K-1 3rd-party lens compatibility

gryhnd · 05-07-2016, 08:59 PM

Tested all of the following on day one and they all work perfectly on initial go around:

Sigmas: 70-200 HSM DG 2.8, 17-50 2.8 DC, 50 DG 1.4, 24-70 DG 2.8, 50-500 Bigma
Bower 8mm fisheye
Super Albinar 28 2.8 (old school)

An interesting point: I've had many troubles with focusing issues on the 24-70 2.8. The lens has had a troubled life. It first arrived with the wrong firmware, identifying itself as a 70-200. I sent it in for repair and also complained that it wouldn't focus properly (at distance in particular) on either my K5iis or K3 (even trying to tweak it with in camera profiles). Sigma reprogrammed it and said there were no issues with focusing, yet they persisted and I set the lens aside.

Curiously, near as I can tell so far, the focusing issues have gone away under the K-1! I used it for about two dozen or so shots and they all look spot on. For example..

Last edited by gryhnd; 05-08-2016 at 10:05 AM. Reason: fixed 20-200 to 70-200

**felixkh** · 05-07-2016, 09:24 PM

I have an older Sigma 70-200/2.8 APO EX DG which works fine with my K1. This is the non macro with an aperture ring version.

Mock · 05-08-2016, 09:22 AM

I encountered an issue using my Sigma 24-60mm f/2.8. After mounting the lens, it would frequently lose contact with the pins on the lens mount. The aperture would flicker between "--" and my selected one, I also lost AF during the times it was displaying no aperture. So it was losing contact with the data pin, at minimum. Holding the lens in any one position, or pushing it onto the pins did not generate any consistent improvement.
The lens did not exhibit any problems mounted on my K-5. I think the pins Sigma uses on this lens (and others) do not protrude as much as the pins Pentax uses.

I first tried tightening the lens mount screws on the lens, but this did not help, nor would I expect it to since the K-5 had no issues. With hesitation, I then tightened the screws on the lens mount of my K-1, they were all able to tighten about 1/5 of a turn without using much force. After tightening the screws on the K-1, the Sigma 24-60mm functions perfectly, contact with the pins is 100%.

The downside is that I now have to dial in a +1 focus adjustment on my DA* 55, since tightening the mount changes the registration distance ever so slightly, causing that lens to back-focus.

edit: Actually it's happening again now, maybe the pin doesn't connect inside the lens properly. It tends to lose function when zooming.

gryhnd · 05-08-2016, 10:04 AM

Originally posted by Mock

After mounting the lens, it would frequently lose contact with the pins on the lens mount.

Did you clean the lens contacts? This happens to me often on lenses I use a lot. Just requires proper maintenance. Another poster said the same thing and all works now after I mentioned it.

I just use a q-tip with some isopropanol.

Mock · 05-08-2016, 10:18 AM

Originally posted by gryhnd

Did you clean the lens contacts? This happens to me often on lenses I use a lot. Just requires proper maintenance. Another poster said the same thing and all works now after I mentioned it.

I just use a q-tip with some isopropanol.

Yeah, I cleaned everything first. I'm starting to suspect something electrical. The Sigma lens has more resistance (~700ohm) across pin 7 than any of my Pentax lenses (~450 ohm). Perhaps the K-1 doesn't supply the lens enough power, I'm going to compare the current from both cameras.

edit: As you would expect they're putting out the same voltage, the K-1 may actually be outputting slightly more on average, but that may come down to the battery being a fuller charge. Gonna check inside the lens for any issues now.

edit: Finally isolated a cause! If I hold the lens lock button down, communication is fine. The lens lock pin is somehow to blame.

