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My first attempt at PixInsight

astrophotography refractor
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#1 khursh

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Posted 30 May 2020 - 12:33 AM

I took a stab at the Draco trio of galaxies. I had one decent night and then the clouds rolled in for a week in addition to the fuller moon. 

 

Gear:

Orion EON 120mm FPL 53 Doublet with .80x reducer

CEM60

ASI533MC pro @-5C

ASI290 guiding on 50mm guide scope

No filters (yes I know I need a UV/IR cut filter)

 

SGP for acquisition

120s x 116 = 3:52

30 darks

25 flats

25 dark flats

100 bias

 

Stacked in DSS before processing in PI

I need a $50 UV/IR cut filter or a $2000 triplet.


get.jpg?insecure

 

Thanks for looking

 


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#2 44maurer

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Posted 30 May 2020 - 12:44 AM

Kevin , PI takes a lot of practice/learning/YouTube. This is a good image, there are a lot of areas you can improve on. BUT it comes with practice. I’m still learning my way around PI, it is amazing, just takes a lot of effort to learn. Keep at it, again, nice image.



#3 Jim Waters

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Posted 30 May 2020 - 01:37 AM

I agree with 44maurer.  You should stop using DSS and move to PI 100%.


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#4 the Elf

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Posted 30 May 2020 - 01:39 AM

Here is a tutorial I made:

https://www.youtube....h?v=mvuMrHEWaS8

Make sure you watch on 1080p. The files processed can be downloaded, link in the description. Hope it helps.



#5 khursh

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Posted 30 May 2020 - 08:12 AM

I actually did use your tutorial, Elf. I am a little stuck in my (one-week) old ways and used DSS for the stacking. I will re-watch the portion on integration. Thank you for creating it for us newbies.



#6 SimonIRE

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Posted 30 May 2020 - 10:55 AM

When I made my transition from visual to AP, I decided I'd approach it the same way I approach my research; get a mentor, embrace the technicality and learn from the ground up in a structured way.

 

I've been studying Adam Block's PI Fundamentals and its been excellent. At $180, it's an investment (but then when you look at what you spend on kit, its not so much). You make quantum leaps when you're being hand held up the steep part of the curve; this is difficult to replicate if you are a complete novice and trying to learn on your own. 


Edited by SimonIRE, 30 May 2020 - 10:57 AM.

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#7 the Elf

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Posted 30 May 2020 - 11:31 AM

You have to draw a line between understanding the general procedure that is needed to create an image and the various ways one program or another is used to achieve that. The general procedure is well described in Charles Bracken's famous book. Youtube is not a good source. I picked a random video about calibration frames and the guy was wrong about dark frames. Furthermore there is common knowledge what a certain calibration frame or procedure does in general. Knowing how much this affects you in your situation and circumstances and your equipment is a different story. It took me almost 3 years to develop a feeling which steps I need to do for my images and what does not make a difference at all. Gaining this knowledge is crucial but it will take time. For the time being you have to follow someone's friendly advice and be aware that it might be not optimal for you and you correct it one day. Totally independent from that is how to use the software to get it done and which traps there are when you set one of the million options wrong. My video only refers to how to use PI.

The thing I am concerned about in DSS is this: if the result is fine there is nothing to worry about. But if it is not you are in a trial and error mode. If (important: if!) you have an idea of what each step is supposed to do and how the result supposed to look the step by step approach helps to find problems exactly when they happen.

 

Some equipment has it's flaws and one might wish to compensate for it during the processing. In many cases it is possible but often you have to invest a lot of time. There are people who feel like heroes when they buy a cheap telescope/mount/camera and manage to process the flaws out in hours and hours of struggle. I prefer to start with good data in the first place. That makes processing much easier. Looking at your image the question is do you want to learn how to process the halos away, do you want to try filters to dim them down or do you want to trade in the scope for one that does not create the halos. This is a decision only you can make. If you get a scope with a FPL53-Triplet or a scope based on mirrors the halos will be gone. If you want to process them away you can either desaturate blue, leaving white halos behind or you can split channels and deconvolute blue or morphologically reduce the star diameter in blue. If you want to take the filter approach I am afraid you need to take color without filter and luminance with an orange filter. Then you do an LRGB-combination in processing. A better scope means cry once and never bother with halos again.


