Tamron Adaptall P/KA Adapter Problems

[noddywithoutbigears]

Hi Guys

I recently picked up a Tamron Adaptall 35-135mm complete with the PKA adapter but unfortunately I can't get it to work in the Aperture Priority setting as it does not recognize the lens or aperture, it asks for the lens focal length and the F is just flashing on my K200D.

I've set it to 32-AE on the lens ring, cleaned the contacts and re-mounted it numerous times all to no avail, any hints / tips to get it to recognize the lens and work?

Thanks
Neil

[Lloydy]

There is a difference between 'Adaptall' and 'Adaptall 2' - I'll check my PK Adaptalls later

http://www.adaptall-2.org/

will possibly answer the question.

[scsambrook]

I have a Tamron PKA mount which behaves in exactly the same way as Neil's. It 'misbehaves' on both my K100D and K10D, yet works perfectly on my P30 and P30T. This seems odd, and I think the problem may be with the inability of the contacts on the mount to line up correctly with those on the body. If I set any of my Tamron lenses to the 'A' position and the camera to 'P' and then lock the lens on the body I get the same response as if using a regular PK mount. But if I release the locking bolt and VERY gently start to rotate the lens as though removing it, Bingo! everything that should appears on the lcd panel ! If I continue to turn even the tiniest bit further, everything vanishes again.

Although it's a bit inconvenient to use like this, the lenses usually remain in place for most of the time. There's no real danger of them falling off.

But even stranger, the results from the K100D are fine, while those from the K10D are slightly overexposed.

Lloydy mentions that there's a difference between Adaptall and Adaptall 2. In this case I think that may not be relevant; the original adapters were never made in PKA, and the 35-135 was only produced in the -2 series.

I wish Neil luck trying to get the mount to work correctly. If he finds a way, I hope he'll broadcast it on here !

[Nesster]

While I haven't (yet!) had this problem, one of my PKA adapters disintigrated while mounted on camera. Screws got loose, and when I took it off the camera the whole thing came apart.

[mo]

I know this has nothing to do with the PKA adapter, but I have the K200D and sometimes the normal PK Tamron adapter has little issues (It does not seem to sit smoothly). I remove the adapter, turn the bottom half of it ( in other words give it a jiggle ) then reset it back on the camera...it then works as it should.

Congrats on the PKA mount,I hope it all works out for you.

[noddywithoutbigears]

Unfortunately I'm still struggling with it, tried turning the adapter very slightly to see if it'll register but unfortunately not, also tried it on my 80-210 (103A) but the same result, zero response and the only other Pentax camera I've got is a film KX but this has no Aperture Priority so I can't check it on that either, bugger.

[scsambrook]

Neil - I can let you have a "sort-of-working" P30 if you want to try it on a film body

To get mine working I only need rotate the mount by a TINY degree. A really tiny amount . . .

I suppose there must be some sort of "circuitry" in the mount. If so then we could have electrical rather than mechanical problems. Or perhaps the locking slot on my mount is a wee bit mis-located. "Tis mystery all" as the old hymn goes !

[mo]

Can you post a picture of the offending adapter?...just to see if there is any slight physical differences with Stephens adapter.

[scsambrook]

I looked at mine again yesterday evening - it looks distinctly "scruffy" !

[noddywithoutbigears]

[scsambrook]

Neil -

yours looks to be in better condition than mine! The locking slot on my mount is worn on the side away from the contacts, although I'm not sure if that is responsibe for my "problem". Looking at your picture, it seems that the middle contact - the sping-loaded ball - isn't sticking up, but that might just be the effect of the lighting.

I've now looked at my other PK AF lenses and all of them have more contacts than the Tamron mount. I wonder if there are varieties of Adaptall PK AF mounts? Is the plot thickening? Are we wallowing in ignorance? Are we the victims of a now-defunct conspiracy?

[scsambrook]

A bit more unhelpful information . . .

I bought a Macro Teleplus MC7 converter last week in PK Af fitting. I've just been fiddling with it and it works perfectly with all my PK AF lenses but I can't get the Adaptall mount to work with it at all, no matter how I jiggle it. I think we have an "incompatibility" situation.

[Farside]

I seem to recall a contact or resistor problem within the PKA mount. I don't recall the details, though. If I cudgel my memory further, there might be a notion that a resistor (it's very simple circuitry) goes open circuit or erratic.