Aug 27, 2013

PixInsight: Creating a Luminance Mask

A view from above Kofa
Photo by Chris Hanrahan
I had big plans to do some real writing this weekend, but we had four days of rain in Arizona.  For me, this meant a trip out to the desert to play in the rain.  With temperatures 40 degrees (Fahrenheit) below normal the day was spent hiking in the Kofa National Wildlife Refuge - my favorite place on Earth.  

As a result, not much actual writing got done.  And when I say "not much", I mean no writing got done.  Instead, for the uninitiated, here's a step by step process on creating a luminance mask in PixInsight.  As you'll see - it's really easy.  And in PixInsight, this is a technique you'll use in various ways over and over and over.  Enjoy!!

Creating a Luminance Mask

Aug 7, 2013

PixInsight Deconvolution

 After commenting recently on a thread in the AZ-Observing mailing list about PixInsight it sparked multiple side conversations with other list members asking some questions about deconvolution in PixInsight.  This animation does pretty much sum up the experiences of many including myself when it comes to getting good results.  After much trial and error and gnashing of teeth I have reached a point where I can get some decent results.  The conversations from the mailing list encouraged me to go ahead and put together a video and post on deconvolution in PixInsight.  I'm not saying it's the best way, but it does work and I've enjoyed some good results with it.

World class imager Manuel Jimenez put together a tutorial some time ago that taught me much about PixInsight's implementation of deconvolution.  His tutorial can be found at his website. There are a few points to remember in order to get the best results.

1 - Do deconvolution on a linear image.  Before you stretch.
2 - There's only so much deconvolution can do.  It can't rescue a bad image, but it can make a decent one really "pop".
3 - Use the Dynamic PSF process module.  It's your friend.
4 - Create a star mask for local deringing support in your image.
5 - Create a luminance mask to limit the process to high signal areas.

The Final Result

Like the image in the video I also did deconvolution on the OIII and SII data that I had collected in my attempt to recreate the Pillars of Creation image.  Shown below is the end result.  This was shot with my Explore Scientific ED152 f/8 Apo triplet from southern Arizona.  It's a total of 37 hours of exposure time and processed entirely in PixInsight.  Thanks for watching.  Please contact me if you have any questions, comments or improvements to my process.

Here's a link to a larger version of this image:
M16 - Eagle Nebula in Hubble Palette
37 hours of exposure