Mosaic with a large aperture Vs single picture with small

[Ratlet]

Having played with my new camera on my 130pds (650mm/f5) I've been looking at imaging opportunities with my 200mm (takumar 200) and 300mm telephotos.

I was wondering though, is there a point where I get better data doing a mosaic with the 130pds with its larger aperture Vs trying to capture the image in one go with a smaller aperture?  My 200mm would be stopped down to f5.6.

Would I get more/better data doing a 9 panel mosaic with the 130pds 1 hour per panel Vs doing 9 hours of a single panel with the takumar? I feel there should be a simple answer but I can't wrap my head around it.

[Adam J]

On 03/10/2022 at 09:50, Ratlet said:

Having played with my new camera on my 130pds (650mm/f5) I've been looking at imaging opportunities with my 200mm (takumar 200) and 300mm telephotos.

I was wondering though, is there a point where I get better data doing a mosaic with the 130pds with its larger aperture Vs trying to capture the image in one go with a smaller aperture?  My 200mm would be stopped down to f5.6.

Would I get more/better data doing a 9 panel mosaic with the 130pds 1 hour per panel Vs doing 9 hours of a single panel with the takumar? I feel there should be a simple answer but I can't wrap my head around it.

The theory is that if both scopes have a similar f-ratio then to long as the shorter focal length scope has the same total integration of the mosaic then the end SNR will be similar across the two if you bin the 130pds to the same pixel scale. What this really shows you is the power of a larger sensor (if you can afford optics to cover it). As in this situation it might mean you are collecting data much faster.