OK. A bit of scotch tape over the lens mount hole on the lens fixes the issue, which I also encounter to a lesser extent with my Sigma 400mm f/5.6 APO Tele Macro. For a short while my Sigma 105 Macro wouldn't work either, but it has since returned to normal. I still can't say what the issue is definitely. I think the tape is pushing back the lens-lock pin enough, which creates a connection that tells the camera to look at pin 7. Would this be new behaviour for K-mount? I can't imagine this is the cause though, it's not as if Sigma locking-holes are deeper than Pentax ones. Regardless, I've partially filled the hole on my 24-60 with superglue so something pushes against the pin...so far so good.

theEight · 05-09-2016, 08:57 AM

Just tried my Tamron SP AF 17-50mm f/2.8 XR Di II LD, bit surprised to discover that lens was meant for APS-C to begin with. I have my K1 set to full frame and with the Tamron , I got the dark circle - turning on auto crop mode allowed the camera to recognize the lens as an APS-C lens. The 17-50 will remain permanently with my K5iis, so looking for a wide angle for the K1, preferably an FA or even A older prime (24, 28)

**UncleVanya** · 05-09-2016, 09:12 AM

Originally posted by theEight

Just tried my Tamron SP AF 17-50mm f/2.8 XR Di II LD, bit surprised to discover that lens was meant for APS-C to begin with. I have my K1 set to full frame and with the Tamron , I got the dark circle - turning on auto crop mode allowed the camera to recognize the lens as an APS-C lens. The 17-50 will remain permanently with my K5iis, so looking for a wide angle for the K1, preferably an FA or even A older prime (24, 28)

As far as I know all of the 16 or 17 to 50 lenses are APSC.

funktionsfrei · 05-09-2016, 09:23 AM

Originally posted by UncleVanya

As far as I know all of the 16 or 17 to 50 lenses are APSC

That's the case. With a focal length of less than 24mm and a full-frame image circle a lens is considered an ultra-wideangle lens, and those beasts are both expensive and seldom to be seen.

The ultimate for Pentax users used to be the 12-24/4.5-5.6 from Sigma, but for some reasons Sigma ceased their specific kind of Pentax support* with the second iteration of this lens (that added HSM, Sigma's name for what Pentax names SDM).

Which I consider a pity; I would very much like to get a full-frame complement for my APS-C 8-16/4.5-5.6 HSM, which I used on my K-5 without any problems whatsoever. That lens is compatible with the K-1, but definitively shows it's smaller image circle (and it's fixed lens-shade) on the K-1's full-frame sensor, as can be seen here:

*) we all know about the woes with Sigma's reverse-engineered implementation of the K-bayonet, especially with the 70-200/2.8 DG Macro II HSM ...

gryhnd · 05-09-2016, 09:45 AM

Originally posted by funktionsfrei

That lens is compatible with the K-1, but definitively shows it's smaller image circle (and it's fixed lens-shade) on the K-1's full-frame sensor, as can be seen here:

And ditto their 17-50, and the Bower 8mm (which looks horrid FF, lol).

Rudy · 05-09-2016, 04:00 PM

My Sigma lenses quick check with K-1:

Sigma 24-70/2.8 EX DG HSM .... It works fine both live view and viewfinder - If your crop setting is in AUTO, K-1 thinks this lens is CROP, ... Change your crop setting to FF and it works fine.
Sigma 70-200/2.8 APO EX DG OS HSM .... It works fine both live view and viewfinder - If your crop setting is in AUTO, K-1 thinks this lens is CROP, ... Change your crop setting to FF and it works fine.
Sigma 12-24 4.5 EX DG .... it works fine in both Live view and viewfinder
Sigma 15 2.8 DG Fisheye 180 degrees .... it works fine in both Live view and viewfinder

I hope it helps

Enigmaticca · 05-10-2016, 02:37 AM

Originally posted by Raffwal

Can you comment on the IQ and AF accuracy using this lens?

