Graeme

2 hours ago, iapa said:

My paint if flaking off the SCT’s interior so, need some sort of remediation.

The paint started flaking on the inside of my Celestron 9.25SCT whilst it was still under guarantee. The supplier sent it to the UK Celestron agent and he said it was my fault for using chemicals to clean it!!! I hadn't, a shocking abrogation of responsibility. Very disappointing. Celestron said they had never heard of it happening before. Interesting that you have the same thing happening Iapa!

Thanks for the Protostar Flockboard tip John. I'll look into it.

Regards

Graeme

Thanks Gabrielle.

I'm quite pleased the OAG appears to have sorted out my misshaped stars problem.

Regards

Graeme

And a moody starless version just for lols!

The Iris Nebula in Cepheus from last night. 25 from 30 x 360 sec subs. 5 darks (I thought there were more in the library!) 30 flats, 30 dark flats. C9.25, ASI 294MC Pro, using the new OAG. CPWI, NINA, PHD2, Stellerium. Lost the camera after the sequence, had to restart for the flats. 

PixInsight this morning.

Quite chuffed with it!

Regards

Graeme

55 minutes ago, michael8554 said:

Hi Graeme

Very similar star shape to my LodeStar on a 8" SCT with Full-Frame imaging.

Similar HFD, but stars nearest the bottom of the prism are best.

Obvious question is:

Do you have the prism adjacent to one of the long sides of the ASI294MC Pro sensor ?

And as Newbie said, lower the prism stalk until it just doesn't show on flats.

Michael

Cheers Michael

Yes, the mirror is on the long side of the sensor but it's a good few mm back from the edge. I'll move it in a bit to line it up with just short of the edge of the sensor and see if it shows on the flats. Just as soon as we get a clear sky here!

There's one at Greenwich.

That's a lot of detail Paul. 7 hours really makes a difference. I shot the same target with the same camera the night before you did but only for 2 hours!

Here's my go at the Crescent Nebula. Significant as it's the first go out using my new OAG.

I kept loosing the guide star due to poor guide camera focus so there's a bit of eggyness and the flats haven't quite done their job and there were no darks in the mix because there are no 60 second ones in the library. But other than that I'm well pleased because the flexure was getting progressively worse with each session using the 80mm guide scope.

132 x 60 second lights, 30 x flats, 30 x dark flats
CPWI. NINA, PHD2, Stellarium
PixInsight for calibration, stacking and processing.

It's just a quick process, I'll have another go when I've made some 60 second dark frames.

3 hours ago, adyj1 said:

If you move the framing box, then press 'load image' to re-centre your view

 

Didn't know that!

Thanks.

4 hours ago, ninjageezer said:

is the tab saying slew and centre the same now ? I was watching a video tutorial and noticed my latest build of Nina just says slew and centre I'm now thinking this is the same thing .

 

 

The Slew to target button is now a Slew and centre drop down box. There is a Slew option in the drop down if you want to move to the target without plate solving.

3 hours ago, newbie alert said:

You found stars so it's low enough.. but I'd shoot some flats just to check that it's not too low and impeding into the light cone too much 

Yeah you can focus better pulling the camera in or out, but not much movement make alot of difference

PhD doesn't have an issue guiding on oblong stars but the better the focus is the better the snr

I use a 8 inch SCT and I think my hfd is a little lower , can't remember it in the 5's... Maybe  in the 3-4  area, so don't think you're  too far away 

Well my flats showed no sign of the mirror at all so maybe I'll experiment with moving it a little closer in. I need to get it accurate so that the Stellarium ocular sensor frame is a true representation of what's going on.

And perhaps I just need to practice focusing the guide camera some more.

Thanks for your help.

Regards

Graeme

30 minutes ago, newbie alert said:

Is that the best focus you got using the fine focus adjustment? Its not much adjustment from having seagull looking stars to round ones

I'd expand the box parameters on the guide star as you may lose the guide star quite frequently ( within the settings)

How well is the main scope collimated?

