Hi Guys
I picked a cheap used GSO 8" F/5 newt on IIS the other day and after setting It up with the Skywatcher F/5 coma corrector and getting It ready for imaging I decided to review my findings on the setup and performance of the Skywatcher F/5 Coma Corrector.
First of all some specs on the unit.
Back focus spacing: 55mm
Best for F/5 scopes...that's It?cool just the way I like It.
Once you've connected the spacers required to get you to the 55mm backfocus your ready to take the next step.....you guys still with me?
The unit is designed to slip into a 2"eyepiece holder on the telescope end(I've seen those adds)and, although, a screw in unit would be preferable for astrophotography, I didn't have too much trouble getting It to sit fairly square in the focuser(I wouldn't of had the focus travel with a screw on anyhow's)
Ok,got past that hurdle so on to the next....hows the star field look? and is my spacing right?
Now for the back story!
Using an old QHY8(which has the early APSc size sony sensor)I had to look up the back focus for It and after googling and finding a dozern people all with differing measurements? I decided to go with the 14.1mm the previouse owner had on a sticker on the camera(lol..didn't see It)got to start somewhare!
Are we there yet? nope....noooot quite, but luckerly I stumbled across this link on CN which saved me chasing my tail.
https://www.astro-physics.info/tech_...ing-change.pdf
Conclusion? is good!
A 7 x 5min test shot of the field(sorry heavy jpeg compression)
