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12-22-2009, 09:01 PM   #1
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"Other lenses" focus adjustable with K7?

Wondering if "other lenses" , i.e: non-Pentax, can be adjusted for FF/BF with the K7?
JP

12-22-2009, 09:29 PM   #2
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Hi Jaccques,

I'd say Yes with a qualifier, though it's a small one. It seems that some Sigma lenses are misidentified by the K20 and K-7. I don't have specific examples, but I've read a few posts about this. This seems to be caused by some glitches in Sigma's reverse engineering of lens chips, and causes the camera to ID some lenses incorrectly. This might cause a problem if you happen to also own one of the lenses that the body recognizes the Sigma for, and any focus microadjustments of one would automatically be applied to the other, whether it needed it or not.

I doubt that this will cause too many real life problems as the odds are that one person won't own two lenses that share the same ID, and my experience has been that I rarely need the AF point adjusment, and I have quite a few lenses.

The only feature that I'm aware of that is only Pentax DA lens specific is for optical and color aberrations.

Scott
12-22-2009, 10:05 PM   #3
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Just tested with a 18-250mm Tamron. No Problems setting and remembering adjustment.
12-23-2009, 05:57 AM   #4
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No reason why it would not work. At least, my Sigma 17-70 is adjustable.

The only caveat is that Sigma has been known to reuse lens ID codes for different models (and in at least one instance I'm aware, the lens ID of a Tamron model ), so if you have a lot of lenses you could theorically end up with two lenses with the same ID, and therefore the same AF adjustment for both. Practically speaking, I believe this is highly unlikely to happen.

12-23-2009, 08:55 PM   #5
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QuoteOriginally posted by snostorm Quote
Hi Jaccques,

I'd say Yes with a qualifier, though it's a small one. It seems that some Sigma lenses are misidentified by the K20 and K-7. I don't have specific examples, but I've read a few posts about this. This seems to be caused by some glitches in Sigma's reverse engineering of lens chips, and causes the camera to ID some lenses incorrectly. This might cause a problem if you happen to also own one of the lenses that the body recognizes the Sigma for, and any focus microadjustments of one would automatically be applied to the other, whether it needed it or not.

I doubt that this will cause too many real life problems as the odds are that one person won't own two lenses that share the same ID, and my experience has been that I rarely need the AF point adjusment, and I have quite a few lenses.

The only feature that I'm aware of that is only Pentax DA lens specific is for optical and color aberrations.

Scott
Snostorm ... Gosh! That name reminds me of the several hours spent shovelling snow for the past 36 hours!

OK, well, I do not own Sigma lenses any more, but I do have one Tamron (Macro 90/2.8) and a Zeiss ZK 85/1.4.
This far, I had to make slight adjustments on both my DA*'s and still have a FA 50/1,4 to check.
It didn't look like much though ... I could have left them alone but I am picky.

JP
12-23-2009, 08:56 PM   #6
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QuoteOriginally posted by Sideways Quote
Just tested with a 18-250mm Tamron. No Problems setting and remembering adjustment.
Glad to know that. I have a Tammy Macro 90/2.8 and I will check if it needs fine adjustment.
Thanks,

JP
12-23-2009, 08:57 PM   #7
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QuoteOriginally posted by RBellavance Quote
No reason why it would not work. At least, my Sigma 17-70 is adjustable.

The only caveat is that Sigma has been known to reuse lens ID codes for different models (and in at least one instance I'm aware, the lens ID of a Tamron model ), so if you have a lot of lenses you could theorically end up with two lenses with the same ID, and therefore the same AF adjustment for both. Practically speaking, I believe this is highly unlikely to happen.
Good to know that and at least I don't own a Sigma anymore; what's left to check is a Zeiss and a Tamron.

JP
12-27-2009, 10:01 AM   #8
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I have tested my Zeiss 85/1.4 with the K7 and it works just fine, although I did try to do some AF adjusting ... the camera is showing, for this specific lens: "Apply All" only. So, I decided to just leave it alone.
That is likely to happen with the Tamrom Macro 90/ as well, I wonder?

