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The coveted Blue Dot

Kirks518

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As many of you know, I suffer severe GAS. I also seem to have the Mamiya strain of the illness, and as such, I'm always looking for something.

I have a C220 and a C330. I have the 55mm, 80mm, and the 180mm. None of them have a blue dot, and the 180mm isn't even the Super, just the plain old 180mm.

What is the deal with the Blue Dot? Why is it more sought after then the other lenses? I've read better shutters, or better coatings, but I don't seem to have any troubles with the boring plain no-dot lenses.

As a 'test' for flare, I took the shot below, expecting some flare, since I have the lesser variants of the lenses (this was the 55mm). But alas, I see no flare. So what does one gain with the Blue Dot lenses?

 

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Ken Nadvornick

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Mainly youth. Meaning a better chance for parts availability and a successful repair for the more recent shutters and lenses.

Ken
 

Xmas

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Reduction in GAS pressure...
 

AgX

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What is that Blue Dot about? A mark on the lenses?


(The blue dot that came to my mind at once when reading the title was the blue dot on flashbulbs, indicating they are still sealed at negative pressure.)
 

MattKing

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What is that Blue Dot about? A mark on the lenses?


(The blue dot that came to my mind at once when reading the title was the blue dot on flashbulbs, indicating they are still sealed at negative pressure.)

The latest version of the lenses/shutters for the Mamiya C series TLRs is distinguishable by a blue label on the end of the cocking lever for the shutter. Those blue "dots" are round and have a diameter of about 2 - 3 millimetres.
 

mgb74

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Mainly youth. Meaning a better chance for parts availability and a successful repair for the more recent shutters and lenses.

Ken

I can see the benefit of a shutter that - on average - should have seen less use. But aren't they the same Seiko shutters as the non blue dot (but still "black") lenses?
 

Old-N-Feeble

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How else can one relieve himself of GAS but with such a lovely result?
 

grahamp

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Mamiya USA claimed a lack of parts for the early Black Seiko shutters a while back, and the later ones with the blue enamel infill were still supported. Though that was a few years back, and I am not convinced Mamiya or their agents even remember their early cameras By and large, a working shutter has no impact on the optical performance of the lens.

However, since the TLR lenses can be switched around easily, there is no guarantee that what you are looking at is the original combination. Test each one and judge its value accordingly.
 

Ken Nadvornick

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I can see the benefit of a shutter that - on average - should have seen less use. But aren't they the same Seiko shutters as the non blue dot (but still "black") lenses?

My understanding from past reading is no, at least not for the purposes of repairs. But I will defer completely to Graham's above post on this subject, as he is the acknowledged expert on the Mamiya TLR system cameras.



Ken
 

grahamp

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I think(*) Mamiya had five different shutters on their C series. Early Seikosha 1/400, Seikosha-S (1/500), Copal (80mm f3.7), Seiko (black, no dot), Seiko (black, blue dot) in rough chronological order. They are all out of production.

* There are tales of another Copal shuttered lens, but I have yet to see pictures. Some early Seikosha-S shutters had a different shutter arm throw that makes them a sort of sub-type. I think five is enough for this discussion!

Graham