DSO images with a Minitower Alt-Az mount

[zakky2k]

Guess I'm a glutten for punishment, limiting myself to 45 seconds tops exposure time, normally even less.

I'm using the Minitower from Ioptron with an Orion 102mm f/7 Premium.

I reached the stage where I'd decided life was challenging enough, so I've just upgraded the scope with a new focuser from Moonlight. At least now the camera stays in focus when pointing to the zenith!

Next purchase will hopefully be a more suitable mount for DSO photography!

M13 Globular cluster - 11 frames 3m21s

M27 Dumbell nebula - 5 frames 3m15s

M45 Pleiades - 17 frames 12m15s

All stacked in DSS

Unmodified Canon EOS 1D mk3

[Dangerous-Dave]

Good work. I started off with a ZS80FD piggy backed on an alt-az LX90 and could get 2-3 minutes before field rotation became a problem. Planetary should be even easier, but avoid large lunar mosaics.

[gary1968]

Cracking images, thanks for sharing.

Gary

[Macavity]

Great stuff. Just shows what can be done, with the Mini-Tower.

Perhaps without blood pressure raising aspects of Equatorials.

[hunterknox]

Excellent results. ADM do an equatorial wedge for the minitower should you need it, but on this evidence that might be a while!

[zakky2k]

Excellent results. ADM do an equatorial wedge for the minitower should you need it, but on this evidence that might be a while!

Thanks for your encouragement!

Believe it or not I actually have the ADM wedge, but due to very restricted opportunities to image (I work abroad), and some initial difficulty when I first tried to install it, have not got around to really using it yet!

I have to admit that although the idea is a good one, I love the quick set-up times with this mount, one of the key features that would be lost if set up in EQ mode, and even then I doubt it would perform as well as a dedicated EQ mount, hence my dwindling enthusiasm !

All the best,

Zak

[zakky2k]

Good work. I started off with a ZS80FD piggy backed on an alt-az LX90 and could get 2-3 minutes before field rotation became a problem. Planetary should be even easier, but avoid large lunar mosaics.

Hi Dave,

I'm not really sure why my exposure times are so limited, and also it seems to depend on the position of the target. I dont have examples to hand, but some targets will track for 45 seconds, others even 20 begin to trail.

The 1D is a heavy camera, so maybe I'm reaching the weight limit, or its not correctly balanced...

I would expect however, maybe incorrectly, that my exposure times to be reduced due to the greater focal length of the 102mm vs your 80mm?

Zak

[zakky2k]

Cracking images, thanks for sharing.

Gary

Thanks Gary! I've got a few more that I'm working on. Hopefully I'll get them posted this week.

All the best,

Zak

[Macavity]

Random previous finding on t'internet:

http://autostarsuite.net/forums/storage/19/4981/Field%20Rotation%20V3.pdf

Would have "think" about such things.

[zakky2k]

Random previous finding on t'internet:

http://autostarsuite.net/forums/storage/19/4981/Field%20Rotation%20V3.pdf

Would have "think" about such things.

Aha! Superb resource, thanks for sharing Chris.

So thats why East and West ojects were easier than N/S/Zenith...

I really thought there was something going on in the mount, like the gears had built up a lubricant deposit in one place or something equally, erm, wrong...

Cheers,

Zak

[RogerTheDodger]

Fantastic images, I especially like the M45 shot

[ollypenrice]

We've all seen a great deal worse from equatorials! Really very impressive.

Olly

[zakky2k]

Fantastic images, I especially like the M45 shot

Thanks Roger! The data was actually captured last year, and although I made several attempts at processing, this is the best I could manage at the time.

There's still a few flaws I'd like to correct, and hopefully add some more data to stack eventually.

Cheers,

Zak

[zakky2k]

We've all seen a great deal worse from equatorials! Really very impressive.

Olly

Thanks Olly! When you see so many amazing shots it gets a bit intimidating posting one's own inferior work!

I still have yet to master correct calibration. Most of the time I simply perform dark subtraction in-camera (long exposure noise reduction) but dont bother with flats or biased frames. Maybe I'm doing it wrong, but whenever I try to process with flats, the results end up worse!

Eventually I'll get around to learning how to use MaximDL to its potential (only recently started that learning curve), but all the shots I've taken so far were aligned, stacked and initial processing performed in DSS.

All the best,

Zak