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#8 OldManSky

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Posted 30 May 2020 - 11:40 AM

I'm similarly transitioning to PI.  While powerful, it is indeed complex and takes a lot to learn.  And so many of the operations it does (many of which can be done in other packages), it does just so...differently!  

So keep at it, try lots of combinations of values and processes around the basic steps in the tutorials, and keep track of what each thing does.  You'll get there.  We both will (I hope!) :)


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#9 khursh

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Posted 30 May 2020 - 12:26 PM

I agree with everything everyone says. I really like the idea of saving my progress at several steps.

 

I will read several books on PI. It is a lot to learn, but somehow I don't find it frustrating like some other packages that make the processes so opaque that you feel you have no control.

 

I am in the market for a triplet from TS (TS 130 F/7 in particular). I believe I will still need a good UV/IR cut filter. I may wind up getting half or more of the cost of the new scope from the sale of the current one, that isn't too much to cry about.


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#10 Stelios

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Posted 30 May 2020 - 01:44 PM

I agree with the multi-source approach to PI, although I think Adam Block + LVA (for Narrowband which AB doesn't yet cover but plans to) is all you need. For the "fundamentals" nothing comes close to Adam.

 

The image is nice, but something went off with the magenta star color in particular. Did you try PCC? 



#11 khursh

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Posted 30 May 2020 - 02:15 PM

I did not try PCC Stelios. I will check it out. This is not the first time I've heard about Adam Block's tutorials. I may head down that road. 



#12 Stelios

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Posted 30 May 2020 - 02:21 PM

I did not try PCC Stelios. I will check it out. This is not the first time I've heard about Adam Block's tutorials. I may head down that road. 

PCC (Photometric Color Calibration) works like a dream and is entirely automatic. But since you didn't stack in PI, You will likely may have to enter all the parameters as if there's no .FITS headers. You will need object coordinates, date (and time, but date is enough) of acquisition, pixel size and focal length. Then just click a button. It performs BN (Background Neutralization) at the same time.

 

It's best used on linear images (before stretching). 



#13 khursh

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Posted 30 May 2020 - 02:27 PM

Sorry for my ignorance, but wouldn't there be FITS headers created in DSS?

 

Also, I think I will give stacking in PI a go. Before yesterday, I didn't even know it did that.lol.gif



#14 Stelios

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Posted 30 May 2020 - 04:30 PM

Sorry for my ignorance, but wouldn't there be FITS headers created in DSS?

 

Also, I think I will give stacking in PI a go. Before yesterday, I didn't even know it did that.lol.gif

It has been so long since I used DSS, I forgot if it generates a .FITS or .TIFF, sorry. I edited my previous post.



#15 the Elf

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Posted 31 May 2020 - 03:17 AM

I don't think the image information is so important. PCC does two major steps: 1) plate solve the image, 2) identify stars with color data available and adjust the channels to them. I found 1) fails very often because the solver is not a blind solver. It needs somewhat good start values. If you look closely at the PCC option you will find that the default setting is not to plate solve if the coordinates are in the image. My standard procedure now is this:

 

- use scripts/image analysis/solve. The resolution of your setup does not change. For the first solve use an estimation, form then on you know it. Position can be searched online or entered (e.g. from a book, stellarium, etc.) The positions in books are Jan 1st, 2000, so select this date. Downloading the star catalogue to the local HD once speeds up the solving process a lot.

- now apply PCC, it won't solve but do the color adjustment only

 

If the image is difficult to solve solving the extracted L instead may work. scripts/utilities/copy coordinates can be used to transfer the result to the color image.



#16 khursh

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Posted 31 May 2020 - 10:19 AM

Thank you. Great info!



#17 khursh

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Posted 31 May 2020 - 10:20 AM

I was wrong earlier, DSS outputs a TIFF file. Another reason to start from scratch




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