My 1st attempt at THe Flame Nebula

[Dbswales]

After having a go at M42 and getting some fantastic advice, I thought I'd have a go at the Flame. I kind of knew that this was going to be way out of my league but not having the most confidence in my GoTo I thought that I should be looking or imaging in at least the right ball park.

A bit like my attempt with M42, it was buzzing with LP due to it being quite low and that flaming tree of my neighbours still hasn't had the chainsaw treatment as yet!

I've finally accepted that around 45 to 60 second subs are the best I'm going to get so started off getting a great focus set up and waited for the 1st of my 60 second light subs to show on the preview on APT. Strange, those stars are looking decidedly trailed, maybe the weight needs to go lower to create a bit of off set balance to work against the gears a little bit. Nope, that wasn't it. Ok, it must be that I'm only looking at 45 subs. Sure enough, started again, took more time than I could afford but waited for the preview and yet again, trailing stars.

So, my set up is only going to be 30 seconds, its worked with M42 but honestly thought I'd get more especially as the wind was non-existent.  

Set up once more and.......yep, more trails. I couldn't believe my bad luck especially as it was such a great night to be out and trying my hand at one of my favourite nebs.

Ok, time for a re-think, put the kettle on and don't panic. Still got an hour and a half before I lose the Flame behind an oak tree.

I sat in the kitchen pretty clueless but thought I'd go back down the garden for anther go. My wife jokingly said, 'take your glasses this time, maybe it's not as bad as you think and you may see something that your glasses will help with'.

So, armed with a mug of tea and my glasses, I set off down the garden again to have another attempt. I looked at the screen preview on APT and I thought to myself, those aren't trailing stars, they look like stars that are being focused with a ...........Bahtinov mask!!! 

Being in such a mad dash to make the most out of the night, I'd left it on the front of the scope. I don't use the mask facility in APT, I just focus and with the mask on the end of the scope and see how they look in the live screen mode so the software didn't nudge me to check I'd removed it. Pond life comes to mind!!

So anyway, my subs were eventually quite short. 15 of 60 secs, 15 of 30 secs and 15 of 15 secs. ISO 800, dithered, with the same number of darks and bias before it went down south behind the tree.

This was a real challenge this time, so much harder than M42 as the brightness obviously wasn't there so I've spent much of the afternoon processing the stacked frames in Pixinsight. I'm relatively happy with it, if only for the fact that I've managed to get something resembling it out.

Thanks for reading and looking at the post, looking forward to hopefully getting some more great advice from you. (Preferably not about removing a mask for the scope though!!)  Oh, BTW, what's the blue face above the nebula???

Dan

 

[wornish]

This is weird but I did exactly the same thing on Thursday night.  I took 30 x 60 sec shots before realising I had left the Bahtinov mask on.  Guess what DSS won't stack shots taken with the mask still on it can't find any stars !!

I gave in and went to bed.

Your Flame Nebula looks great by the way.

[Starlight 1]

Look very nice and the horse head is only 1" down on the right hand side.

[wimvb]

Great image. The flame is much fainter than the Orion Nebula.

Since you use pixinsight, try this for noise reduction (I found it in the PI forum, just can't remember where)

On the non-stretched image:

1. create a preview with just background and measure Std Dev (this is the noise)

2. Use TGVDenoise with strength standard 5.0, Edge protection at 10% of the measured Std Dev, iterations set to 1000 (yep: one thousand), use a local mask (you will have to tweak the settings for this)

3. Go do something else, 1000 iterations take time

4. Do the same again (denoise) but this time with a 50% gray mask.

5. Go do something else again

I found it does wonders to the noise in unstretched images. You will have to test on a preview and tweak the settings for the local mask.

When stretching the image, you can start with a masked stretch. This does a better job of keeping the stars under control.

 

Good luck

[Dbswales]

Thanks for your comments and advice. I'll definitely give the noise reduction tip a go although I can guess how long all those iterations will take.

i was hoping to maybe get out again over this weekend but no chance with the cloud cover so I spent some more time processing some subs of the flaming star but Pixinsight really didn't like what I was feeding it and I ended up with error comments about failing to get star matches. It must have been pretty bad as the number of detected stars in the subs were thousands. 

The whole processing thing is a major learning curve so thanks for your advice.

 

[Astrosurf]

That's a cracking image. You have the same camera as me, but I get awful red star halos. I ussume from what you said that you don't use a light pollution filter? I suspect the LPF is my problem.

Alexxx

[Debo]

Nice image.

