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Hello everyone, I'm wondering if I could get some help, sort of ripping my hair out a little.
I have the EXOS2 PMC-8 and last night I used Sharpcap to Polar align, I set the mount up as usual and adjusted until Sharpcap said excellent Polar alignment.
So my next step was to do a 3 star alignment I was using a program called Explorer Stars to achieve this, so when I asked the mount to slew to the first star it was way off even in the finder scope, is that normal? So I used the controls to get the star in my FOV and centred it, it was the same for the next two stars way off. so I did the same.
I finished the 3 star alignment and when I asked the mount to find an object the object was not centred it was bottom right of the quick photo I took.
I've made sure all the information is correct by setting my Longitude and Latitude and also made sure my time is correct, the mount is balanced and level and pointing North. I think I'm doing something wrong somewhere.
Also may I ask should my counterweight bar be parallel with the mounts front leg? I have two little arrows on the mount that should be pointing at each other when in the home position but when they are the counterweight bar is pointing to the right quite a fair bit.
I'm new to all this only been doing it for a few months so a lot of things are quite confusing.
Thanks in advance Bill.
The other night, I got a rather weird thing happen using Sharpcap. In live-stacking, the first image arrived and it was full of stars. So, without changing any settings, I did a "platesolve" (which also realigns the scope) to centralise my target. It did its single frame capture and I got a practically blank screen and a message saying it could only detect 3 stars. I tried reducing the "sigma" setting, as advised by the on-screen message, with little effect. What gets me is that the same settings produced a whole mass of stars in each of the subs that were being live-stacked. Never had this happen to me before, and no, of course I didn't do anything intelligent like saving the log file!
I can always try to replicate this next time (although I always find trying to replicate something that isn't working to be a weird activity in itself!), but on the off-chance that anyone can see what was happening without the log file, I thought I would ask.
This is Markarian's Chain shot from my back garden over three nights in late March. Probably the deepest single image I've taken in terms of integration time...which leaves me feeling my processing is not quite doing the data justice...maybe I'll come back to it.
In any case, this is an incredible part of space; looking away from our galaxy reveals countless others!
The crazy number of Lum subs took a whole day for APP to chug through and so I've resolved to lower the gain from unity going forwards to get more manageable sub lengths than 15 seconds!
L: 1050 (!) x 15s R: 92 x 60s G: 165 x 30s B 165 x 30s....total integration time 8.2 hours.
Captured using APT, stacked in APP and processed in Pixinsight.
Thanks for looking!
Edit: Link to higher res version
I am starting to get to grips with some of the features on Sharpcap and last time out I tried to use the focussing assistant using a bahtinov mask.
The first thing I noticed is how sensitive it is. The attached screenprint involved the tiniest movements of the fine focusser knob on my Star71, which caused it to sweep from +1 to -1 without stopping in the middle. I decided I wasn't going to do any better than that (but could probably waste an awful lot of clear-sky-time trying!), so decided to accept that. After all, from what I have read, an FWHM of about 1 is reasonable.
But now comes my confusion. I was assuming that the scale was FWHM units. But, as can be seen from the screenprint of the log, the FWHM of each individual sub was just under 4. I realise it would not necessarily be the exact same figure as when I was focussing, but 4x that figure? This would seem to suggest that either the scale on the focussing assistant is not FWHM units (so what is it?), or my focussing went way out during my imaging session. The resultant image can be seen here.
So, are these the sort of results I should be expecting? Or where am I going wrong?
Outside there is something coming out of the sky that strongly resembles the Atlantic Ocean being poured through a seive, so I thought I would give the 'sensor analysis' option in sharpcap a go on one of my cameras. This resulted in the table attached.
I'm sure all the figures are great, but as to helping me decide which gain setting I should use for this camera, I am not a lot wiser. There definitely seems to be something strange (impressive?) happening to the read noise between 60 & 61, but it continues to decline after that so I'm not sure that gets me very far.
So, it's time to get educated ... (1) which is my best option, and (2) why?
224 sensor analysis.txt