The EQ3 DSO Challenge

[mikey2000]

Oops!  Corrected....

[Stub Mandrel]

The Leo Triplet from last night. Still a bit noisy.

[bobro]

Here's my Leo Triplet from last night - 20 subs @ 4min, 800ISO.

[Stub Mandrel]

59 minutes ago, bobro said:

Here's my Leo Triplet from last night - 20 subs @ 4min, 800ISO.

Mine was 59 subs at 2 minutes, so about half as much again. I suspect the difference is my merciless over-processing, I reckon you can squeeze a bit more from your data :-)

[bobro]

34 minutes ago, Stub Mandrel said:

I reckon you can squeeze a bit more from your data :-)

Yes - didn't spend more than 15 minutes processing, so more should be possible. I tried dithering for the first (APT to Lin_guider) - failed as Lin_guider control seemed to go into DEC oscillation. So I turned dithering off for the above image. There seems to be something going on with DEC guiding (oscillation) - it looks like backlash, although it didn't show in earlier guiding. RA is fine. Needs investigation.....this stuff keeps us busy!

[Stub Mandrel]

Busy proving that bumblebees can fly again tonight - 2 minute subs with a 150PL on an EQ3. NGC2903 look really promising and benefiting from all that extra FL.

Edited March 25, 2017 by Stub Mandrel

[mikey2000]

perhaps I should have posted in here...  I have asked a question in the general Mounts Discussion forum.   The good people at the PHD forums looked at my guide logs and discovered a short period (about 20s) repeating error in my RA tracking.  The details are here: short period error on EQ3Pro

Any suggests on how to combat or mitigate my tracking errors? Thanks!

[Stub Mandrel]

Here's NGC2903 and M50 from the session on the 25th - I have posted these elsewhere on the forum, but I feel I should report back.

The M50 is just this year's data, a combination version using last year's as well didn't have such good colour, possibly because there was a lot more LP around a year ago (street lights have been switched off and I got a skyglow filter).

 

[Peco4321]

These are cracking images @Stub Mandrel. 

[wimvb]

Great, Neil. Much better than my attempt at ngc2903. What camera settings did you use & nr of subs?

[alacant]

31 minutes ago, mikey2000 said:

mitigate my tracking errors

Hi. Have you tried PHD2's new predictive PEC algorithm? It's out of beta testing and available as a development build. HTH.

[Stub Mandrel]

58 2-minute subs of NGC2903 and just 28 2-minute subs of M51, but I manually selected the best ones from 100 on each target. I was pushing my luck with the 150Pl especially as M<51 is near the zenith and that is where the EQ3 does struggle.

I have lots more subs of M51 from last year with the same setup, but at iso1600 and only 30s and they don't seem to improve the image.

Neil

[Nigel G]

I have had the chance to add some more subs to NGC 1499.

I took a total of 6h 40 m and used 4h 40m of the best ones. I didn't use any of the 6m subs just the 4 minute.

Still fighting the canon banding but now have a couple of programs to use, Fitswork has a good function as does Pixinsight. Startools module doesn't seem aggressive enough.

I'm wondering if I lower the ISO to 400 if that might help.

California nebula. 4h 40m of 240s ISO 800. modified Canon 1200D with CLS filter - Darks, flats & bias. 80ED Pro - EQ3 Pro.

No colour work done other than saturation.

DSS - Startools - Fitswork & PS express.

Thanks for looking.

Nige.

Edited March 31, 2017 by Nigel G

[happy-kat]

Did you use the bias as a master dark flat file?

The difference I got on my much simpler image was really quite large when I did that bias trick. Why not try it and stack this with dark from the master bias file and a dark flat from the master bias file and see if the banding is less. (don't use the darks you took in the stack just use the bias file trick).

[Nigel G]

2 minutes ago, happy-kat said:

Did you use the bias as a master dark flat file?

The difference I got on my much simpler image was really quite large when I did that bias trick. Why not try it and stack this with dark from the master bias file and a dark flat from the master bias file and see if the banding is less. (don't use the darks you took in the stack just use the bias file trick).

