Star Adventurer with SW Black Diamond ED80

[lineout]

Hi all,

Hope you can help with a question have. I own a Sky Watcher Star Adventurer and really like it. I am thinking of buying a SW Black Diamond Ed80 to mount on it but am worried about it being too heavy. The ED80 weighs in at 2.47kg and the Star Adventurer is rated at 5kg. Obviously there will be the additional weight of the camera, counter balance etc, but I'm interested to hear from anyone who has mounted a scope and what results they've had.

Regards

Rene

[OzEclipse]

I don't own the Star Adventurer so I can't comment on its stability. I have used an ED80 on a small mounting of my own construction and can make some general remarks that will apply to your situation.

If you hang a camera or a 2" diagonal and say a 26-40mm 2" eyepiece, that will add about 1 - 1.5 kg to the payload. I use an Andrews 30mm UWA (80 deg) eyepiece with an ED80. Fantastic sharp wide field view 4 degrees with a 4mm exit pupil. Good for old eyes! But it does add most of 1kg to the back end. You may even need to hang a counterweight band around the lens hood if the balance point gets shifted backwards past the end of the dovetail.

For a given weight of OTA, a short OTA like a Maksutov will sit more steadily than a long refractor of equal weight. The longer tube applies more torque and will oscillate more.

The illustrations of this mount frequently show the OTA well away from the polar axis and counterweight extended toward the end of the thin counterweight shaft. This will cause it to oscillate like a pendulum.
http://gerrygibbscamerawarehouse.com.au/images/en_mounts_caty01398815932.jpg (http://gerrygibbscamerawarehouse.com.au/images/en_mounts_caty01398815932.jpg)

This can be minimized by pushing the dovetail so that the OTA is as close to the polar axis as possible, not hanging out like they show in all the illustrations. Bolt a counterweight to the 1/4" tripod screw at the other end of the dovetail _ a camera with lens if nothing else so that the counterweight on the shaft can be moved as close to the polar as possible. This will minimize bouncing.


Joe

[colinmlegg]

I bought one a couple of months ago and last week ran a 2 camera + telephoto setup ... 6D + Canon 70-200 f/2.8 II and A7s + Canon 400 f/5.6. Both were shooting silent (electronic shutter) and my Troopy was shielding the setup from a light easterly. Attached is a pic of the setup + a cropped stack (100 x 10 sec) of Comet G2 MASTER through the 400 that night.

Setup weight - 4.127 kg

Joe, good tips on how to minimize bounce.. I'll keep that in mind when running 1 camera + counterweight.

[raymo]

Quoted mount payloads are usually just that, the useful load that it can carry, excluding counterweights, so I would check with the supplier on
that point.
raymo