Unfortunately I have yet to have the opportunity to get a proper play with that lens. It will need some forward AF adjustment and my initial impression with regards to IQ has been unconvincing thus far

**clackers** · 05-10-2016, 02:47 AM

Originally posted by theEight

Just tried my Tamron SP AF 17-50mm f/2.8 XR Di II LD, bit surprised to discover that lens was meant for APS-C to begin with.

Shouldn't have been, theEight.

That's what the Di II means for a Tamron lens - APS-C.

Sigma's code is DC.

**Papa Lazarou** · 05-10-2016, 03:45 AM

Sent my 70-200mm HSM II to Sigma UK yesterday. Hoping a lens firmware update resolves my issues.

rawr · 05-10-2016, 04:17 AM

Originally posted by Papa Lazarou

Sent my 70-200mm HSM II to Sigma UK yesterday. Hoping a lens firmware update resolves my issues.

In Australia the national Sigma distributor is also the long term Pentax distributor. If any Aussies have any K-1 and Sigma problems, hopefully that will make any necessary fixes easier to arrange.

aju3169 · 05-10-2016, 04:53 AM

I have the older Sigma 70-200 F2.8 APO DG EX - works perfectly with the K1 and my k5 II. It is very fast focusing on both cameras although no HSM. It has very good user reviews and might be an option for those wanting this zoom range and aperture. It's a bit cheaper too if you can find one on the second hand market.

05-08-2016, 09:22 AM	#123
Mock Veteran Member Join Date: Feb 2009 Location: Edmonton Photos: Gallery \| Albums Posts: 314	I encountered an issue using my Sigma 24-60mm f/2.8. After mounting the lens, it would frequently lose contact with the pins on the lens mount. The aperture would flicker between "--" and my selected one, I also lost AF during the times it was displaying no aperture. So it was losing contact with the data pin, at minimum. Holding the lens in any one position, or pushing it onto the pins did not generate any consistent improvement. The lens did not exhibit any problems mounted on my K-5. I think the pins Sigma uses on this lens (and others) do not protrude as much as the pins Pentax uses. I first tried tightening the lens mount screws on the lens, but this did not help, nor would I expect it to since the K-5 had no issues. With hesitation, I then tightened the screws on the lens mount of my K-1, they were all able to tighten about 1/5 of a turn without using much force. After tightening the screws on the K-1, the Sigma 24-60mm functions perfectly, contact with the pins is 100%. The downside is that I now have to dial in a +1 focus adjustment on my DA* 55, since tightening the mount changes the registration distance ever so slightly, causing that lens to back-focus. edit: Actually it's happening again now, maybe the pin doesn't connect inside the lens properly. It tends to lose function when zooming. Last edited by Mock; 05-08-2016 at 09:36 AM.

05-08-2016, 10:18 AM	#125
Mock Veteran Member Join Date: Feb 2009 Location: Edmonton Photos: Gallery \| Albums Posts: 314	Originally posted by gryhnd Did you clean the lens contacts? This happens to me often on lenses I use a lot. Just requires proper maintenance. Another poster said the same thing and all works now after I mentioned it. I just use a q-tip with some isopropanol. Yeah, I cleaned everything first. I'm starting to suspect something electrical. The Sigma lens has more resistance (~700ohm) across pin 7 than any of my Pentax lenses (~450 ohm). Perhaps the K-1 doesn't supply the lens enough power, I'm going to compare the current from both cameras. edit: As you would expect they're putting out the same voltage, the K-1 may actually be outputting slightly more on average, but that may come down to the battery being a fuller charge. Gonna check inside the lens for any issues now. edit: Finally isolated a cause! If I hold the lens lock button down, communication is fine. The lens lock pin is somehow to blame. OK. A bit of scotch tape over the lens mount hole on the lens fixes the issue, which I also encounter to a lesser extent with my Sigma 400mm f/5.6 APO Tele Macro. For a short while my Sigma 105 Macro wouldn't work either, but it has since returned to normal. I still can't say what the issue is definitely. I think the tape is pushing back the lens-lock pin enough, which creates a connection that tells the camera to look at pin 7. Would this be new behaviour for K-mount? I can't imagine this is the cause though, it's not as if Sigma locking-holes are deeper than Pentax ones. Regardless, I've partially filled the hole on my 24-60 with superglue so something pushes against the pin...so far so good. Last edited by Mock; 05-08-2016 at 03:38 PM.

