After my previous 3 minute Andromeda Galaxy comparison, I decided I needed to get a light pollution filter to get better pictures from my driveway given our Bortle 7 skies.  I picked up a SkyTech 2” LPRO-MAX CCD Filter and the image above is the result. 

For comparison, here is a picture using the same settings and location with no filter.

And here is a picture using the same settings from Bortle 2 skies.

All these pictures used the same equipment and settings.  For the purposes of this comparison, I did not do any processing.  I think the filter was worth it.  Dark skies are definitely worth it!

Camera geek info:

• Canon EOS 60D in manual mode, 179 second exposure, ISO 1600, custom white balance 3500K
• Williams Optics Zenith Star 73 III APO telescope
• Williams Optics Flat 73A
• iOptron CEM40

I also experimented with settings to use from my driveway.  Results are in the table below.  Lowering the exposure length and ISO cut down on the sky noise.  I’ll have to see what I can do with the 1 minute ISO 400 images in PixInsight.  

Site	Bortle	Filter	Exposure Length	ISO	Result
Dell City, Texas	2 – 3	None	3 minutes	1600	Gorgeous detail in M31, M32 and M110 visible
Friendswood, Texas	7	None	3 minutes	1600	Almost all white picture
Friendswood, Texas	7	Light Pollution	3 minutes	1600	Bright blue background, M31 as a fuzzball, M110 visible, M32 not obvious
Friendswood, Texas	7	Light Pollution	2 minutes	1600	Teal blue background, M31 as a fuzzball, M110 visible, M32 not obvious
Friendswood, Texas	7	Light Pollution	1 minutes	1600	Dark blue background, M31 as a fuzzball, M110 visible, M32 not obvious
Friendswood, Texas	7	Light Pollution	1 minutes	400	Very dark blue background, M31 as a smaller fuzzball, M110 visible, M32 not obvious