Sabalias

Out of the blue (or black) last night was clear as a bell here 😁. Managed to get some more time on the Iris Nebula - now 4 hours 18 mins.

Stu

Started out beautifully clear here last night with both the Met Office and Apple weather agreeing that there would be 2 good hours ahead. Dashed around setting up all my kit and 20 mins later started checking Astroberry connectivity (no connection but easy fix); when I went outside to recycle the Astroberry low cloud and fog were beginning  to drift in ☹️.

In my neck of the woods the last 3 months have been appalling, by and large 🙄

Stu

Thanks everyone. It’s reassuring to read that things aren’t as bad as I thought they might be 😁. I bought the scope with an old version Baader Steeltrack focuser added so comments about the focuser are particularly interesting. I’ll investigate that possibility. 
 

Stu

34 minutes ago, alacant said:

Remove/disable the EAF and go again.

They're great on reflectors and top end refractors, but will most likely need a carefully calibrated offset with an 80ed.

Cheers 

Thanks Alacant. I’ve managed to get good focus but the example above was deliberately out of focus to see if a star test would work with a camera (you probably realised that). 
 

Stu

Hi All,

I've done a star test using my highest power eyepiece and all seemed good (though it wasn't easy to see for certain). I thought I'd try a star test using a camera and got the following result:

Does this mean anything?

Many thanks,

Stu

Thanks Lee.  Fortunately I’m not in the middle of a town but I am kind of surrounded by them so your information is very useful. I do need to add more data (clouds permitting).

2 hours ago, SteveNickolls said:

I've been keeping records of observing and imaging sessions for years (11 observing 7 imaging) and this September has been the poorest on record. Rather hoping the coming seasons will improve chances as I didn't vote for this. 😁

Here's to clear dark skies.

Cheers,

Steve

That’s interesting Steve. I haven’t been at this pastime very long but I found myself trying to remember if previous Septembers had been as poor. 
 

Stu

Hi All,

I've been doing a bit of imaging (getting to grips with the 1600mm and filters) and I have a question. I get quite a lot of sky glow (I'm assuming it's light pollution as the moon was not an issue at the time and there isn't any in the narrowband images) and I was wondering if I would be better using a light pollution filter at the end of my field flattener or processing out the gradient (which creates its own problems)? Obviously, narrowband imaging is a solution but not for all targets (I understand). I'm not very happy with the star shapes but that is a separate issue I am working on. First image is just cropped and a bit noisy, but you can see the gradient; the second is the full size image but the gradient has been removed in processing (which is leaving a kind of black speckling across the image). Images below are from only a couple of hours total subs (LRGB and narrowband) processed in DSS and then in Affinity Photo.

Many thanks,

Stu

3 hours ago, pipnina said:

I am not sure that this is a spacing issue. In the top and bottom left you see one corner with saggital shaped stars and the other corner with tangential shaped stars. If it were a spacing issue, as I understand it, both corners should exhibit either tangential OR saggital distortion?

The opposite sidenon the right seems to be much rounder, but I am zooming in on a phone right now so it might be a trick of the eyes!

Thanks Pipnina. I’d be interested to read what you have to say if you get a chance to confirm. 

5 minutes ago, Stuart1971 said:

Those figures above show a bit of curvature, as the central figure is lower than the four corners…so a flattener may help, or if you have one fitted, then maybe adjust the spacing….you have an APC-s size sensor so with that scope, a flattener will help loads I would imagine…👍🏻

I dont think that is tilt at all….

Thanks Stuart. I'm using a flattener with recommended back-focus measured using a vernier calliper. I'll go back a check everything on that front in case I went wrong.

Thanks Alacant. I'm using a ZWO EAF  which I'm still getting to grips with so I'll work on that.

Hi all,

I wonder if someone could help me please? I've been experimenting with my new camera on my (second hand) Skywatcher ED80 and I'm getting some odd star shapes. I'm thinking that there is some tilt in there but I'm also wondering if I have a coma problem (top right corner seems more than just tilt). The picture below is a lights only stack through a luminance filter but all frames the same. Any thoughts and advice on correcting would be most gratefully received. 

