William Optics GT71 with WO Field Flattener 6A2

Configuring a lightweight portable astrophotography imaging system

I use an assortment of telescopes, micro four thirds cameras as well as dedicated astrophotography CMOS cameras not to mention tracking mounts. With many different possible camera / telescope configurations, I find It important to document the imaging train setup of working systems for future reference.
The main dedicated astrophotography one shot colour camera I use is the ASI294MC Pro. When attached to the William Optics GT 71 there is considerable optical distortion on the periphery, ie the field is not flat. Fortunately William Optics sell an optional field flattener, the 6A2  to correct for this.

William Optics GT71 with 6A2 field flattener

William Optics Field Flattener 6A2

Attaching the ASI 294 MC Pro one shot colour CMOS camera to the William Optics adjustable field flattener 6A2 is simple using the two extension rings as supplied by ASI. The optional WO T- mount (or equivalent) is necessary to attach the camera and flattener to a telescope, in this case the William Optics GT 71. The field flattener is adjusted to 9.3mm as specified by William Optics.

Optical train - William Optics GT71 with 6A2 field flattener
Close up - William Optics GT71 with 6A2 field flattener

William Optics GT 71, Field Flattener 6A2 & ASI 294 MC Pro

A close up on the “business end” on the imaging system.

William Optics GT71 with 6A2 field flattener

M7 captured with William Optics GT 71, Field Flattener 6A2 & ASI 294 MC Pro


Swan Nebula captured with William Optics GT 71, Field Flattener 6A2 & ASI 294 MC Pro


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