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    Re: Lens Review: Goerz Dagor 19" (480mm) f/7.7

    And for color film, any Dagor except an MC one needs a UV-blocking filter - a real one like Wratten 2b, not a fake piece of glass with a "UV" tag. Dagor's glasses are exceptionally transparent in the...
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    Re: Schneider Tele-Xenar 270mm f5.5

    I've just traded my 270mm Tele-Xenar for some other glass to a fellow photographer. The guy has spine problems and avoids heavy gear. Besides, he needs a back-up shutter for his 270mm Dagor, and the...
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    Re: Lens Review: Goerz Dagor 19" (480mm) f/7.7

    That's my main lens for 8x10" (the coverage is excessive). Stop it down at least to f/10 for the better background blur. With considerable movements, stop it at least to f/22 for better field...
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    Re: Any Lenses for 14 X 36"?

    Still please feel free to PM if interested in an appropriate 505 mm or 1200 mm.

    (Sorry I am not sure if such a post violates the forum rules. Please remove it if it does)
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    Re: Rodenstock Sironar 150mm

    Yes that's certainly subjective. Myself, I am not fond of Petzval swirly background (made up by severe vignetting in those long-barrel lenses) either. And most of the soft-focus lenses (the long...
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    Re: Rodenstock Sironar 150mm

    - except the single Protar VII cells and especially the single Half-Dagor cells which a much better still; but those are way inferior in sharpness.
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    Re: Rodenstock Sironar 150mm

    Yes a lot of tessar-type lenses are better than the best of plasmats in their out of focus rendition but in tessars, almost all the spherical aberration is gone when the lens is stopped down beyond...
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    Re: Rodenstock Sironar 150mm

    While I agree with your general observations on the lens generations,

    (1) Plasmats can easily be optimized for the background blur, too. Just no manufacturer ever bothered to design them to be as...
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    Re: Rodenstock Sironar 150mm

    Symmetry has nothing to do with the out of focus rendition. The OOF rendition depends on the residual spherical aberration (SA), and SA is not dependent on symmetry at all. A prime example are those...
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    Re: Schneider-itis: The Perennial Problem

    When there is no time to make the hood adjustment precisely, one can always make a fast rough adjustment. There will be more sideways light rays getting into the lens than with a perfect hood, but it...
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    Re: Rodenstock Sironar 150mm

    That's the original Sironar, without any additional letters in the name. It's a convertible lens contemporary to (and of the same class as) the plasmat-type Convertible Schneider Symmar. The...
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    Re: Schneider-itis: The Perennial Problem

    I think that's because in LF, the shades' shapes are dependent not only on the lens but also on the format, on the amount of tilts and shifts, on the focusing distance, and so on. So as B.S.Kumar...
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    Re: Schneider-itis: The Perennial Problem

    One of my Schneider lenses of the plasmat type builds up quite a bit of haze on its internal glass surfaces in every several years. I've got a habit to take it apart from time to time and wipe the...
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    Re: Schneider-itis: The Perennial Problem

    That's the point. Sadly enough, too few photographers pay the proper attention to their lens hoods, worldwide.

    The 210xl's image circle is 50cm at infinity, so the total illuminated field is at...
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    Re: Schneider-itis: The Perennial Problem

    That would be the most useful if you perform accurate tests before and after the repair, with all the conditions exactly the same.
    I think a lot of people will appreciate that.
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    Re: Schneider-itis: The Perennial Problem

    (1) I usually check the direction of any possible reflections from the surfaces I am going to paint black. If any of the reflections can go directly to the image plane, I use mat black. If not, I...
  17. Thread: ICA Niklas

    by ridax
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    Re: ICA Niklas

    Your description most probably suggests a modified Petzval type.

    But with the lens in your hands, why not to try it - at least looking at the image on the ground glass only - instead of asking...
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    Re: A question for the opticians here.

    The diaphragm position has critical influence on many aberrations, and especially on coma. And at least with simple lenses like menisci and achromats, the minimal coma is the criterion of the optimal...
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    Re: Process Lens & Close Work

    (1) I am not talking about any '3d look' (which sounds quite a bit mystically, and I always strictly avoid anything non-scientific). I am talking about the out of focus background rendition in 3-D...
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    Re: Process Lens & Close Work

    Or even Half-Dagors when the background is really far away (https://www.largeformatphotography.info/forum/showthread.php?163832-Protar-Lenses&p=1623018&viewfull=1#post1623018)...
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    Re: Process Lens & Close Work

    My practice-based opinion is here: https://www.largeformatphotography.info/forum/showthread.php?133358-2024-quot-enlarger&p=1394698&viewfull=1#post1394698

    But that's all about the purely technical...
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    Re: Tominon Lens Specification

    The 60mm f/5.6 Componon was made for the 4x4cm (Baby Rollei) format. But I use it for 24x36mm and prefer it to any 50mm enlarging lenses, including the ones with the 'APO-' lable.

