Unfortunately this seems to be a common problem with the 80mm lens. I am now on my second example. I gave up on the first lens after it had been sent for repair three times. It would be ok for a few months and then the problem would return. I now have the same problem with it's replacement (bought secondhand). I have not had any trouble with the 150mm C or 35mm N lenses that I also use. I do not know what to do next. Any comment from Mamiya would be appreciated.

By Brian McNeilly on Friday, October 03, 2003 - 10:37 am:

I have just sent a 55mm lens off for repair with this very same issue (for 1000s)...and I can confirm that oil on the iris blades is a prime suspect. It is possible to remove the front lens element on the 55mm and oil was visible on the blades. Have been quoted ~ £50 for repair through Ffordes in Beauly Inverness-shire.

By Alan on Monday, September 01, 2003 - 10:32 am:

Ed,

It sounds as though a slight trace of oil has found its way onto the iris blades and this causes the sluggish action, leading to overexposure. I suggest you get the lens looked at by a camera technician.

By Ed on Sunday, August 31, 2003 - 10:15 pm:

I've got a 645 1000s w/ standard 80mm, the apeture is sticking as i try to stop it down either when the lens is set to M or when using the depth of field preview. I opens out again fine but needs coaxing to the smaller apetures. Seems to work as the shutter fires, but i don't know how much longer for... Any one come across anyhting similar?

Ed