[Steinback]

I haven't seen any mention of this workaround elsewhere yet.

I received my Sigma 70-200 II HSM and 120-400 HSM back from Sigma service with shiny new mounts and updated software but they still cause the K-1 to lock up as soon as the body is turned on (Firmware 1.1). To turn the body off and unlock it the battery must be pulled.

In testing the lenses further with a friend we discovered that taping over the HSM contacts on the lens allows us to use a Sigma HSM 50mm f/1.4 and the HSM 70-200 as manual focus lenses with full aperture control without our cameras locking up (so far). Not really a long term fix, but at least the lenses are acting like KA mount manual versions of themselves. I will try my 120-400 on the weekend and see if it reacts the same way. Once Sigma confirms that they have a hardware or software fix that actually works both of my lenses will be heading back for another try at service.

[Adam]

Interesting. By the way, also try updating the camera to 1.2. Maybe Pentax silently fixed the bug on their end, though I wouldn't count on it.

[Steinback]

With an unmodified lens 1.2 works like 1.0. Sometimes the body locks up at boot, sometimes it freaks out for awhile and makes a few attempts to AF or lets a photo be taken before it freezes. In computer terms it feels like the camera is trying to process either way too much data or settings it can't understand and it is slowing down and acting erratically until it has a fatal error.

[rawr]

they still cause the K-1 to lock up as soon as the body is turned on

Interesting. Even after Sigma updated the lens firmware? That was supposed to correct the lens type ID for the 70-200 HSM II.

My Sigma 70-200 HSM II (Lens Type: 8 16) on the K-1 just keeps on shooting and focusing without any problems, touch wood. I haven't sent it back to Sigma to fix the mount yet. Maybe I won't now, for fear of introducing some gremlins into the system via their firmware.

[MightyMike]

Most of you by now should know that there are some (just a minor few) Sigma HSM lenses that for whatever reason aren't working on the K-1.

My Sigma 50mm F1.4 EX DG is one of them, Now i had it in for servicing and a new mount at Gentec; they fixed the mount and sent it back without addressing the other issue, I know some of the people working there so i called up and chatted with them about it, they looked into it and will be checking if a new circuit board will fix the issue. They also informed me the mount they might have used as the replacement a Sigma 35mm F1.4 Art mount initially recommended by Sigma may not actually be the correct fit and they will replace it with the proper replacement mount when i get the lens back in.

I was discussing this stuff with a fellow Pentaxian a friend who has issues with his Sigma 70-200mm F2.8 EX DG HSM Macro II and Sigma 120-400mm F4-5.6 HSM... His also came back with mount replacements but still not working on the K-1, He said they worked marginally better under firmware 1.0 but just crashed the K-1 under any newer firmware. Anyhow we got looking into what taping/shorting some of the pins might do. It would appear that if you tape over the HSM contacts the camera doesn't crash however catch in focus doesn't work anymore. To enable focus trap you have to short the data pin. Strangely on my 50mm F1.4 if i do this the aperture range the camera offers is F5.6-F32, and it over exposes 4 stops. if I short the data pin and the next pin I get F2.8-F32 and of course 2 stops over exposure If i short out the data pin and the next 3 pins I get F1.4-F22 with proper exposure except at F22 as the lens is only designed for F16 it over exposes by 1 stop. Just a note, if i don't short out the data pin the aperture range is accurate.

This is not a solution, however for those with problem lenses who want to test them out on the K-1 for quality by manually focusing you can do so this way. Strangely shorting the data pin seems to throw off the binary pin-out used by A-series lenses.

For a Pin-out diagram and look-up chart for A-series pins here is a link, the data pin is the bottom most pin not shown in this write-up

Features and Operation of the Ka Mount

*Also would just like to add for the purposes of testing you don't have to remove the battery to get the camera unfrozen again, just pressing the release button and rotating the lens slightly will unfreeze the camera.

[stevebrot]

Thanks for the detailed description and information from Sigma on the subject.

I was discussing this stuff with a fellow Pentaxian a friend who has issues with his Sigma 70-200mm F2.8 EX DG HSM Macro II and Sigma 120-400mm F4-5.6 HSM...

Might this be the forum user who reported the continued issue and manual focus workaround yesterday on this site?

https://www.pentaxforums.com/forums/190-pentax-k-1/327255-manual-focus-workar...lenses-k1.html


Steve

[MightyMike]

Thanks for the detailed description and information from Sigma on the subject.



Might this be the forum user who reported the continued issue and manual focus workaround yesterday on this site?

https://www.pentaxforums.com/forums/190-pentax-k-1/327255-manual-focus-workar...lenses-k1.html


Steve

I hadn't realized he posted as well

[stevebrot]

I hadn't realized he posted as well

The mods merged the threads!


Steve

[banep]

With an unmodified lens 1.2 works like 1.0. Sometimes the body locks up at boot, sometimes it freaks out for awhile and makes a few attempts to AF or lets a photo be taken before it freezes. In computer terms it feels like the camera is trying to process either way too much data or settings it can't understand and it is slowing down and acting erratically until it has a fatal error.

Would you be so kind to publish LENS ID from jpg exif data.
I have a doubt that lens firmware was not updated.
If it is not possible to take a shot on K-1 try with older body.
Thank you.

[Steinback]

Lens ID from the 70-200 is 8 255. According to the work order I got back from Sigma they did update the software on the lens. It is possible that they put the wrong software on the lens, that they didn't actually perform the update, or that it needs a more substantial change like having the circuit board swapped to a newer version.

[rawr]

Lens ID from the 70-200 is 8 255

Aha. The Lens ID that works nicely with the K-1 is 8 16, as a few other 70-200 HSM II owners have discovered.

You might invite your Sigma service centre to have another go at updating the lens, or explain in a bit more technical detail why they can't implement Lens ID 8 16 for you.

[funktionsfrei]

Lens ID from the 70-200 is 8 255. According to the work order I got back from Sigma they did update the software on the lens.

I'd say that something went wrong with that.

Some weeks ago I had my 70-200 serviced, prior to that it was a "8 255" lens (and made the K-1 freeze), but after the servicing it changed to "8 16".

Since then the lens works fine on my K-1.

So I recommend that you'll return that lens to Sigma, cause using it in "full manual" really is no fun.

[faf704]

I sent two of my lenses off for updating
- Sigma 70-200 f2.8
- Sigma 150-500 f5-6.3
and they are now working although the 150-500 is a little slower