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Thread: Shadow Mountain Aurora

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    Default Shadow Mountain Aurora

    I was in Jackson, WY back in June. My friends and I spent a few nights up on Shadow Mountain. We were fortunate enough to catch the aurora borealis on one of those nights. The camera saw more color than I did. The pillars were more golden than magenta. However, what you see is not a white balance anomaly. I've tried "correcting" the color numerous times and what you see was what the camera saw. I had two cameras going, one time lapse, one still. I interrupted the time lapse camera a few times to check the images so there were gaps. The ISS passes through the scene during the initial the initial start of the movie. Then, in the first few seconds, you'll see what appears to be a bolide changing direction 180 degrees in the upper right corner. It's actually an Iridium flare that happened to be caught between two frames of the time lapse.

    Last edited by Michael Lloyd; 09-15-2012 at 10:48 AM.

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    Hi Michael,

    Way cool. I've been trying to get out and see aurora this year but I have not yet succeeded (and during trips up north to Alaska and other places, the sun was quiet),

    Please tell us what lens, camera and exposures you did to make the video.

    Roger

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    The initial sequence was shot with a 14mm f2.8L II lens on a 60Da. The lens was set to manual focus (I think. If it wasn't it should have been). The camera was in manual. Settings were:

    ISO 1000
    f4@ 20s

    Note- Why I had the lens stopped down to f4 I have no idea. It should have been at f2.8. I suspect that being tired was a big part of it. I spent 2 weeks in Jackson and we shot the aurora toward the end of the trip. We got up at 4:30 every morning and didn't stop until after 10 or 11pm every night.


    The later sequences were shot with the same camera / lens combo. I managed to catch my f stop error and I wanted a shorter shutter speed so settings were

    ISO 5000
    f2.8@10s

    Note: This was my first outing with the 60Da. I've since settled on ISO 3200 as max (when it's hot out, I'm curious about what it's going to look like when it's cooler out). I've switched to the Zeiss Distagon T* 2.8/21 ZE lens. It's so magnificently sharp that when I shoot stars I see trailing even at 10s. I often tell people that it's so sharp I have to wear eye protection when I use it. I'll typically shoot nightscapes, stars, time lapse at 10s @f2.8 these days. I start with ISO as low 1600 and usually push 1/2 stop in ACR.

    I thought that I had shot some TLV with the 5DMKII but I guess I only shot stills with that camera.

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    Hi Michael,
    Thanks for the info. I haven't analyzed a 60Da sensor myself, but it is probably identical to the 7D sensor. With the 7D I would do ISO 1600 max. At that ISO, fixed pattern noise is minimized, and one gets a factor of 2 more dynamic range than at iso 3200. That keeps more color in brighter stars, but still gets the low end as well as the sensor can. Then I'll increase mid and low levels with the curves tool.

    I'm doing night sky images with a 24 mm f/1.4 L lens on a 1D4 (which has less banding noise than any canon camera I have tested; the 7D I tested as second best, so the 60Da should be similar). I expose at ISO 1600, f/2. An example of a 30-second exposure (tracked) is here: http://www.clarkvision.com/galleries...1.c-1000v.html
    I have not tried a movie with it yet, though. Making a movie would be a lot of images to run curves on, but a simple action would ease that effort.

    I too find that at 10 second exposures, trailing is just visible.

    Keep up the great work!

    Roger

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    Roger,

    The a in 60Da stands for astronomy. The camera is Canon's second release for the astronomy community. The sensor is more sensitive to Ha (hydrogen alpha) light and it has pretty decent noise characteristics. It still has filtering on the sensor so it can be used during the day (I don't) but it's more sensitive to red and takes less exposure time for night shots.

    After Effects and Premiere Pro are good tools for movie making. It's very easy to make the transition from photoshop to Premiere and AE. LRTimelapse is a great "smoothing application. Guenther Wegner has done a great job with the creation of this tool. It used to be shareware but he's switched to paying for it recently. Unfortunately for me, he uses PayPal (I despise that company) so I am stuck with an older version of software.

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