[Racer X 69]

I finally had a chance, and the energy, to get out last night and try the K-1 out for some night work, with the Sigma 16mm f2.8 Rectilinear Fisheye mounted. This was my first ever digital star trails effort, only having use Kodachrome before, many years ago (I gotta find those slides and copy them with the K-1).

Combined with StarStax, post processed in Photoshop.

Same set, squeezed a bit differently each time, resulted in slightly different colors in the stars.





I have plenty of room for improvement, and will get out again, and try for more shots over a longer period of time.

Next up, Racer tries that pesky Astrotracer feature.

Stay tuned . . . . .

[Racer X 69]

And here we go.

Astrotracer, take one.




This one I tried to light paint the house with a hand held spotlight.







I tried the calibration thing, but it didn't seem to want to finish, as there was never a confirmation of successful completion, and when I tried to exit and start shooting it said it wasn't done.

How long does it take?


Not sure if the stars around the edges are trails from star movement, or if it is coma from the lens.

[Racer X 69]

I had one shot where I fumbled the shutter release. The camera was set for bulb shooting, and I managed to double tap the button, causing a very short exposure. A bit of processing in Photoshop and I have a nice map of the major stars looking North. Looks like the big dipper to the left.

[Racer X 69]

I have no idea what happened here. Perhaps the mirror wasn't fully retracted when the shutter fired.

[gifthorse]

"I tried the calibration thing, but it didn't seem to want to finish, as there was never a confirmation of successful completion, and when I tried to exit and start shooting it said it wasn't done.

How long does it take?"

The question should be "How short does it take?" Rotate the camera on all three axes as quickly as possible. Repeat the rotations until you get confirmation. It may take several rotations around each axis before the calibration is accepted. You don't have to swing or spin the camera a full 360 degrees. 180 in each direction will work. I'd suggest putting the camera strap around your wrist during the rotations in case the camera slips out of your hands. Anytime you shut off the camera it has to be re-calibrated and I will usually re-calibrate every hour or two throughout the night.

[Kevin B123]

How long does it take?

You must press the OK button after calibration, It takes two minutes if you have a cup of coffee while doing it.
You have good results here for the star trails already.
I won't publish my latest efforts.
When in bulb mode and tracking, observe that the green button in the rear display is showing 'on', if not you will be trailing,

[MossyRocks]

I tried the calibration thing, but it didn't seem to want to finish, as there was never a confirmation of successful completion, and when I tried to exit and start shooting it said it wasn't done.

How long does it take?

It can be a bit fiddly until you get use to it. Smoothness in movement and limiting movement to only one axis at a time seem to be the biggest factors on getting a good calibration. The first couple of times I used it I got sub-optimal results but the more I used it the better I got. I would suggest practicing calibrating it during the day until you can consistently get it to say it completed. To check your calibration stick a telephoto lens on and do a 20 or 30 second exposure on a bright star. You shouldn't see any trails but if you see short ones redo the precise calibration, if they are long trails redo the both the coarse and precise calibrations.

I don't turn it super fast but even then a run through of all the rotations only takes about 20 seconds and I usually rotate it closer to 230 degrees back and forth instead of the minimum 180 that is necessary. Every once and a while it will state it has completed after just a rotation in one direction which I know is wrong. Most of the time by redoing that calibration it will complete after doing 3, but even then there have been a handful of times when it would just keep completing after 1 rotation. At this point just turning it off and starting fresh seems to be the only solution.

[Kevin B123]

I don't turn it super fast but even then a run through of all the rotations only takes about 20 seconds and I usually rotate it closer to 230 degrees back and forth instead of the minimum 180 that is necessary. Every once and a while it will state it has completed after just a rotation in one direction which I know is wrong. Most of the time by redoing that calibration it will complete after doing 3, but even then there have been a handful of times when it would just keep completing after 1 rotation. At this point just turning it off and starting fresh seems to be the only solution.

These are well observed points. I have had failures after accepting a complete calibration with only two axis completed. That was me being sloppy and I paid for it.

[Racer X 69]

I spent several hours shooting 226 frames the other night, from just after sunset, until the moon came up. I processed the image a couple of different ways. Here is a couple. Click through to my Flickr album to see them all.

The arc from left to right is a pass by the international space station.

