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philosomatographer
24-Dec-2010, 03:50
Hi,

Much as I loved my original Linhof/Schneider Symmar 150/5.6 Convertible lens, the poor flare resistance due to the primitive coatings have ruined a number of strongly backlit images for me.

To address such situations, I purchased a (mint) Linhof-branded APO Symmar 150mm, beautiful in it's late-model black Compur 0 shutter and correct recessed lens board.

One thing that puzzles me, is that at the f/5.6 setting the (5) aperture blades never really clear the cylindrical aperture of the lens, they protrude by about 2mm+ on each side. The aperture is thus never properly circular, it's a pentagon with curved edges. My my amateur measurement, front entry pupil seems to be about 25mm, which is more like f/6.

I just wanted to find out from other owners of this lens if this is normal? I'm not in the least concerned (photographically-speaking), and doubt whether I will be able to notice an exposure difference on B&W negative film if it is indeed f/6, but as a geek, I do need to know whether this is something I can/should fix sometime or not.

All advice appeciated,
Dawid

Neal Chaves
24-Dec-2010, 18:11
Open the shutter on bulb and you may find that the tips of the shutter blades protrude into the opening as well. This may be the way the factory set them up. Are you sure you are looking at aperture blades and not shutter blades?

philosomatographer
24-Dec-2010, 23:14
Open the shutter on bulb and you may find that the tips of the shutter blades protrude into the opening as well. This may be the way the factory set them up. Are you sure you are looking at aperture blades and not shutter blades?

I would be in some trouble if I were using a large format camera, and didn't know the difference between aperture and shutter blades, don't you think? ;)

I am definitely looking at the aperture blades. The shutter blades clear the opening completely when open, i.e. are not visible at all.

Could anybody who actually also owns this lens check theirs, please?