Observing at Coyle Field
Evening of April 5, 2016

Here's a wide-angle view of Coyle Field on April 5, 2016, at 7:44 pm EDT, 18 minutes after sunset. It's centered towards the north-northeast and shows my 12.5-inch dob setup behind my car, left of center. Dan P's 18-inch dob is to the right at the end of the runway. The next two photos zoom in on our scope setups. Taken with a Canon EOS 6D digital SLR camera, on a fixed tripod, and a Sigma 20 mm F/1.4 DG Art lens, then cropped to a 16:9 ratio. Exposed 1/30 second at f/2.8, ISO 640.

 

 

My car and scope at 7:49 pm from the same location as the previous wide-angle picture (I went southwest down the runway to get a better viewpoint for low-altitude Mercury). Taken with the 6D camera on a tripod, but this time with a Sigma 70-300 mm f/4-5.6 APO DG zoom lens set to 300 mm focal length. Exposed 1/20 second, f/5.6, ISO 12800.

 

 

Dan P's car and scope at 7:51 pm, taken from the same location as the previous two pictures with the same 6D camera on a tripod, and a Sigma 70-300 mm zoom lens set to 300 mm focal length (then lightly cropped). Exposed 1/15 second, f/5.6, ISO 12800.

 

 

While observing and taking pictures of Mercury low in the west, I swung around and took a single snapshot of Jupiter in the southeast (at 37.5° altitude) with the 70-300 mm zoom lens. I wanted to see how well the Galilean satellites were resolved at the 300 mm setting with this relatively inexpensive lens that I acquired at the end of 2015. Here's the result, cropped to 20% of the original linear dimensions to magnify the view. Taken at 7:59 pm with the 6D camera on a tripod. Exposed 1/2 second, f/5.6, ISO 3200 (an automatic exposure, so it's probably overexposed at least a few stops for bright Jupiter and its satellites against a darkish background).

 

 

Here's a picture of Mercury at 8:16 pm, taken from the same spot as the previous three pictures, but now looking roughly west. Mercury was at magnitude -1.1, 4½° altitude and 284° azimuth. Taken with the 6D camera on a tripod and the Sigma 70-300 mm zoom lens set to 300 mm focal length. Exposed 1/3 second, f/5.6, ISO 3200. Mercury was first spotted at 7:48 pm with 16x70 binoculars, then it was relatively easy to see with unaided eyes (there were no clouds along the horizon like the evening of April 3rd). The post-like structure rising from the tree top is a wind sock (although we infrequently see aviation activity here, Coyle is an airfield).

 

 

Observing at Coyle Field
Morning of April 6, 2016

It was now past midnight, becoming the morning of April 6, 2016. This view of the Ophiuchus-Scorpius area, including the relatively tight triangle of of Saturn, Mars and Antares, was captured at 1:22 am EDT. Of particular interest, Comet 252P/LINEAR was in eastern Ophiuchus, near the globular cluster M14 (mouseover for labels). Taken with a Canon EOS 6D digital SLR camera on a fixed tripod and a Canon EF 40 mm f/2.8 STM pancake lens. Exposed 6 seconds at f/3.2, ISO 4000.

 

 

Here's a closer view of the Saturn-Mars-Antares triangle (roughly 6° to 9° on the sides) and the upper part of Scorpius at 1:33 am (mouseover for labels). Taken with the 6D camera on a fixed tripod and a Canon EF 100 mm f/2.8L macro lens. Exposed 6 seconds at f/3.2, ISO 4000.

 

Here's a closer view of Comet 252P/LINEAR near M14 in the northeast quadrant of Ophiuchus at 1:38 am (mouseover for labels). Taken with the 6D camera on a fixed tripod and a Canon EF 100 mm f/2.8L macro lens. Exposed 6 seconds at f/3.2, ISO 12800. Besides 252P, we also observed comets C/2013 US10 (Catalina) and C/2014 S2 (PANSTARRS) earlier in the night. I did not take pictures of the latter two, but visually, C/2014 S2 was at least as good as 252P (S2 was quite high, just north of the Big Dipper's bowl, and by the early morning hours when we finally were able to see 252P, it was  low in the east, and it seemed that transparency had declined a bit).

 

 

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