As the title indicates, is this a good long lens for 5x7? Barrel model. It stops down to f260! Does anyone have experience with exposures at f260?
As the title indicates, is this a good long lens for 5x7? Barrel model. It stops down to f260! Does anyone have experience with exposures at f260?
Yes, 5x7 has a diagonal of 210mm. 4/4 dialytes like the Artar, Ronar, Apo-Nikkor, etc cover as a rule of thumb, 45 degrees at infinity, so they have an image circle about equal to their focal length, in your case about 360 mm for a surplus of about 150 mm.
No experience at f260.
Cheers, Steve
Thanks Steve, thi information is appreciated. The f260 was news to me too.Originally Posted by Steve Hamley
Moved to the Lenses subforum.
Rick "carry on' Denney
The 360mm F9 Apo Ronar at 1:1 covered 14 x 18" film. It was optimized for f22 as it is shorter then 600mm. From 600mm up the Apo Ronar was designed for F32. So beyond F22 you will be entering diffraction and by F260 you should be in severe diffraction.
The 360 F9 Apo Ronar in shutter covered 318mm at infinity at F22 and was also designed to be used at f22. 318mm on 5x7 allowed for 74mm of rise and 62mm of shift in landscape format at infinity at F22. When in a shutter it will not get to near F260.
Thank you Bob,
If 8x10 needs 310 then 318 is tight if it were to cover at all and with no movements possible. So indeed 5x7 @ f22 gives the optimum flexibility. I had 5x7 in mind when I bought it. The lens is on the way, it's nearly new in barrel. I put in a Lower bid before I went to bed and in the morning I had won it for $78.00. I can't complain!
Enjoy it!
On 810 it gave 4mm of rise and 3mm of shift in landscape position at infinity @F22.
Thank you very much Bob I will!
Hello from France
To the best of my knowledge, the f/260 setting on process lenses like the Apo Ronar series was not used for taking pictures, but only for certain very specific tasks in analogue photogravure, a forgotten technique in an era where direct Computer-to-Plate is today the standard printing process.
But Bob S. can certainly elaborate about this much better than me.
And regarding f/260, for sure the lens will be diffraction-limited and the minimum recordable feature has a size of about 260 microns.
However the look of the image will certainly be different using a F/260-stopped-down apo ronar VS. a f/260 pinhole camera.
Projected at 360 mm behind the pinhole, a f/260 pinhole camera will need a pinhole diameter of 360/260 = 1.4 mm
This diameter is much larger than the optimum pinhole diameter @360mm projection distance, which for visible light is about 0.7 mm ( = (1/28) . sqrt( distance in mm) according to Leslie Stroebel's book on view camera technique)
Hence a 360 mm apo ronar lens stopped down to f/260 will yield a much better image than a f/260 pinhole camera image projected @360mm
And if you take into account that a good pinhole bought from a reliable vendor is not that cheap, you'd better use an apo ronar in all cases
The 318mm are more the extrem conservative, I even use my 300mm APO Ronar on 8x10 stoped down to f32 at infinity no dark corners!
The 360mm give very nice movements on 8x10 more the a inch shift at f32 is not any problem!
This is from a user which also has the brochure from Rodenstock in german of course;--))) Also Schneider's statement about the covering power is always very conservative.
Cheers Armin
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