[hoffm141]

My K3ii was behaving strangely last night during an attempted astrophotography session.
After a half hour of shooting, a half press of the shutter (which I usually use to quickly cycle out of 'review' screens and go back to live view) was actually causing the shutter to release. Turning the camera off/on in the field did not stop the behavior.

After another half hour or so, I finally got too frustrated (and cold) and came inside to sort things out. Removing/replacing the battery did not change the behavior, and setting to a different mode (TAv) didn't either. Since I had TAv set in continuous drive from the last use, it merrily fired off a half dozen frames with a half-press.

I switched lenses to a DA 16-85 and the behavior stopped. I put the 300mm back on, and the behavior did not return. Body and lense had warmed up? I've worked in colder 15-20F (-9 to -6.7) temperatures before without any issues, but I was using an infrared shutter release app in those conditions.

Equipment : K3ii (~15K actuations), DA 300mm* attached. 2x 64MB class10 SD cards. Pixel pro programmable cable release, in wired mode. Tripod.

Camera Settings:
- Bulb mode with astotracer on.
- Live view. After some review of my notes of last years' successes and failures and a scan of postings, I see that mirror lockup is preferred. Noted.
- AF off on body, AF behavior set to back button AF only
- high ISO NR off, Slow Shutter Speed NR off

Conditions:Clear, steady at 35F (1.7C), 60% humidity, wind ~5mph (8 kph)

Question(s):
Is this an equipment issue with the camera body that needs repair, or an interaction with the wired remote?
My fall/winter goal is a nice stack of Andromeda, and I'd like to have things sorted out before the next session (not for at least a week, according to the weather gurus). I'm up for experimenting on cloudy nights to get to the root cause.

As an aside, I got poor max tracking times with Astrotracer relative to previous efforts, but I had chalked that up to poor calibration and opted to just go with more, shorter, sub frames. Calibrating the k3 with the 300 on it has been challenging to do right. Is it advisable to calibrate with just the body cap on and put the lens on 'hot' without turning the camera off?

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Last edited by hoffm141; 11-23-2019 at 02:49 PM.

[Not a Number]

With your hands cold and/or gloved are you sure you were only "half" pressing?

After several hours with the body back at room temperature does the shutter still trigger on half press?

See if it happens again under similar conditions.

There may have been condensation build up in the body that particular night. When you changed the lens the humidity levels inside and out equalized.

[hoffm141]

Thanks for the feedback
My hands were getting cold, but the slightest touch of the shutter release snapped pictures.
The half-press behavour ended within 10 minutes of being back at room temperature (and after a lens change).
I'll try some experimenting this week under similar conditions.

[hoffm141]

Update:
I recently purchased a second K3ii body and took it out for a clear-night spin in 22F conditions to see if I could replicate the shutter release situation in the cold. After about an hour (with the cable release attached) the camera eventually started releasing with just a half press of the shutter.

My next experiment will be without the cable release attached. I can do that in non-shooting conditions (my cold garage) and see what happens.

[tuggie76]

All I can say is I was out in -20c, (-4f) and my k3ii worked perfectly, as for me, not so much!