    My wife is an...
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    Re: Tominon Lens Specification

    Yes indeed.



    I like the 127 and the 105 but not the 75. The 75 is worse in its sharpness than the extremely cheap Russian (domestic for me) enlarging Industar 75mm f/4. Worse in the out of...
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    Re: Tominon Lens Specification

    What I found out testing the Polaroid Tominons personally is that the 50mm f/4.5 was actually a process lens optimized for 1:1 (it covers 6x9cm at 1:1). Though Polaroid recommended it for quite...
  25. Re: Filter size of Carl Zeiss Jena Apo-Tessar 60cm F9?

    I'd just cement an empty filter ring on the barrel front - inside or outside that 83mm. If pressed against the original barrel, the ring will be perfectly parallel to it. And no centering is needed...
  26. Re: Filter size of Carl Zeiss Jena Apo-Tessar 60cm F9?

    My 60cm f/9 CZJ Apo-Tessar (later version) has M83x0.75 on the front.
    My 1961 60cm f/9 Industar-11M which is a copy of the previous CZJ Apo-Tessar version, has M84x0.75.
    Neither make any sense,...
  27. Re: Filter size of Carl Zeiss Jena Apo-Tessar 60cm F9?

    I don't have it at hand (I think I'll be able to measure the threads tomorrow) but I am sure the thread is totally non-standard, and no manufacturer ever produced filters in sizes like that.

    Mine...
  28. Re: Using a Neutral Density Filter on a Rear Lens Element

    No. No stray light is used in making an image. Only the rays that come into the lens directly from the subject are. And no the light that goes out of the lens to make the image is never collimated....
  29. any standards for 12x16"/30x40cm or slightly bigger holders?

    I'm in the process of adapting an old 30x40cm (circa 12x16") camera to my own needs. The original holder is to be replaced with something more suitable for film, not plates, and lighter in weight....
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    Re: Question: What is this?

    I own about half a dozen lenses with separations like that - several Rodagons, a Mamiya RB lens and somewhat else.... I actually do not remember which ones exactly, because they all perform just...
  31. Thread: Protar Lenses.

    by ridax
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    Re: Protar Lenses.

    Yes that's exactly my own guess. As I said in that other thread, almost all my Turner-Reich cells have balsam degradation at the edges as I preferred to buy them cheap. They seem to be never...
  32. Thread: Protar Lenses.

    by ridax
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    Re: Protar Lenses.

    Well, I've done it. No not half a dozen of complete double anastigmats but still 7 single cells (3 complete lenses + 1 more cell) came to my place to get tested a couple of months ago. And I've not...
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    Re: Turner-Reich modifications?

    I've got and tested that beast, too. It's single cells are nowhere near the Protar ones and not worth discussing. The complete lens is not bad but also nothing to write home about. Its character...
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    Re: Turner-Reich modifications?

    Answering my own question now....

    I've got several 12" Turner-Reichs of both 'types' at least, the ones with the cells labled 19.7" + 25", and those with 21" + 28" marked cells. The answer is,...
  35. Thread: Protar Lenses.

    by ridax
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    Re: Protar Lenses.

    A correction: the above was said about distant views with lots of fine details. I've tried virtually all my lenses on different formats from 8x10" to cropped digital for close-ups recently, and the...
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    Re: Old lenses and optimal performance

    A couple more thoughts about the close distance vs. infinity image quality:-

    At close distances the angle used is smaller, and the outer portions of the lens field are outside of the film. As...
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    Re: Old lenses and optimal performance

    Petzvals are a special case but perfectly symmetrical lenses such as Aplanats / RR's and the early double anastigmats are naturally better at 1:1 than at infinity.
  38. Re: 490mm f/6.2 OR-451M: fine OOF background for a $100

    Sorry nothing on-line yet....
  39. Re: 490mm f/6.2 OR-451M: fine OOF background for a $100

    I've also tried putting negative supplementary lenses in front of the OR-451M. A -0,25 diopter lens made too little difference to the lens's focal length, and a -0,75D spoiled both the sharpness and...
  40. Thread: Protar Lenses.

    by ridax
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    Re: Protar Lenses.

    I forgot to mention I use my 840mm Half-Dagor on 8x10" and my 290mm Half-Dagor on 9x12cm without any movements to stay within the center of their fields. I consider my 590mm to 650mm Protar-type...
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