Squid Nebula - I'm going to chalk this one up to experience

[Snoani]

After a period of limited opportunities, the latest new moon period has given a lot of clear skies on the Isle of Wight and I took the opportunity to experiment a little using a new setup involving a camera lens and cooled camera.  The exact setup is a Sigma 105mm macro lens, ZWO ASI 533MC Pro, Optolong L-Extreme filter, mounted and guided on a HEQ5.  

I could have attempted an easier target but having done some research and with the lens stepped down to F4, I decided to image the Flying Bat Nebula and Squid Nebula.  I regretfully lost about 6 hours of data to a guiding issue that I couldn't identify the cause of, but in total I managed to acquire 16h 50m of data.  I probably could have captured another 6 hours in the last few days but having seen what I had at this point, I decided to abandon my attempt.   

This was a test of the lens setup as much as the target and while I am encouraged by the widefield capabilities, I was genuinely optimistic and disappointed that I couldn't capture more of the Squid Nebula.  I've only processed it relatively quickly in Pixinsight and Photoshop but I don't think I can tease out much more of the OIII data.  

I'm glad I tested the capabilities of the lens, filter camera combo, but I do rue to loss of 20h hours that I could have used to image something substantial via my primary rig.  it looks like I may be about to pick up a second-hand OIII filter and therefore may return to attempt this target in a different way in the future, but for now I have moved onto a new target and the Squid Nebula will have to remain on my astrophotography to do list.  

This hobby wouldn't be interesting if it was easy and so I will continue to dream and develop (and spend too much).  

[The Lazy Astronomer]

It's definitely there, but very very faint. I think I would have expected more from 17hrs - I'm left wondering if your filter bandpasses are not as advertised at f4 (know anyone with a spectrometer?)

[Budgie1]

There has to be something not right with the acquisition or the filter. Not only is the Oiii very weak, the Ha is a lot less than I would expect from the L-eXtreme filter on the ASI533MC with that sort of integration time. 

What gain & offset settings where you using and what was the sub exposure times? Also, is it likely the Moon or any LP has affected the subs?

As an example, below is a very rough 2h25m process of the Spaghetti Nebula I took back in March using Samyang 135mm at F2.8 with the ASI294MC Pro and L-eXtreme filter. I also abandoned this project as the flats didn't work (I now know why - gain setting) and I haven't had enough clear skies this year to give this target the time it needs, but I wanted to show the amount of Ha this setup has captured with such a short integration time.

[Snoani]

20 hours ago, The Lazy Astronomer said:

It's definitely there, but very very faint. I think I would have expected more from 17hrs - I'm left wondering if your filter bandpasses are not as advertised at f4 (know anyone with a spectrometer?)

Regretfully I don't.  

 

12 hours ago, Budgie1 said:

There has to be something not right with the acquisition or the filter. Not only is the Oiii very weak, the Ha is a lot less than I would expect from the L-eXtreme filter on the ASI533MC with that sort of integration time. 

What gain & offset settings where you using and what was the sub exposure times? Also, is it likely the Moon or any LP has affected the subs?

As an example, below is a very rough 2h25m process of the Spaghetti Nebula I took back in March using Samyang 135mm at F2.8 with the ASI294MC Pro and L-eXtreme filter. I also abandoned this project as the flats didn't work (I now know why - gain setting) and I haven't had enough clear skies this year to give this target the time it needs, but I wanted to show the amount of Ha this setup has captured with such a short integration time.

 

The gain was set at 100 but because I used an ASIAIR and can't control the offset, although the FIT file states it was set at 70.  

I haven't used the filter for over a year when I moved to a mono camera but I did use it successfully to capture targets when I was originally using a DSLR. 

The moon shouldn't have been an issue as all data was captures between the last and first quarter.  I do has some light pollution in my northern sky but the target was at 60 degrees and over, which doesn't normally cause me too many issues. 

 

[carastro]

The Squid is extremely faint.  L have tried a number if times and got very little with a mono camera and even 30 minute subs.  
 

Carole 

[powerlord]

I'm trying to get teh squid at the moment. I've done 3 sessions so far, and only now just about making it out. that's with zwo 7nm oiii and astro 6.5nm oiii.

Im shooting with a SY135, and even stopped down two, its a quick lens, and I think from my Ha I can see its affecting the amount of Ha I'm getting as I've just elephant trunk in frame too and both should be stronger there than I'm getting.

llast week I was up to 15 min subs and still only JUST making it out, bit also masses of oiii noise everywhere making it hard to do anything useful with it.

Every time its clear, the ruddy moon is out which isn't helping either. The easiest way to see if you are getting it is to remove the stars from the oiii (green channel if shooting OSC). you should then make it out.

[tooth_dr]

@Snoani I think that is a decent attempt and maybe more selective processing might bring out the oiii more.   I also have the same lens and think it’s pretty darn good and flat across the field.

For comparison, here is a 16 hour squid I took with a similar OSC (2600MC) and a dual band filter at 485mm F4.65

[old_eyes]

The Squid is a really tough target. So far with a mono camera good filters and a fast scope, I have ‘seen’ it, but never got enough integration time to produce a quality image. Some of the images on astrobin have insane integration times that I don’t have the patience for. Too many other easier targets to catch first 😉

[Snoani]

I appreciate all of your responses.  

I was attempting on the lens and colour camera because I didn't own an Oiii filter and just had the L-Extreme, and didn't think I could fit the flying bat and squid into the frame on my primary scope, which is about 382mm focal length.  I genuinely thought they were much larger than they are and when I worked it out I realised that I could just fit them in.  I did pick up a second hand Baader Oiii filter this week and used last night to test it, with 95% moon.  Below is 2 hours of Oiii data uncalibrated using a mono camera.  I've pushed the data quite hard but in 2 hours of 95% moon I'm not far off what I achieved in 20 hours of new moon period above.   I therefore think I will dedicate some time on my main scope in the next couple of months and see what I get. 

I haven't entirely written off the lens attempt just yet because I have also ordered the new Skywatcher Star Adventurer GTi mount this week which would give me GoTo and plate solving for the lens lens, allowing me to not lose valuable imaging time on my primary setup, so I may add to this data as well at some point.  

You've taken a very nice image by the way Walle.

Edited July 16, 2022 by Snoani