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11-06-2006, 01:07 PM   #1
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K100D with Adaptall Lenses - Help Pls!

Hi All,

Last week, I got a Tamron SP 70-210 F3.5 Adaptall with the P/KA adapter. I was playing with it this past weekend and observed this weird behavior on my K100D. I searched but couldn't find any discussion on it before, so here goes....

With the lens at AE (32), it should work like a Pentax-A lens, right? However, when I mount the lens and turn on the K100D, the camera does not display the aperture value. Then I thought that the adapter contacts are dirty, loose or whatever. So I cleaned the adapter, the contacts etc but still the no sign of aperture value. So I thought maybe I got a bad adapter

But then I noticed that the info for the pics I shot with the lens are showing the correct aperture value. And moreover, the metering is also in matrix-mode. So the camera is getting the aperture information after all. But this is not shown either on the top LCD or VF at the time of composing the shot (I just get a F__). And another strange thing is, with the camera in A mode, if I turn the command dial then the shutter value changes appropriately - as if the aperture is changing - but still the camera does not display the aperture value

Aaaargghh!! What is going on? Have I gone nuts? Is there some setting in the menu that I forgot to change? Or is the K100D playing tricks on me? Or maybe the K100D has compatibility issues with the Adaptall system? I'd be very grateful if someone with a K100D and an adaptall lens could confirm this weird behavior. Any comments/advice/suggestions on how to solve this problem are welcome.

And just so you know, when I put on a SMC-A 70-210/4 the camera works like a charm. So I am pretty sure I didn't mess up any settings in the camera.

Thanks
Teja

11-06-2006, 05:34 PM   #2
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I don't know if that helps at all but here is my experience. I had a SP 90mm Macro with Adaptall 2 mount and it worked in Automatic mode at times. It seemed to me that it was not seating correctly with the contacts. If I turned the lens a little bit more after mounting it usually worked. Try to give it a little more twist. I cannot look at mine to help you, since I already sold it.


Edit: I used mine on the DS and D (not on a K100D) but the mount is identical.

Last edited by HogRider; 11-06-2006 at 05:35 PM. Reason: Camera type
11-07-2006, 04:01 PM   #3
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QuoteOriginally posted by RedHawk Quote
Edit: I used mine on the DS and D (not on a K100D) but the mount is identical.
Yes, the mount is identical, but the camera software is different. Till now only previous model DSLR users (D, DS, DL) have confirmed that the adaptall lenses work well with their cameras.

Looks like I am the first K100D user to venture into adaptalls. Well they don't work well with my camera at least. I am hoping someone else with a K100D and adaptall could confirm what I observe so that I can decide whether to keep those adaptall lenses or sell them.
11-09-2006, 10:52 AM   #4
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Interesting

QuoteOriginally posted by Teja Quote
Yes, the mount is identical, but the camera software is different. Till now only previous model DSLR users (D, DS, DL) have confirmed that the adaptall lenses work well with their cameras.

Looks like I am the first K100D user to venture into adaptalls. Well they don't work well with my camera at least. I am hoping someone else with a K100D and adaptall could confirm what I observe so that I can decide whether to keep those adaptall lenses or sell them.
First it looks only to be a display glitch. You are sure that the data is accurate? A shot at say f16 is showing the proper DOF. The reason I ask this is to be sure that the lens is functioning correctly even though it is not showing the aperature.
If I remember correctly, metering pattern is not a definitive indicator. I believe screw mounts will show "matrix" or "spot" when in actuality they are not metered this way. At least that is how I understand it. Not real happy w/ EXIF lying to you if that is the case.
So if the lens is behaving perfectly as an "A" lens except for the display, looks to be a glitch in the software (accidental or on purpose). The only reason to do it "on purpose" would be to annoy Tamron . Well there is one more reason, some Adaptall lenses do not show the correct aperatures (this would not include your lens BTW) due to their aperatures not falling into the correct "table of values" as set by the "A" mount. So Pentax could have "skipped" displaying aperature values for all third party lenses. NOT likely but who knows. Sigma may be partially immune because they sometimes code a Pentax value in one of the fields that the camera reads. Many Sigma lenses have a Pentax name in the Pentax software. This would fool the camera IF it was screening lenses.
Very curious. From your post you seem to have other Tamron adaptalls???
Are these the same?

