Deep Sky High Bortle area reduce exposure time

[Tracy]

Is it better to reduce the exposure time in a high Bortle area and increase the number of captures to avoid light pollution?
What say you?

 

[Sheridan]

I am I am still trying to figure that 1 out. I'm leaning towards going with shorter individual exposures and just collecting a lot more of them

 

[OhNo]

Sorry no help here.

 

[Tracy]

I am I am still trying to figure that 1 out. I'm leaning towards going with shorter individual exposures and just collecting a lot more of them

I'm leaning towards shorter exposure and more captures so far.

This was my IC1871 with 240s exposures (Ha, OIII and SII)

IC_1871.jpg

• Tracy
• November 13, 2022

and this is the same target with 210s exposures, but about twice as many captured frames (processed pretty much the same in PixInSight except this used background neutralization.

IC1871 (11/28/2022)

• Tracy
• November 29, 2022

Capture using
29 Ha
13 OIII
6 SII

Minimal processing done in PixInSight (masked stretch, linear...

During processing I didn't notices as much "brightness" in the background with the 30 second shorter exposures.

 

[OhNo]

When you say "background neutralization" do you mean Dynamic Background Extraction (DBE)? My workflow if I feel the image requires it is to use ABE (Automatic Background Extraction) first and if more is needed I go to the DBE.

 

[Tracy]

When you say "background neutralization" do you mean Dynamic Background Extraction (DBE)? My workflow if I feel the image requires it is to use ABE (Automatic Background Extraction) first and if more is needed I go to the DBE.

Using this in the colorized image with the defaults.

I haven't played with the DBE or ABE yet... maybe I need to.

I grabbed a few more captures of IC1871 so I'm going to reprocess them again as fresh.

 

[OhNo]

DBE is a bit of a PITA to set up. I save my tools into a file with the changes to the default. When the tools is needed I don't have to mess with the settings that work for the task at hand. This really helps with DBE as a lot of the boxes appear on the screen and are easily moved around. Easy to add or subtract boxes as required.

With the above image you mention using "Masked Stretch". I occasionally will use it depending on the target and the SNR. Stretching using Masked stretch or Screen Transfer Function (STF) is always the first step, and probably the choice which too to use can make or break an image. However you can also use Histogram Transformation to manually stretch. The beauty of using it is one of the oldest premises in any photography. "Black conceals, white reveals". The developer of the Histo-Trans script was wise to expand the tool for a lot of elements of your image to be fine tuned. Same with Curves Transformation (Curves_Trans).

I don't use Histo_Trans much, but every image I play with I use Curves_Trans. Not saying it is correct, right or anything, just the way my workflow goes with the needs of my data. Remember Processing is the interface between technical (Data gathering) and ART (processing to what our minds imagine DSOs look like).

 

[Sheridan]

What processing software are you talking about?

 

[Tracy]

Playing around with DBE some... lots of options, which can make a major change. Close to the original... but seems to have a little more distinct areas.

IC_1871 (11302022) DBE.jpg

• Tracy
• December 2, 2022

 

[Tracy]

What processing software are you talking about?

I'm talking about PixInSight... hard to learn... but worth taking the time to.

 

[OhNo]

When you are combining your stacked filter data in Pix (LRGB Combine) you can also use a percentage of each filter. You have a lot less SII data so you would lower you % of the HA and Oiii to balance your data if you wanted to....This is possible to do in Pixel Math also, but way more research to find out how to do it.