Imaging Companion, D7200 DSLR Messier Galaxy Imaging
Posted: 19 April 2015
Open: Saturday, 18 April 2015, 1906 MST
Conditions: Clear, slightly dusty sky
A new friend who was visiting Tucson came to Cassiopeia Observatory to do some Deep Sky Object imaging using his 8" Celestron HyperStar telescope:
My plan for this night was to image several Messier Catalog galaxies for my Messier Astrophotography Album. 1919 MST: while John was continued to set up his equipment, I viewed Venus, 83X, then Jupiter, 83X and 222X. Three moons were visible at Jupiter. 2019 MST: the Zodiacal Light was nicely visible. I could see it nearly all the way to Castor and Pollux, about 80° elevation.
2035 MST: viewed the following galaxies, 83X, in preparation to image them with the D7200 DSLR (using JPEG, since the Raw converter was not yet available for this new camera): M84, M85, M86. I then slewed to the star Arcturus, mounted the D7200 DSLR at prime focus + extension + off-axis guider, and did a focus test image using the Bahtinov Mask on the 8" LX200-ACF.
Slewed to M84 (galaxy); it was visible centered in the camera viewfinder. And in a rather unique occurrence, a good guide star was nearly centered in the illuminated reticle guiding eyepiece! This is a 5 minute, ISO 5000, guided exposure of M84:
This guided 10 minute, ISO 6400, exposure shows the galaxies M86 (center), NGC4388 (left), and PGC40659 (just left and below M86):
Next was M85. This guided 5 minute, ISO 5000, exposure shows M85 (center), NGC4394 (right), and IC3292 (left):
This is a 10 minute, ISO 6400, guided exposure of M88:
M98, guided 10 minute, ISO 5000:
2314 MST: I took a short break from imaging and sat on the observatory patio, enjoying the view of the night sky from my dark site, and chatted some with John. 2328 MST: went back inside the observatory and resumed DSO imaging.
M91, guided 10 minute, ISO 6400:
And my best image of the night, M99, guided 5 minutes, ISO 6400:
My final DSO imaging target was M104 (Sombrero Galaxy). I did several 30 second exposure framing test images while trying to locate a guide star. I never found one. Rather than rotating the off-axis guider and possibly needing to redo the focus, I decided to just try a 1 minute unguided exposure at various ISO settings. I would go for a longer exposure on the next session. This is an unguided, 1 minute, ISO 12800, exposure:
All of the above images were processed in Aperture, Neat Image (to reduce digital noise in the original JPEG images), and GraphicConverter, and are cropped from the full-frame images.
0058 MST: ended DSO imaging. Removed the camera from the telescope and at 0115 MST, viewed Saturn, 83X and 222X. Four moons were visible: Titan, Rhea, Dione, and Tethys.
0148 MST: viewed M63 (Sunflower Galaxy), M83, and M102 galaxies, 83X. These galaxies will be imaged on the next session.
0213 MST: final look at Saturn, 83X.
It was enjoyable having a fellow amateur astronomer join me for this long night at Cassiopeia Observatory. John, I hope you got some great images.
Close: Sunday, 19 April 2015, 0246 MST
I have posted my review of NightCap Pro v6, which is an amazing iOS app for astrophotography. If you have an iPhone, check it out.
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