I need a little more info,

I use the master bias file and add that as a single dark frame, then the same file for a dark flat ?

 

[The Admiral]

14 minutes ago, Nigel G said:

I need a little more info,

I use the master bias file and add that as a single dark frame, then the same file for a dark flat ?

That's my understanding Nige, but if you use DSS I think you might have to re-name one of the bias files 'cos it doesn't like duplicate files. I guess whether it's a dark flat, or just the bias, doesn't really matter.

You might find something in this recent thread: https://stargazerslounge.com/topic/289900-does-it-work-out-with-bias-and-flat-frames-only/

Ian

Edited March 31, 2017 by The Admiral

[Stub Mandrel]

Nige - that's very nice, it has a very natural look to it, where most of my pictures look over-processed.

 

A dark flat frame is a dark but with the exposure length matched to your flats, not your subs.

Neil

[Filroden]

2 hours ago, Nigel G said:

California nebula. 4h 40m of 240s ISO 800. modified Canon 1200D with CLS filter - Darks, flats & bias. 80ED Pro - EQ3 Pro.

No colour work done other than saturation.

Beautiful image. And it must be so nice not having to deal with hundreds and hundreds of subs to achieve that overall exposure

[happy-kat]

1 hour ago, Stub Mandrel said:

Nige - that's very nice, it has a very natural look to it, where most of my pictures look over-processed.

 

A dark flat frame is a dark but with the exposure length matched to your flats, not your subs.

Neil

Ignore the 'proper way' and follow the link Ian gave. after all this is a test.

Use DSS flats lights bias and register, then copy the master bias created. Now add the master bias as your dark and add the copied master bias as your dark flat, now stack.

[Nigel G]

29 minutes ago, Filroden said:

Beautiful image. And it must be so nice not having to deal with hundreds and hundreds of subs to achieve that overall exposure

Thanks Ken.

I have found the whole EQ3 process quicker and more efficient than my Altaz.

For this DSO I kept the camera attached to the scope at all times, I checked the focus every session at least 2 times but never had to adjust it in 4 nights.

Setting up to guided imaging took about 15 minutes, just place mount on marks, mount scope, align 2 star with live view, mount guide scope, find DSO, choose guide star, calibrate, re centre DSO, start imaging.

I check the PA every other session but haven't had to adjust it. I don't drift align but will manual drift at the beginning of every session.

The only subs I dump are any with cloud drifts in.

The only time PHD drops out is when dew has built up on the guide scope but a dew shield has been added. Once it dropped out as a low flying well lit jet plane flew across the guide star.

DSS stacks quicker.

[Nigel G]

2 hours ago, The Admiral said:

That's my understanding Nige, but if you use DSS I think you might have to re-name one of the bias files 'cos it doesn't like duplicate files. I guess whether it's a dark flat, or just the bias, doesn't really matter.

You might find something in this recent thread: https://stargazerslounge.com/topic/289900-does-it-work-out-with-bias-and-flat-frames-only/

Ian

 

16 minutes ago, happy-kat said:

Ignore the 'proper way' and follow the link Ian gave. after all this is a test.

Use DSS flats lights bias and register, then copy the master bias created. Now add the master bias as your dark and add the copied master bias as your dark flat, now stack.

I have studied the link and at first it was slightly confusing  but I have got my head around it and am about to give it a go

Thanks guy's.

[happy-kat]

Just don't use the darks you actually took.

[Nigel G]

2 hours ago, Stub Mandrel said:

Nige - that's very nice, it has a very natural look to it, where most of my pictures look over-processed.

Thanks Neil, it was very easy to over do this, It has very little processing, adding more lights has helped a lot. 90% of the processing was noise reducing.

[Nigel G]

Failed attempt. got a blank image. hmmm

[The Admiral]

Failed indeed! What file did you put where? Bias frames taken at same ISO? Was it totally blank?

Ian

Edited March 31, 2017 by The Admiral