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  1. #11

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    Nov 2003
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    Quote Originally Posted by sanking View Post
    Michael,

    I have sold off most of my Dagor type lenses so mostly agree with your comments. Modern plasmat type lenses are sharper at large apertures than Dagors, and probably have better coating.

    However, the design itself did not reach the end of the line in the 1970s with the multi-coated Kern dagors, which are some of the most contrasty lenses ever made. The fairly recent Schneider 550mm XXL Fine Art lens is in fact a true Dagor design which takes advantage of new glasses and computer design. So with all the background of lens design Schneider chose a Dagor type design as the one that best delivered the specific image qualities they thought important in a lens of this type.

    Sandy King
    You are spot on Sandy. The ability of Schneider to access the wide range of optical glass and modern coatings melded well with the known ability of the Dagor to to produce a very large and highly desirable image circle for the class of customers these Fine Art Lenses were targeted for - ULF photographers. Schneider was also able to excise most of the undesirable components of this lens in the design as it sounds based upon your observations, that it is a marvelous optic to have in the field. Clearly the price to accomplish this package is a bit steep compared to the used market for Artars and others, but after I learned how financially challenging it is to bring a simple Artar type optic into the ULF market, the price now seems very reasonable for what is being delivered. Coming up with the money for it is a whole other matter.

    One of these days I hope to own a 550 XXL. But in the meantime I need to close some more deals in my business and then find one for sale. Eventually I found my 30" Red Dot and 305 Computar based upon your recommendations and am pleased with their performance.

    Cheers!

  2. #12

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    Quote Originally Posted by Michael Kadillak View Post
    At one point or another we all have a tendency to get inspired by Mr. Dagor.

    ...

    When I was recently working on a lens project with an optical physicist and mentioned the Dagor he looked back at me like he had just bitten into a lemon. "Surely we can do much better than that," he commented. He showed me the curves and pointed out the deficiencies of the design and we moved on. .. - there are many other alternatives that are much less costly and perform much better.

    Cheers!
    I'd have to add that Michael's optical physicist is ... sort of right. That's the problem when dealing with physicists and engineers, you only get a technical opinion. I feel safe saying that since I do have a degree in physics.

    So let's have the optical physicist tackle all the criteria for which the Dagor is desirable, and not just the optimum optical performance. Here's what I'd ask the optical engineer to design:

    It has to have the the same, or better, circle of illumination to 5 lpm (coverage) as the Dagor

    It has to have the same, or better, circle of sharp coverage as the Dagor

    It can't weigh any more than the Dagor

    It can't cost any more than the comparable plasmat that replaced it.

    I'd be interested if such a lens is possible. And it might very well be possible. I've always maintained that if Schneider made the Super Symmar XL series at f:6.8 to f:11 in more focal lengths (like the Dagor), there wouldn't be any discussion at all about Dagors, they'd all be sold.

    Cheers, Steve

  3. #13

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    Nov 2003
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    Quote Originally Posted by Steve Hamley View Post
    I'd have to add that Michael's optical physicist is ... sort of right. That's the problem when dealing with physicists and engineers, you only get a technical opinion. I feel safe saying that since I do have a degree in physics.

    So let's have the optical physicist tackle all the criteria for which the Dagor is desirable, and not just the optimum optical performance. Here's what I'd ask the optical engineer to design:

    It has to have the the same, or better, circle of illumination to 5 lpm (coverage) as the Dagor

    It has to have the same, or better, circle of sharp coverage as the Dagor

    It can't weigh any more than the Dagor

    It can't cost any more than the comparable plasmat that replaced it.

    I'd be interested if such a lens is possible. And it might very well be possible. I've always maintained that if Schneider made the Super Symmar XL series at f:6.8 to f:11 in more focal lengths (like the Dagor), there wouldn't be any discussion at all about Dagors, they'd all be sold.

    Cheers, Steve
    I asked precisely the same questions that you posed Steve to my lens design expert a while back. You can get to these criteria with a lens design program and then you come full circle to the realities of this situation. Because of fixed set up costs and volume purchasing requirements necessary to obtain decent pricing you need to be able to sell hundreds of these lenses to attain an affordable price point inclusive of your margin for the average LF/ULF photographer. If you get realistic about the number that you can sell (or your project risk tolerance) which is a far lower number you find that the need to make sure that it is truly an exceptional optic that you produce because your sales price needs to increase due to the smaller lot produced. Then at some point you realize that the market for these products is only so big and already seasoned with old Artars. Ronars, Dagors, Protars and a wide range of other repro lenses that find their way to the lensboard of a LF/ULF camera. Add a poor economy to the mix and it becomes even more unlikely that it could be done. I agree with you about the Super Symmar lens series. Lets start a petition for Schneider to do this?

    Cheers!

  4. #14

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    Michael,

    I'd love to get Schneider's opinion/input. I think they're aware of such issues as evidenced by the 350mm Apo Tele-Xenar, which fills a "hole" in the lightweight 4x5 lens lineup at that focal length.

    As you noted, simply producing new Dagors is probably not desirable because they'd be competing against a huge used market and the Goerz brand. And a f:6.8 - f:8 - f:11 SS XL series might not need much in the way of re-engineering or setup, since the basic design would seem to be completed, and glass and shutters could be very much smaller. I can see that as a true replacement for all the features of the Dagor, except probably price - but you can't have everything.

    Sign me up.

    Cheers, Steve

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