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vilva
Joined: 04 Mar 2007
Posts: 785
Location: Porvoo/Borgå, Finland
Expire: 2015-05-27
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 Posted: Mon Dec 10, 2007 3:41 pm Post subject: |
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vilva wrote:
The Dagor arrived to-day, somewhat later than usually, but this was due to the Finnish Independence Day, which is a bank holiday.
The lens was easier than normal to mount because of the kind soul who had fixed it to a Leica Screw Mount tube - I just added a M39-to-M42 adapter ring 
It is a dark December evening outside so I could only do some preliminary tests. Here are two crops, the Dagor fully open, mounted on the 350D, no sharpening, no contrast adjustment:
and one crop at about f/11:
and two down-sampled frames at the full aperture to give an initial idea of the bokeh behaviour:
Well, this is an about ninety years old WA LF lens, the first symmetrical anastigmat, designed in 1892, here used as a tele lens on a crop dSLR. As an LF lens it doesn't perform very well fully open, the resolution drops to zero at the edges of the usable image circle - usable at f/22-f/64, where it is diffraction limited. However, mounted on a dSLR, only the center matters, and according to some tests I've seen, the center resolution is pretty good, something like 85 lines/mm in the center and about 65 lines/mm at the edges of a FF, certainly sharp enough. At f/22 it is diffraction limited to 70 lines/mm for the whole frame, still sharp enough. All these figures are for a correctly centered lens.
Now, looking at my test shots, I'd say that my specimen seems to be correctly adjusted. The lens is uncoated, which will somewhat affect also the resolution, especially when shooting fully open, but anyway both the resolution and the contrast seem to be OK, even fully open. The ruler was tilted in order to give some leeway in focusing, which explains the slightly OOF portions of the fully open crop. NB. the print on the ruler isn't black but dark blue.
Much cannot be said about the bokeh, but indications are that it is reasonably or even very good.
Veijo |
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Orio
Joined: 24 Feb 2007
Posts: 29545
Location: West Emilia
Expire: 2012-12-04
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| Posted: Mon Dec 10, 2007 4:06 pm Post subject: |
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Orio wrote:
| Quote: |
| the center resolution is pretty good, something like 85 lines/mm in the center and about 65 lines/mm at the edges of a FF |
Well, these are monster figures!!!
-
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Orio, Administrator
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Ballu
Joined: 28 Feb 2007
Posts: 912
Location: Columbus, OH. USofA
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| Posted: Mon Dec 10, 2007 5:46 pm Post subject: |
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Ballu wrote:
| Orio wrote: |
| Quote: |
| the center resolution is pretty good, something like 85 lines/mm in the center and about 65 lines/mm at the edges of a FF |
Well, these are monster figures!!!
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And Orio.. did you forgot to check the bokeh... although its not a real test... but to me, its very creamy/smooth... I love these old LF lenses of pre-20's...
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-Ballu
http://balyanpage.blogspot.com/ |
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Richard_D
Joined: 21 Oct 2007
Posts: 2378
Location: Faversham Kent UK
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| Posted: Mon Dec 10, 2007 6:00 pm Post subject: |
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Richard_D wrote:
Very impressive results!
_________________
Richard
The interesting bit:
Nikkors: 20mm f2.8 AIS, 24mm f2.8 AIS, 28mm f2.8 AIS, 35mm f2 AIS, 50mm f1.4 AI, 50mm f1.48AI, 50m f2 AI,
55mm f3.5 AI'd, 105mm f4 AI, 135mm f2.8 AI'd, 135mm f3.5 AI'd, 200mm f4 AI'd .
Nikon E Series: 100mm f2.8 .
Soviet Nikon Mount: Zenitar 16mm f2.8, Arsat/arax/photex 85mm T&S f2.8 .
Other: Asahi Super Takumar 55 mm f2 (M42) ,Tamron 300mm f5.6 SP, Tamron 500mm f8 SP.
DSLR: Nikon D700. 35mm SLRsNikon FE, Pentax S1a.
TLR: Rolliecord II.
Sub-Minature: Pentax Auto 110, 18mm f2.8, 24mm f2.8, 50mm f2.8.
More to come... |
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Laurence
Joined: 26 Mar 2007
Posts: 4809
Location: Western Washington State
Expire: 2016-06-19
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| Posted: Mon Dec 10, 2007 6:17 pm Post subject: |
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Laurence wrote:
Though I'm only seeing the two "bokeh" shots....it looks phenomenal!
Resolution and sharpness, as well as "positioning" of the lens, looks very very promising.
What a great find!
_________________
Assent, and you are sane;
Demur,—you ’re straightway dangerous,
And handled with a chain.
Emily Dickinson
Cameras and Lenses in Use:
Yashica Mat 124 w/ Yashinon 80/3.5,
CV Apo-Lanthar 90/3.5SL, (Thank you Klaus),
Pentax 645,
Flek 50,
Pentax-A 150
Pentax-A 120 Macro
Voigtlander Vitomatic I w/Color Skopar 50/2.8
Konica TC and zoom lenses (thanks Carsten)
Contax AX
Yashica ML 50/2
Yashica ML 35/2.8
Carl Zeiss Contax 50/1.4
Tamron Adaptall SP 17/3.5
Tamron Adaptall 28/2.5
Tamron Adaptall SP 300/2.8 LD (IF)
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