Hi there, Pentax owners!
Tonight I managed to utilize the K-3's astro-landscape photo features quite a lot. I did a couple timelapses using a motion control device, (the Syrp Genie, also doing a review currently) ...as well as a couple still images using the O-GPS 1 for "star stabilization" plus the K-3's "additive" compositing for breaking the 30 sec. barrier.
Before I publish my final (pt2) review on SLR Lounge, I have a few questions. (I felt like an idiot when I stated that there was no viewfinder indicator for the current function of the 4-way control pad and a couple readers politely corrected me. Hopefully I can avoid anything similar this time!)
First and foremost, is anybody else as bummed out as I am that ONLY when using the astro-tracking option can we push past the 30 sec. barrier? When I first turned it on and saw that I could just keep cranking my shutter speed all the way up to 300 seconds, I got a little giddy. But it seems, these shutter speeds are ONLY available when using the astro-tracking function...
Speaking of going to 300 sec. with the astro-tracking function, I wish there was a way for Pentax to know which focal lengths will "max out" which shutter speeds; for example I tried a 300 sec. exposure with the 15mm f/4 and it still produced star trails. They looked like the star trails from a ~1-3 minute exposure given that focal length, so hey that's still not bad! But I wish Pentax could have put some sort of intelligent limiter on the shutter speed so that you automatically know how long you can expose before stars begin to move.
Can anybody expand on which focal lengths work at which shutter speeds, by the way? To get all the way to 300 sec. without the stars moving, do I basically need to be shooting with a fisheye? What about that fantastic 200mm f/2.8 that I've seen people post Andromeda etc. images from; how many seconds can you get away with exposing at 200mm and have motionless stars?
I mostly used the Pentax 15mm f/4 and the Rokinon 16mm f/2, and neither of them seemed to be able to shoot at more than 80-90 sec. before the stars all around the edges of the frame started to move, and by 120-150 sec. the entire frame was showing star motion blur. I did a calibration thing, and the camera seemed to think that I had done it successfully, but I just want to know if anybody has significantly different results.
NEXT, I had a little bit of trouble when using an external timelapse device to trigger the K-3 in single exposure mode. (Meaning, I didn't use the K-3's built-in intervalometer)
For whatever reason, even with the AF switch set to MF, the camera still beeps when it thinks things are in focus, and what's worse, it seems to refuse to click a shot at the command of the cable release trigger. This seemed to happen every four clicks, it would beep as if it were hunting or acquiring focus, but it wouldn't shoot.
I think I fixed / reduced this problem by switching from single point to all AF points, but why is this even an issue when I'm in MF? I also checked on my timelapse device because it does have an option to trigger AF or not, and that option was set to off. So, can anybody replicate / explain this? I was doing slow exposures in pitch-black conditions. I was also able to set the timelapse device to increase it's "fire" signal to a whole 1000 ms which seemed to improve the consistency in half-decent light. Still, I'd like to know if the camera is actually refusing to fire because of focus, or another issue that I haven't suspected. (I think it might also have to do with waking the camera up for intervals of 30-60 sec...?)
Anybody have anything they want to mention to me for testing, as far as tips go for the numerous shooting modes that the K-3 has? Stuff like the additive layer stacking is pretty awesome if you ask me, but there might be some other purposes in addition to star trails and compound exposures that I'm not thinking of.
Last but not least, I can't figure out how to turn auto-ISO on. In the quick menu and the deeper menu it gives me all the options for it, but there doesn't seem to be an on/off switch somewhere. I could have sworn I saw something about this though when I first poured over the menus and the user manual, but now I can't figure it out. Long story short, I tried to timelapse a sunset today in P mode with auto-ISO set to 100-6400, so that I could transition smoothly from a beautiful sunset to stars in the sky. Basically the camera meter was (to my surprise) able to maintain almost a perfect exposure until the aperture was wide open and the shutter speed was up to 30 sec, ...but the ISO stayed at 100 so the timelapse just quickly went to black at that point. What am I missing?
Thanks for your time and take care,
=Matt=
(The image below is a blend of a 100 sec. exposure using the O-GPS 1 for the stars, and an additive composite for the foreground of 12x exposures @ 30 sec, f/5.6, ISO 1600)