The "blue face" that you mentioned is the bright reflection nebula IC432

[glowingturnip]

On 01/04/2016 at 00:18, Dbswales said:

So, armed with a mug of tea

there's your problem right there - clearly at that time of night, beer is much more suitable !

I have a checklist file I keep on my laptop screen when I'm imaging, with all the steps I need to take or even consider, just to make sure I don't forget anything, and one of those steps reads 'TAKE MASK OFF !!!'

Very nice image btw

[Dbswales]

42 minutes ago, Astrosurf said:

That's a cracking image. You have the same camera as me, but I get awful red star halos. I ussume from what you said that you don't use a light pollution filter? I suspect the LPF is my problem.

Alexxx

Hi Alexxx, no I haven't got a light pollution filter as yet but anticipate getting one quite soon which will hopefully reflect positively when trying to image 'lower in the sky targets'. I've had a look on Flo and the IDAS D1 Light Pollution Suppression Filter looks like the way to go. A couple of people on here have also recommended this one. Bit of an expense but I've worked out that nothing is particularly cheap with AP.

14 minutes ago, Debo said:

Nice image.

The "blue face" that you mentioned is the bright reflection nebula IC432

Wow, thanks very much for the information. I just thought I'd managed to get some problematic element going on.

[Dbswales]

2 minutes ago, glowingturnip said:

there's your problem right there - clearly at that time of night, beer is much more suitable !

I have a checklist file I keep on my laptop screen when I'm imaging, with all the steps I need to take or even consider, just to make sure I don't forget anything, and one of those steps reads 'TAKE MASK OFF !!!'

Very nice image btw

Lol, yes you're probably 100% correct there!!

Great idea about the checklist. I thought I was getting so much better getting everything set up before I started imaging, with polar, then star alignment, connecting to eqmod, stellarium and APT. I guess I got into a comfort thingy before being bitten on my backside for  taking things for granted.

Thanks for the advice, its something I will definitely do from now on and thank you for your comment about the image too.

[wimvb]

On ‎2016‎-‎04‎-‎03 at 23:18, Dbswales said:

Thanks for your comments and advice. I'll definitely give the noise reduction tip a go although I can guess how long all those iterations will take.

i was hoping to maybe get out again over this weekend but no chance with the cloud cover so I spent some more time processing some subs of the flaming star but Pixinsight really didn't like what I was feeding it and I ended up with error comments about failing to get star matches. It must have been pretty bad as the number of detected stars in the subs were thousands. 

The whole processing thing is a major learning curve so thanks for your advice.

 

 

Some tips to get the registration process working.

1. Do cosmetic correction after debayering (make sure you click the CFA box in cosmetic correction). This will remove remaining hot pixels.

2. In the registration process, under "Star Detection" set "Noise Reduction" to 2. This prevents noise / hot pixels from being mistaken for stars. If PI tries to register the images on noise, you typically get a 0.0 offset in dx and dy.

3. If PI can't find any suitable stars, try to tweak "Maximum Distortion". PI assumes that stars are fairly round objects in your frames. If your images suffer from trailing stars or coma, this is not the case and PI may not detect them.

 

BTW, I often use the "manual" stacking process following Kayrons excellent tutorial on LightVortexAstronomy. It gives me a better feel for the process.

http://www.lightvortexastronomy.com/tutorial-pre-processing-calibrating-and-stacking-images-in-pixinsight.html

You can also use BatchPreprocessing to do the calibration and then do the registration and integration of light frames for themselves.

A better description of all of this is in Kayrons tutorials.

 

BTW, tgvdenoise takes at least one hour on my Quad core laptop for a 14 Mpixel image (usually cropped down to maybe 10+ Mpix). This is per pass (not iteration). So make sure you test on smaller previews when tweaking the paratmeters. I usually have a preview which contains the faintest detail I want to preserve, as well as some fairly bright stars. In your image, you could try with a preview of the flame and the reflection nebula above. i don't think you will be able to preserve detail in the Horse head, but you can always try.

[Dbswales]

Thats awesome. Its information like this which helps total newbs like myself to try and get a better understanding of the processing element. 

Thank you so much for your help.

[wimvb]

On ‎2016‎-‎04‎-‎04 at 13:23, Astrosurf said:

That's a cracking image. You have the same camera as me, but I get awful red star halos. I ussume from what you said that you don't use a light pollution filter? I suspect the LPF is my problem.

Alexxx

yep, now that you mention it, I also have seen red star halos when using an LP filter (Baader's, which has a transmission peak near 650 nm)

[wigggyy]

Great image thanks for sharing