Home · Register · Search · View Winners · Software · Hosting · Software · Join Upload & Sell

Moderated by: Fred Miranda, JimFox
Username   Password

FM Forum Rules
Landscape Posting Guidelines
  

FM Forums | Landscape Photographer | Join Upload & Sell

1       2       3              9      
10
       11              17       18       end
  

Nightscapes using AstroTrac Tracking Mount
  
 
Fred Miranda
Offline
Admin
Upload & Sell: On
p.10 #1 · p.10 #1 · Nightscapes using AstroTrac Tracking Mount


RobDickinson wrote:
Well I guess that proves a point? Also when are you buying an 800?

BTW what do you do when you cant see the circumpolar point?

And how does the auto guiding work?

Autoguiding sight + PC links to the astrtrac and controls its movements?


Hi Rob,
I'm not an expert on this as I have owned the Astrotrac mount for about a month. However, I'm glad to share my progress and what I've learned.
I'm sticking with my 400 f/5.6, 500 f/4 and extenders for astro shooting...

As far as auto guiding, it basically allows you to stay on your target. The auto guiding camera is connected to your computer and autoguiding software. It also connects to the Astrotrac mount using a special cable. It works quite well even though Astrotrac only corrects in RA.

It seems complicated but in about 3 minutes, you are ready to start your shooting sequence. I used BackyardEOS to connect to the camera.
http://www.backyardeos.com



Mar 24, 2013 at 07:13 PM
RobDickinson
Offline
• • • •
Upload & Sell: Off
p.10 #2 · p.10 #2 · Nightscapes using AstroTrac Tracking Mount


Thanks Fred, sounds like its not as complex as it sounds..


Mar 25, 2013 at 07:06 AM
danws6
Offline

Upload & Sell: Off
p.10 #3 · p.10 #3 · Nightscapes using AstroTrac Tracking Mount


Fred Miranda wrote:
Hi Dan,
The heaviest combination I've tried using a guiding camera was with the 7-pound Canon 500mm f/4L IS II lens on my Canon EOS 6D. The Astrotrac was attached to the "Wedge".


Awesome. Thank you for all the info Fred, your pictures look great!

Now to wait for the astrotrac to get back in stock.



Mar 25, 2013 at 03:12 PM
Fred Miranda
Offline
Admin
Upload & Sell: On
p.10 #4 · p.10 #4 · Nightscapes using AstroTrac Tracking Mount


dgdg wrote:
Fred,
Any tips on your experience regarding the astrotrac 1) polar scope collimation and also adjustments with the 2) polar scope fitting onto the handle?
Saw this http://astrograph.wordpress.com/2009/09/14/collimating-the-astrotrack-polar-scope/
Not sure what and how much one would need to do.


Hi David,
Yes, you may have to collimate your scope. Mine was slightly unaligned.
Here is a great PDF file explaining the process.
All the best,
Fred



Mar 26, 2013 at 05:31 AM
Mickey
Offline
• • • •
Upload & Sell: On
p.10 #5 · p.10 #5 · Nightscapes using AstroTrac Tracking Mount


Here is s simple solution to keep that Polar alignment scope from falling out. Place a rubber band around the top or bottom, give it a twist and then up and over the other end. Then even if you bump it and knock it loose it does not fall.



Edited on Mar 27, 2013 at 02:12 AM · View previous versions



Mar 26, 2013 at 10:32 PM
Fred Miranda
Offline
Admin
Upload & Sell: On
p.10 #6 · p.10 #6 · Nightscapes using AstroTrac Tracking Mount


Mickey wrote:
Here is s simple solution for that Polar alignment scope falling out. Place a rubber band around the top or bottom, give it a twist and then up and over the other end. Then even if you bump it and knock it loose it does not fall.


Very clever Mickey!
I can see you already got the 'thumbscrews' to aid collimation.
An alternative to the elastic band is a 'Slip Joint Washer'.
Fred



Mar 27, 2013 at 01:05 AM
JB Goessman
Offline
• •
Upload & Sell: Off
p.10 #7 · p.10 #7 · Nightscapes using AstroTrac Tracking Mount


I've been following the thread to the point where I've finally ordered the AT. Peer pressure at its best! Has anyone found a source for "the wedge"? I'm striking out.

Thanks.



Mar 27, 2013 at 01:16 AM
Mickey
Offline
• • • •
Upload & Sell: On
p.10 #8 · p.10 #8 · Nightscapes using AstroTrac Tracking Mount


There must have been a slight change in the design of the polar scope. The one I have has very little shoulder for the "Slip Joint washer" to grip to after the scope is put in place. Only maybe an 1/8th of an inch.


