Mamiya 105 D TLR Lens

[Grim Tuesday]

This is not an urban myth, it's an objective fact that can easily be inferred by taking a look at the assembly.

The foam should be in a position that presses the frosted groundglass (actually an acrylic piece) against the four studs that are in the camera body.

Almost ALL C330 cameras i've seen have this foam rotten. I replaced it in my screens, this is something you can do with a little patience. This isn't a "rare" case, it's the most common case!

Hmm, so just to be clear, the issue only occurs if the foam rots and causes the "ground glass" acrylic to stick, right? When the foam rotted in mine, it got dry and flakey, and gravity caused the acrylic to still meet the four studs, and didn't cause a focus error. Perhaps the climate the camera is stored in causes different kinds of foam "rot"

 

[lenshood]

So, the big white elephant in the room is...

Have you repaired the foam that presses the ground glass against its proper seat in the camera?

If not, all lenses will have sharpness problems.

hm, I have not looked at that. I will do presently. But I had good sharpness in images taken at f/11 and f/16.

 

[MattKing]

If there is a problem with the position of the ground glass on a Mamiya TLR it won't reduce the resolution, contrast or edge contrast (acutance) of your photograph.
It will simply give you problems with obtaining focus at the plane where you want it.

 

[lenshood]

If there is a problem with the position of the ground glass on a Mamiya TLR it won't reduce the resolution, contrast or edge contrast (acutance) of your photograph.
It will simply give you problems with obtaining focus at the plane where you want it.

I was thinking of an indirect effect: if the ground glass is positioned incorrectly, I thought it would lead to focusing errors, since the distance from lens to focusing screen would be different from the distance from lens to film plane?

 

[lenshood]

I was thinking of an indirect effect: if the ground glass is positioned incorrectly, I thought it would lead to focusing errors, since the distance from lens to focusing screen would be different from the distance from lens to film plane?

Oh wait, never mind, I see what you said. Wasn’t reading carefully, sorry.

 

[flavio81]

If there is a problem with the position of the ground glass on a Mamiya TLR it won't reduce the resolution, contrast or edge contrast (acutance) of your photograph.
It will simply give you problems with obtaining focus at the plane where you want it.

... which will be interpreted by the owner as "less resolution" since the intended focus point is slightly blurred. Only the added depth of field at f16/22/32 will mask this effects

hm, I have not looked at that. I will do presently. But I had good sharpness in images taken at f/11 and f/16.

See above.