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Topics - rtemen

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I have a set of 8 jpg shots of an asteroid moving through a constellation.
I would like to line them up and make a mosaic.
But, I actually want to just position the shots over each other manually and them form them into a mosaic.
So far, all of the suggestions seem to direct me to Star Alignment or Dynamic Alignment.
I am not able to get either of these tools to work.
Is there a way to just manually drag the pics over each other and then make a mosaic of the views as they sit on the screen?


I have taken ten shots of the 2014 J025 passing through a constellation.
Each shot was a time exposure, and when the path of the asteroid about filled the view, I stopped the photo capture, move the camera to the right and then took another time exposure. Therefore, I have a path of shots across the constellation that I wanted to make a mosaic out of.

I would like to align the 10 shots to overlay/mirror my ten shots over the actual constellation.
This should show the path of the asteroid as it traveled through the constellation.
I have tried several times to use the Mosaic tool, but I cannot get anywhere with it.

Can anyone guide me to how to align the shots to make my mosaic?


I have a situation where the CC is not eliminating all the hot pixels.
When I use the Real Time Preview window zoomed in on a particular area, when sliding the Sigma level to the left (smaller) this pixel will not go away.
In fact, when the Sigma slider goes all the way down to 0, it turns that one pixel into three pixels.

Any help is appreciated.


Image Processing Challenges / Help with ImageCalibration results
« on: 2018 January 14 08:41:49 »
Hi, all.
I was wondering if I could get some guidance on my first step of processing my lights.
I have a before and after file in my dropbox.

It looks to my untrained eye that the before is nicer and cleaner than the after.
Here I used my light with my MasterSuperBias, MasterDark and MasterFlat.
Is the after supposed to look like this, or is there something wrong with my Masters?


I have been trying to learn the best way to determine that I have suitable flats.
I have a Canon T3i that I use for my shots.  I have a lightbox for taking my flats.

I seem to be finding two different philosophies while trying to google info on determining the best flats.

1. Take flats so that the histogram hits at about 1/3 of the way from the left.
2. Take flats so that the median just a touch over half the maximum, around 51%. (this data is in the Statistics for the shot in PI)

What I seem to find is that the two methods cannot meet. 
For example, if I put the histogram at 1/3 of the way, the percentage is like 80% to 90% or more.
Or, if I start changing the exposure to bring the percentage down towards the 51%, then the histogram is off the scale to the right.

So, what is the proper way to determine that I have the best exposure for my flats?


I was wondering if there is a guru out there who would like to process my files and log the steps to help me learn how to better process files myself.
I have been following several tutorials, but of course, none of them can tell about my files exactly.
The latest tutorial is from Kayron Mercieca on Light Vortex.
This made a big difference in my results, but there is still an issue with ringing on some of my stars.
Upon doing some more research, it is suggested that I use the DeConvolution process to help with this problem.
So, now I don't know what to do.
When should I have used the DeConvolution, and how do I tell that it is doing something positive?
I have saved my project, and I assume that I should be able to backtrack in my history and inject the DeConvolution Process???
Or do I just need to start over.

Kind of a long message, but thank anyone who might be willing to help.


I followed the tutorials on Light Vortex by Kayron Mercieca where he processes Andromeda.
When I finished, there is some significant ringing, especially around some of the start in front of the galaxy.
Could someone guide me as to where in the process I should have done some steps that would have removed the ringing?
I saved my project, so I should be able to backup to the proper step and work on the ringing.



In the tutorial at Light Vortex by Kayron Mercieca, describing pre-processing, I have a question.
At the end of Step 4, it indicates that if I have One Shot Color camera it is time to DeBayer the lights.
So I did DeBayer my shots.

In Step 5 it indicates that the input files should be the Calibrated and Cosmetically-Corrected files.
In my case, should I use the DeBayered files, or is there a reason to use the ones just before DeBayering?


Greetings.  (this is kind of long  :) )
I have been working with Pixinsight for a goodly while now, and I am 'stuck' on a couple of issues.
For about a half a year now, I have been following the image processing video by Richard Bloch.
After some practicing, I have been getting better at processing.
However, I seemed to be at a point where I couldn't get things any better.
After several discussions on this forum, one member told me that when using a camera like my T3i, I needed to process all of my flats, darks,bias, etc, using the Raw and CFA settings in the Format Hints, and only when I get to the point that the Lights have been calibrated, do I use the DeBayer tool to convert the pics to color.
After following the examples that he pointed me to, my results are much worse than my Richard Bloch results.

So, here are the big questions:
Is it true that all of my processing should be done in the RAW CFA formats?
If so, is there a tutorial that will walk me through a thorough workflow on processing my files in this mode?


I am using my Canon T3i for my lights.
I am at the point in my workflow where I need to Debayering my files, but I do not know the difference between the Debayer Process and the Batch CMYG Debayer Script or which is the appropriate on to use at this point.

Thanks for any guidance.


A quick lead in so you know where I am coming from.
Lately, I have been doing a lot of reading of posts on several big astronomy forums.
I have come across two major items.
1. One post explained that today's DSLRs usually subtract the bias information automatically before creating your raw result.  Therefore, he indicates that running the process of removing the bias again is actually hurting the picture quality.
2. Another post points out that my DSLR (Canon T3i) has a feature to enable long exposure noise reduction automatically for each picture.  If this is enabled, I will not need to do some additional pre-processing steps.  His result was that now I would only need the cleaned up Lights and the Flats.
If this is the case, what are the processing steps to go through to pre-process my pics with only the Lights and Flats?

Thanks for any opinions on all of this, and if this is ok to try, what are the steps and in what order.


Hi, all.
Well, I have been viewing several tutorials on the process of calibrating and stacking.
In most cases, when the tutorial shows the resulting light after the masterflat has been applied, there is almost no vignetting left, and the background seems very even all across the field.
When I do these procedures, I get a horrible result. (At least I think they are horrible.)
I am attaching one of my lights, one flat, the masterflat and a calibrated result.
Could anyone look these over to see if there is a basic problem with any of these files?
Any suggestions on what might be wrong would be appreciated. Or if the files are ok, then what I might be doing wrong.
I have tried both Automatic and Dynamic background extraction and I frankly cannot see any difference in the results.
Thanks for any assistance.
Here are the files.

I have 10 lights of M104 and I have tried a dozen times or more to get them to star align.
I have tried many tweaks of various parameters, to no avail.
Would anyone be able/willing to look at the two sample files and let me know what I need to do to get them to align?

Here are the two files:


I took many 3 minute exposures of the asteroid moving through Coma Berenices the other night.
Is it possible to stack some of them together to create a 'mosaic'  showing the trail of the asteroid among the stars.
I am able to align the stars but would like to blend them together to see the total path of the asteroid.


I have a Celestron C11, and last week I purchased a Meade f/6.3 reducer.
Before adding the reducer, I was doing fairly well with taking lights and flats and getting a pretty good result.

Now, after adding the reducer, I cannot seem to get anything to work right.
The calibrated file looks horrible, and I do not know enough about PI to determine what is up at this point.
I tried diligently to take my flats the same way as I did with the scope before the reducer was added.

I am attaching a Light, a flat, a masterflat and a calibrated result.
Would anyone be able to examine these files to see if there is something wrong with any of them, and what I need to do to correct the problem?
Here is the folder with the 4 images.
The folder is M101-Flats
Thanks for any help on this.
I think the dropbox link aboce should allow you to get all four files.
If not, let me know.


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