Mamiya C TLR Interchanging Lenses

Carlini Fotograf · Jun 4, 2021

Ive googled searched for this topic before and only found some very old threads on the subject.
Have any of you Mamiya C users ever swapped rear or front elements from viewing and taking lenses?
From my understanding all the Mamiya lenses are identical, except the later 80mm S. I know this kinda
puts Mamiya in a class by itself, as most TLR's use different viewing and taking lenses that cant be
swapped.

I have a 105mm Seikosha-S that has a scratch and lite haze on the rear element of the taking lens. So I
swapped it with the rear view element. The two elements look identical. I also have the 65mm Black (Blue dot),
that has those stupid metal filter guard rings, and the ring on the front taking lens is on so tight, it will not come off.
The view lens ring comes off. I want to use filters. So again both front elements look identical, so I should be able
to swap them with no issue. I found an old thread from another forum where someone said they swapped theirs
with no problems. I haven't shot with either lens yet, so I guess I will find out after I test them out.

So just thought I would ask if anyone here has done this or heard more about it.

cramej · Jun 4, 2021

I haven't done it. Even if they are identical in every way, keep in mind that viewing and taking lenses may have a different set of shims at the mounting flange. These, in combination with a different rear lens group may not produce ideal results. Simply swapping shims wouldn't solve the problem, either. You would need to collimate the lens groups to eliminate the variables. Doesn't hurt to try. I would mark the barrels so I could remember which was which originally.

Tel · Jun 4, 2021

I have exchanged these lenses and it worked. However, I always re-collimate both the viewing and taking lenses to make sure that the focus is correct and that they're in sync with each other.

Jojje · Jun 4, 2021

I've done it on 180mm and 250mm lenses with no ill effects.

Carlini Fotograf · Jun 4, 2021

Jojje said:
I've done it on 180mm and 250mm lenses with no ill effects.

Cool, I heard it works on all lenses except the latest black 80mm S. Did you re-collimate the lenses too or no?

Carlini Fotograf · Jun 4, 2021

cramej said:
I haven't done it. Even if they are identical in every way, keep in mind that viewing and taking lenses may have a different set of shims at the mounting flange. These, in combination with a different rear lens group may not produce ideal results. Simply swapping shims wouldn't solve the problem, either. You would need to collimate the lens groups to eliminate the variables. Doesn't hurt to try. I would mark the barrels so I could remember which was which originally.

Good to know, on the 65mm, the front element are in 2 sections and I only switched the very front elements
that look identical with the exception of the metal filter guard on the one which is the reason I'm swapping them..
I want to use filters and the metal filter guard is on so tight it wont come off.

The 105mm, I switched the rear elements which are 2 elements in one housing, and again the view and taking rears look identical. I didn't see any shims...

I will shoot a test roll with both lenses and if they are out of focus, I will then attempt to re collimate them...Doesn't hurt to try...

Jojje · Jun 6, 2021

Carlini Fotograf said:
Cool, I heard it works on all lenses except the latest black 80mm S. Did you re-collimate the lenses too or no?

Did not. If my eyes cannot tell the difference, that's enough for me.

Grim Tuesday · Jun 6, 2021

Each individual sample may vary, but I was curious about this so I swapped front elements on my 65mm and stuck the camera in my autocollimator. There was no change in resolution, sharpness or focus position.

Nokton48 · Jun 6, 2021

Hmmm. I miss my Mamiyaflex.

Mamiya_Repair · Jun 7, 2021

As noted, you can swap out the elements in most of the Mamiya TLR lenses with the exception of the 80mm f/2.8 S lens and the 80mm f/3.7. But it is important to check focus on the lens pairs to insure that they are tracking focus together. All of the C lenses have washer/shims installed. There are between three and four different thickness of shims depending on the lens. You will not see these shims just by taking off elements, they are between the shutter and the lens board and the viewing lens mount and the front of the lens board.

Added: There are six different versions of the 105mm lens so not a good idea to swap elements between examples unless they are of the same version.

Carlini Fotograf · Jun 11, 2021

Mamiya_Repair said:
As noted, you can swap out the elements in most of the Mamiya TLR lenses with the exception of the 80mm f/2.8 S lens and the 80mm f/3.7. But it is important to check focus on the lens pairs to insure that they are tracking focus together. All of the C lenses have washer/shims installed. There are between three and four different thickness of shims depending on the lens. You will not see these shims just by taking off elements, they are between the shutter and the lens board and the viewing lens mount and the front of the lens board.

Added: There are six different versions of the 105mm lens so not a good idea to swap elements between examples unless they are of the same version.

On the 105mm , My rear taking lens had scratches and Haze. So I just swapped it with the rear view lens which appears to be the exact same. So they are coming
from the same example.

On my 65mm I just swapped the front view and taking elements. As grim tuesday said he did the same on his and seen no difference. The reason
being is I want to use filters and the filter guard ring on the front taking lens is so tight, that it will not come off. The view lens filter guard came right
off. So I just swapped them so that I could use filters.

I also have two 80mm Chrome Seikosha-S 2.8. One shutter fires on all speeds, but has very bad hazy lenses, the other fires on all speeds except
1 sec, 1/2 sec, and 4th of a sec and has perfect lenses.

Could I take the front & rear View and Taking lenses out of the bad shutter and put them in the lens board with the good shutter with no issue?

When you said 80mm S cant be swapped, I'm assuming you mean the latest Black 80mm 2.8 S and not the earlier Chrome Seikosha-S 2.8.

Thanks!

Mamiya_Repair · Jun 12, 2021

Yes, you can take the front and rear lenses from the chrome 80mm and swap them with another chrome 80mm. But as mentioned, these lenses have a series of shims for adjustment underneath the shutter and the viewing lens mount. Important to check that focus on the viewing screen and the film plane is the same. While ideally the taking and viewing lenses should be shimmed independent of the body, this is not practical without the proper tools so using a know good body will work close enough. For reference, here is how I do this particular task:

Carlini Fotograf · Jun 15, 2021

Mamiya_Repair said:
Yes, you can take the front and rear lenses from the chrome 80mm and swap them with another chrome 80mm. But as mentioned, these lenses have a series of shims for adjustment underneath the shutter and the viewing lens mount. Important to check that focus on the viewing screen and the film plane is the same. While ideally the taking and viewing lenses should be shimmed independent of the body, this is not practical without the proper tools so using a know good body will work close enough. For reference, here is how I do this particular task:

Thanks for the info. So would the shims vary from Chrome 80mm to Chrome 80mm? You would think they would have a
set standard for each focal length lens board. So transferring both front and rear elements from one Chrome 80 lens board
to another same 80mm Chrome lens board would require collimating?

Also I sent you 2 emails asking for a quote on repairing my 80mm Chrome shutter that has No working 1 sec,1/2 sec, 4th of sec
speeds. Not sure if you got them or not?

Thanks

Mamiya_Repair · Jun 16, 2021

The shims are a standard size (four sizes) but you use one or more to adjust each lens to compensate for individual variations on the lenses.
I have responded directly to your email regarding the Seiko repairs.

Mamiya C TLR Interchanging Lenses

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