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Comet Lovejoy Last Night

Comet C/2014 Q2 Lovejoy has reached its maximum brightness. This is a photo of it last night, as seen under the dark skies of the Eastern Sierra. Knowing where to look (near the star cluster Pleiades) I was able to just make it out with my eyes, then find it with a 70-200 mm lens.

It showed up well in photos captured on a full frame DSLR with 16 – 35 mm lens at 30 mm focal length with no star tracking mount, but for the 200 mm shots I used a tracking mount so the stars wouldn't "drag" in the photo from the rotation of the earth.
#science #news #astronomy #astrophotography #photography
www.JeffSullivanPhotography.com

 

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42 thoughts on “Comet Lovejoy Last Night”

  1. +Gary Randall Thanks, i was pleasantly surprised at how much of the tail I was able to pick up. Over the course of four nights I tried just about every option with my Canon 70D and 5D mark III, including Bulb exposures as long as 1, 2 3 4, 5 and 6 minutes, as well as ISO settings up to "H1" (51,200)! Everything over a minute or so in shutter speed wasn't steady enough for the stars to turn out as single spots. I'll have to look up these particular files to see how long they were exposed for; I'll get back to you on that shortly.

  2. +Jeffrey J Davis One of the first things I tend to do when I get a new camera is turn off high ISO noise reduction, singe that feature typically disables your camera for the same length of time as your original exposure. One of the things they seem to be doing is taking a "dark frame" to detect hot pixels.

    In cameras with a second CPU like the Canon 5D mark III and I think the 5D mark II, the camera seems to be able to perform noise reduction in the background, in parallel with taking the next exposure. I don't know how that could include hot pixel detection if the shutter is open, but in ambient temperatures of 60 degrees or less I rarely see more than a small handful of hot pixels (maybe two to six), so I don't really worry about it.

    When I get the cameras out tonight I'll try to remember to check the long exposure noise reduction settings, but I strongly suspect that they're off.

  3. +Steve Montalto I used the iOptron SkyTracker. I haven't tried the others on the market, so I can't really comment on how it compares, but it does have a "polar scope" for accurate alignment with the North Star, Polaris, so in theory it should at least calibrate really well to your latitude and to North.

    Here's time-lapse video I captured of Comet Lovejoy:
    http://youtu.be/0D2tdjiE9PQ?list=PLlLN6Bdq3jrkPpSZ-sc8hi7T5BxJuzuZx

    The second two clips were taken using the tracking mount, at 320mm effective focal length then 640 mm. I should contact the manufacturer of the mount to see if I have something not set right for the 3rd and 4th clips to be a little jumpy.

  4. +Jeff Sullivan Thanks for responding, you answered my question. I shoot Nikon D7000 but you are right, there is approx 20 – 25 seconds processing between shutter releases shooting RAW with high ISO NR on. That's not acceptable in many situations, and I guess you can always NR it in post processing in Lightroom and make sure you get all the shots you want.

  5. +Gary Randall I combined exposures of 20, 25 and 30 seconds shot at f/4 on the Canon 70-200 f/4 IS lens. At 200 mm on my Canon EOS 70D the equivalent focal length was 320 mm. I added a 2X teleconverter last night to bump the focal length up to 640mm, but that reduced the fastest aperture to f/8, so I used 1 minute exposures and settled for darker results. I just posted a time-lapse video from 147 images last night here on G+:
    https://plus.google.com/107459220492917008623/posts/Scbh5e7Ghek.

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