PixInsight Cribsheet

[jkmorse]

PI World,

Several people have graciously sent replies indicating that they find my cribsheet useful (a copy of my latest version, Rev23, is attached below).  I have also had a request to set up a distribution list so that, when I do a new version (need to update this one to add the superbias tool), I can automatically send it to interested PI users without them having to wait or take the risk that they miss a posting.  I am more than happy to accommodate.

As a result, if you are interested in getting updates to my cribsheet as I develop them (with no guarantees as to quality or how often updates come out), please just drop me an email to jkmorse57@gmail.com and I will add you to my distribution list for updates.  Being on the list has the added benefit of being able to get a Word version (with some additional material with tool details) so that you can modify the cribsheet to fit your own workflow.

Best,

Jim

[martin farmer]

Hello Jim,

Well I think that's a very good service you are prepared to offer.
It's a very useful document to have to hand at times when processing.

Thanks Jim

Regards
Martin

[jerryyyyy]

Hi Jim, as we were chatting offline, here are my icon sets.... they sorta follow your outline....  I have recently come under the influence of the French AIP PI group that does more de-noising in the linear phase....

[jkmorse]

Jerry,

Thanks for that and I have had a new leaf on life as well since MLT came out.  It does a superb job of cleaning up noise in the linear phase so that is definitely a base part of my workflow these days.

I will play with your sets and let you know how they work for me.  I hope others take the opportunity and do the same.

Best,

Jim

[jerryyyyy]

I am afraid I have gone completely over to the AIP side after using the techniques in the article for a few days now.  This is my new set of icons. 

What may not be apparent is I am now merging either RGB or NB images using their script or PixelMath resulting in a linear image.  I clean the images as discussed in linear first.  I then stretch that image with Masked Stretch, set the shadow dark point to say 0.5% and this gives me a nice histogram to the left of the graph.  I then stretch that histogram using Curves as they suggest.  This allows me not to stretch the dark left side of the histogram (just leave that linear) but stretch the middle and right side. 

[jkmorse]

Jerry,

Nice Idea, will need to give that a try.

Best,

Jim

[jerryyyyy]

I have published a trasnaltion of the heart of the French Atronomie articles here:



An the icon set used is included.

[dayers]

Please help me out, if you will. What is unique about AIP processing? What would be a good way to bring myself up to speed on this processing workflow, if that is what AIP amounts to?

Dave, ignorant but curious.

[jerryyyyy]

Please help me out, if you will. What is unique about AIP processing? What would be a good way to bring myself up to speed on this processing workflow, if that is what AIP amounts to?

Dave, ignorant but curious.

PI processing like a lot of image processing requires many steps.  The Cribsheet that started this post is 21 pages long.  From what I can see it is the most comprehensive list available. 

AIP refers to the French Astro Image Procesing group.  They just put out one that is 30 steps long and 4 pages in their magazine.  While not as complete, it was very helpful for me with specific ideas on how to do masking, stretching and the use of their multi-channel synthesis scripts that are included in PI.  There was no documentation of how to use these scripts available in English.  I translated and posted the basic ideas with an image over on Astrobin.

[CharlesW]

Jerry, I just read your workflow over on Astrobin. I appreciate the effort but it's a really difficult read with all of the Google translator double-speak. Now that you've had some time to process it yourself, would you mind translating the translation?

[jerryyyyy]

Charles,

I think if you are starting out best to follow Jim's crib-sheet on this first post of this thread.  The French stuff would require me to translate 4 pages and refer to diagrams etc etc... plus it is copywritten. You need a subscription to their magazine.   

Jim's is very detailed and is a play by play guide.  The main differences are that the French use the AIP Script to integrate the LRGB images, and there is a Proc for that in PI, and that the French do a lot of stretching with the Curves Proc rather than HT etc...

Jerry Y

[jkmorse]

Charles,

Here is a pdf of my latest version.  If you are interested in a word version and future updates, just drop me an email at jkmorse57@gmail.com. 

Best,

Jim

[jkmorse]

Jerry,

On a completely different subject, I have been thinking about adding a Takahashi 180ED to use with my SBIG STF8300 and I see you are running almost that exact rig.  How do you like it?  I am having lots of fun using my STF8300 with various Canon lenses to get wide field images as my secondary setup, but the size and speed of the 180ED is really intriguing and my Losmandy backup mount should handle the weight just fine.  Curious about how you find it for imaging.

Thanks,

Jim

[jerryyyyy]

I can speak volumes about the 180 ED.  I am very happy with my set-up now, but it took me 6 months to collimate.  I bought it cheap and used, I assume because the prior owner could not collimate it.  The crucial focus distance (thickness) is 17 microns (MICRONS).  This was never a problem with my C8, which was F10.0 and F6.3 with the focal reducer.  The thickness formula is F squaredx2.2... I have this memorized.  So for the 180ED it is 2.8x2.8x2.2.....   Hair thickness ranges from 40-120 microns.

I could not do it in the field with CCDInspector.  Eventually I sent it to Tak USA and they did pretty good but not perfect.  I bought a laser collimator and the manufacturer told me how to check the plane of the CCD.  Turns out the STT was slightly off... not noticeable with slower scopes that have a wide crucial focus.. but with the Tak you see it.  With SBIG help I corrected the CCD.  Then with the laser I got the right collimation... at least near perfect... but good enough... perfection is the enemy of good. 

Other complications include the STT line has a smaller backfocus than the STP line and required a custom connector... STP is standard fare.  I have an extra if you want it.  Previous owner had a STP.  Also with the STP you can get standard RoboFocus attachments. 

Since the focus is so crucial, I bought a laser cut Bhatinof mask and use the Tak microfocuser to get really crisp manual focus... remarkably it holds over a couple nights. 

At the end of the day, I learned a lot about optics and I have the F2.8 working.... this translates to 200-300s saturated subs...

I found mine on Astromart... frustrated collimators often post there... if you buy a new one it should be perfect... mine was 7 years old.  You can tell from the serial number how old it is. 

Send a p-mail for other questions- do not want to hyjack your thread too much...

[jkmorse]

Jerry,

Now that is dedication to the art!!  Must have been frustrating as hell when you wer trying to get your head around all of that.  In any event, thanks, lots of food for thought.

Best,

Jim