mamiya sekor c 80 mm 1.9 out of focus??

is this a bad lens or am i expecting to much of my handheld shooting at 1.9. i can see the lens has som fungus.

i mean ..the focus is there on the shirt/neck but not in the face. thanks

 

 

...and on the stairs

Im uding a mamiya 645 super btw

I don't know this lens; I have the f/2.8; but I don't think Mamiya made any bad lenses.

How long have you had the camera; and what is your experience with other lenses on it?

It is quite a big camera to hand-hold, but this doesn't look like camera-shake blur.

 

What focusing screen have you got in the camera? If you're using the one with the microprism and split-prism focus aids, you shouldn't have any problem getting good focus with a subject that stays still. Also, what VF do you have? With a waist-level, I can only focus precisely using the magnifier. If the camera's new to you, it's worth checking if it has a vision-correction lens in place from the last owner. And of course, you need to use any glasses or contacts that you wear, to focus accurately.

 

Check if your mirror rest is ok. There is a plastic piece that sometimes breaks* (at bottom of the lens-mount, on the right if you're looking at the front of the camera; should be a tiny plastic cube, more or less). Breaking that leaves the mirror sitting at the wrong angle, which would mean the focus you see isn't what you get on the film; but I think the effect is usually much more pronounced than what you have here. Hope it's not this, because it's hard to get it fixed these days.

 

 

 

*Rodeo Joe, you're up! ;)

Thx dustn. No the mirror rest is ok. Looking through the lens shows a hole lot of fungus in the rear element especially. I have a 2.8 ill try to day to see if its ok.

...the camera i mean

Looks like a little camera shake in the first shot, but not the second.

 

You say you're using a Mamiya 645 Super. Oh dear!

 

I strongly suspect that you've got the common fault of those placky Mamiyas; a broken mirror-rest.

This crappy piece of plastic is prone to cracking, and then the mirror doesn't sit in the correct position for accurate focussing. I'd suggest you double check its condition.

 

If it is cracked, then condolences. Your camera is pretty much dead and unfixable, since spares haven't been available for quite a few years.

 

Suggest you get a near-indestructible metal M645 as a replacement instead.

I have 5 of them and they're still going strong. OTOH, my plastic Supers and a ProTL are all dead from one internal ailment or another.

I assume this is a second-hand lens? It may be worth looking for tool-marks on the fasteners of the lens, to see if maybe someone has opened it up, to try to clean the inside surfaces.

 

If you have a piece of ground glass, you could mount it in the frame area at the front of the film back, and check the focus without exposing any film. Set the camera up on a tripod, and leave the door of the film back open. Arrange something like a ruler (or just a plank of wood with lines marked on it), receding from the camera. Focus carefully, then open the shutter on 'B' and look at the ground glass, ideally with a magnifier. Check that the same marks appear in focus on the focusing screen before opening the shutter and on the ground glass after. I haven't done this with my Pro, but I think it should work.

 

If you don't have ground glass, you could make a substitute by sanding a piece of clear plastic, as long as it's quite flat and rigid. Use the finest sandpaper you have.

 

Even if you find the focus is ok, I don't think the extra stop of aperture over the f/2.8 lens is worth having 'a lot' of fungus.

I think you're on the wrong track with the lens Dustin. It's obviously capable of sharp and reasonably contrasty images from the examples shown. And an SLR should show the same focus on the viewing screen as on the film, ruling out a registration error in the lens (unless scale focus is used of course).

 

No. This is almost certainly a camera body fault. If not the mirror rest, then maybe a slackly fitting magazine back, or a badly seated focussing screen.

 

The actual focus is falling behind the intended subject, and this indicates that the focus screen is too far away, or the light path from lens to screen is longer than it should be.

 

A cracked mirror rest would certainly give this result, and isn't that easy to see. You have to put slight pressure on the rest to test for any 'give'. It shouldn't move without its retaining spring also moving. If you can detect any flexing of the plastic lever, then it's broken and needs replacement. That's a major issue I'm afraid.

 

OTOH, a loose film back would put the film-plane further away from the lens than the focussing screen, and would result in front-focussing, not the back-focussing that we see in the above examples.

 

FWIW, my 80mm f/1.9 gives as accurate focus as my f/2.8 version. Although with my preferred plain ground screen it's a little more demanding to get exact focus, due to the very shallow DOF.

 

PS. It's possible that a previous owner replaced the mirror-rest, but didn't adjust it afterwards. The plastic part wasn't supplied with its adjuster screw by Mamiya, and the screw has to be swapped from old part to new. After which the mirror position needs to be setup by carefully turning the adjuster screw until accurate and even focus is achieved.

Edited September 16, 2018 by rodeo_joe|1