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View Full Version : pentax lens incompatabillity


BobRob
8th July 2010, 03:01 PM
Just been given a Pentax S1A camera body...everthing works ok but
the apperture actuating pin seems to foul on the camera plate.

I can use the camera, but have to cock the shutter a second time an then fire it to release the lens.

tried using the lens in ''stop down'' mode but with no improvemet
have to say this ''sticking ''does not happen every frame but more ofthen than not it does.

the lenses work just fine on my spotmatic body

any advice / help will be most welcome

thank you.

Bob robertson.

Sandeha Lynch
8th July 2010, 04:59 PM
If the back catch is attached to the back door, rather than to the body, then it may be the early type of S1A, made up until 1964. In some cases only the pre-1964 lenses may work comfortably.

http://www.aohc.it/tak00e.htm

BobRob
8th July 2010, 05:22 PM
the catch is attached to the camera back as you say
so maybe I am stuck with the problem...can the operating plate be
modified ???

bobrob.

Sandeha Lynch
8th July 2010, 06:02 PM
Probably not in any good way. The article suggests that the entire mirror box was redesigned. It might not be too difficult to find compatible lenses.

BobRob
8th July 2010, 06:38 PM
was expecting this little ''bonus'' to give me a 2nd body.

do not really feel the need to carry two sets of lenses.

the problem seems to be related to contact between the pin on the lens and the camera plate that moves it.

comparing the S1a with the spotmatic the S1 A's plate is the same shape but rather smaller from top edge to btm. I think when it moves forward to actuate the apperture pin goes over the top edge of the plate thus sticking, you can see a shiny mark on the edge where this MAY be happening.

re-winding the lever releases the plate and thus the apperture is also
opened again.the shutter curtains cover the film, so no fogging of the film would seem to be likely..

other views on my conclusions would lbe most welcome.

bobrob

Steve Smith
9th July 2010, 06:17 PM
I have an S1A body which could be used for spares. I'm not sure about the compatibility though as mine has the catch attached to the side of the body. This one initially appears to work o.k. and is in good condition but the shutter only fires at one speed regardless of setting.

If it is of any use to you, you can have it for the postage cost.


Steve.

BobRob
9th July 2010, 06:37 PM
Hi Steve.

Thank you for your generous offer however I do not have the skills to
take advantage of your camera body and I believe it would not be right to take it if I cannot use it properly.

Best regards and many thanks once again.

Bob.