Mar 27, 2013 at 01:50 AM
sky-candy.ca
Offline

Upload & Sell: Off
p.10 #9 · p.10 #9 · Nightscapes using AstroTrac Tracking Mount


Hi all,

I'm new to these forums, and am very happy to have stumbled upon this discussion! I am an astrophotography guy as well, and from my little experience can say that Fred's results with the astrotrac are really excellent. Especially after just one month!

As you can see from all the great images in this thread (though some might have been captured with larger-aperture optics and guided equatorial mounts) good deep-sky images have one thing in common: lots of total exposure time.

Image stacks with low total noise can be stretched further to show subtle detail. You get low-noise stacks by using many exposures. There is a point of diminishing returns of course, but generally you should capture as many frames as you have the patience / clear skies for.

Another consideration is aiming for the longest possible exposure for each indiv frame ... the time limits should be limited by star trailing (due to tracking error/polar alignment), and by overexposure due to the skyfog limit (light pollution or moon sky glow). For DSLRs, a great rule of thumb is to check the histogram after a test frame -- try to have the main peak of the signal about 1/3 to 1/2 away from the left side of the histogram. This helps to separate the signal from the dark noise floor. Too far to the right and you risk overexposing stars (leading to white, bloated stars) and losing some dynamic range.

Apologies for the unsolicited advice, of course there are many approaches. Earlier in the thread there was some great advice to check out Jerry Lodriguss' guides.

Thanks for reading,
Adam



Mar 27, 2013 at 03:00 AM
Todd
Offline
• • •
Upload & Sell: Off
p.10 #10 · p.10 #10 · Nightscapes using AstroTrac Tracking Mount


Mickey wrote:
Here is s simple solution to keep that Polar alignment scope from falling out. Place a rubber band around the top or bottom, give it a twist and then up and over the other end. Then even if you bump it and knock it loose it does not fall.

http://postmyimage.com/img2/930_rubberband.jpg



Great idea. I thought of using gaffer tape to hold mine on, but the rubber bands will still allow the scope to be rotated. My polar scope doe not have the external thumb screws like yours does. Did you install them yourself? Are they used to align the reticle?

Todd



Mar 27, 2013 at 03:19 AM
 

Search in Used Dept. 



Fred Miranda
Offline
Admin
Upload & Sell: On
p.10 #11 · p.10 #11 · Nightscapes using AstroTrac Tracking Mount


Todd wrote:
Great idea. I thought of using gaffer tape to hold mine on, but the rubber bands will still allow the scope to be rotated. My polar scope doe not have the external thumb screws like yours does. Did you install them yourself? Are they used to align the reticle?

Todd


Todd,
Check out this PDF file written by Darryl Hedges.
It explains where to get the thumbscrews and collimate the polar scope.



Mar 27, 2013 at 05:16 AM
Mickey
Offline
• • • •
Upload & Sell: On
p.10 #12 · p.10 #12 · Nightscapes using AstroTrac Tracking Mount


(East coast folks) The Rockland Astronomy Club is sponsoring a conference on astro photography in a few weeks that looks very interesting. Even some beginner workshops for us newbies. Jerry Lodriguess is going to be there and is conducting a couple of the workshops including a night one. I plan on going and wouldn't mind meeting up with anyone else for FM that might be going.
Here is the link.

http://www.rocklandastronomy.com/neaic/



Mar 27, 2013 at 01:42 PM
jhenderson0107
Offline

Upload & Sell: Off
p.10 #13 · p.10 #13 · Nightscapes using AstroTrac Tracking Mount


Fred -
Did you find it necessary to use a cable such as the DSUSB from Shoestring Astronomy to actuate the shutter on your T4i/6D when it is being controlled with Backyard EOS? I'm surprised that long duration (bulb) exposures can't be controlled via USB alone on these cameras.



Mar 27, 2013 at 02:31 PM
Fred Miranda
Offline
Admin
Upload & Sell: On
p.10 #14 · p.10 #14 · Nightscapes using AstroTrac Tracking Mount


sky-candy.ca wrote:
Hi all,

I'm new to these forums, and am very happy to have stumbled upon this discussion! I am an astrophotography guy as well, and from my little experience can say that Fred's results with the astrotrac are really excellent. Especially after just one month!

As you can see from all the great images in this thread (though some might have been captured with larger-aperture optics and guided equatorial mounts) good deep-sky images have one thing in common: lots of total exposure time.

