Schnieder Componon S 50mm enlarging lens aperture issue

[ymc226]

I just discovered that when I stop down from wide open to around 5.6 or 8, I see the aperture close down, but if I stop further, no further closure of the aperture occurs. Is this an easy fix or should I toss it? The lens is cosmetically mint.

 

[ic-racer]

Whoa don't toss perfect glass. I'm sure there are plenty of Componon-S lenses with fungus and "cleaning marks" out there.

 

[fschifano]

Shouldn't be too hard. It's not like there's a shutter in there. See if you can open it up and fix whatever is preventing the blade4s from closing down. If you really don't want to do that and are seriously considering chucking the lens, send me a PM. If you are in the US , I'll gladly pay the postage for you to send it to me. I'll have a whack at it. This is a great lens.

 

[Worker 11811]

Does your lens have a stop-down lever?

Some lenses have a lever where after you set up your aperture you can open it up all the way for focusing and composing then, when you are ready to shoot, you flip the lever and stop down to your original setting.

If the stop-down lever is partially engaged or if it is somehow jammed or broken, this might happen.

 

[ymc226]

Does your lens have a stop-down lever?

Some lenses have a lever where after you set up your aperture you can open it up all the way for focusing and composing then, when you are ready to shoot, you flip the lever and stop down to your original setting.

If the stop-down lever is partially engaged or if it is somehow jammed or broken, this might happen.

Thanks Randy,

I checked and it actually has this feature. The lens is actually fully functional.

 

[artonpaper]

Componons are sharpest at 5.6 and 8. The data sheet that came with my 50 mm, 2.8, said between 5.6 and 8 was optimum. At smaller apertures they begin to be less sharp. at wider apertures they can get soft out at the corners. So your lens should function perfectly well. If your exposures become to short you can use a lower wattage bulb, or put some filtration in the filter drawer. I've used frosted mylar, which has a nice soft effect. But a neutral density filter would be best - 0.6 ND being two stops less light.