iexos-100 wobble and bad star alignment

Matt Hallett


Pretty new to astrophotography but many years experience in regular photography. Very steep learning curve this year has taken me from a regular DSLR/lens/tripod and shooting at high ISO to minimise star trail, to the IEXOS-100 goto mount, Sky-watcher Startravel 102mm scope lens and multi-minute exposures with lights, darks and stacking.

Tried out the mount a few days ago and noticed two pretty fundamental issues (I think), which I'd appreciate advice on.

First up, when I was positioning the mount for polar alignment I noticed it was quite wobbly on both the right asc and dec axis. Definitely some visible play when I put a little bit of pressure on the mount. Presume there must be some gears and cogs that can be tightened up to remove that level of play. Any pointers on where and how would be great.

And then after polar aligning (roughly but still relatively accurately) I did a two star alignment test. However, the mount was way off in its initial auto alignment. And when I say "way off" I mean I tried to align at Vega but the scope was pointing closer to Mizar/Alioth. I did a manual adjustment to get it pointing at the correct star but then when I did a goto test to Andromeda galaxy it wasn't even slightly close. It ended up pointing me somewhere closer to Capella!

Entirely willing to accept this is down to user error. I checked my lat/long coordinates and they're correct. As mentioned, the scope was pretty closely polar aligned (yes, I could have been more accurate but the margin of error wasn't enough to account for the error in the goto pointing).

So first up I'm wondering if the axis wobble and the poor alignment are related. Is the mount thinking it's tracking to the right point in the sky but there's so much wobble and slip that the gears don't actually turn the mount far enough? Or is is a software issue, or maybe I've just entered the wrong details, so the scope thinks I'm in a completely difference place in the world?

Secondly, if I can't get the goto bit working properly can I still just use the mount to track "dumb" and follow the celestial object that way, assuming I'm more accurate in my initial polar alignment?

Any advice for a newbie would be well received.

#alignment #astrophotography #ExploreStars #iEXOS-100 #polaralignment


Mount: iexos-100 with PMC-8
Scopes: Startravel 102
Camera:  Nikon D7500
Software: Deep Sky Stacker, Siril, Photoshop

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