Many thanks,

Stu

Unfortunately I’ve not been able to do anything on the astro front this September. Some forecasts have been clear but the reality has been anything but. Missed Jupiter in opposition too. Very disappointing but I guess that’s the joy of this hobby in the British Isles.  On the plus side I managed to see the aurora borealis on a trip to Norway at the beginning of the month 😁

Stu

I don’t buy much of my kit new but a recent windfall allowed me to splash out. FLO, as always, went above and beyond. 

I’m not very experienced either but I think that’s pretty good for 90 mins exposure. What’s the DSLR and what bortle level are your skies?  For what it’s worth these are my efforts from Friday night; 27 x 300 seconds, bortle 5, QHY 8L-C:

Stu

Just a quick update. I changed the nosepiece on the camera (and cleaned the sensor while I was at it) and the difference is startling. No spikes and no dust spots either (I thought the dust spots were in the scope or FF but they weren’t. 

Anyway, thanks to everyone for their help 👏

Stu

8 hours ago, 7170 said:

Do you have any filters in the light chain by any chance?

Only the filter on the camera nosepiece (replacing this) and the FF.  I got out again last night and took some more shots of Pleiades - most of the spikes had gone so there had been something crossing the light path on the previous night; however, some are still present and move when I rotate the camera so I put it down to the larger of the scratches. 

Stu

Do you mean upgrade EQ5 to EQ5 Pro Go-To?

Sky-Watcher SynScan PRO Go-To Upgrade Kit for EQ5 | First Light Optics

Stu

If I understand your question correctly then I don't believe you can use any of your EQ5 to upgrade to and HEQ5 (other than the tripod, synscan handset and cable; unless you can buy individual component parts I suppose) - they're different models. 

Sky-Watcher EQ5 PRO Go-To Astronomy Mount | First Light Optics

Sky-Watcher HEQ5 PRO Go-To Astronomy Mount | First Light Optics

Stu

Ok, so I've managed to find a few minutes to look at some of the other subs and it does look as though there is a line intruding on the field of view, so that would definitely explain some of the spikes (which I believe should be perpendicular to the line). Unfortunately it doesn't explain why some of the other spikes exist; that said I have been able to source a replacement front end so a small job for me to undertake sometime this week will be to release the resin sealing the unit, and replace the front end. Thank you all for your helpful input 👍

Stu

6 minutes ago, tomato said:

Those scratches don’t look good, they could explain the different orientation of the spikes. They will be present in every image however, if they are the cause.

It looks like a lens, but dedicated Astro cameras don’t normally have a lens associated with them? If it is just a window, it shouldn’t be too hard to replace.

Yes, I need to see if the same problem happens on a different night pointing in a different direction. The glass is a filter built into the front end of the camera which, I believe, I can replace (need to check with a specialist).

Stu

Hi Malcolm,

Now that’s a coincidence - I was looking at your thread just as the alert for your post came in 😂.  Though there is a phone line in the vicinity of the field of view I don’t think it was intruding but also I have spikes in all sorts of directions which is very strange. I need to try a different object next clear night just on case.

Stu

I guess my worry is that it might be down to small scratches on the camera glass. Please tell me it’s not! If it is then I think I might be able replace the front end but I’d rather avoid that.

I also wondered about that and I am certain that it wasn’t pointing near the horizon and there were definitely no branches in the way.

Perplexing. 

17 minutes ago, tomato said:

I can get these spike effects on a refractor if the scope starts to be occluded by the dome aperture edge. The other way this can happen is if a power line or washing line is across the field of view, or branches of tree perhaps?

Thanks for the reply. I presume you’re referring to the edge of an observatory dome? Sadly I don’t have one of those. I don’t think there were any wires in the way but I’ll have to try a different target next time it’s clear. 

Cheers,

Stu