Astro-Tech Dedicated 0.8x reducer/field flattener for the Astro-Tech AT80ED

I paired this reducer/flattener with my AT80ED f/7 scope to bring the focal length down to 448mm at f/5.6. This gives my scope extra speed and a wider FoV for imaging large objects like the Andromeda Galaxy etc. I tried it out with my OGMA AP26MC monochrome APS-C 28.3mm sensor and am very happy with the performance! I am able to image luminance using short sub exposures without even needing guiding (ZWO AM5 tracking only). I saw minimal vignetting in two corners that I corrected with the free GraXpert AI gradient removal tool and didn't even bother shooting flats! Stars are round throughout the center, but I could probably add another 0.5mm spacer in my imaging train to improve the very far corners even more. Barely noticeable after using StarNet++ as the starfield is stretched less and separately than the galaxy/nebula.

I love how the combination of this rig allows me to image even on windy nights with poor seeing or for the larger wide-field targets. I do recommend using a UV/IR cut filter as the very blue UV light and very red IR light could potentially bloat your stars a bit especially if you are doing longer exposures. Using any sort of narrowband filters (even the lower cost 12nm dual band etc) remove this problem completely, and in my opinion remove the need for more expensive APO triplets!

This scope and reducer/flattener give good results when used properly, and in my opinion are a *great* value for beginner and intermediate level imagers.

Results: https://ubergarm.com/images/2023-10-07-M31.jpg (Posted on 10/10/2023)