M42 test

[The_bluester (Paul)]

So, I pulled my mount apart and packed the clutches out with paper card shims per my 47 Tuc thread and set up last night to test it. Polar alignment is not quite right as I could see that the clouds were going to beat me and wanted some data. This is a stack of 40 minutes integration time, 5, 10, 30, 60 and a couple of 120 second subs before the clouds rolled in. Integrated in APP (I think I will have to buy it once the trial expires) with some minor tweaking in GIMP post stacking. No dark, flat or other calibration frames.


C925 scope with the Celestron 0.63 reducer (Spacing is larger than it should be so maybe 0.6) and an ASI294 OSC cam.




Still plenty of learning to go.

[RyanJones]

Nice work Paul

Nice subtle textures, I like it

[The_bluester (Paul)]

I am hoping to have a really decent crack at M42 while it is up, with a range of sub times out to maybe five and ten minutes, so time to pull my finger out.


Ideally I would love to get my pier in the ground (Finally) so I don't have to set up and polar align each time but that is probably pushing it this year.

[Karlzburg (Karl)]

Looks good Paul, some nice sharp dust lanes between M42 and M43.
I did a 10 min sub the other week and brought out so much more detail in M43 but showed a lot more around the edge in M42.
What's your space between the reducer and sensor?

[The_bluester (Paul)]

I have to measure it properly but it is more like 130mm than the 105 or so it is supposed to be. I need to get a different adapter for the connection between the scope and OAG as it is the only one I have.

[Outcast (Carlton)]

Paul,

Is that measurement the length of the extension tube you are using or the distance from focal reducer to sensor?

I note you say it should be 105mm, I don't have an extension tube for the Meade f6.3 focal reducer I just acquired so & am discovering through my thread on M42 that my sensor might not be far enough back to be getting full benefit of the reducer..

Cheers

Originally Posted by The_bluester

I have to measure it properly but it is more like 130mm than the 105 or so it is supposed to be. I need to get a different adapter for the connection between the scope and OAG as it is the only one I have.

[The_bluester (Paul)]

Reducer to sensor distance. It is a bit of an estimate, I need to look up the back focus distance on the ASI294

[assbutt94]

Beautiful shot! I wish I could get as much sharp detail!

[The_bluester (Paul)]

The only bit I am not happy with is some odd streaks of various colours that show up in the stacked image, you can just see some of them even in that small version down in the bottom left. I am not sure where they are coming from as I can't find anything like them on any of the subs no matter how hard I stretch them.

[multiweb (Marc)]

That's a cool shot. You'll have to start flat fielding to get the most out of your image. That will bring out more details on axis and also the fainter stuff at the edge of your fov. Can't see the streaks you're talking about?

[Imme (Jon)]

Great effort!

[The_bluester (Paul)]

The streaks are there if you look closely enough, I actually cloned out the couple that were really obvious even in this reduced size, but that is now how I want to deal with them long term.

I have not got flats sorted yet, I took flats and they looked good but over compensated somehow. I ended up with reversed vignetting where the edges were a light brighter than the middle.

Still this was basically just a test to see if the mount worked properly after the change to the clutches so as a result I am pretty happy with it.