11-09-2006, 05:01 PM   #5
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QuoteOriginally posted by jeffkrol Quote
First it looks only to be a display glitch. You are sure that the data is accurate? A shot at say f16 is showing the proper DOF. The reason I ask this is to be sure that the lens is functioning correctly even though it is not showing the aperature.
Yes, the aperture data is accurate. I've tested this. Wide open, the exif shows 3.5, and as I turn the rear wheel the value gets higher and perfectly matches the lens' aperture settings. The DOF (I have it set for optical preview) also works perfectly.
QuoteQuote:
If I remember correctly, metering pattern is not a definitive indicator. I believe screw mounts will show "matrix" or "spot" when in actuality they are not metered this way. At least that is how I understand it. Not real happy w/ EXIF lying to you if that is the case.
I rechecked the metering, and though it allows me to set matrix in the menu, the exif actually says center-weighted. Don't know what that means.
QuoteQuote:
So if the lens is behaving perfectly as an "A" lens except for the display, looks to be a glitch in the software (accidental or on purpose). The only reason to do it "on purpose" would be to annoy Tamron . Well there is one more reason, some Adaptall lenses do not show the correct aperatures (this would not include your lens BTW) due to their aperatures not falling into the correct "table of values" as set by the "A" mount. So Pentax could have "skipped" displaying aperature values for all third party lenses. NOT likely but who knows. Sigma may be partially immune because they sometimes code a Pentax value in one of the fields that the camera reads. Many Sigma lenses have a Pentax name in the Pentax software. This would fool the camera IF it was screening lenses.
Myself reaching to the same conclusion - that Pentax changed something in the K100D firmware to prevent the use of third party lenses in A mode I think I will send e-mails to both Tamron and Pentax and see if they respond with any meaningful reply.
QuoteQuote:
Very curious. From your post you seem to have other Tamron adaptalls??? Are these the same?
Yep, I picked up a SP 70-210mm F3.5 and a SP 60-300mm F3.8-5.4. The 60-300 was sold along with a 28-70mm that I took because both came with Pentax KA adapters. The 70-210mm came with a Nikon adapter and I needed the additional PKA adapter. All-in-all I think I got a very good deal, but what's the point if they are not working with my K100D? I guess I will put them up for sale as soon as I give up getting them to work properly.

I also picked up a Pentax-A 70-210mm F4 and it works very well with the K100D. I wish the SP 70-210/3.5 worked similarly so I could compare them and decide on which one to keep.

Thanks for your interest. Let me know if you have any theories/ideas on getting them to work on the K100D.

Cheers
Teja
11-14-2006, 07:37 AM   #6
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I haven't given up finding the answer yet
01-16-2007, 11:06 PM   #7
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I'm going to revive this thread since I seem to be having a similar issue with my P/KA adapter + tamron sp 90 + K100D combination. Last night, I tested it for the first time and found that the aperature would only open up to f4.0. I cleaned the adapter and the lens at the contact point, plus tested it with the 1:1 adapter. Now I get f2.4 as my min. apperature. At various other times, I have gotten ---- (blanks - assumed that the contact points are off again), f3.5, f2.8 and so on. If anyone has any new answers, I'm all ears. I hope that this is a firmware issue rather than a problem with the adapter itself.

A.-
01-17-2007, 07:06 AM   #8
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Oddly enough, there has been no help given here or at dpreview. My gut feeling it is just the "mount" issue. On older cameras (D ect.) this could be tested by a light "twist" on the lens while mounted. There is usually enough play to go in and out of contact with the body. A few other things to check is to test the aperature blades manually to see if there sticking ect.
On one of my adapters I drilled the "lock" hole out to allow better contact. Should be back filled eventually but haven't got to it yet. Same adapter sometimes has problems actually locking into "A" and is a bit loose in slipping out of A without having to push the plastic release on the lensmount. Of course checking that the 2 "earrs" are in their respective slots and the mount firmly locked on is also prudent. There is a small circuit board inside that has some traces and some wiper contacts attached. Not sure of their function since I think all the A mount does is give the camera body max and min aperature and this is just done w/ go/no go contacts. See
Features and Operation of the Ka Mount
for contact info
Except for the fact that the OP had multiple Adaptall failures, I would still think it's the mount but ????? Since there aren't multiple posts to this thread of Tamron Adaptall II P/KA mount successes w/ KxxD series of cameras, I'm at a loss....

01-17-2007, 10:17 AM   #9
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Thanks for the reply.

