Medium format astrophotography and TEC 180 FL

I recently made the move into medium format imaging. I have been working with full frame for years, and it has served me well, but the idea of opening things up even further with optics that are fully capable of it was hard to ignore.

Once you step into that sensor size, everything else has to follow. To match it properly I went with Chroma 3nm square filters. There is not much point in cutting corners when the goal is to actually use the field you are paying for.

I have already put one of my 6200MM systems with Chroma filters onto the Epsilon 160ED in the observatory, replacing an ATIK 16200. That older CCD has always been a solid performer, but the difference in field and efficiency is noticeable right away. I have already captured Markarian's Chain with the new setup.

Now I am looking at where the ASI461MM makes the most sense. The TEC 180FL is the first candidate. On paper, the imaging circle should support somewhere in the range of 55mm to 60mm, which puts it in a usable range for the sensor.

At the same time, the Takahashi TOA 130NFB offers a guaranteed 90mm imaging circle, which removes any question about coverage and gives a bit more breathing room across the field.

So the question becomes less about what works, and more about what works best.

Would you run the 461MM on the TEC 180FL and take advantage of the aperture and focal length, or pair it with the TOA 130NFB where the imaging circle is fully covered without compromise?

I would like to hear your thoughts.