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Postby guybunce » Sat May 14, 2016 1:46 pm

Dear all,

I am pretty new to astronomy and I am having some difficulties using my Altair GPCAM AR0130C COLOUR.

My setup is:
Sky-Watcher Skymax-127 AZ SynScan GO-TO Maksutov-Cassegrain Telescope.

I have a Telrad finder which I know to be perfectly aligned as when I use it with my 10mm lense and 2x Barlow whatever I put in the finder is centre vision. However, if I then replace the lense with my GPCAM (say for example when looking at Jupiter) nothing shows up and I have to blind hunt to find the object I was looking at. Any tips?

Also, does anyone know if it is possible to adjust the field of view of the GPCAM as I should like to take a photo of Jupiter and its moons.

Many thanks,

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Joined: Sat May 14, 2016 1:39 pm


Postby Aratus » Sat May 14, 2016 4:51 pm

There are a couple of potential problems. You may not be able to 'see' Jupiter when you switch to the camera because the focus will be different. I suggest you start with something like the moon, (difficult to lose!) and remember the adjustment needed to bring it into focus (clockwise or anti-clockwise, and how far) You can then use the same procedure with Jupiter.

The camera sensitivity or exposure may be set too low. Set them high to begin with. You can reduce them once you've found the planet.

The other problem is that if the camera weighs more than the eyepiece then using the camera pulls down on the telescope slightly. Since the field of view is so much smaller with a camera that can be enough to take it out of view. You may have to take that into account and position Jupiter a little lower in your eyepiece, and the weight of the camera may then pull it up and bring it into view.

Removing the barlow will give you a wider field of view. Try doing that first, and use the barlow afterwards once you have Jupiter in position without it.
I use an 11" reflector (Celestron CPC 1100) and a 3" refractor, (Sky-Watcher ST80) mounted on an equatorial wedge, housed in a 2.2m Pulsar observatory. I use a ZWO ASI 120MM, ZWO ASI1600MC and Canon 1300D for imaging.
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Location: East Lincolnshire


Postby guybunce » Sat May 14, 2016 6:01 pm

Many thanks for your tips. I think you may be right that the camera moves the telescope. I have found that if I slew the telescope after putting the camera in I can find Jupiter again and the focus isn't too bad without adjustment. It is just really annoying as I have to slew it by trial and error. I have checked in my finder scope post switching out the lense for the camera and it doesn't seem to have moved. It might be that the camera's field of view is off centre. What I might try is finding Jupiter with the camera attached and realign the finder scope!

Many thanks once again.
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Joined: Sat May 14, 2016 1:39 pm

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