Mamiya C330 focusing
I'm on Mamiya C330 no.3, it's been a challenge to get a working one. This one is a bargain KEH body and an excellent KEH 80mm lens.
I'm wondering about the focusing. It seems like it comes in from blurry and slowly gets sharper and sharper, and then becomes blurry again, without ever getting perfectly sharp in the ground glass. It gets really close but it's still a touch soft, and then begins to get blurry again.
Is this normal? It seems to be less of a problem in close up shots than in shots a couple of feet away.
Generaly these are not a problem but you could check the following
1) When you fitted the lens, did you cock it first? If not the cocking lever on the lens fouls with the cocking lever on the body which stops the lens sitting squarely on the body.
2) Turn the body upside down and check that the lens panel has not been knocked out of true of the body. Both body and base of the lens panel should be square to each other at all sides, top, bottom and sides.
The image on the ground glass isn't produced by the taking lens but rather
Originally Posted by Sully75
the upper viewing lens. I wouldn't worry about it unless the resulting images
on film are not sharp.
It should be sharp, something is wrong.
Step 1, make sure that you can focus on the boundary of the central focus spot with your finder. Use the flip-up magnifier on the waist level finder. I am assuming that you are using a microprism screen. If the flip-up finder won't let you do it, take the finder off and use a loupe.
2. focus the camera so that both the focus spot boundary and the image are in sharp focus. Use something with clear edges for the test.
It does help to keep stray light out of the finder. If you cannot get the focus aid edge sharp, then you need to adjust your eye correction somehow. Either with the finder or with glasses.
You can do a sanity check with a piece of translucent tape taut across the film guides with the back open. Lock the shutter open on B with a cable release and verify the focus of both lenses.
It is not uncommon to rack lenses back and forth to find the peak of focus, but you should be convinced that there was a point of focus as you go past it.
The screens can be a bit lacking in snap, a good way is to start from infinity, pull in just past the point of focus, then rack back out just past the point, then fine tune on the back in. An old shooter taught me this, if you have a slight mis-focus due to operator error using this technique then the point of focus is slightly closer, which visually speaking seems less abrupt and jarring to the viewer. Also consider the most common Mamiya TLR focussing problem, search the web, over the years I've posted the same info about this camera. The foam surround on the focussing screen frame gets compressed and sticks, causing a very minute error. This leads to a very wrong 'mismatched lens pair' diagnosis, and all the incorrect ways to fix that 'problem'. I've 'repaired' soft lenses that had a non-factory shim placed on the threads of the viewing lens, removed the shim and magic, lens is sharp on a properly foamed body. I've posted how to do the fix many times. As a matter of course I refoam my 2 TLR's if I haven't used them very often, probably once a year.
There is another thing you should try. I had a 180 Super lens that was optically disappointing. As a last resort I swapped the front lens groups. Result :a great improvement.
Have a look at the mirror, easiest by looking through the front with the lenses off.
It can get dusty or covered in age film, giving a poor ground glass image, but can also be damaged easily by clumsy cleaning...
Also check that the mirror hasn't been flipped. People have been known to do this to improve the appearance of a mirror with cleaning marks/foxing but it throws the focus out.
As Sirius Glass says the mirror is front-silvered - or should be!