My cruddy attempt at M51

[umbra]

So I finally got a wedge for my CPC1100 and was working on drift aligning that sucker. Sort of got my head around how its done but as you can see in this pic I dont have it down pat as there is still drift. I think part of my problem is I have my rig sitting on a scopebuggy. I am planning on building a concrete pier sometime in the near future but the present set up will do for now.

On to the photo:

M51 - The Whirlpool galaxy

http://www.tristanmolina.org/picz/Astro/M51.jpg

10 60sec exposures
Shot with a modified 40D prime focus through a Celestron Onyx 80EDF piggbacked on a APT Astro wedge mounted CPC1100
Captured and stacked with Nebulosity2
Some editing in Nebulosity2 and some in Photoshop CS4

Please please critique this...I need some tips lol!

Also a shot of my rig:

http://www.tristanmolina.org/picz/scope.jpg

[scott stokes]

Thats cool and your rig looks expensive.

[chris.bailey]

I suspect the scope buggy is a part of the problem as well. A very rough Polar Alignment should get you pretty crisp 60 second subs through the ED 80. I was managing 60 seconds with my LX200 ALT AZ! Simple Polar Home alignment on a wedge got me decent 3 minute subs. I also found that my LX200 was very balance critical and notice you dont seem to have any means of balancing other than moving the piggy back scope front to back.

Was you rig photo taken in Forida? Wedge looks a bit steep for a 27-29 deg latitude but might just be the picture angle.

[umbra]

I suspect the scope buggy is a part of the problem as well. A very rough Polar Alignment should get you pretty crisp 60 second subs through the ED 80. I was managing 60 seconds with my LX200 ALT AZ! Simple Polar Home alignment on a wedge got me decent 3 minute subs. I also found that my LX200 was very balance critical and notice you dont seem to have any means of balancing other than moving the piggy back scope front to back.

Was you rig photo taken in Forida? Wedge looks a bit steep for a 27-29 deg latitude but might just be the picture angle.


Chris, thanks for your reply. To answer your last question first, yes the photo was taken in my back yard. It is just the camera angle as it is set for about 27 degrees. I used a grade school protractor to do the rough guestimate of the angle and have polaris dialed in with a little tweaking.

I do have counterbalances you can't see in the picture. I have an ADM dovetail on the bottom with 8.75 pounds of weight on it as shown here:

http://www.tristanmolina.org/picz/riggarage.jpg

By the sounds of your setup I suspect the problem is with the scopebuggy. I have it set up on top of buried pavers which the leveling bolts screw down on. When I set it up I notice there is alot of lateral movement when it is sitting on the bolts. By alot I mean I can shake the entire rig. I'm guessing when the telescope skews after I do my alignment process the entire rig shifts a little. I think the next night I set up I am going to take the scope off the scopebuggy and see.

-Tristan

[Jeff]

Is that an asteroid you caught in there?

[chris.bailey]

When I set it up I notice there is alot of lateral movement when it is sitting on the bolts. By alot I mean I can shake the entire rig. I'm guessing when the telescope skews after I do my alignment process the entire rig shifts a little. I think the next night I set up I am going to take the scope off the scopebuggy and see.


I think that will make a big difference. There is quite a lot of momentum to that setup as it tracks and any slack in the support will affect that tracking, hence people burying large steel tubes into the ground!

[Nighthound]

Tristan that's a great start. Not bad at all for so little time. It's a bit of a stubborn one.

I also suspect the scope buggy playing a part in your alignment problem. I place steel barbell weights under my tripod legs when setting up on soil. I've adhered a thin dense foam material over the top of the weight to help with dampening vibration. Even seemingly hard soil surfaces can give way over the course of an imaging session and even a slight amount of settling of one tripod leg will throw your alignment off.

Are you fine tuning your alignments with the Iterative method? Taking the extra time to do so will help a lot with extending your exposures. Auto guiding would add considerable time.

[A.S.I.G.N. Observatory]

Tristan, you have the makings of a fantastic setup there mate. I previously owned the Nexstar 11 GPS on a wedge and had problems with tracking.

I got alignment all sorted perfect on a permanent pier, but it was the gearing and backlash that let this big fork mount down.

I hope you don't drag that thing behind your golf buggy with the scope mounted do you?!!!:eek: Potential for huge damage there.

Your M51 is way better than my first attempts mate. Take heart that you are off to a flying start! It is well worth your time to get those tracking errors sorted out first though.

Warm regards,

Barry.

[Adrena1in]

As with Baz, that's way better than my first attempt on M51...(note to self, M51 is in prime location at the moment, so give it another go!).

Is that an asteroid you caught in there?

I was wondering what that dotted line is as well. In each 60s sub it hardly seems to leave any trail, so unless you were waiting several minutes between each photo I can't image what sort of object it is!?

[A.S.I.G.N. Observatory]

As with Baz, that's way better than my first attempt on M51...(note to self, M51 is in prime location at the moment, so give it another go!).



I was wondering what that dotted line is as well. In each 60s sub it hardly seems to leave any trail, so unless you were waiting several minutes between each photo I can't image what sort of object it is!?

Depending on if the stacking was mosaic or centre framed, it could be a hot or dead pixel. The rest of the stars would match up, but the if the tracking was off, the hot pixel , although in the same place on the sensor, would appear in different spots between the stars.

Edit: There are ten dots and you took ten subs. I reckon what I said is correct.

[umbra]

Thanks for all the replies guys! I really appreciate it. To answer your questions in order:

Jeff- no not an asteroid lol...it is just a hot pixel. The photo was riddled with them but its one I forgot to clean up.

Chris- Thank you for your reply again bud!

Nighthound- I am taking the time to drift align. All seems fine until I skew the scope to past the meridian then back to something else. So I do think it is indeed shifting or something on the scopebuggy.

Barry- Thanks for your kind words. This was my first attempt with imaging on a wedge so this is all very new to me. No I don't tow the scope behind the golf cart lol. That would be scary! It's even scary just pulling the thing across my yard. I get a sick feeling (because of the paranoia of it tipping) when I have to pull the scope up my driveway to my garage because it is kind of steep and dirt lol. The golf cart is more my mobile desk for where my cases, cat, and laptop sit. I also haven't messed around with the PEC yet but will mess with it the next time I am out.

Adrena1in- Barry is indeed correct, it is a hot pixel. I showed that pic to my buddy and he freaked and thought it was a UFO hehe.

Thanks for the replies guys. I think the permanent pier is going to be built sooner than I thought. I have plans to build an enclosure around it but that wont be till after hurricane season. Oh and since I've posted this photo, the clouds have rolled in and are of course preventing me from dragging the rig out and messing with this stuff more...

-Tristan

[cruiser]

Hi Tristan,

Thats a great attempt first up. I look forward to seeing what you come up with when you get a more permanent setup.

Brett

[umbra]

Thanks cruiser. I did experiment last night with my mount and attempted to re-shoot M51. This is the result:

http://www.tristanmolina.org/picz/Astro/m51new.jpg

Still a little blurry but I have to work on focusing better with my STI Stiletto. I found that one of the pavers I had the scopebuggy sitting on was cracked right where I screw down the stablizing bolt. That combined with the soft soil of my backyard was enough to make the scope drift (the tripod + wedge + scope + acc are easily over 150 pounds). I just did a rough EQ alignment and was able to get 90 second subs without too much drift.