CONTAX CLUB Carl Zeiss 討論區

[davidlam]

http://www.dchome.net/viewthread.php?tid=285856&extra=page%3D3

Anyone would like to try?

[章魚]

有人肯幫我改，收費合理，我立即出部 ist* DL
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~ 八 足 怪 ~

[FR]

wouldn't it be far more reasonable to convert the lens to PK mount by simply swapping the mount flange ( bayonet bladed side ) instead of the body. After all, C/Y is no more, and converted C/Y lens can then be used on old, current and future Pentax PK mount bodies, film or digital ...
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[lofan]

[ryhl]

Wanna share my little experience over converting the C/Y lens / Pentax body mount. My initial attempt to adapt the C/Y lenses to the Pentax body was, as FR said, by converting the lens mount. By increasing 0.4-0.5 mm of the distance between the blade and the bottom of lens body, C/Y lens can be put on Pentax body. But the drawback is that this method is only suitable for lenses of shorter focal length as the blade for the lenses of longer focal length (e.g. 135/2) is molded in one single piece with the rear part of the lens, which renders the above method not applicable. Also, even for the lenses which can be converted by the above method, the metal pins protruding from the rear of them may obstruct the normal functioning of the camera due to the direction of rotation (anti-clockwise) of the lenses into the camera.

Because of the above, I then attempted for converting the body mount instead. Thanks to the design of the K mount, by removing relative little portions of the rear part of the mount, all of my C/Y lenses can be fitted to the Pentax body in clockwise direction, thereby avoiding the abovementioned problem. At the same time, K mount AF lenses can still be used in full function. The camera is therefore in fact more versatile than before the conversion. Also, the aggregate amount of work for converting the body mount is smaller than converting the lenses (to speak the truth I dare not to damage the C/Y lenses). In order to save future effort, I have planned to fit the modified mount to my future Pentax DSLRs

[jason.lau]

[ryhl]

[fuwen]

[ryhl]

[章魚]

ryhl .. 幫我整部，得唔得，當然我唔係話免費。
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~ 八 足 怪 ~

[fuwen]

Why is it that when convert lenses need 0.4-0.5mm clearance whereas converting body no need?
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CONTAX RTS III, Aria - Rolleiflex 3003, SL2000F - Rollei 35RF / Voigtlander R4M - Rolleiflex SL66 / SL66E
Carl Zeiss C/Y T* - QBM HFT - M HFT, ZM T*
www.fuwen.net

[ryhl]

The 0.4-0.5mm space is to allow for the C/Y lens mount to screw in the K body mount (the space between the blade/rear of lens is larger for Pentax lenses than C/Y). By removing the obstructing parts (around 0.5mm thick) in the body mount and the protruding 限位片(for M42 adaptor's use) in the thin metal for gripping the lens tight to the mount, this also serve the purpose and the screw in direction can be in reverse (thereby preventing obstruction of the functioning of the camera). Really quite difficult to explain in plain text. You would see it when you see the illustrative photos.

[Choyin]

[Choyin]

ryhl, I have found out that you used K100D in the other forum.

[ryhl]

Hi Choyin, mine is K100D (C/Y lenses with SR, so cool ). I have D25, D35/1.4, P50/1.4, P85, P135 and S180. All of them can be put on the camera. The lenses cannot be locked in the normal way as on the C/Y bodies, but they are in fact tightly fitted to the body once screwed in, especially for those lenses with the mount blades molded into one with the rear part of the lens (e.g. P135, S180 and P100 or MP100 as well). They are very secured with minimal chance of falling out from the body.

I have indeed found a solution to address the lock problem - simply drill a small hole at the rear part of the lens at the same position of the lock of Pentax and this will serve the purpose. However, by doing so means that the lenses must be damaged. Balancing the risk and the damage to the lenses, I dare not to do in this way. But sure this is a convenient solution to the issue