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  1. #21

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    Quote Originally Posted by Harrigan
    As far as a 180 for big coverage there aren't any that come to mind.
    The 8X10 Series V Protar, which is about 180mm in focal length, will easily cover 400mm. In fact, the one I have just barely misses the corners of 7X17 at f/45, which puts its coverage circle at about 455mm. Focused at 20-30' it would in fact cover fully the 7X17 format, which might make it useful for interior work (if you can live with the f/18 maximum aperture).

    The Zeiss Protar will cost more, but in my experience the B&L version is every bit as good.

    Sandy

  2. #22
    Ole
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    The pre-WWII Angulons have a less abrupt end to the "coverage", so that the corner unsharpness is less obvious. For contact printing purposes, I'm willing to say that my 210mm Angulon covers 30x40cm (12x16") at very small stops.

    EDIT:

    I forgot to mention that I recently tried a 150mm Busch ROJA Wide-Angle Aplanat on 24x30cm. It covers, at f:64. Optimum sharpness is less than that of a Protar, but the price and availability more than compensate for that. A 210mm WA Aplanat should easily cover 30x40cm.
    -- Ole Tjugen, Luddite Elitist
    Norway

  3. #23

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    Quote Originally Posted by jimgalli
    The answer to your question is "no". If a Protar V of 8 3/8" shows up you'll be bidding against me. In spite of all the hype, the Computar 210 does not get the job done. Nice to wish for but I have one and to cover 11X14 you're focusing "in" at 80 feet or less and stopping down to f64 to try to get the corners covered. That isn't an 1114 lens in my book. There was a pretty 210 pre-war f6.8 Angulon from a seller in Japan earlier this week. I have no experience but Ole swears they'll cover amazing things.
    I had a 210mm f/6.8 Angulon at one time in the past and the circle of illumination was slightly greater than that of my 210 Computar. However, performance at the corners, even for contact printing, was dismal. The 180mm (8X10) Protar V I have gives much better performance on the corners than the 210 Angulon, as does the 210 Computar.

    No surprising, since the Angulon is really nothing but a Dagor by another name, and Dagors are simply dreadful beyond about 85 degrees.

    Sandy

  4. #24
    Ole
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    Quote Originally Posted by sanking
    No surprising, since the Angulon is really nothing but a Dagor by another name, and Dagors are simply dreadful beyond about 85 degrees.
    A Dagor and an Angulon are as similar as a Petzval and a Tessar. All the glasses are different, all the curvatures are different, and the order of elmnts is different. They are both 3+3, but that's the only similarity. Like Petzvals and Tessars are both two pairs - one cemented, one not.

    Also, the Angulon design has been changed around WWII. As I said earlier, the older ones have less very sharp image circle, but a better acceptably sharp image circle for contact printing purposes - and if you don't really need ultimate sharpness in the corners.
    -- Ole Tjugen, Luddite Elitist
    Norway

  5. #25

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    Quote Originally Posted by Ole
    A Dagor and an Angulon are as similar as a Petzval and a Tessar. All the glasses are different, all the curvatures are different, and the order of elmnts is different. They are both 3+3, but that's the only similarity. Like Petzvals and Tessars are both two pairs - one cemented, one not.

    Also, the Angulon design has been changed around WWII. As I said earlier, the older ones have less very sharp image circle, but a better acceptably sharp image circle for contact printing purposes - and if you don't really need ultimate sharpness in the corners.
    There is nothing at all similar in coverage and performance between Petzval and Tessars. On the other hand, all of the older 3-2 symmetrical designs such as Dagors, Angulons, Collinears, etc, have very similar performance characteristics in terms of angle of coverage and performance at the center and at the far corners. The curvatures of the glass may be different, and the order of elements may be reversed, but the final result on film is virtually identical, give or take a few degrees of coverage. I have used many Dagors and Angulons and my experience is that for any given focal length there is very little difference in performance between the two designs, either in sharpness at the center of the field or ithe useful circle of illumination. A Dagor of 210mm focal length gives a useful circle of illumination as large as that of a 210mm Angulon, when stopped down to f/45 or f/64. The Angulon may in principle throw a larger circle of illumination but I have not found anything beyond 90 degrees to be useful.

