17 hours on the California Nebula (NGC 1499)

[tooth_dr]

45 minutes ago, tomato said:

Reading the thread again, I didn’t realise you had a dual rig. I was trying to work out how you had 17hrs+  of imaging time in one night, now I understand...

A superb result, quality data, expertly processed?

Thank you so much for your high praise.

[davew]

Speaking from personal experience I will agree that the OIII in this area is a bit dim !

However, once you have it then the image jumps to a different level because most people won't bother.

Go on, you know you want to ?

Dave.

[tooth_dr]

5 minutes ago, davew said:

Speaking from personal experience I will agree that the OIII in this area is a bit dim !

However, once you have it then the image jumps to a different level because most people won't bother.

Go on, you know you want to ?

Dave.

Dave

I was driving home from work today, and was thinking about Oiii, then I suddenly remembered that this is a mosaic (albeit the smallest possible mosaic)!

I was planning on shooting Oiii and Sii at the same time, binning 2x2, 600s exposures, for each of the two panels.  As I'm wet behind the ears, does this seem like a sensible idea?  Or should I do 1200s exposures unbinned, or even 2x2 1200s?

 

[davew]

I did think the fact that this was a mosaic muddied the water somewhat. I was never over keen on binning this chip but if the focal length is long enough then try it. Seriously, try one image binned and one not and see where you get.

I wouldn't bother doing SII for my own use but you'd have a scope sat there doing nothing as I doubt you have two OIII filters ! On the other hand, do you have 2 OIII filters ?

I did 30 minute subs with a wider lens so I can't really advise on exposure.

Dave.

[tooth_dr]

20 minutes ago, davew said:

I did think the fact that this was a mosaic muddied the water somewhat. I was never over keen on binning this chip but if the focal length is long enough then try it. Seriously, try one image binned and one not and see where you get.

I wouldn't bother doing SII for my own use but you'd have a scope sat there doing nothing as I doubt you have two OIII filters ! On the other hand, do you have 2 OIII filters ?

I did 30 minute subs with a wider lens so I can't really advise on exposure.

Dave.

I do have two of each of Ha Oiii and Sii ?

However I currently only have one FW as I rather hastily sold the other one, so at present I’m just threading filters onto the 2” adapter.

[Xiga]

43 minutes ago, tooth_dr said:

Dave

I was driving home from work today, and was thinking about Oiii, then I suddenly remembered that this is a mosaic (albeit the smallest possible mosaic)!

I was planning on shooting Oiii and Sii at the same time, binning 2x2, 600s exposures, for each of the two panels.  As I'm wet behind the ears, does this seem like a sensible idea?  Or should I do 1200s exposures unbinned, or even 2x2 1200s?

 

My advice would be 100% to shoot 1200s subs over 600s ones. The signal is so faint that the only chance you'll have of bringing it out will be with longer subs. If there isn't enough signal in a single sub to separate it from the noise, then it won't really matter how many subs you have. Also, not only is the signal weak, there's also virtually no structure to it. So worst case scenario, you could always just remove the stars, stretch it and use it for tonemapping. 

[davew]

I would have prised that extra OIII filter out of your hand a few years back. I did 5 hours of 30 minutes subs at f4 with a 5nm Astrodon, if that helps with your decision.

I've just spotted Ciaran's post above and would agree there's little structure to the OIII.

If you wish, I'll find my image and show you what I got. As they say across the big pond, your mileage may differ.

Dave.

[tooth_dr]

7 minutes ago, davew said:

I would have prised that extra OIII filter out of your hand a few years back. I did 5 hours of 30 minutes subs at f4 with a 5nm Astrodon, if that helps with your decision.

I've just spotted Ciaran's post above and would agree there's little structure to the OIII.

If you wish, I'll find my image and show you what I got. As they say across the big pond, your mileage may differ.

Dave.

Thanks Dave, please post your image here if you can find it.

[tooth_dr]

16 minutes ago, Xiga said:

My advice would be 100% to shoot 1200s subs over 600s ones. The signal is so faint that the only chance you'll have of bringing it out will be with longer subs. If there isn't enough signal in a single sub to separate it from the noise, then it won't really matter how many subs you have. Also, not only is the signal weak, there's also virtually no structure to it. So worst case scenario, you could always just remove the stars, stretch it and use it for tonemapping. 

Cheers Ciaran.  I've your coloured version saved on phone the blue from the Oiii does add a nice bit of colour to the middle.

[davew]

3 minutes ago, tooth_dr said:

Cheers Ciaran.  I've your coloured version saved on phone the blue from the Oiii does add a nice bit of colour to the middle.

I must have missed that one.

Here's mine. HOO to give a false RGB. 

Dave.

[tooth_dr]

Thanks Dave, much appreciated.

[Taff]

That is a cracking capture with you, nice work.Mark

[tooth_dr]

2 minutes ago, Taff said:

That is a cracking capture with you, nice work.Mark

Cheers Mark ??