Re: Mounting camera to EXOS2 #EXOS2 #astrophotography


You'll probably get a bunch of suggestions. Here's mine:

- I made a wooden Vixen dovetail, long enough to extend back past the mount casting (toward South); then attached an inexpensive ball mount biased toward the rear
(South). The ball mount will probably need a 3/8" screw through the wooden dovetail. Of course, if you have a proper dovetail, it might already have holes. The trick is to
be able to slide the dovetail forward & backward until the mount balances. The included counterweight will be too heavy for balance about the RA axis; you might need a
really small counterweight, like a 2.5 lb, barbell weight. I found that the small barbell weights have a 1" bore, so they fit the 20mm. shaft loosely. I filled in the gap with a PVC
plumbing adapter. A Pair of 20mm. shaft collars on each side keeps it in place,...kinda.

-Then I added a cheap red-dot finder onto the camera's flash shoe. There are plenty of ways to use your ingenuity here! Your junkbox is your friend!

- Then I co-aligned the camera to the mount's RA axis. To do that, I used the polar finder and Alt/Az adjusters to get Polaris on the cross-hair marks (not the circle). The
camera was aimed at Polaris, and I checked that Polaris was in the center of the frame, by making an exposure. I adjusted the ball mount until it was perfectly centered.

- The last step is to align the red-dot finder to Polaris, too. With that done, everything was co-aligned.

- Don't forget to re-adjust the polar alignment to the real North Celestial Pole (not the cross-hairs)!!!

- You could use any convenient target rather than Polaris, but it was easy to see, and required only a small shift of the RA.

I'm a rank newbie, too; so I hope I've got that right. Seems to have worked for me...

Chuck Lewis

Scope: Nikon kit lenses, TBD
Mounts: Exos2GT-PMC8, homebrew barndoor tracker
Camera: Nikon D7000
S/W:  Backyard Nikon, DeepSkyStacker, Paintshop Pro 2020

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