    Granted, both of these designs were made over a very long period of time and significant differences in performance exist between lenses of the same design so I leave the door open to surprises in performance of individual specimens.


    Sandy
    Last edited by sanking; 06-04-2006 at 09:27 PM. Click to view previous post history.

  6. #26

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    Quote Originally Posted by sanking
    I had a 210mm f/6.8 Angulon at one time in the past and the circle of illumination was slightly greater than that of my 210 Computar. However, performance at the corners, even for contact printing, was dismal. The 180mm (8X10) Protar V I have gives much better performance on the corners than the 210 Angulon, as does the 210 Computar.

    No surprising, since the Angulon is really nothing but a Dagor by another name, and Dagors are simply dreadful beyond about 85 degrees.

    Sandy
    I agree that dagors perform very badly beyond 85 deg! I thought I was the only one who felt this way.

  7. #27

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    I did a quick test with the 240mm Graphic Kowa I have yesterday - Sandy's 520mm image circle seems spot on at f64. Interesting that the test shot I did shows the lens to be tack sharp right up to the edge of the image circle - the lens really is a screaming bargain if you can find one.

  8. #28

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    Quote Originally Posted by Donsta
    I did a quick test with the 240mm Graphic Kowa I have yesterday - Sandy's 520mm image circle seems spot on at f64. Interesting that the test shot I did shows the lens to be tack sharp right up to the edge of the image circle - the lens really is a screaming bargain if you can find one.
    Just make sure that the lens fits into a shutter, if that's what you want to do. Some do, some don't. At F64, I doubt a shutter is really needed, though. Do ULF shooters tend to use lenses in shutters?

  9. #29

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    I only use lenses in shutters, but I know a lot of people don't. Personally, I find the hat trick or a lens cap too risky given the effort required to get a ULF camera to where you want it to risk vibration caused by not having a shutter. Yes, a Packard is a solution too. At present, with the current availability of a fast film with great reciprocity charateristics like Tmax 400, I find that I am shooting a lot at around 1/2s which is a bit tricky without an accurate shutter. Also, it probably depends what process your negatives are destined for: If you print on Pt/Pd, you really do not want to have a negative which is a stop denser than you need (because you couldn't get an accurate exposure) - I loathe printing when exposure times get beyond 20 minutes - it really destroys my productivity and takes the fun right out of it.

    You are right with the Kowa - 240mm. On some, the front element cannot be simply unscrewed and then put into a Copal 3S shutter - however, I can tell you first hand that SKGrimes can easily remount the front element from this type into a "Copal 3S" fitting mount for about $200. If you spend about $200 for a Kowa which cannot be unscrewed, you can still end up with one of the very best 240mm wides for ULF for around $700 by the time you've found a Copal 3S shutter ($300 with a bit of luck and $200 for the remount by SKGrimes). I actually sold my 210mm XL as soon as I had tested my 240mm. Yes, on occassion the slightly shorter focal lengh would be nice, but not $2000 more appealing. The 210mmXL is also a beast to lug around. I never carried it on me.

  10. #30

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    Quote Originally Posted by Peter De Smidt
    Just make sure that the lens fits into a shutter, if that's what you want to do. Some do, some don't. At F64, I doubt a shutter is really needed, though. Do ULF shooters tend to use lenses in shutters?
    All of the Computars that I have seen screw directly in Copal shutters, the 210mm into a Copal 1, the 240, 270 and 305 Computars into a Copal 3.

    All of my Computars are in shutters. Some ULF shooters use lenses in barrel mount and that is practical for some applications, but most of my exposures are in the range where a shutter is very useful, say 1/2 to 1/30 of a second.

    Sandy

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