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03-14-2018, 07:12 AM   #1
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Adaptall P/KA; no automatic onboard flash

Hi all;

Just took delivery of an Adaptall P/KA adapter. It looks very new, but in testing it out there are some quirky behaviors I've noticed when using it on my K-S2. The lens I'm using it on is the 90mm f2.5, 52BB.

Aperture control seems to be working fine on the AE setting. The aperture closes down successfully on shooting. Indicated aperture shows up on the rear screen, but not in the viewfinder information, which shows "F_ _".

The built in flash operates inconsistantly. It will fire if it is set manually, but will not fire if the flash is on auto. The flash ready icon shows in the viewfinder, but the flash will not go off. However, it fires on auto if I have either my Vivitar Macro Focusing 2X teleconverter, or a deglassed teleconverter, both with A contacts, between the camera and lens. It seems strange that it should operate properly with TC or tube and lens, but not just the lens. Any ideas?

03-14-2018, 07:53 AM - 1 Like   #2
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There is a thread in here that will help, the lack of a F stop showing would seem to indicate that the adapter is not communicating properly with the body.
Fixing Tamron Adaptall P/KA Adapter
If you copy and paste into search the forums you will find it. Sorry, I still do not know how to link to other threads.
03-14-2018, 07:58 AM   #3
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But the F stop is showing up on the back screen and the lens is stopping down properly on shutter release. So there is communication and connection happening. If I turn the lens a bit, the back screen blinks between indicating selected aperture and F_ _. The viewfinder aperture reading remains at F_ _ whatever happens with the rear screen.

---------- Post added 03-14-18 at 11:04 AM ----------

QuoteOriginally posted by Skodadriver Quote
There is a thread in here that will help, the lack of a F stop showing would seem to indicate that the adapter is not communicating properly with the body.
Fixing Tamron Adaptall P/KA Adapter
If you copy and paste into search the forums you will find it. Sorry, I still do not know how to link to other threads.
I'm guessing this is it? Thanks, I'll look it over. I'm at work and the patient is at home, but I'll try the suggested fix9es) once I'm there.
03-14-2018, 10:00 AM   #4
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If the aperture isn't showing on both the lcd displays then there's a problem. May just need wiggling. May need the screw scratching as per fix thread. Other issues I have encountered with these include the locking button on the edge not fully clicking into place at AE.

Se also

https://www.pentaxforums.com/userreviews/tamron-adaptall-mount-adapter.html


Last edited by marcusBMG; 03-14-2018 at 10:10 AM.
03-14-2018, 10:08 AM - 1 Like   #5
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QuoteOriginally posted by Thagomizer Quote
If I turn the lens a bit, the back screen blinks between indicating selected aperture and F_ _. The viewfinder aperture reading remains at F_ _ whatever happens with the rear screen.
The P/KA adapters are rather famous for positional problems. If one sees F-- in the viewfinder or any of the displays, the body is NOT able to control the aperture and features such auto-exposure and P-TTL auto-flash will not work.

The "scrape the contact fix" suggested on various threads on this site is probably no more effective than simply giving the three contacts* (particularly the center "A" contact) a good cleaning with a micro-fiber cloth.** In practice, a slight nudge of the lens position will probably do the trick if the problem recurs even after cleaning. Edit: After a careful examination of both my adapters under magnification, it appears that one has resin applied over a slotted grub screw and the other has no foreign substance and a slotless "plug". The scraping fix is probably more effective when the resin is present and less so when it is not.

Note that even after doing all you can to get the "A" feature working, P-TTL flash with a non-AF lens will sometimes result in poor exposure. High ISO at moderate-to-close distance will often result in P-TTL failure. This is a problem with all "A"-series lenses.


Steve

* The fourth contact shown in some instructions is actually an index mark from the manufacturing process. Yes, Tamron does the magic with only three contacts and an insulated patch.

** I have two P/KA adapters, one of which has never worked properly despite receiving the full "scraping" treatment. The other has only been cleaned with a microfiber cloth and functions perfectly. Go figure...

