Great video, I had to look this up as I've upgraded from a DSLR lens to a telescope and my clip in filter is now casting a shadow around the edge of the sensor. Only way is to go with a circular filter.
One pitfall to avoid is that 1.25 inch filters do not have 31.75mm of clear aperture. They usually have somewhere between 26-28mm of clear aperture depending on the mount.
Thanks for this Cuiv, it definitely applies to my situation where currently I have a 1.25 inch filter which I try to get as close as possible to the ASI294mcpro window and I often wonder if this is the best solution but its all I have right now, however If for example I were to purchase a 2 inch filter and screw this in front of the coma corrector before placing the assembly into the focuser, then surely there could not be any light getting to the sensor that didn't go through the filter first, so...also no vignetting?. Is that correct? Cheers Dave
Hey Dave, I think the 1.25 inch filter works fine for the ASI294MC Pro, as long as you don't have a very low/good focal ratio, so I'm of the opinion that if it ain't broke, don't fix it. A two inch filter place in front of the 2 inch FR works as well - I used to do that when I had a refractor. And yes, there would be no vignetting (or at least no vignetting introduced by that filter)!
Another of your informative examples as to the reason(s) behind doing something, Thank you for the background.
Thank you!
Great video, I had to look this up as I've upgraded from a DSLR lens to a telescope and my clip in filter is now casting a shadow around the edge of the sensor. Only way is to go with a circular filter.
One pitfall to avoid is that 1.25 inch filters do not have 31.75mm of clear aperture. They usually have somewhere between 26-28mm of clear aperture depending on the mount.
Thanks for this Cuiv, it definitely applies to my situation where currently I have a 1.25 inch filter which I try to get as close as possible to the ASI294mcpro window and I often wonder if this is the best solution but its all I have right now, however If for example I were to purchase a 2 inch filter and screw this in front of the coma corrector before placing the assembly into the focuser, then surely there could not be any light getting to the sensor that didn't go through the filter first, so...also no vignetting?. Is that correct?
Cheers
Dave
Hey Dave, I think the 1.25 inch filter works fine for the ASI294MC Pro, as long as you don't have a very low/good focal ratio, so I'm of the opinion that if it ain't broke, don't fix it.
A two inch filter place in front of the 2 inch FR works as well - I used to do that when I had a refractor. And yes, there would be no vignetting (or at least no vignetting introduced by that filter)!
Merci Cuiv!
Very interesting video, thanks
Glad it was useful!
Neet!