Image stacks with low total noise can be stretched further to show subtle detail. You get low-noise stacks by
...Show more

Welcome aboard Adam!
Thanks for the advice. I have been capturing long exposures at around 30 - 40% from the left of the histogram.
I have tested this and it seems that going further than this range will mainly record sky glow and not data from your target.


jhenderson0107 wrote:
Fred -
Did you find it necessary to use a cable such as the DSUSB from Shoestring Astronomy to actuate the shutter on your T4i/6D when it is being controlled with Backyard EOS? I'm surprised that long duration (bulb) exposures can't be controlled via USB alone on these cameras.


I use the original USB cable to connect the camera (T4i or 6D) to the computer (BackyardEOS).
No problems there.
If you are using the Canon 6D, you will need a beta version of BackyardEOS, which is currently not available for download. From my tests, it is working great and should be available soon.



Mar 27, 2013 at 05:55 PM
harshaj1
Offline
• • • • • •
Upload & Sell: On
p.10 #15 · p.10 #15 · Nightscapes using AstroTrac Tracking Mount


Latest Sky and telescope magazine has a review of iOptron's skytracker . They like it. One of the best trackers for the price they say.
Harsha



Mar 31, 2013 at 01:52 PM
Andrew Welsh
Offline
• • • •
Upload & Sell: On
p.10 #16 · p.10 #16 · Nightscapes using AstroTrac Tracking Mount


I am amused Fred has caught the astrophoto bug. I followed the opposite path.. I bought a DSLR for astrophotography in 2006 and got the photo bug!

I greatly enjoy imaging with the 400/5.6L - it is on par with most quality 80mm refractors and has the added benefit of autofocus and daytime use on my camera Here's a stack of 5 min exposures of M45/ Pleiades with a Canon 40D:






I am very interested in portable mounts, as my current setup is to piggyback on my 8" SCT, and moving it around and aligning is cumbersome.

A question for you, sir: you mention autoguiding your astrotrack mount.. what are you autoguiding with? My current autoguiding setup is rather involved, so I'm interested in hearing about simpler solutions.



Apr 02, 2013 at 05:00 PM
astro-ep
Offline
• • •
Upload & Sell: On
p.10 #17 · p.10 #17 · Nightscapes using AstroTrac Tracking Mount


Similar to Andrew's interests. Mine have gone from Photography, to Astro (via modified DSLR) then to a full-blown CCD imaging system. However, my DSLR astro efforts lead me back photography, doing IR photography. It's all fun...

Thanks for sharing your M45 shot...

Eric



Apr 02, 2013 at 05:19 PM
JameelH
Offline
• • •
Upload & Sell: On
p.10 #18 · p.10 #18 · Nightscapes using AstroTrac Tracking Mount


Has anyone tried using a mirror lens for astro photography?


Apr 02, 2013 at 11:32 PM
StarNut
Offline
• • •
Upload & Sell: On
p.10 #19 · p.10 #19 · Nightscapes using AstroTrac Tracking Mount


JameelH wrote:
Has anyone tried using a mirror lens for astro photography?


If by "mirror lens," you're talking about the Maksutov-Cassegrain-type lenses which used to be fairly common, I wouldn't recommend it.

Unless you have a very fine mount (and by "very fine," I am talking about mounts that cost many thousands of dollars), you really want to image with fairly short focal length lenses (I wouldn't want to go over 400 or 500 mm with a budget mount), and it's a large benefit to have fast focal ratios. Mirror lenses tend to be very slow, and often artificially long focal length (the purpose of the mirror system is to pack long focal length into a short package).

Additional issues are that mirror lenses tend to have poor optics (not talking high-quality scopes here, but photographic lenses), and the central obstruction causes issues with the amount of light that reaches the sensor and the contrast of the images produced.



Apr 03, 2013 at 12:06 AM
astro-ep
Offline
• • •
Upload & Sell: On
p.10 #20 · p.10 #20 · Nightscapes using AstroTrac Tracking Mount


+1 on starnut's comment. I've used one as a guide scope, with reasonable results. It was a 300mm f6.3. I also had a 500mm f8 that I tried, but the f# was too slow (dark) for my guide camera to reliably see stars, with out longer exposures (which defeats the purpose of the guide camera). Here's a shot of it on the 80mm Stellarvue refractor I used to have:

http://smu.gs/JRqOOa

You'll also get better resolution with a refractor or regular camera lens (no central obstruction). That being said, if you have one, try it. However as a purchase, it might not be the best choice for astrophotography.

Eric





Apr 03, 2013 at 12:47 AM
1       2       3              9      
10
       11              17       18       end




FM Forums | Landscape Photographer | Join Upload & Sell

1       2       3              9      
10
       11              17       18       end
    
 

You are not logged in. Login or Register

Username   Password    Reset password