Last edited by stevebrot; 03-14-2018 at 12:48 PM.
03-14-2018, 10:11 AM - 1 Like   #6
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QuoteOriginally posted by stevebrot Quote
The P/KA adapters are rather famous for positional problems. If one sees F-- in the viewfinder or any of the displays, the body is NOT able to control the aperture and features such auto-exposure and P-TTL auto-flash will not work..
+1
The screw position definitely interferes with the connection, and the scratch fix is definitely effective, I have had half a dozen PKA's that needed this.
03-14-2018, 10:31 AM   #7
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Thanks, all. Will try this when I get home. Curiouser and curiouser...
03-14-2018, 10:46 AM - 1 Like   #8
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My adapter will communicate properly with the body, but only if I give it a slight clockwise twist after it is mounted.

03-14-2018, 12:13 PM   #9
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QuoteOriginally posted by stevebrot Quote
The "scrape the contact fix" suggested on various threads on this site is probably no more effective than simply giving the three contacts* (particularly the center "A" contact) a good cleaning with a micro-fiber cloth
I haven't had this problem with Adaptall mounts in particular, but I have had occasional problems with contacts on old Vivitar and Sigma 'A' lenses, and I can tell you that sometimes no amount of cleaning (even with contact cleaner or alcohol) will work but scratching up the contact is an instant fix. It would seem that whatever material that some of those old contacts are made of gets some sort of (basically invisible) oxidation layer and you do in-fact have to scratch up the top layer to restore conductivity. Again, I don't know if that is the case with Adaptalls, but it definitely is a thing sometimes where cleaning does no good but scratching (and then cleaning) does.
03-14-2018, 02:53 PM   #10
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Hi all.

Well, I tried remounting the mount, scraping contacts and wiping them with alcohol. My results have not changed. Even without the aperture reported in the viewfinder (but on the rear screen), aperture control through the e-dial is operating. Built in flash does not fire in AUTO. If I press the lens releaser button and turn the lens a teeny, tiny bit, the aperture value appears in the viewfinder and the flash does fire in auto. As soon as I turn it back enough for the pin to re-click into the lens, indication and flash functionality disappear. A-contact TC or tube allow proper functioning of display and flash. Weird.

---------- Post added 03-14-18 at 05:53 PM ----------

Hi all.

Well, I tried remounting the mount, scraping contacts and wiping them with alcohol. My results have not changed. Even without the aperture reported in the viewfinder (but on the rear screen), aperture control through the e-dial is operating. Built in flash does not fire in AUTO. If I press the lens releaser button and turn the lens a teeny, tiny bit, the aperture value appears in the viewfinder and the flash does fire in auto. As soon as I turn it back enough for the pin to re-click into the lens, indication and flash functionality disappear. A-contact TC or tube allow proper functioning of display and flash. Weird.
03-15-2018, 07:17 AM - 1 Like   #11
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QuoteOriginally posted by Thagomizer Quote
Weird
Unfortunately only too typical of these pka mounts. You can get this with different mounts, or with the same mount on different lenses... .

Try wiggling (rotationally) the lens on the camera fairly firmly without pressing the release button. Normally that will bring back the f number display, you can note if it seems to be one way or the other that succeeds.
You can also try enhancing the connection with the data contact with foil like here:

TESTS: Plated vs Painted (conducting vs non-conducting) lens mounts on K-r: whats t - PentaxForums.com
03-15-2018, 09:13 AM   #12
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QuoteOriginally posted by marcusBMG Quote
Unfortunately only too typical of these pka mounts.
Yep...I have found it easier and more cost-effective to not pour money into P/KA adapters and to buy the regular P/K version instead.


Steve
03-15-2018, 09:25 AM   #13
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I've tried twisting (without pressing the release button) with no luck. I find it strange that there's full functionality with the tube and TC.I guess there's more (or less) slop in the tolerances of the accessories than the camera body.
03-15-2018, 12:43 PM   #14
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QuoteOriginally posted by Thagomizer Quote
I've tried twisting (without pressing the release button) with no luck. I find it strange that there's full functionality with the tube and TC.I guess there's more (or less) slop in the tolerances of the accessories than the camera body.
Can you try it on another body?
Stupid question, you will probably already thought of doing that.
I have 3 PK-A adapters and I have just tried them all on my K-5 and SP90 (52BB), result was that one of the three needed jiggling on the camera to get the F stop registered on the top LCD. Not noticed this happening on my K100D.
You may be right that is just tolerances.
03-15-2018, 12:59 PM   #15
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Good thought, but I only have the one body.
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