Tracking issue with Skywatcher AZ GTI

[ChrisRo]

Hey, 

I've just recently purchased a Skywatcher Skymax 127 Telescope with an AZ GTI mount and I'm having issues with long exposure shots,  I was trying to take some pics of Pleiades with a 30 seconded exposure and the tracking wasn't working correctly. I tried doing the pole alignment method  and the GoTo does kind of work but its not super accurate, I have a feeling that this might be causing the tracking issues, or is 30 seconds just to long for this mount?  

DSC00328.ARW DSC00346.ARW

[michael8554]

If my interpretation of your Pleiades framing is correct, the stars are "dumbell" shaped in the Az plane.

By which I mean that the mount is alternating between two slightly different positions during exposures, giving the appearance of two stars joined by a faint streak.

Perhaps the scope is wobbling on the mount, maybe due to backlash in the drive, or it's flex in scope to mount and/or camera to scope connections.

From what I can see online, the AZ GTI is a Alt-Az mount.

So when you say "pole alignment", have you mounted it on a wedge, to turn it into an EQ mount ?

Michael

[happy-kat]

Hi it would help if you used a jpg image when wanting to share something to look at.

Are you using the mount in altaz or eq mode?

Was it windy when you were taking images?

Was the mount on solid ground or decking?

 

[Adam J]

I think it's best I am honest and say that as a AZ GTI owner I don't believe that the skymax 127 is suitable for DSO imaging with this mount. It's more a visual solution on a AZ GTI. Even with heavy counter weights and perfect balance I think the focal length is too long to enable tracking at sufficient accuracy to produce a DSO image without elongated stars or similar issues. I found that my AZ GTI required tuning to handel even a short focal length refractor well. 

 

Did you purchase it for DSO imaging or do you also use it for visual? 

Adam

[sthow]

I also have the AZ GTI and use it currently in ALT-AZ mode but I use a StarTravel 102 and can manage 30sec images. I did have a few issues though and only recently sorted them. What I found was make sure you have good power, the power adapter I was using wasn't good enough. Make sure its level and the clutches are nice and tight, that made the biggest difference for me. I also do 3 star alignment, starting by being level and pointing towards Polaris. Since doing this I have been fine, I think you should be able to manage 30 seconds. 

[ChrisRo]

Thanks for the suggestions, the mount is in Alt-Az mode and I'm using the tripod that comes with the AZ GTI, unfortunately its not very stable, however it was on paving and I stood away from the Telescope while the images were taken.  It also wasn't very windy. 

I have purchased this scope for some DSO Imaging but also for viewing the planets. So far the only decent pic Ive taken is of the Moon

I'll try a 3 star alignment and see if that improves the behaviour, but I have my doubts. I'm thinking I will try replacing the tripod to see if that helps as the weight shifts when the scope is moving so its never truly level.