Is there anyone on here who knows all about this issue?

I have a Pentax K100D body and since purchasing it, have used my old K-mount lenses on it. However, after switching it off, the damned thing has always chewed thru batteries, ie within a few days they are flat.

Today I noticed that the body has a series of seven contacts but that the Pentax lens (off my old ME Super) has no contacts and is thus shorting all of the contacts together. My question is would this explain the flat battery issue? I am aware that using this older lens limits the functionality of the camera but can live with that, but can't live with dead batteries.

The question is, which lenses should the camera have on it?

tegretol - 2021-10-06 15:26:00

Not sure about the battery shorting issue, if the battery has no contacts at all how does it power up the camera at all?
From memory the Pentax K100 series is about 10 years old now and my guess is the battery might just be nearing end of life status. I did have a Canon battery which gave up the ghost after some years.
Do you have another battery?
Also I think the lens were KA or K with adapter?

From DP Review:
• Pentax KAF2, KAF, KA mount lenses
* Power zoom not available
* K mount lenses available with (function limited)
* S mount lenses available with adapter (function limited)
* 67/645 lenses available with adapter (function limited)

cjohnw - 2021-10-06 15:58:00

Batteries are brand new rechargeables. I'm assuming that the battery connections are (as well as powering the body) on two of the lens contacts - or are they? If they are then fitting a lens with no contacts could theoretically be shorting those battery contacts and thus flattening them.

tegretol - 2021-10-06 16:28:00

tegretol wrote:

Batteries are brand new rechargeables. I'm assuming that the battery connections are (as well as powering the body) on two of the lens contacts - or are they? If they are then fitting a lens with no contacts could theoretically be shorting those battery contacts and thus flattening them.

Hmmm, strange. I just cant see how a lens would have no contacts with the camera. How does it communicate with the camera?
Just looked at all my lenses (admittedly not Pentax) and all the lenses have pins and contacts.
The camera just uses rechargeable AA batteries or similar?

cjohnw - 2021-10-06 16:38:00

cjohnw wrote:

Hmmm, strange. I just cant see how a lens would have no contacts with the camera. How does it communicate with the camera?
Just looked at all my lenses (admittedly not Pentax) and all the lenses have pins and contacts.
The camera just uses rechargeable AA batteries or similar?

Yep, uses 4xAA's. Yep the rear of the lens has absolutely no contacts on it. Will try leaving the camera a few days with the lens off and see what happens.

tegretol - 2021-10-06 17:52:00

cjohnw wrote:

Hmmm, strange. I just cant see how a lens would have no contacts with the camera. How does it communicate with the camera?
Just looked at all my lenses (admittedly not Pentax) and all the lenses have pins and contacts.
The camera just uses rechargeable AA batteries or similar?

ME super is a film camera, K-mount lenses are for film cameras. The only connections between the two are mechanical.

Edited by oramac at 6:08 pm, Wed 6 Oct

oramac - 2021-10-06 18:07:00

tegretol wrote:

Yep, uses 4xAA's. Yep the rear of the lens has absolutely no contacts on it. Will try leaving the camera a few days with the lens off and see what happens.

I would also try those batteries in another appliance to see what happens.
Not unheard of to get a dud battery occasionally. Especially those rechargeable types.

cjohnw - 2021-10-06 18:09:00

If you are happy to leave the lens off as a test for a few days why not just pop open the battery lid whenever you aren't using it instead. I had a rarely used Fuji camera that would drain the batteries if not used for a month or two, I just opened the battery flap as part of my turning the camera off regime, that solved it completely.

skull - 2021-10-06 22:35:00

skull wrote:

If you are happy to leave the lens off as a test for a few days why not just pop open the battery lid whenever you aren't using it instead. .....

Coz that method does not address the fundamental question.

tegretol - 2021-10-07 15:13:00

Can you put a little bit of insulation tape on the lens where it would possibly be contacting the camera body connections to preclude the possibility of electrical contact with the lens?

tygertung - 2021-10-07 15:42:00

tegretol wrote:

Coz that method does not address the fundamental question.

? Your response is a little ungracious..

Anyway it is a good tip that I am going to try to stop my batteries running down in my camera when the camera is not in use. Thanks.Skull.

Edited by shanreagh at 5:13 pm, Thu 7 Oct

shanreagh - 2021-10-07 17:12:00