Astro_mark_c Posted January 17, 2021 Share Posted January 17, 2021 Hi, last night I PA with SharpCap and got an excellent for PA. I looked through my polar scope out of curiosity and Polaris wasn’t where I would of thought it would be? This normal? Also even after PA in SharpCap I was still getting oblong stars (especially the smaller ones) for 60s unguided. ive checked my balance and everything seems balanced. Link to comment Share on other sites More sharing options...
david_taurus83 Posted January 17, 2021 Share Posted January 17, 2021 How far out was Polaris in the polar scope? I use Sharpcap every time also. Its very good. But perfect polar alignment doesn't mean you will get perfect tracking. Still need to guide to compensate for periodic error etc Link to comment Share on other sites More sharing options...
shropshire lad Posted January 17, 2021 Share Posted January 17, 2021 And is your tripod perfectly level? Link to comment Share on other sites More sharing options...
Astro_mark_c Posted January 17, 2021 Author Share Posted January 17, 2021 9 minutes ago, david_taurus83 said: How far out was Polaris in the polar scope? I use Sharpcap every time also. Its very good. But perfect polar alignment doesn't mean you will get perfect tracking. Still need to guide to compensate for periodic error etc When looking through the polar scope it was inside the middle circle of the reticle but not where an app like PS align says it should be. im just asking as I’m trying to figure out why after PA with SharpCap I was getting oblong stars unguided at 60s. I’ve checked the balance and to me it’s balanced. Link to comment Share on other sites More sharing options...
Astro_mark_c Posted January 17, 2021 Author Share Posted January 17, 2021 13 minutes ago, shropshire lad said: And is your tripod perfectly level? Yeah it is, my back garden is half concrete slabs which are level. Link to comment Share on other sites More sharing options...
Ricker Posted January 17, 2021 Share Posted January 17, 2021 The tripod being level makes no difference. The polar axis has to be aligned regardless. I would suspect that the polar scope reticle is not aligned in the polar scope. I use to scope to make sure the polar axis is roughly aligned and then sharpcap to align. Link to comment Share on other sites More sharing options...
david_taurus83 Posted January 17, 2021 Share Posted January 17, 2021 I've had 3 SW mounts. EQ5, AZEQ6 and Star Adventurer. Not one of them had an aligned polar scope when I got them. The AZEQ6 was brand new and the polar scope reticle was loose! 2 Link to comment Share on other sites More sharing options...
Astro_mark_c Posted January 17, 2021 Author Share Posted January 17, 2021 1 minute ago, david_taurus83 said: I've had 3 SW mounts. EQ5, AZEQ6 and Star Adventurer. Not one of them had an aligned polar scope when I got them. The AZEQ6 was brand new and the polar scope reticle was loose! This is my second pole scope for my mount as the first one I tried to calibrate it and one of the small screws fell into the chamber... that’s why I bought SharpCap pro! 1 Link to comment Share on other sites More sharing options...
Ricker Posted January 17, 2021 Share Posted January 17, 2021 Sharpcap is great for polar alignment. Link to comment Share on other sites More sharing options...
newbie alert Posted January 17, 2021 Share Posted January 17, 2021 I found sharpcap pretty good, especially the speed it does it at.. but it's not as accurate as drift aligning..so don't expect it to be perfect Link to comment Share on other sites More sharing options...
Astro_mark_c Posted January 18, 2021 Author Share Posted January 18, 2021 Set up SharpCap PA tonight, got an Excellent for setting it up took like 5mins all good. By the end of my play around it was sitting at Fair... Should it really shift that much? Link to comment Share on other sites More sharing options...
Roy Foreman Posted January 28, 2021 Share Posted January 28, 2021 I recently used SharpCap to polar align my EQ6 and I have to say I was impressed by how quick and easy it was to do. As you probably know the software provides two methods of adjusting the PA. The first is by adjusting the mount until a highlighted star - later two parallel lines - coincide with each other. The second is by watching the RA and DEC offsets reduce in magnitude as you adjust the mount. If using the latter method it is important that SharpCap knows your latitude and longitude for accurate results. I managed to get my PA down to 25 arc sec, and the reason I could not get better than this is because the adjustments on the EQ6 were just not fine enough to achieve any better, so it is a very sensitive procedure. Just mounting a scope on the mount can shift the alignment by a small amount, particularly if it is a big heavy OTA. As for your star trails, if they are east-west then it is most likely down to periodic error, if at some other random direction then probably polar alignment. Since doing my PA I haven't had a clear night to try it out. When I do I will report back and let you know my findings Good luck and clear skies Link to comment Share on other sites More sharing options...
Jonk Posted February 5, 2021 Share Posted February 5, 2021 Are you guiding or planning to guide? Do you have backlash in your RA? You may find a perfectly balanced mount is 'floating' between the gear teeth. Try and offset the balance to the E so the weight pulls the gears together and hopefully reduces the bouncing / floating. Link to comment Share on other sites More sharing options...
malc-c Posted February 6, 2021 Share Posted February 6, 2021 Having precise polar alignment doesn't compensate for backlash or PE in the mounts drive train. Even if perfectly adjusted your EQM-35 has a 2.8 arc second resolution, so you can expect some drift. If you factor in PE, backlash and any balance issues then it can be noticeable when imaging (visually you wouldn't notice). This is why we all use guiding when imaging. Link to comment Share on other sites More sharing options...
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