[MossyRocks]

I spent several hours shooting 226 frames the other night, from just after sunset, until the moon came up. I processed the image a couple of different ways. Here is a couple. Click through to my Flickr album to see them all.

The arc from left to right is a pass by the international space station.

Have you thought about turning that pile of images into a time lapse image? I don't know how long each shot was but if the stars are mostly still points it might make for a fun video. It is pretty easy to do using ffmpeg if you have a pile of images already. I think I used this tutorial when I learned how to do it.

[Racer X 69]

Have you thought about turning that pile of images into a time lapse image? I don't know how long each shot was but if the stars are mostly still points it might make for a fun video. It is pretty easy to do using ffmpeg if you have a pile of images already. I think I used this tutorial when I learned how to do it.

Good suggestion, I'll need to look into that.

I did allow the camera to do something like that earlier. The K-1 has a feature where it shoots a series of images, then combines them in camera. I set it to shoot 120 images, each exposed for 30 seconds (the maximum the K-1 will do is 30 second exposures). After all the effort, it was a bit disappointing. Nearly two hours of shooting, and the result is a 15 second video.

Here it is:

You Tube

You Tube

[MossyRocks]

Good suggestion, I'll need to look into that.

I did allow the camera to do something like that earlier. The K-1 has a feature where it shoots a series of images, then combines them in camera. I set it to shoot 120 images, each exposed for 30 seconds (the maximum the K-1 will do is 30 second exposures). After all the effort, it was a bit disappointing. Nearly two hours of shooting, and the result is a 15 second video.

Here it is:

Star Trails In July - YouTube

With ffmpeg you can play around with the framerate and/or repeat images and get longer timelapse videos but in general they are will be short. The last time I wanted to that I screwed up and had the camera doing a composite average instead of shooting individual frames. So instead of being able to get a nice timelapse of a big storm rolling through I got a single awful shot of an averaged storm.

Well, the intent was stars, not trails, but I clearly haven't figured out "astrotracer", yet. This was a thirty-second exposure with a K-1 hanging off the back of a 560mm lens, aimed almost due South (from Virginia). What I thought was interesting about it was the five little dots that didn't make trails. I figure they must be satellites in geosynchronous orbit (23,500 miles up, they're probably catching the morning sun, as this was taken about two hours prior to dawn). The colors of the trails were neat, too.

...Anytime you shut off the camera it has to be re-calibrated ...

What?!?!?! You're kidding, right? Is that an "undocumented feature"? I didn't see it in the (K-1) instructions. It does say (page 75), "Changing the lens or the angle of the monitor after performing a precise calibration may have some effect on the magnetic field environment. In this case, perform a precise calibration again." What the heck "monitor" are they talking about?

Secondly, how precise is "precise calibration" - it's pretty hard to rotate the thing precisely around the sensor-plane, particularly with the battery grip attached. Could I, for example, sit in my swivel-chair and just spin around with the thing in my hand?

[MossyRocks]

What?!?!?! You're kidding, right? Is that an "undocumented feature"? I didn't see it in the (K-1) instructions. It does say (page 75), "Changing the lens or the angle of the monitor after performing a precise calibration may have some effect on the magnetic field environment. In this case, perform a precise calibration again." What the heck "monitor" are they talking about?

Secondly, how precise is "precise calibration" - it's pretty hard to rotate the thing precisely around the sensor-plane, particularly with the battery grip attached. Could I, for example, sit in my swivel-chair and just spin around with the thing in my hand?

30 seconds @560mm is probably pushing it. I've managed 20 seconds at 400mm.

As far a precise calibration I think it is a re-sampling of everything to try and get the error down. I find that I will get a better calibration if I keep where I want to point the camera about in the middle of the calibration movements. I also find it helps if I go beyond 180 degrees to something closer to 250 in each of the movements so like 120 degrees in each direction from where you started. If it ever says calibrated successful after 1 or 2 movements I know something was wrong. I would also check for nearby things that have their own magnetic field. This includes things like power lines, transformers, large chunks of iron/steel, fans or electric motors, etc. Also if you have excessive iron in the soil it will throw it off, I had this problem last weekend up in the iron range of MN and couldn't get a calibration to work or if it did it was way off.

It looks like you weren't tracking at all with the 5 stationary dots but streaks for the stars. I've had the GPS go to sleep if I stepped away briefly and then the next shot I took didn't use it and it turned out bad so I'm wondering if that happened with that one.