05-10-2016, 04:53 AM	#135
aju3169 New Member Join Date: Mar 2013 Posts: 8	I have the older Sigma 70-200 F2.8 APO DG EX - works perfectly with the K1 and my k5 II. It is very fast focusing on both cameras although no HSM. It has very good user reviews and might be an option for those wanting this zoom range and aperture. It's a bit cheaper too if you can find one on the second hand market. Last edited by aju3169; 05-10-2016 at 05:01 AM. Reason: Mistake

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05-07-2016, 08:59 PM	#121
gryhnd Senior Member Join Date: Jul 2013 Location: Southeastern MA Posts: 240	Tested all of the following on day one and they all work perfectly on initial go around: Sigmas: 70-200 HSM DG 2.8, 17-50 2.8 DC, 50 DG 1.4, 24-70 DG 2.8, 50-500 Bigma Bower 8mm fisheye Super Albinar 28 2.8 (old school) An interesting point: I've had many troubles with focusing issues on the 24-70 2.8. The lens has had a troubled life. It first arrived with the wrong firmware, identifying itself as a 70-200. I sent it in for repair and also complained that it wouldn't focus properly (at distance in particular) on either my K5iis or K3 (even trying to tweak it with in camera profiles). Sigma reprogrammed it and said there were no issues with focusing, yet they persisted and I set the lens aside. Curiously, near as I can tell so far, the focusing issues have gone away under the K-1! I used it for about two dozen or so shots and they all look spot on. For example.. Last edited by gryhnd; 05-08-2016 at 10:05 AM. Reason: fixed 20-200 to 70-200

05-07-2016, 09:24 PM	#122
felixkh Site Supporter Join Date: Nov 2008 Location: Singapore Photos: Gallery Posts: 1,201	I have an older Sigma 70-200/2.8 APO EX DG which works fine with my K1. This is the non macro with an aperture ring version.

05-08-2016, 10:04 AM	#124
gryhnd Senior Member Join Date: Jul 2013 Location: Southeastern MA Posts: 240	Originally posted by Mock After mounting the lens, it would frequently lose contact with the pins on the lens mount. Did you clean the lens contacts? This happens to me often on lenses I use a lot. Just requires proper maintenance. Another poster said the same thing and all works now after I mentioned it. I just use a q-tip with some isopropanol.

05-09-2016, 08:57 AM	#126
theEight Junior Member Join Date: Dec 2011 Location: HArtford CT Photos: Gallery \| Albums Posts: 46	Just tried my Tamron SP AF 17-50mm f/2.8 XR Di II LD, bit surprised to discover that lens was meant for APS-C to begin with. I have my K1 set to full frame and with the Tamron , I got the dark circle - turning on auto crop mode allowed the camera to recognize the lens as an APS-C lens. The 17-50 will remain permanently with my K5iis, so looking for a wide angle for the K1, preferably an FA or even A older prime (24, 28)

05-09-2016, 09:12 AM	#127
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,403	Originally posted by theEight Just tried my Tamron SP AF 17-50mm f/2.8 XR Di II LD, bit surprised to discover that lens was meant for APS-C to begin with. I have my K1 set to full frame and with the Tamron , I got the dark circle - turning on auto crop mode allowed the camera to recognize the lens as an APS-C lens. The 17-50 will remain permanently with my K5iis, so looking for a wide angle for the K1, preferably an FA or even A older prime (24, 28) As far as I know all of the 16 or 17 to 50 lenses are APSC.

