Mamiya 645 super lens issue
/forum/topic/788998/0

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forrest5000
Registered: Aug 11, 2004
Total Posts: 1741
Country: Ireland

Hi all,
I just got a Mamiya 645 super with the AE prism, 80mm f2.8 and motorwinder grip in exchange for a Canon 70-300DO lens.
So a quick question.... When I switch the lens to M it doesn't stop down when I movbe the aperture ring. I can't find anything in the manual so am I missing something here or is there a problem with this lens?
I ran a roll of Kodac 160NC through it which I'll drop in tomorrow for processing and see if it is properly exposed on the ones I stopped down.
Thanks,
John



mawz
Registered: Sep 11, 2005
Total Posts: 5068
Country: Canada

The lens should stop down manually in M, but not in A. Something's odd there, but it could just be the switch is broken.



forrest5000
Registered: Aug 11, 2004
Total Posts: 1741
Country: Ireland

Thanks Mawz



sirimiri
Registered: Dec 10, 2007
Total Posts: 2561
Country: United States

If you move the aperture ring to the minimum (f/22?) try fiddling with both the A and the M positions. In each position, slide the small metal rod around, you'll find it in the lensmount, facing towards the mirror box. Adjacent to the rear element.

Play with it. It should move the iris open and closed. If so - your lense is fine.

Welcome to Mamiya-land. Great prices on used stuff, and good image quality.



Ronan O Keeffe
Registered: Sep 15, 2006
Total Posts: 730
Country: Ireland

The Mamiya 645 I gave to a friend a couple of years back is up in Dublin at the mo Forrest. If you're nearby there's a chance ye could compare the two and hopefully see what the craic is.

Nice system to get into by the way, and for what sounds like a good price!



forrest5000
Registered: Aug 11, 2004
Total Posts: 1741
Country: Ireland

Iris is definitely not closing and opening with the lens either on or off the camera. I've to drop in to the shop in the morning so will try a different lens on it, they had a 50 and a 28 mm (i think).
I might take you up on the comparison offer Ronan, I had a look at your site you've some great shots there.



sirimiri
Registered: Dec 10, 2007
Total Posts: 2561
Country: United States

Oh wow, a 28MM M645? Don't even breathe on it, they might charge you!

By they way, if you shoot digital (Canon, Nikon, etc.) there are some nice little adapters that allow you do use the M645 glass as manual focus, stop-down-metering on modern 35mm-style SLRs. You'll be chasing more M645 glass in no time, as they can serve double-duty.

Beware JConner99 - I think that's his handle - he's big into the M645 system stuff too! They are still rather inexpensive used and give quite nice quality. I just ordered a used 150mm (A) f/2.8 from KEH for about $270. It has a built-in sliding hood, too.

New/old stock they run from $800 to to $1500.



mawz
Registered: Sep 11, 2005
Total Posts: 5068
Country: Canada

There isn't a 28mm M645 lens, there is one for the 645AF though. The sole M645 lens in the sub-35mm range is the 24mm Fisheye.



sirimiri
Registered: Dec 10, 2007
Total Posts: 2561
Country: United States

D'oh! Thanks, I overshot on system reach



Ronan O Keeffe
Registered: Sep 15, 2006
Total Posts: 730
Country: Ireland

As coincidences happen as soon as I went to the pub the 645 I mentioned was actually on the table.
My friend had popped down home and I checked out the cam/lens combo and operation and it definitely should stop down. My donated one seems to be stuck at ƒ4 even though it's a ƒ2.8 lens.

It'll be back up in Dublin within the next week though Forrest if you fancy a look.
I also have a Mamiya/Canon adaptor but never got around to using it.

R.



RustyBug
Registered: Feb 02, 2009
Total Posts: 6521
Country: United States

I just got a set of tubes in today ... been playing with the 645 150mm 2.8 (A) on my 1D MK II with tubes to get a closer mfd. Definitely an improvement on the mfd.



sirimiri
Registered: Dec 10, 2007
Total Posts: 2561
Country: United States

Are you using Mamiya extender tubes fore of the adapter, or EF tubes aft?



forrest5000
Registered: Aug 11, 2004
Total Posts: 1741
Country: Ireland

Sorry to get you guys all excited about the 28mm, I was thinking in terms of 35mm lenses Just checked the shop's site and there is a 55 and 45mm f2.8 listed so I'll try one of those.

On the use of adapters on Canon EOS, I assume an 80mm Mamiya lens gives 80mm on a FF sensor and the advantage of only taking the center of the image circle in the same way a crop senor does on a Canon full frame lens?



forrest5000
Registered: Aug 11, 2004
Total Posts: 1741
Country: Ireland

Just back from a very wet cycle into town. swapped the 80mm for a 45mm f2.8as the iris was definitely not working on the 80mm.
J



RustyBug
Registered: Feb 02, 2009
Total Posts: 6521
Country: United States

EF tubes after ...

another advantage (I think) is that with the larger image circle ... using a shift adapter, there is less penalty from the shift than with a smaller image circle lens. NOTE: I've only used shift with the Mamiya 35 3.5 N on a 1D MK II ... never used any smaller format lenses for shift.



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