest is the newer SMC Pentax 67 version).

    There might be a link to Canon's use of CaF2 (calcium fluorite) in the early 1980s as a means of getting rid of the inclusion of thorium in high-end (FD) lenses (among other considerations).

  10. #40

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    Quote Originally Posted by 10speeduk View Post
    Anyone recommend a Pentax 67 CLA guy in the UK?
    http://www.asahiphoto.co.uk/repairs.htm

    http://harrowtechnical.co.uk/

    Try these guys for Pentax repairs. I have no personal experience with either yet.

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