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Thread: Image circle of a Pentax 67 lens (105mm 2.4)?

  1. #1

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    Image circle of a Pentax 67 lens (105mm 2.4)?

    Hi, I realise that this is not a large format lens as such but I am planning on attaching it to a large format camera and using it with a roll film back for portraits. Am looking to try and find the data for the image circle of the Pentax 67 105mm 2.4 and see if it is possible to do small movements on the 5 x 4? Would mainly be small amounts of swing or tilt... Anyone have any ideas or thoughts on this? It would be greatly appreciated! Ok, thanks so much. Best Regards Josh

  2. #2
    ic-racer's Avatar
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    Re: Image circle of a Pentax 67 lens (105mm 2.4)?

    I suspect it would only be usable with small movements on 6x6cm format. In my experience, lenses like this are designed to limit the image circle to help minimize internal reflections in the camera etc and if I were to guess at the image circle I'd say 90mm.

    In fact, my Horseman 105/4.5 SUPER 6x9cm view camera lens allows massive movements on 6x9cm format but still just clips the corners of 4x5in (IC=160mm) and does not allow any movement with 4x5.

    105mm lenses that cover 4x5 are rare (why??). That is too bad because I love 210mm on 8x10 and there are many 210mm lenses for 8x10.

    Also, a 105mm on 4x5 is going to be a quite wide lens for portraits, unless they are 'environmental portraits' or something.

  3. #3

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    Re: Image circle of a Pentax 67 lens (105mm 2.4)?

    Since the lens isn't designed to move when it's on the 6x7 camera for which it's designed, it's presumably just wide enough to cover the four corners of a 6x7 negative, plus maybe a little to spare. So if you measure the diagonal of a 6x7 negative (sorry but I'm too lazy to do it) I would think you'd pretty much have the useful image circle.
    Brian Ellis
    Before you criticize someone, walk a mile in their shoes. That way when you do criticize them you'll be
    a mile away and you'll have their shoes.

  4. #4

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    Re: Image circle of a Pentax 67 lens (105mm 2.4)?

    Thanks so much, pretty much as I expected I guess. Maybe i am better off with a lens that is designed for the 6 x 9 format but is still relatively fast. I know that there is a Xenotar 100/105 2.8 that covers this format. Anyone have any other suggestions? Ok, thanks once again, much appreciated! Best Regards Josh

  5. #5
    Drew Wiley
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    Re: Image circle of a Pentax 67 lens (105mm 2.4)?

    The person who would know is Francis Sakamoto. He's jerry-rigged Pentax 6X7 gear
    more than anyone else I can think of, and probably still has a personal website. I think
    he now uses a big Toyo 8x10 with a Nikon on the back for ultra-telephoto work. But
    these medium format lenses are designed quite a bit different from view lenses, without
    movements in mind. Otherwise, it is a very sharp fast lens.

  6. #6
    Drew Wiley
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    Re: Image circle of a Pentax 67 lens (105mm 2.4)?

    The other thing which comes to mind, is that there probably isn't going to be room to fit a shutter behind this thing anyway. I believe the leaf-shutter version of the lens
    was actually 90mm.

  7. #7

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    Re: Image circle of a Pentax 67 lens (105mm 2.4)?

    Thanks so much once again for all the responses! It is very helpful! I will contact Francis and see if he can help. In terms of the shutter, I was planning to throw it into one of the new Shen Hao XPOs that are available to use with the Sinar Shutter.... I dont know so much about it but I dont see why it wouldnt work.. The only problem is getting sharpness with roll film at a wide open aperture. My tests so far have been less than impressive! Have been testing with a 150mm 2.8 Xenotar and have had some sharp images and some not. Actually, it has driven me a little crazy so I hate to think of it when I actually have people in the shot.. Thanks again..

  8. #8

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    Re: Image circle of a Pentax 67 lens (105mm 2.4)?

    I held the 105/2.4 in front of my Super Graphic and it looked like it was very close to covering. At portrait distances you might just get away with movements, particularly if you shot against a dark background. I tried the 90/2.8 and 150/2.8 and the edges of the image circle were a lot more obvious so I don't think they will work.

  9. #9

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    Re: Image circle of a Pentax 67 lens (105mm 2.4)?

    Hi Paul, Thanks for the response.. When you say that the 105mm 2.4 was close to covering, what are you referring to? A full 5 x 4 frame? Or a much smaller format (like 3 and a quarter )? Thanks.

  10. #10

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    Re: Image circle of a Pentax 67 lens (105mm 2.4)?

    You may want to look at RB lenses, fairly simple to adapt, inexpensive and fairly large image circles. The 90 illuminates 4x5 with room to spare.

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