Another M42 - criticism welcome

Kirkus (Kirk) · #1 26-10-2008, 06:22 AM

After several months of trying to mediate an argument between my mount and guiding software, I've sent them both to their rooms for awhile. I'm concentrating now on learning to drift align and have put auto-tracking on the shelf for the time being.

Taken 2 nights ago, this is my first attempt with drift alignment. I was able to salvage one 120-second exposure along with four @ 90-seconds and four @ 60-seconds, for a total of 12 minutes (I thought for sure, after being out until 4:30 a.m., I had at least 3 hours of data. LOL.)

There's a mix of 400 ISO and 800 ISO. This was shot prime focus with a Canon 400D unmodified through a Meade 6" SN on an LXD75 mount. I applied flats first with PS, then aligned, stacked, and applied darks in Lykeos (Mac), then back to PS for processing.

Anyway, I'm looking for criticism... suggestions on doing a better job.

Hagar (Doug) · #2 26-10-2008, 02:06 PM

Not much to critisize for such short exposures. Get you DA correct. Get guiding working and take a lot more longer subs as well and your image will jump off the screen. Well done. M42 isn't as easy as you think.

strongmanmike (Michael) · #3 26-10-2008, 07:16 PM

Well Captain if the cones in our retina were more sesitive to colour at low light levels that is pretty much what I would expect to see through about an 8" F5 telescope at about 80X magnification..? - very nice

Mike

spearo (Frank) · #4 26-10-2008, 08:19 PM

well done Kirk.

you asked for suggestions: consider using Deepskystacker for stacking your lights, flats, bias etc
might make life a bit easier
well done
frank

Octane (Humayun) · #5 27-10-2008, 07:02 PM

Kirk,

Love the pink plume.

As others have said, get guiding working, take longer exposures, and you're one your way.

Regards,
Humayun

bato (Luke) · #6 27-02-2009, 02:39 PM

Kirk, I know this thread has been dormant for a while but I am trying to find out what the LXD75 mount is like for astrophotography. I have read varied reports, some say its 'wobbly' while others say its quite good. I would have thought your results above are pretty darn good. Have you tried manual guiding or have you got your autoguiding up and running now? I would be very interested to hear what you think of the mount and ofcourse what others think. I am hoping to do some wide field stuff with camera lenses (I have the 400D also with a 17-50 f2.8) and then progress to an ED80. Any help would be greatly appreciated. Thanks.

Luke

Kirkus (Kirk) · #7 27-02-2009, 06:34 PM

Quote:

Originally Posted by bato

Kirk, I know this thread has been dormant for a while but I am trying to find out what the LXD75 mount is like for astrophotography. I have read varied reports, some say its 'wobbly' while others say its quite good. I would have thought your results above are pretty darn good. Have you tried manual guiding or have you got your autoguiding up and running now? I would be very interested to hear what you think of the mount and ofcourse what others think. I am hoping to do some wide field stuff with camera lenses (I have the 400D also with a 17-50 f2.8) and then progress to an ED80. Any help would be greatly appreciated. Thanks.

Luke

Hi Luke.

Short answer: My LXD75 is performing really well. I've got autoguiding working quite well. I've taken exposures as long as 5 minutes without a problem, and I'm confident I could go much longer if conditions allowed for it.

Long answer: I struggled for the good part of a year getting my set up to work for long exposures. But only some of that struggle was due to the mount itself. Much of it was simply my lack of knowledge and experience with astrophotography. This mount was my first.

Focusing on the problems I had with the mount... I ended up completely disassembling both axis and both motor gear boxes and replacing the cheap lubricant that was put on at the factory with a higher quality lubricant. Also, with much trial and error, I've become an expert at adjusting the mesh in the worm gear assembly to eliminate backlash yet keeping the movement free. I also replaced the stock gears on the motor/gear assembly with belts.

These three modifications (plus having learned to drift align) have, in my opinion, given me a mount that I'll be able to use for many years to come. I load it up pretty heavy - about 30lbs. (about 13.5 kilograms?) with OTA, camera, guide scope, counter weights etc. and have been real happy with it.

To be completely fair, I bought mine used and I'm not sure how it was treated before I got it. But the above modifications were all suggestions made by other LXD55/75 owners while I was learning, and now I couldn't be happier with it.

I have PDFs illustrating these modifications if you're interested.

bato (Luke) · #8 28-02-2009, 09:34 AM

Hi Kirk,
Thanks for the detailed reply. Glad to hear you have the autoguiding going.
Doing the work on the mount that you described doesnt realy phase me. I had expected to have to do some of these things to which ever mount i bought at some time. I just didnt want to put in the effort to find out I was exceeding its capabilities.
13.5kg should be plenty for my gear. I would be interested in the PDF's if you could post a link or email. Again thanks for your help.

Luke

Kirkus (Kirk) · #9 28-02-2009, 07:05 PM

Quote:

Originally Posted by bato

Hi Kirk,
Thanks for the detailed reply. Glad to hear you have the autoguiding going.
Doing the work on the mount that you described doesnt realy phase me. I had expected to have to do some of these things to which ever mount i bought at some time. I just didnt want to put in the effort to find out I was exceeding its capabilities.
13.5kg should be plenty for my gear. I would be interested in the PDF's if you could post a link or email. Again thanks for your help.

Luke

I've posted more information (including a link to a PDF) in this thread:
http://www.iceinspace.com.au/forum/s...ad.php?t=41791

I wanted to move the discussion to a more appropriate forum.