Quote:
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Originally Posted by Jackson42South
Hi all,
How accurate are motor drives for large dobs?
Is the tracking good enough for short duration astrophotogaphy?
Any recommendations for a drive for a 12” dob?
Paul.
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Hi Paul,
Good to see you on the forum here and I hope you have been well.
It's been about 3 years since we saw you last in Hobart.
One of the perpetuating myths that appears on various forums is that you can't
perform deep-space CCD photography on a Dob without a hardware field-derotator,
platform, adaptive optics, etc, etc.
To the contrary, a growing number of enthusiasts are performing deep-sky
imagining on motor-driven Dobsonian mounts, often with stunning
results.
For example, consider these images by Johannes Brachtendorf in Germany -
http://homepages.uni-tuebingen.de/jo...r/Galaxies.htm
http://homepages.uni-tuebingen.de/jo...er/Nebulae.htm
http://homepages.uni-tuebingen.de/jo...Kinder/new.htm
All of these images were made on a truss-pole Dob using a ServoCAT
and Argo Navis. The ServoCAT includes an ST-4 compatible auto-guider
port for fine correction. Derotation was performed in software.
Quote:
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Originally Posted by Astroman
The ServoCAT system is a great little add on for trus style dobs, could work with others I guess. Mainly designed for the Obsession style scopes this little unit attaches to the Alt/Az surfaces and drives it effortlessly, unfortunately you need the Argonavis DSC to do GOTO's and make it track, which is a real shame.
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The ServoCAT and ServoCAT Jr. have been fitted to a large variety of mounts,
not just truss pole Dobs. The Jr. is optimized for 8" to 14" mounts. Some
ServoCATs are even installed on equatorial mounts. Both the ServoCAT
units and the Sidereal Technology units can be connected to an Argo Navis
DTC, in which case the Argo Navis performs all the object offset and
tracking rate calculations in real-time. When configured in this way,
full GOTO operation is suppported. However, these units can also
track without an Argo Navis being connected. The ServoCAT system that
provides this feature is referred to as "EasyTrack".
Servo motors systems provide numerous advantages over stepper motor
systems on telescope drive applications. Avoid stepper motor systems if
considering astrophotography. A system that provides autoguider
support is highly recommended.
Hope the above is helpful.
Best Regards
Gary Kopff
Managing Director
Wildcard Innovations Pty. Ltd.
20 Kilmory Place, Mount Kuring-Gai
NSW. 2080. Australia
Phone +61-2-9457-9049
Fax +61-2-9457-9593
sales@wildcard-innovations.com.au
http://www.wildcard-innovations.com.au