05-09-2016, 09:23 AM	#128
funktionsfrei Senior Member Join Date: Feb 2012 Posts: 183 Original Poster	Originally posted by UncleVanya As far as I know all of the 16 or 17 to 50 lenses are APSC That's the case. With a focal length of less than 24mm and a full-frame image circle a lens is considered an ultra-wideangle lens, and those beasts are both expensive and seldom to be seen. The ultimate for Pentax users used to be the 12-24/4.5-5.6 from Sigma, but for some reasons Sigma ceased their specific kind of Pentax support* with the second iteration of this lens (that added HSM, Sigma's name for what Pentax names SDM). Which I consider a pity; I would very much like to get a full-frame complement for my APS-C 8-16/4.5-5.6 HSM, which I used on my K-5 without any problems whatsoever. That lens is compatible with the K-1, but definitively shows it's smaller image circle (and it's fixed lens-shade) on the K-1's full-frame sensor, as can be seen here: *) we all know about the woes with Sigma's reverse-engineered implementation of the K-bayonet, especially with the 70-200/2.8 DG Macro II HSM ...

05-09-2016, 09:45 AM	#129
gryhnd Senior Member Join Date: Jul 2013 Location: Southeastern MA Posts: 240	Originally posted by funktionsfrei That lens is compatible with the K-1, but definitively shows it's smaller image circle (and it's fixed lens-shade) on the K-1's full-frame sensor, as can be seen here: And ditto their 17-50, and the Bower 8mm (which looks horrid FF, lol).

05-09-2016, 04:00 PM	#130
Rudy Senior Member Join Date: Jan 2013 Location: Texas Photos: Gallery Posts: 109	My Sigma lenses quick check with K-1: Sigma 24-70/2.8 EX DG HSM .... It works fine both live view and viewfinder - If your crop setting is in AUTO, K-1 thinks this lens is CROP, ... Change your crop setting to FF and it works fine. Sigma 70-200/2.8 APO EX DG OS HSM .... It works fine both live view and viewfinder - If your crop setting is in AUTO, K-1 thinks this lens is CROP, ... Change your crop setting to FF and it works fine. Sigma 12-24 4.5 EX DG .... it works fine in both Live view and viewfinder Sigma 15 2.8 DG Fisheye 180 degrees .... it works fine in both Live view and viewfinder I hope it helps

05-10-2016, 02:37 AM	#131
Enigmaticca Veteran Member Join Date: Oct 2010 Location: Melbourne Photos: Gallery \| Albums Posts: 311	Originally posted by Raffwal Can you comment on the IQ and AF accuracy using this lens? Unfortunately I have yet to have the opportunity to get a proper play with that lens. It will need some forward AF adjustment and my initial impression with regards to IQ has been unconvincing thus far

05-10-2016, 02:47 AM	#132
clackers Otis Memorial Pentaxian Join Date: Jul 2013 Location: Melbourne Photos: Albums Posts: 16,397	Originally posted by theEight Just tried my Tamron SP AF 17-50mm f/2.8 XR Di II LD, bit surprised to discover that lens was meant for APS-C to begin with. Shouldn't have been, theEight. That's what the Di II means for a Tamron lens - APS-C. Sigma's code is DC.

05-10-2016, 03:45 AM	#133
Papa Lazarou Site Supporter Join Date: Mar 2013 Location: Bletchley, Buckinghamshire, UK Posts: 340	Sent my 70-200mm HSM II to Sigma UK yesterday. Hoping a lens firmware update resolves my issues.

05-10-2016, 04:17 AM	#134
rawr Veteran Member Join Date: Jun 2009 Posts: 11,913	Originally posted by Papa Lazarou Sent my 70-200mm HSM II to Sigma UK yesterday. Hoping a lens firmware update resolves my issues. In Australia the national Sigma distributor is also the long term Pentax distributor. If any Aussies have any K-1 and Sigma problems, hopefully that will make any necessary fixes easier to arrange.