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M31, M32 and M110

astrophotography dslr tripod


Alen Koebel

M31, M32 and M110

This is a 4-minute total exposure composed of four 60-second sub-exposures through a 200mm f/4 SMC Pentax-M lens @ f/5.6 on a Pentax K-3II DSLR. The K-3II was mounted directly on a tripod. One minute exposures (and longer) are possible in that configuration because of the Astrotracer feature that is unique to Pentax, which performs sidereal tracking without needing an external tracking device. This was a test of the feature on my second night of using it. Obviously, more sub-exposures are needed to reduce noise and increase the captured "nebulosity" (which in this case is composed primarily of stars in the Andromeda galaxy and its satellite galaxies). Also, no CA reduction has been applied in post processing and the image sorely needs it. My carefree processing also blew out M31's core - oh my. Note that this image used no flats, darks or bias frames. Dithering between every frame occurred naturally because of the movement of the object between exposures, which was approximately recentered after the second exposure. Taken August 11, 2018 at the Starfest star party 14km north of Mount Forest, ON.

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