Time lapse of Aurora and Airglow

[OzEclipse]

I have rendered a time lapse video covering short sessions over 5 nights in Tasmania. 3 nights of aurorae and two of airglow. I had problems with fogging on a couple of nights.

https://vimeo.com/1088274898?share=copy

Joe

[Leo.G]

Every bit of that is stunning Joe!
What equipment do you use to do the time lapse or is that a timer feature on your K1000?

[OzEclipse]

Hi Leo,

Thanks for your kind words.

The K1000 is a 1970's film camera. My camera is a K1, a full frame 36MPx Sony sensor with a lot of Pentax functions that assist an astrophotographer. Built in star tracking, extended shutter speed range to 20 mins are just two.

Pentax firmware does have a built-in time lapse function but it is part of the video capture menu and renders the video directly in camera. This is not the best for low light capture although some high end Sony cameras can render good low light video directly.

I prefer to capture in raw and render the video in post processing allowing luminosity adjustments and noise reduction to be applied to each frame. I use a cheap $25 intervalometer. I have been using the same models for 15 years. Yes they do eventually fail but at $25 I own about 4 of them with a set of interchangeable end plugs for all different camera types which I use when running my workshops. I think two have failed in 15 years of heavy use.

This is the Neewer badged version($34) of the model I use, some other badged versions are identical models and up to $10 cheaper.
https://tinyurl.com/pc63c9mh

This intervalometer lets you set 4 parameters:
1. Delay until sequence start: up to 100hrs
2. Length of shutter press: up to 100 hrs
3. Interval from end of exposure to start of next exposure: up to 100 hrs
4. Number of exposures in sequence up to 400 frames*

Another method is to set the camera to continuous shooting mode, use a locking cable switch to have the camera shoot exposures in manual mode back to back to back. Most cameras are limited to a maximum of 30s exposures using this method. Most higher end cameras have extended shutter speeds. The K1 for example has an extended shutter speed range up to 20 mins.


Parts of my video capture (eg. the last red airglow sequence was quite faint) were taken with 90s sub exposures using the Pentax internal star tracking (Astrotracer). The Astrotracer is not a total solution and I use mount tracking for many things. The advantage of this function in time lapse is that the sensor rotates using the image stabiliser to minimise star movements. But the sensor resets for every sub so you don't get a constantly rotating horizon. The camera uses tilt sensors and GPS to work out what part of the sky you are pointing at and moves the sensor to minimise star motion over the entire frame. It's not perfect but has its uses. Using an ultra wide lens pointing at the celestial equator, stars are stationary over most of the frame but top right and bottom left corners have stars with short radial streaks because the sensors 2D movement can't correct the circular motion at high north and south declinations.

My workflow is: -

1. Capture raw in camera driven by intervalometer
2. Process raw in Adobe Lightroom
3. Render each session sequence to a video clip in Adobe Lightroom
4. Import clips to video editor. Add titles, transitions, music track. Adjust play speed of each video clip.
5. Export to Video then upload to video streaming site for public viewing

Due to problems with fogging, short events, I didn't have enough frames. Many of the video clips went by so fast they were only 1-2s long at 25 frames per second. So, I rendered all the video at 15 frames per second then set the shortest sequences to play at 1/2 speed inside the video edit. This resulted in some flicker but gave the viewer time to absorb each sequence.

Joe

[Leo.G]

Sorry, I thought I had that wrong and was thinking wasn't that a 35mm film camera. My friend owned the K1000 back in the day.
K1, I'll remember that.
Ah, I was going to ask if the K mount lenses fit but I'm reading the DP review pages and it will with some caveats (no sensor contacts, no auto-focus).



I have the same intervolameter here, one of a few. I have one wireless unit but the batteries don't like the cold and it was nothing but a pain, as is tripping over a lead in the dark. Still the handiest of devices.

[OzEclipse]

My intervalometer stays hanging on the tripod no cord to trip on. Two standard discount alkaline batteries last for several nights of all night shooting. Perhaps 15-20 hours. Nights were short on this trip. I didn’t change batteries and they still have plenty of juice.
Joe

[JA]

Excellent Time lapse sequences Joe :thumbsup::thumbsup::thumbsup:

Best
JA

[Pierre_C]

I think the video is really beautiful, Joe.

I particularly liked the 8 May airglow sequence at Freycinet Peninsula. There is so much interesting movement going on - airglow, clouds, reflections, shaddows, celestial sphere with Milky Way, satellites, ferry (and a lightning storm in the background?)

An excellent composition and series of contrasting events.

[OzEclipse]

Pierre,
Thanks for your kind comments.

Yes there was a thunderstorm over the horizon at Freycinet. Could not see the strikes just the flashes. Boats were more likely to be fishing trawlers. No ferry routes there, certainly not at 4am.
Cheers
Joe

[N1]

Hi Joe, another great sequence! The middle one (Bay of Fires) with the distant lightning is particularly stunning. We missed that part of TAS last year (but did go to Maria Is) so will have to come back sometime...

[astronobob]

Very enjoyable Joe, and without the chill it just doesnt feel the same eh ;)
I also noticed the lightning aswell, , Id have thought you'd have Dew Zapps for the camera lens ?
The exposures are excellently measured for a beautiful histogram curve, looking very natural as a night video-lapse indeed,,
Privileged to watch Thnx Joe :thumbsup:

[OzEclipse]

Hi Bob,

Thank you for your kind comments.

I did have a dew strap but forgot to bring my portable power bank and was out of reach of the car. [Visualise me kicking myself]


I borrowed one from a friend for a couple of days then bought one which I used for the airglow events.

Joe