58mm SA XL on Ebony 23S

Discussion in 'Large Format' started by george_daneliya, Oct 21, 2013.

  1. I heard that rise and fall movements may be restricted on Ebony 23S with certain wideangles having large rear elements - the rear element of a lens hits the back standard. Did anyone met such problem with Super Angulon XL 58mm? How much rise / fall 23S actually allows with this lens? Many thanks in advance!
     
  2. This
    https://www.schneideroptics.com/pdfs/photo/LensCharts.pdf
    indicates that the rear element has a diameter of 60 mm and is 39 mm (70 minus 31) from the ground glass at infinity. It is of course important to be careful not to bring the lens closer to the camera back than infinity focus, otherwise there might be a collision (although the bellows would probably prevent this happening).
    I don't have an Ebony but from this
    http://www.ebonycamera.com/cam/main.23S.html
    it would seem that a recessed lens panel would be a good idea (mandatory for 45 and 47 lenses, with a 58 it would certainly decompress the bellows and allow more camera movements to be used).
     
  3. Thank you, David! Using a recessed board seems to be a good idea in general. However, it won't resolve the problem I'm asking about - when the rear element of the lens hits the top (rise) or bottom (fall) of the frame of the rear standard.
     
  4. George, I of course do not have an Ebony to hand, but from the data sheet it seems that the rear end of the lens will be 39 mm from the focusing screen with the 58 lens focused on infinity. That being the case, will the lens ever hit the back? I would have thought that the limits of a shift movement would be set by firstly the lens coverage and secondly the bellows.
     
  5. David, I mean situation shown on the attached pic.
     
  6. https://www.schneideroptics.com/pdfs/photo/datasheets/super-angulon/super-angulon_xl_56_58_3.pdf
     
  7. Thank you, Dan!
    For those, who are curious, I've got this answer from Ebony Co., Ltd.:
    "With the combination of the 23S and SA XL 58, approximately 2cm of rise/fall would be available."
     
  8. Um, George, I know that the 58 SAXL is an outstanding lens and all that but it seems a bit of overkill -- more coverage than can be used -- for 2x3. Do you intend to use it for 4x5 too?
     
  9. George it would seem the combined efforts of PN have led to an answer. The Schneider data sheets referenced by me and others state the circle of coverage of the 58 is 165 mm – if we take a nominal 6.5 x 9 cm negative (actual size would be a little smaller), we find this has a diagonal of 111 mm, 54 mm less than the circle of coverage, indicating that we could use 54/2 = 27 mm of rise and fall if the camera allowed it. The dimension you drew on your sketch is apparently 20 mm, i.e. after 20 mm of rise with a short (58) lens, the end of this will foul against the body and prevent further movement – with a longer lens the Ebony would allow up to 50 mm of rise.
     
  10. Dan, maybe the coverage of 58 SA XL is indeed a slight overkill for 6x9, but can you really suggest any (not overkill) alternative? I'm aware only of some vintage designs in this focal length. Old 58mm Grandagon or also old rare 53(?)mm SA? I don't think they can compete with 58 SA XL in terms of IQ, especially in corners, and they are of almost the same size. 53mm Biogon allows no movements, etc. The only viable options in this focal today are 58 SA XL or 55 some modern Grandagon. 58 SA XL is too wide for my taste on 4x5, but maybe, someday, I would use it on 4x5 too.
     
  11. David, that was a citation from email I received from the manufacturer - Ebony Co., Ltd. So, I think it is quite accurate. (My sketch was just for illustration of the problem - I never followed any proportions when was drawing the scheme in MS Paint :) since I don't have Ebnoy 23s at hand, and don't know its internal dimensions.)
    Probably 2cm is not that bad with a wideangle?
     
  12. Probably 2cm is not that bad with a wideangle?
    The 165 mm image circle with the 58 is pretty good, crucially it's bigger than 160 mm, which is the diagonal of 4 x 5 inches, so this lens would be usable on this format.
    As I said earlier, the data sheets appear to say that there is 39 mm clearance between the rear of a 58 SA XL and the film plane at infinity focus – I would be surprised if the camera back was deeper than 15 mm or so, so I do not think the potential rise movement would be limited by the back, more likely by the bellows (without a restriction, it appears that the front standard of the Ebony allows 50 mm of rise).
    I do not think that a 58 SA XL would be overkill for 6 x 9 cm (assuming you can afford it). I have a 65 mm f8 Super Angulon, I assume of 1970s vintage - this has an image circle of 155 mm and is hard to find these days in perfect condition. The extra coverage is always handy – even if you’re not doing architecture, being able to get deep focus with a landscape using only front tilt (which of course does not distort the image like rear tilt) is a good thing to have.
     
  13. I dunno, George, my little 58/5.6 Grandagon seems to cover 4x5 with nothing left over. They aren't that rare, but ones without separations are really hard to find. Also, as sold they're quite hard to use. I reshuttered mine.
    You may well be right when you say there are few real alternatives to the 58 SAXL. The only relatively common lenses in that focal length that will cover 2x3 are the 58/5.6 and 60/5.6 lenses for Koni- and Rapid-Omega cameras. f/5.6 and f/8 Super Angulon layouts respectively, but with small rear elements. I have a 60, its ok on 2x3 but not for 6x12. These lenses have to be reshuttered before they can be used on anything but the bodies they fit.
     

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