JP

12-27-2009, 10:43 AM   #9
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AF adjustment works fine in K 7 for my Sigma 300mm and 500mm lenses.
12-27-2009, 11:25 AM   #10
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To those who can do AF adjustments for non-Pentax lenses:

Does the screen show "Apply All" or does it actually identify the lens?
It does recognize all Pentax lenses I have tried this far, one at a time, but when it comes to another brand, it only shows that the AF adjustment can be applied this was "Apply All".

JP
12-27-2009, 07:11 PM   #11
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QuoteOriginally posted by jpzk Quote
To those who can do AF adjustments for non-Pentax lenses:

Does the screen show "Apply All" or does it actually identify the lens?
It does recognize all Pentax lenses I have tried this far, one at a time, but when it comes to another brand, it only shows that the AF adjustment can be applied this was "Apply All".

JP
Hi Jacques,

I think the lens recognition begins with "F" series lenses. I think that this is the first series that uses a chip with lens model and focal length in the information contained in the lens chip, which the K20 and K-7 use to calibrate the SR. All of my AF lenses are recognized as discreet lens models by these bodies (I only have two Sigma AF lenses, and have no other lenses that my K20 or K-7 confuse them with), but my "A" capable MF lenses, Pentax, Tokina, and Tamron all need my input for FL for the SR, and default to "ALL" in fine focus adjustment, using the last setting applied.

If you only have one lens that defaults to "ALL", then it's safe to calibrate the focus adjustment for it, as the only lens that the adjustment will apply to is this lens. If you have more than one, then each will use the adjustment last dialed in for any of them, so you have to remember the settings for each, and remember to set the focus adjustment correctly for each.

This is just speculation on my part, not definite knowledge of the information contained on the different chips, so take this only for what it is -- my experiences with the lenses that I have and use -- and the procedures I've set up for myself based on these.

Scott
12-27-2009, 09:06 PM   #12
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QuoteOriginally posted by snostorm Quote
Hi Jacques,

I think the lens recognition begins with "F" series lenses. I think that this is the first series that uses a chip with lens model and focal length in the information contained in the lens chip, which the K20 and K-7 use to calibrate the SR. All of my AF lenses are recognized as discreet lens models by these bodies (I only have two Sigma AF lenses, and have no other lenses that my K20 or K-7 confuse them with), but my "A" capable MF lenses, Pentax, Tokina, and Tamron all need my input for FL for the SR, and default to "ALL" in fine focus adjustment, using the last setting applied.

If you only have one lens that defaults to "ALL", then it's safe to calibrate the focus adjustment for it, as the only lens that the adjustment will apply to is this lens. If you have more than one, then each will use the adjustment last dialed in for any of them, so you have to remember the settings for each, and remember to set the focus adjustment correctly for each.

This is just speculation on my part, not definite knowledge of the information contained on the different chips, so take this only for what it is -- my experiences with the lenses that I have and use -- and the procedures I've set up for myself based on these.

Scott
Thanks a bunch, Scott.

So, I am hoping that the settings for the Zeiss won't mess up with the Tamron.
Additionally, I am in the process to get a Tamron 70-200/2.8 which might need tweaking, hopefully not though.
Your input is very much appreciated.

JP
12-27-2009, 09:11 PM   #13
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I am confused... the Zeiss is AF? I thought it was MF.


With mf why does one adjust an AF adjustment function?


If it is AF, my apologies... I have been pretty jerky of late
12-27-2009, 09:15 PM   #14
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But if you do need to adjust AF on MF lenses... that would explain why 80% of my shots are out of focus!
12-28-2009, 10:15 AM   #15
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QuoteOriginally posted by Igilligan Quote
But if you do need to adjust AF on MF lenses... that would explain why 80% of my shots are out of focus!
Sorry ... I really goofed here. Yes, the ZK is MF, and the Tamron Macro is AF.
I need to check the Tammy, only!

JP
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