28mm f/2.5 Question; Battery/Meter Stuffgreenspun.com : LUSENET : Konica 35mm SLRs : One Thread
I recently purchased an Autoreflex T outfit including a 28mm f/3.5 lens (serial number 7175561). The lens is in near-mint cosmetic condition (barrel and glass) and it gives no indication of any operational problems. However, it will not focus at infinity. In fact, it will not focus beyond roughly 3 feet...at which point the lens is indicating a distance of 10 feet or so. Let me be clear about this: the focusing ring turns all the way to the infinity symbol, but the lens itself is not focusing at infinity. The helicoid seems to be turning, and there's no physical sensation that would suggest damage. Has anyone else encountered a similar problem with this lens?
Also (following up on an earlier post regarding battery types and voltages), I found the camera's meter to me "overoptimistic" (to say the least) when alkalines were installed. I've now installed the 1.4v zinc-air cells, and the problem seems slightly improved, but by no means cured. Shooting outdoors today with 200 ASA film, I was literally unable to shoot below 1/500. Since the zinc-air cells are close enough in voltage and discharge characteristics to give a fair test, should I now assume that I may be looking at a meter recalibration?
Thanks for your help!
-- Anonymous, March 11, 2001
Seems to me that your lens is going to need adjustment, as both of the 28mm's that I have work fine to infinity. Could be that someone has opened the lens before and tried to adjust it, and disturbed the calibration. As for the light meter, it might need a calibration, maybe send the body in for a good CLA.
-- Anonymous, March 11, 2001
I agree that someone may have been "messing" with that lens and have reassembled incorrectly or set the infinity limit incorrectly. Also could be a loose element inside. Alternatively it could be that the helicoid is binding and/or the focusing ring has slipped. Is that the Vivitar 28/2.5? Oh, in your text it looks like it's a Hexanon 28/3.5. Either way, it's pretty standard construction, just about any repair shop should be able to look at it for you and give you some idea what's wrong.
As to the meter, you didn't mention the f/stop you were using, but if you had full sun conditions, 200 ASA at f8, 1/500 might be reasonable ("Sunny 16 Rule: 200ASA = 1/250th at f/16). A handheld meter for comparison would be the best way to confirm the camera meter accuracy. I'd wait have the film developed, see if it looks under-exposed before assuming anything. May be that the indicated F/stop in the viewfinder is incorrect and the camera is actually exposing correctly.
I'm using the zinc air 1.4V batteries in T3, TCs, T4s and getting meter readings that are right on the money, shooting slide film which has very little latitude (yes, some messed up exposures, but I blame that on operator error!). I would have the batteries tested to see that they are, in fact giving full output. Zinc airs take an hour or so to come up to full power once the little seal is removed allowing air into the battery. They also "crash" in a hurry when at the end of their lives! Not as long-lived as the old mercury cells, but darned cheap!
If the pictures come back poorly exposed, you may have a sticky meter or the aperture setting linkage in the camera or in the lens may be stiff/sticky. A good CLA might solve it all!
Keep that Konica shooting!
Alan Myers San Jose, Calif.
-- Anonymous, March 12, 2001