Getting back into imaging after a long break

[Gina]

I'm not happy about the star shapes either.  In fact the whole image is rubbish!

[Dr_Ju_ju]

?? as in out of focus ?  elongated ?.....

[Gina]

Just checked the captured images in Blink in PixInsight and the sky was pretty clear for the whole run up to 02:30 this morning but seems the mount thought it had hit the horizon 50m earlier and stopped tracking.  It hadn't though as the images continued.  So that's something else to sort out.  I have a lot to learn about this KStars/Ekos/INDI system!  That's not to say I don't like it - it seems much more logical than the Windoze software collection and I know it's going to be much better once I get it sorted out.

[Dr_Ju_ju]

Although I had a better night, except for the early part where I wanted to finish 2 sequences, but nothing would play ball   

A sequence for NGC7331 at least gave me some data to play with, but it needs to complete the sequence..

 

[Gina]

8 minutes ago, Dr_Ju_ju said:

?? as in out of focus ?  elongated ?.....

Both.  Elongated towards the edges.  Normally that would indicate a curved field but these lenses gave flat field over a 36mm x 24mm image plane on film - the ASI1600MM is considerably smaller.

[JamesF]

I wonder if that's why the image wouldn't plate solve?

James

[Stub Mandrel]

16 hours ago, Gina said:

Great!  I have an electroluminescent panel for flats.  Works well.

Me too, just done them tehy will do for both nights. 🙂

[Gina]

18 minutes ago, JamesF said:

I wonder if that's why the image wouldn't plate solve?

James

I wouldn't be at all surprised!  This lens doesn't seem as good as the 28mm f3.5 I used when I started imaging again after the long break.  I thought the greater aperture of the 55mm lens would give me better subs but maybe not.  Having got a few other things sorted out I might go back to the 28mm lens.  Trouble is, that lens gives rather too wide a FOV.  OTOH if I can get sharp images with that I can crop out the part I want and no doubt do better than with the 55mm lens.

[Gina]

This is an image taken with the 28mm lens.  It's clearly a lot sharper than anything I captured with the 55mm lens!

[Stub Mandrel]

17 minutes ago, Gina said:

This is an image taken with the 28mm lens.  It's clearly a lot sharper than anything I captured with the 55mm lens!

I'd be very chuffed with that 🙂

[Gina]

I was, to the point that I entered it into the 30s imaging competition. 

Just brought the rig indoors and taken the 28mm f3.5 lens out of my astro box ready to put back on the imaging rig.  This will give a good FOV when Orion comes back into view as it will cover the lot, including the whole of Barnards Loop.

[JamesF]

Indeed.  It looks much better.

James

[Gina]

Both lenses are from the same "stable", Asahi Optical Co. of Japan but the 55mm is an earlier one called "Super Takumar" whereas the 28mm is "Super Multi Coated Takumar" and a later model.  The 55mm lenses were the standard lens supplied with the Pentax Spotmatic SLR camera.  Whether the later models are tat much better I don't know as the 105mm f2.8 lenses which I've found very good are just "Takumar".  All these lenses with the exception of one of the 55mm were bought second hand from ebay with no knowledge of their provenance.

[Gina]

28mm lens is back on and I'm just waiting for a bit less light to set up coarse focus - remote focussing is quite fine.  Minimum exposure on the ASI1600MM is 32µs and even with a 3nm NB filter and aperture set to the smallest of f16 the camera still overloads on a daylight scene.

Edited August 26, 2019 by Gina

[Gina]

I missed a setting in the camera setup 16bit rather than 8bit.  I have now set up rough focus with aperture of f8.

[Gina]

There may be a small chance of testing the rig with the 28mm lens tonight but I'm not counting anything.  With rain a possibility later I shall have to make sure I close up before I go to bed regardless.  I haven't yet got my automatic ROR closing when rain detected though I have have a couple more bits for it delivered today.

[Gina]

The clouds appear to be clearing and I've opened up and set up my imaging rig ready for dark.  Fingers crossed!

[Dr_Ju_ju]

Yeah, they appear to have come my way....

but I wish you all the best.

[Gina]

They're back!!

[Dr_Ju_ju]

Metcheck shows it a little iffy here later on....  https://www.metcheck.com/HOBBIES/astronomy_forecast.asp?zipcode=kt15+1ss&locationID=59338&lat=51.4&lon=-0.5

[Gina]

I shall be keeping a close eye on the weather, ready to dash out and close up if the rain comes.  Auto roof closing on rain detection is not ready yet.

[JamesF]

No rain forecast here until Wednesday, but the forecast isn't good enough for me to trust.

James

[Gina]

CO for here says rain in the early hours of tomorrow morning.

[DaveS]

Yeah, I've got something similar. Got the 'scope set up and pointing in the general direction of the Deer Lick and Stephan's Quintet, but more in hope than expectation. Not cooling the camera yet.

[JamesF]

11 minutes ago, Gina said:

CO for here says rain in the early hours of tomorrow morning.

Indeed.  It's just changed according to the Met Office, too.

James