Connection plan

[TiffsAndAstro]

31 minutes ago, Vroobel said:

I'm at the same point with my Askar FMA230: at this moment the back focus is 52.5mm instead of the 55mm, while it's still not the end. 

God bless Russell Croman with his 'X' series... 👍 😁

 

so you fixed your back focus by using 52.5mm, or,  52.5mm is close enough not worth fixing it?

[Vroobel]

4 minutes ago, TiffsAndAstro said:

52.5mm is close enough not worth fixing it

 

... for a while. I should do it, but my camera and filter wheel work with another scope now.

 

[TiffsAndAstro]

Just now, Vroobel said:

 

... for a while. I should do it, but my camera and filter wheel work with another scope now.

 

if mine looks 'ok' ill worry about perfecting it once i get a rotator. i know square sensor makes it less necessary, but its needed for mosiacs for proper framing and some look like the captain's wheel from a pirate ship. 

[Vroobel]

You are lucky with your 72ED and the IMX533 sensor. If I'm not wrong you have 420mm fl and flattened, no reducer.

 

 

Below is what it would look like with a popular 135mm, like a Samyang lens. I would go in this direction later, like many other owners of the IMX533. There is also a cheaper alternative, an Askar FMA135, but it's much slower than the F/2.0 Samyang.

 

 

 

 

[TiffsAndAstro]

Right now I hope I can do decent mosaics to cover the bigger stuff but plenty seems to fit nicely in one frame.  

I couldn't fit east and west in one frame on my dslr without rotation. Everything fits in a 4x4 mosaic, just

[TiffsAndAstro]

stack of 11 x 5sec exposures i found. no calibration frames but it was enough to do a first go at seeing any tilt and/or focus tube slop.  sensor looks untilted enough for me not to worry about it. i think there is a little slop shown on the stars on the left hand side, maybe. hard to tell from such a quick test. 

[TiffsAndAstro]

15 x 60sec test on veil nebula. its ok for 15 mins quick test and quick stretch. Stars in some of the corners are egg shaped. not certain if this is tube flop and/or back space problem. picked up more detail than my dslr did in 90 mins i think it was.

 

 

[TiffsAndAstro]

also did a 20x60sec test on m101 earlier because of clouds. quick stretch but i upped the red saturation as i think i've gotten emission nebula inside m101 arms? might just be noise not sure  if this was more than a quick test i'd redo the flats.

 

also couldn't resist an m31 test two panel mosaic, incoming when i get a couple mins...

 

Edited Monday at 09:54 by TiffsAndAstro

[TiffsAndAstro]

two panels 42 and 44 x 60sec in each. over stretched but shows promise. 

 

[TiffsAndAstro]

I see pink/red blobs scattered about m101. Are they Ha or hot pixels or noise?

If I squint I swear I can see similar in m31. Makes me thinks Ha or at least some ir? Need more time on single nebulae target next few clear nights.