FIRST LIGHT

Sky at Night Magazine - - FIRST LIGHT -

and a 640x480 ROI. With Mars be­ing low and in the midst of its dust storm it was hard to re­solve de­tail, but the re­sults did show that the camera can be a bit of an all-rounder at imag­ing.

A few nights later we switched over to an f/2.2 Rowe-Ackermann Sch­midt Astrograph (RASA) tele­scope. In full frame mode the camera will run out­side the imag­ing cir­cle on this type of setup and cre­ate vi­gnetting, so it gave us a good chance to try the ROI modes. The first tar­get was the Whirlpool Gal­axy, M51, run­ning 30-sec­ond ex­po­sures with the cool­ing set to –30° be­low am­bi­ent tem­per­a­ture. The camera per­formed very well, not drop­ping any frames when cap­tur­ing in high bit mode. We moved through a few tar­gets in­clud­ing M13, the Great Globular Clus­ter in Her­cules, and M27, the Dumb­bell Ne­bula.

In full-frame mode the camera is best suited to an aper­ture of around 70-100mm, so we set the camera up on a 70mm quad re­frac­tor for the next out­ing, go­ing for wide-field tar­gets like the North Amer­ica Ne­bula. Setting longer ex­po­sure times of 180 sec­onds worked very well. There was no amp glow in the im­ages in USB2 mode, even when con­nected via 10m USB2 ex­ten­sion leads, and this made pro­cess­ing with cal­i­bra­tion frames very easy. Setting up with a 152mm triplet we took a chance on M31, the An­dromeda Gal­axy, which was ris­ing in the north against a bit of a light blue sum­mer night sky. Run­ning in full-frame at 60 sec­ond ex­po­sures for 50 min­utes re­solved lots of nice de­tail in the dust lanes and the core. When we pro­cessed the im­ages, it was nice to see some rich colours from a CMOS camera.

The ZWO may have an ex­pen­sive price tag, but it re­ally is a great per­former.

M13 (left) and M27, both cap­tured with an f/2.2 RASA; 50x30“ex­po­sures

The Moon im­aged us­ing the ZWO ASI094MC Pro and a 125 EDF re­frac­tor; 20 frames stacked from 20 cap­tured

The North Amer­ica Ne­bula taken through a 70mm quad re­frac­tor; a sin­gle 10-minute im­age

A dusty Mars; 300 frames from 3,000

M51 with an f/2.2 RASA; 100x30“shots

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