Hello NA

Yes, that's the best focus I could get. There is no fine focus adjustment, the main scope was focused accurately and then I focused the guide camera by moving it in and out manually whilst watching the PHD2 HFD figure. The main scope collimation was good. 

The OAG allows rotational movement to a few degrees and mirror height adjustment but I can't see any adjustment that would allow me to improve the quality of the guiding image other than adjusting the distance from the mirror to the guide camera sensor.

Would a mirror height adjustment make any difference? I didn't try that to avoid fiddling in the dark with an allan key!

Hello

My first night out with my new OAG was an almost complete success! I set it up during the day and was happy everything was about right. Then pointed at the Crescent Nebula last night. I found some guide stars but struggled to get a good focus on them. I got the PHD2 HFD down to just under 5.5 but failed to get a sharp focus due to some out of collimation looking aberration thing.

Can anyone suggest a fix or a place to go to read up on OAG set up fine tuning please?

ZWO OAG
QHY5-iiM Guide camera
ASI294MC Pro Imaging Camera
9.25 SCT on a CGX
CPWI NINA PHD2

Thanks

Regards

Graeme

Here's the open star cluster NGC7380 surrounded by the Wizard Nebula in Cepheus from last night. Captured using my new screw in SCT T adapter for the first time. 

Captured with NINA, guided with PHD2 and processed this morning in PixInsight. 46 (from 57) x 240 sec lights.  -10°C 125 gain. 30 darks (from library), 30 flats, 30 dark flats.

I was happy with the collimation adjustments before I started, I had a 4" total PA error and good focus. But there is still an odd shape stars thing going on to the right of the image. Could differential flexure be the culprit?

2 hours ago, CCD-Freak said:

Seeing is probably the biggest reason for soft and bloated stars. 

 

 

Yes, the jet stream is often overhead. Cloud free night skies are rare enough though! Perhaps some of the PI EZ Star Reduction settings could be tweaked.

10 hours ago, The Lazy Astronomer said:

It may be some tilt in the imaging train as the stars on the right look a bit elongated, but the ones on the left look pretty round to me. 

Good shout! I have always thought the camera in the eye piece holder was a weak link. Perhaps a T Adapter with the camera screwed into the train would help.

I have considered a reducer to open up my field of view but I've not done it yet! I did notice the eggy stars when I was setting up and had a go at tweaking the collimation but it's tricky with the dew shield on. I must get into the habit of collimating first thing and then putting the dew shield on and re-balancing. 

Here's my go at the Needle Galaxy in Coma Berenices from last night. I fitted a new dew heater ring on the SCT yesterday and it did a great job. The guide scope was just starting to mist up at the end of the session. The plan was for a 2200 to 0200 four hour session, from just past meridian to sinking in the West. As it turned out I got started at 2250 and finished at 0150 with an HFR rising to 6.8 in the light dome of London.

9.25 SCT CGX ASI294MC Pro, captured with NINA, guided with PHD2 and processed this morning in PixInsight. 42 (from 58) x 180 sec lights, 8 removed for satellite trails, 8 removed for London LP.  -10°C 125 gain. 30 darks (from library), 30 flats, 30 dark flats.

Collimation needs sorting out! Is that what's causing the soft focus?

Thanks OE

The final jpg looks a bit blocky/blotchy! And the overall soft focus is disappointing but overall it's not too bad!

This data was captured in March this is a stack of just 13 x 240 second frames out of 40 captured using a USB to ethernet converter to allow me to stay in the warm indoors! Communication was repeatedly lost, so in future I'll be using  Teamviewer to connect the capturing laptop to the pc indoors. 

9.25 SCT CGX ASI294MC Pro. Captured with NINA, processed in Pixinsight.

NGC 2403 (aka C7) intermediate spiral galaxy in Camelopardalis.

I captured 40 x 240 second images 24/04/22 but the wind was a bit too gusty and knocked out the guiding a couple of times, 13 of them didn't get used. 30 flats, 30 dark flats and 10 darks from library.

C9.25 SCT, ASI294MC Pro. 125 gain, -10°C, Captured with NINA, Processed in Pixinsight.

This one probably needs a good 3 hours to show off the outer regions.

Regards

Graeme