Sinar Macro Sinaron SE 180mm F/5.6 Question

[roscoetuff-Skip Mersereau]

My apologies for a fairly basic puzzle, but I'm trying to figure out how to work my LF lenses and having some difficulty with the Macro. I'd picked up a "BGN" copy from KEH of this "Sinar" (Rodenstock?) lens. Seems in fine condition. Not sure I understand this lens. Put it on my camera last night and finding focus was a bit tough - my way of saying I gave up1. Read somewhere that it has 1:1 and 2:1 and the bellows extension would be 1) in range for the 1:1 but 2) not for 2:1 - given the bellows extension limits on my camera. Doesn't seem to be - as a newby - a switch on the lens for Macro like you might see on a Nikon 35mm format lens. How do I get unlost and get this to function? I thought the Infinity focus distance for a lens tended to be the focal length of the lens. Maybe I need to read more?

I've also read that in some cases, macro-type focus can be achieved by reversing lenses... but that's a whole 'nuther kettle of fish.

Appreciate your insight or pointing me to a good resource. Thanks!

[Bob Salomon]

It is corrected from 1:5 to 5:1. That is from 1/5th lifesize to 5 times lifesize.

You should have no problem focusing it at 1:5. To reach lifesize (1:1) you will need 360mm of bellows extension. To reach 2x lifesize you will need 720mm of bellows, etc.

Before the 120 and 180mm Apo Macro Sironar Rodenstock made the 210 and 300mm Makro Sironar. These were designed for 1:3 to 3:1.
To use it from 1:3 to 1:1 you used it as it came from the factory. For 1:1 to 3:1 you reversed the front and rear lens groups. They printed very clear pictographs on both lens groups illustrating how they were to be used.
The 120 and 180 Apo Macro Sironars do not reverse the groups. You have the Sinar branded Apo Macro Sironar.

[Bernice Loui]

180mm Macro lens on camera, check focus at infinity by pointing camera & lens out into a far distant object then racking the camera & bellows out-in until the image on the ground glass comes into focus. Note the distance between front and rear standards of the camera. This is aprox distant object focus length of this lens on your camera. To focus on a close up object, point the camera & lens at the object to be imaged and rack the camera's front-rear standards out-in until the object comes into focus on the ground glass.

~Know at 1 to 1 or "life-size" the aprox distant between front to rear standards will be 2X the lens focal length or in the case of a 180mm lens, 360mm between front to rear standards. If the camera is not capable of extending to 360mm, 1 to 1 or life-size image on the ground glass cannot happen. What makes "Macro" lenses different, they are optically optimized for non "infinity" objects or images.

~Other important item, exposure MUST be compensated for the increased distance between lens to film. If this is not done, the film will be under exposed due to the lens "f" stops being calibrated to objects focused at or near infinity. Once that calibration moves away from objects focused at or near infinity, distant the light is forced to travel from lens to film has increased or effectively spread out reducing the actual amount of light reaching the film.

*Add two "f" stops for a lens focused at 1 to 1 or life size.* Less with lower magnifications or object to film image size ratio.



Bernice