The good/bad news is that there's not much give at the mount. It's actually quite difficult to get the lens out of contact with the body, although it can be done. I may look into the contact points using the link you posted later on. What I'd really like is to be able to test the adapter with a different lens or on a different body. I will try to get my hands on a cheapie 80-210 and possibly test it on a friend's DL. I'll give an update once I'm done...
01-17-2007, 05:41 PM   #10
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QuoteOriginally posted by jeffkrol Quote
Oddly enough, there has been no help given here or at dpreview. My gut feeling it is just the "mount" issue.

On one of my adapters I drilled the "lock" hole out to allow better contact. Should be back filled eventually but haven't got to it yet.

Except for the fact that the OP had multiple Adaptall failures, I would still think it's the mount but ????? Since there aren't multiple posts to this thread of Tamron Adaptall II P/KA mount successes w/ KxxD series of cameras, I'm at a loss....
Hi Jeff,

Nice to see you are still on this case

I've been a bit busy at work to experiment, but I more or less narrowed my problems with the Adaptall to one of the following two reasons:

- A software glitch in my K100D is preventing displaying A value. Might go away with a new firmware (haven't flashed my K100D to the new FW yet), but I wouldn't count on it if Pentax did it on purpose.

- A very very slight mis-alignment between the contacts causing the display to behave the way it does. This could be because my adapters were from an older production batch with greater manufacturing tolerances than Pentax, but I don't know for sure. I have been meaning to drill a small extension to the lock pin hole (just like what you did), but never got to it because of a)work and b)might have to re-sell the adapter and don't want to mess with it unless I am sure.

But I am getting familiar with using the K100D in M mode, so atleast I am learning a new skill. I only wish the K100D had a better screen for manual focusing screen.

Cheers
Teja
01-24-2007, 03:31 AM   #11
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Solved

Well, both my P-K/A adapters are working just fine now.

a) I upgraded my K100D to v1.02
b) Gave the mount contact points - both on camera and adapters -a very thorough cleaning using rubbing alcohol and lens cleaning tissue.

Then tried them again, and both the adaptall lenses (70-210/3.5 and 60-300/3.8-5.6) are working just fine with the K100D in 'A' mode. The aperture is showing up properly both on the LCD & VF, and is responding correctly to the control dial adjustments. I am quite happy. Thanks for all your help & suggestions.

Now to decide which lens to keep, the Pentax-A 70-210/4 or the Tamron SP 70-210/3.5. Any inputs?

Cheers
Teja
01-24-2007, 07:47 AM   #12
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Glad to see you got them working. As to which to keep??? Don't think it matters much between the 2. They both seem to be highly rated. Best to see which you like better in terms of those "other qualities" ie color rendition, bokeh, handling ect. Personally, if both seem equal, I'd stick w/ the Pentax "A" lens for ease of use (A vs adapter). As to selling them, at the current inflated Pentax prices the Pentax may sell for more, and the Tamron, if you sometime decide to switch brands, COULD be a plus as to the mount interchangeability, though your options (and cost of adapters) may become more limited due to manufacturer's changing compatability..... Good luck in choosing. I'd probably keep both "just because".....
02-26-2007, 09:47 AM   #13
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I had a Ricoh XRM and used Tamron lenses. I sold all of them but my 500mm Tamron mirror lens and the mount I used on the Ricoh works fine on my K100D. The mount says RI on it but I think its the same as the K or KA (anyone know?).

My only problem is the exif data does not have the f-stop of 8. Is that normal?

Not sure if the RI is any different, I have heard its the same a K or KA.

Last edited by vinniet; 02-26-2007 at 09:53 AM.
02-26-2007, 06:23 PM   #14
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Hi All,

After much frustration with my KA adapters, I found this post at DPR:

Re: How to fix bad Tamron KA mount: Pentax SLR Talk Forum: Digital Photography Review

It seems that the screws coming from the lens side of the adapter are locktited and there is a thin film of it on the tips of the screws, one of which (closest to the contacts) is in precisely the right place to prevent the pin on the camera body from contacting the adapter body. By scraping the end of the screw with a pocket knife, you can remove the insulating substance and allow the correct contact. I have 4 different adapters that wouldn't show aperture, and after scraping the screw tip on all of them, they all work as they should.

Scott
08-10-2007, 11:24 AM   #15
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Anyone looking to sell their K/A mount or lens with a K/A mount on it? I have a 38-100 that needs a K/A mount on it Or know of anywhere to get them?
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