My bi-polar dream

[kalasinman]

Thank you Derek. There has been some great information and experience shared here. Taking it all into account, I have changed from leaning towards the QHY21 plus extras to the QHY9. At under 2k USD with great cooling and a wheel, I can add a 3- 36mm unmounted NB filter kit for just over $300 (Baader).

I still have concern that with an item like M1, to crop to the framing I'd want would result in a poorer image than with the QHY21, but maybe I'm wrong. I haven't actually figured the scale, so that's likely. Anyway I do really appreciate every comment.  I know they were given in the spirit of helping, and for that thanks to all!--Jack

[Physopto]

Thank you Derek. There has been some great information and experience shared here. Taking it all into account, I have changed from leaning towards the QHY21 plus extras to the QHY9. At under 2k USD with great cooling and a wheel, I can add a 3- 36mm unmounted NB filter kit for just over $300 (Baader).

I still have concern that with an item like M1, to crop to the framing I'd want would result in a poorer image than with the QHY21, but maybe I'm wrong. I haven't actually figured the scale, so that's likely. Anyway I do really appreciate every comment.  I know they were given in the spirit of helping, and for that thanks to all!--Jack

Baader do some great value for money filters. They are highly rated by some of the best asto photographers. Their new ranges look very good.

One FREE program that might help you decide is Ron Wodaski's "ccdCalc". it allows you to specify almost any camera and scope including what field flattener and barlow you are using or might want to use. You can select loads of different targets and see exactly what image size  you will see for the camera and scope combination.

Derek

[kalasinman]

Baader do some great value for money filters. They are highly rated by some of the best asto photographers. Their new ranges look very good.

One FREE program that might help you decide is Ron Wodaski's "ccdCalc". it allows you to specify almost any camera and scope including what field flattener and barlow you are using or might want to use. You can select loads of different targets and see exactly what image size  you will see for the camera and scope combination.

Derek

Well, I already put the leading candidates in Stellarium as "sensors" for my 150/750 f/5 newt. Is that the same, or close enough?

[kalasinman]

Going through the thought process here, considering FOV, reminded me of the fun I had with camera and lens. I was looking at a 300mm f/4.5 prime Nikor for quite cheap. Not right now, but I bet adapting it to a full NB rig would produce some amazing images.

[Physopto]

Well, I already put the leading candidates in Stellarium as "sensors" for my 150/750 f/5 newt. Is that the same, or close enough?

Can't help there as not using Stellarium, sorry.

Derek

[kalasinman]

OK, I think it's the same . Gives you a rectangle over the star field equal to the size of the frame you would get with the combination of lens, scope, barlow/reducer, etc. you enter. Now that I have ASCOM, I just click on the object and enter CTRL1 and it slews the scope there. I've put in At also, so I should be able to solve a quick 10s image and fine tune the framing. Haven't had a clear night to try that, though.