How to Best Combine OSC Broadband Data With Dual Bandpass Data in Pixinsight

[Juno16]

Hi Everyone,

Just a quick question. Well, hopefully anyway.

I might get lucky and get out tomorrow night get to collect some more data on M101. I got about 3 hours one night last week, but got shut down due to clouds.

I was thinking that if I got a good evening and can collect another 3-4 hours of data (all data so far collected is broadband using an IDAS LPS D-1 lp filter), I will switch to the L-Enhance filter for a couple of hours to try to collect some data on the Ha areas of M101.

Is this a major undertaking in Pixinsight? Just a wild guess I would think that you would have to process each image and then combine the two with Pixelmath. Of course, both images would have to align and not sure how that would work.

If it is not a somewhat simple process, I will just collect more broadband data with the IDAS filter. When just playing around with the data so far, it seems that the Ha areas have a yellowish coloration.

Thoughts?

[STEVE333]

Hi Jim - Combining the OSC with the Ha will not be a problem.

1) Process the OSC and the Ha images separately.
2) Open the PI StarAlignment process. Enter the name of the OSC image as the Reference image. Drag the diamond icon (lower left corner) from StarAlignment onto your Ha image. It will add "_Registered" to the name of the Ha image. This "Registered image is now aligned with your OSC image.
3) You can use the Ha image to "boost" the Ha regions of the OSC image using the LRGBCombination process.

• Open the LRGBCombination process.

• Make sure that the L box is checked but the R, G, and B boxes are UNCHECKED!

• Enter the name of the Ha image into the L box.

• Drag the blue triangle from the LRGBCombination process onto the OSC image.

The OSC image will have been enhanced by the Ha highlights.

Let me know if this isn't clear.

Good luck,
Steve

[Juno16]

The process that you described sounds very uncomplicated!

Can’t wait to give it a try. I am getting conflicting sky reports about the conditions tonight. Hopefully, I can get the data collected.
I only have about 3 hours broadband data now (not near enough in my skies). If I can get about 3 more hours broadband data tonight, I might swap to the L-Enhance for a few hours. Or, just collect broadband all night (as long as possible) and hope for another clear night soon.
Either way, I have your much appreciated instruction that I have already copied to my Pixinsight notes document.

Thanks a bunch Steve! Even if I don't collect the L-Enhance data tonight, I have your instructions and I will let you know how/if/when it happens!

[STEVE333]

The process that you described sounds very uncomplicated!

Can’t wait to give it a try. I am getting conflicting sky reports about the conditions tonight. Hopefully, I can get the data collected.
I only have about 3 hours broadband data now (not near enough in my skies). If I can get about 3 more hours broadband data tonight, I might swap to the L-Enhance for a few hours. Or, just collect broadband all night (as long as possible) and hope for another clear night soon.
Either way, I have your much appreciated instruction that I have already copied to my Pixinsight notes document.

Thanks a bunch Steve! Even if I don't collect the L-Enhance data tonight, I have your instructions and I will let you know how/if/when it happens!

You're welcome Jim.

If the L-Enhance image (the one being used for Luminance in the LRGBCombine) is noisy, that noise will show up in the LRGBCombine image. I recently posted how to use LRGBCombine to make finished images "pop". In that post I talked about how to reduce the noise in the "L" image, and, those comments would apply for this process too. The comments about sharpening would also apply if you wanted to try that also. Hope this makes sense.

Good luck with capturing more data.

Steve

[Juno16]

Thanks a bunch Steve!

Yes, I did copy that post to my PI notes also. Thanks for reminding me of that.

Things are looking good for tonight, but I am still not sure if I am going to just image as long as possible with the IDAS LPS D-1 or try to add some time with the L-Enhance.
Ideally, I would collect all night with the broadband filter and collect the L-Enhance data the following night, but I rarely get two good nights and it is not forecast to be clear again for the next two weeks.
If I don't use your instructions this time, I will definitely hold on to them for a future project. I always wondered how this was done and thanks to you, I have the tools thanks to you.

I also agreed today to foster another 7 month old lab mix (third one!) and that will slow things down some for awhile. Takes a lot of time, but it is very rewarding. Feels really good to help get a dog out of a shelter and off to a good life with a family. The past two dogs that I fostered brought clear skies, but I was busy with the pups!

Hopefully, later this month I will receive a new Sharpstar 61 which I am very much looking forward to for nebulae season. I really enjoy the ES ED102/ASI 533 combo, but the field is just two small for lots of nebulae. It will be lots of fun having a completely different (widefield) setup.

Thanks a bunch Steve! I will let you know how things work out when I get a chance to collect the L-Enhance data!