[tim60]

Ok, so I have the exact same lens and it performs flawlessly on the KP, however when I connect it to the K-1 I get a lot of weirdness;

• AF doesn't always work. Sometimes I have to switch the mode dial to Manual and then the AF works and I can then toggle back to Av where it will work.
• On switching the camera on it wants a Focal length, further cementing it thinks it's manual focus glass.
• I think I might not always be able to get the mirror up, hitting the Info button to access the shortcuts (to change FF>APS Crop Mode), sometimes it won't let me in, kicks me back out

All in all it's just weird on the K-1. KP however it acts like every other lens.

What gives?

I have heard of the same phenomenon with a Sigma lens that worked fully on one body but did not work properly with another. Cannot remember the details.

[5r82]

I'm sorry to hear about troubles with this lens. This Sigma is screw drive lens, right? At least the one I have is. No issues at all. Behaves in the same way as it does on another Pentax camera K-5 II. Have you heard of stories of any other screw drive lens that has issues on Pentax K-1? I haven't. It could all be related to the Sigma lenses that have motor in them. Maybe your lens is faulty or camera.

[BruceBanner]

I have heard of the same phenomenon with a Sigma lens that worked fully on one body but did not work properly with another. Cannot remember the details.

I'm sorry to hear about troubles with this lens. This Sigma is screw drive lens, right? At least the one I have is. No issues at all. Behaves in the same way as it does on another Pentax camera K-5 II. Have you heard of stories of any other screw drive lens that has issues on Pentax K-1? I haven't. It could all be related to the Sigma lenses that have motor in them. Maybe your lens is faulty or camera.

Yeah it's a bit of a weird one. I think it must be the lens. Every other lens I have owned and used that is also Screw drive behaves perfectly fine between the two systems. Odd indeed.

[Le Fanfoué]

K-1 ii + DA* 300mm F/4.
The association of these two products is terrible.

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Last edited by Le Fanfoué; 02-12-2019 at 03:42 AM.

[Hattifnatt]

Few pictures from a cold spell we had over here in Bucharest recently... everything was frozen.

[longbow]

A couple more of the otters from yesterday morning- DFA 150-450

[WPRESTO]

Few pictures from a cold spell we had over here in Bucharest recently... everything was frozen.

The second image is the one that makes me want to stay near the fire,

[jcdoss]

Glory Hole Falls
Newton County, Arkansas
Pentax K-1 mII Ltd Silver, A100f2.8 Macro & Tamron 1.4x

[fs999]

K-1 • FF Mode • 100 ISO • Tamron SP AF Di 90mm F2.8 Macro • Metz Flash 52 AF-1 Digital with softbox


K-1 • FF Mode • 1600 ISO • Sigma Art 18-35mm F1.8 DC HSM


K-1 • FF Mode • 100 ISO • Pentax FA 35mm F2 AL

[jva59]

Quite a storm today in Toronto

[clackers]

*Of course* I've collected stamps. Isn't it obvious?

K-1, Sigma 105mm f2.8 Macro, cheap extension tubes.

[clackers]

Ok, so I have the exact same lens and it performs flawlessly on the KP, however when I connect it to the K-1 I get a lot of weirdness;

• AF doesn't always work. Sometimes I have to switch the mode dial to Manual and then the AF works and I can then toggle back to Av where it will work.
• On switching the camera on it wants a Focal length, further cementing it thinks it's manual focus glass.
• I think I might not always be able to get the mirror up, hitting the Info button to access the shortcuts (to change FF>APS Crop Mode), sometimes it won't let me in, kicks me back out

All in all it's just weird on the K-1. KP however it acts like every other lens.

What gives?

This is a hazard of third-party lenses. They rely on reverse engineering. They don't actually know the protocols of the Canon or Nikon or Pentax AF system, they figure out what they can from an oscilloscope connected to a camera as they try stuff - and they didn't have a K-1 when the 10-20 was designed.

The Sigma 70-200 can have real problems, but a new firmware is available for it if someone's copy is affected.

[clackers]

Portrait of a Texas ranch hand. Tamron 70-200 f2.8 Macro 122mm@ 1/125 f7.1

Love this sensitive shot, Bob … is it a composite?

[BruceBanner]

This is a hazard of third-party lenses. They rely on reverse engineering. They don't actually know the protocols of the Canon or Nikon or Pentax AF system, they figure out what they can from an oscilloscope connected to a camera as they try stuff - and they didn't have a K-1 when the 10-20 was designed.

The Sigma 70-200 can have real problems, but a new firmware is available for it if someone's copy is affected.

Could my 10-20 be updated on the Sigma dock perhaps, so that it works with the K-1?

[eaglem]

Summery colours