Help processing flaming star nebula

[Jannis]

Not much went as planned last night, but i did at least manage to capture 14x 600s exposures of the flaming star in Ha (7nm) at F/2.8 with a 50mm lens.

I guess not much can be expected with a none-cooled QHY5L-II-M, but I was hoping for a bit better result though - mainly more even background. Is this caused by the moon/light pollution, or is it actually faint Ha gas? I added darks and flats, and the dust and amp glow was removed from what i could see, but it's still not very clean.

Or am i just expecting too much from a QHY5L-II-M at ~-4c and 2 hour 20 minute exposures at F/2.8 with the moon up?

Untouched TIF attached, as well as my result so far

Flaming star Ha 50mm 12g 14x 600s f2.8_2.TIF

[alan4908]

1 hour ago, Jannis said:

Not much went as planned last night, but i did at least manage to capture 14x 600s exposures of the flaming star in Ha (7nm) at F/2.8 with a 50mm lens.

I guess not much can be expected with a none-cooled QHY5L-II-M, but I was hoping for a bit better result though - mainly more even background. Is this caused by the moon/light pollution, or is it actually faint Ha gas? I added darks and flats, and the dust and amp glow was removed from what i could see, but it's still not very clean.

Or am i just expecting too much from a QHY5L-II-M at ~-4c and 2 hour 20 minute exposures at F/2.8 with the moon up?

Untouched TIF attached, as well as my result so far

Hi Jannis

From my location in the UK, CCDNavigator informs me that IC405 is too close to the moon for imaging in either LRGB or Narrowband. It's about 30 degrees away, so even with my 3nm Ha filter, I'd wouldn't image it, since I'd loose too much contrast.

For imaging with the moon up, I follow an algorithm that was developed by the University of Berkeley astronomical department, which allows you to work out which objects you can image with the moon up. This takes into account the phase of the moon and the type of filter. CCDNavigator and ACP implement this so called Lorentzian algorithm, allowing you to work out which objects can be imaged without impacting quality.

Alan  

[LightBucket]

A quick run through PS with Gradient Xterminator, and two goes with levels and curves

 

RedoneFlaming star Ha 50mm 12g 14x 600s f2.8_2.tif

[SteveBz]

5 hours ago, alan4908 said:

For imaging with the moon up, I follow an algorithm that was developed by the University of Berkeley astronomical department, which allows you to work out which objects you can image with the moon up. This takes into account the phase of the moon and the type of filter. CCDNavigator and ACP implement this so called Lorentzian algorithm, allowing you to work out which objects can be imaged without impacting quality.

Hi Alan,

I'd love to know what I can image and what I can't.  I was imaging a few nights ago and indeed everything was burned out by the Moon.  What Berkeley Algorithm is this?

Steve.

[alan4908]

11 hours ago, SteveBz said:

Hi Alan,

I'd love to know what I can image and what I can't.  I was imaging a few nights ago and indeed everything was burned out by the Moon.  What Berkeley Algorithm is this?

Steve.

Hi Steve

As mentioned above, to avoid light pollution from the moon, the University of Berkeley created the Lorentzian algorithm, which tells you when you can image. Here, the object your imaging needs to a certain angular distance away from the moon. This minimum angular distance is a function of the type of filter and the moon's phase. Taking a worst case scenario of a full moon, then the algorithm says the object your imaging needs to be at least 120 degrees away for LRGB or OIII filters and 60 degrees away for Ha or SII. If the moon is not full then you get closer than these values.

As you can appreciate, if you want to use this approach you need a piece of software that can work out the relative angular position of the imaged object with respect to the moon, it also needs to know the moon's phase. CCDNavigator and ACP are two software applications that support this approach. 

To give you an example, say I'm interested in imaging the galaxy NGC2903 tonight (31st December 2017) at my site.  If I type this into CCDNavigator, I get this output:

This is telling me that the moon will be almost full (97%) and that it is OK to image in NB but not in LRGB. This is because it is 67 degrees away from the moon. The green dotted line is my (tree obstructed) local horizon which shows me that the object will be visible for two periods during the night.

The implementation in ACP also allows you to adjust the values when you believe it is acceptable to image, so for instance if you have a 3nm Ha filter and you are convinced that you can image closer than 60 degrees without impacting quality, then you can adjust this minimum value.

I use CCDNavigator in conjunction with ACP Expert, so I've defined the dark start to be when the Sun is at -12 degrees below the horizon for both ACP and CCDNavigor. I've also programmed in my local horizon into both programs, so ACP knows that NGC2903 will disappear from view between 01:49 and 04:03 (since it's behind a tree !), during this period it will look for a different object to image, again checking to see if this object is at a sufficient angular distance from the moon for the particular filter type.

Alan