2019 November: Complete LRGB Tutorial of NGC292, The Small Magellanic Cloud by Christian Sasse, Astronomer in Charge of iTelescope.net
2019 September: Astro Pixel Processor and iTelescope.net celebrate a new Partnership!
Synthetic layer creation ant proportion of the contribution of each indicators in the calculation of "Quality"
Hello Mr. Mabula Haverkamp,
Your application for astrophotography that you have developed is truly superb! There is something for all levels of astrophotographers! Thank you for all the tutorials and the forum which are of great help.
I have practiced astronomy for almost 50 years and more seriously astrophotography for 10 years with free processing software (DSS, IRIS, Pixinsight LE, etc.) except for Photoshop5.
I bought APP 1.075 at the end of 2019 and I don't regret my gesture even if I have to invest a fair amount of time in it to fully understand its potential and its use. I like to learn and understand how to use the tools that allow me to achieve my goals.
I have two questions :
Q1-Can we carry out mathematical operations with the layers such as for example to create a synthetic green layer (G) from R and B (ex. G = (R + B) / 2)?
Q2-Throughout the pre-processing (tab 1 to 5) which culminates with integration (tab 6) we have different indicators such as SNR, RMS, Star Shape, etc ... Among these, there are to the one entitled "Quality" and according to the help texts it would be composed on the basis of "Noise" & "Star density" & "Star Size" & "Star Shape". What is the proportion of the contribution of each of them in the calculation of "Quatlity"?
I have two suggestions:
S1- It would be interesting if we could make a dynamic crop (with height and width adjustment tags) to take advantage of the zoom and thus refine our framing.
S2- It would be useful if we could benefit, without visually overloading the interface, from a function with a keyboard shortcut in order to see before and after a calculation. This would be particularly helpful when using the powerful Light pollution removal tool.
Thanks in advance for all the work done in the development of APP.
Thanks for the kind words and the purchase of APP!
Q1; No, at least not yet. I think Mabula is thinking about giving users some of these options in a future version.
Q2; Good question; during all steps, this score is updated constantly, based on the new results it gets from a certain step. I think star shape is one of the biggest contributors. You can always sort the table by right-clicking on it and sorting on various parameters, like quality. Again right-clicking you can then show a graph (all the way down in the list that pops up) and check things like noise, star shape, etc. to visualize their contributions per frame.
S1; Yes, good idea and I think Mabula has this on his radar as well, have to double-check him for that. @mabula-admin
S2; Yes, that would be nice as well, loading the data however is memory intensive so I think this is why frames are not kept in memory to allow for a quick back-and-forth comparison. But I'll ask him about this as well.
Thanks for all suggestions!
Thank you Max for your kind words 😉 that is highly appreciated !
In answer to your questions:
Q1 - yes, with the RGB Combine tool, load a red and blue frame/integration and assign them both for 50% to green, that creates a synthetic green channel.
Q2 - i have on my todo list, to make it possible that you can choose which formula to use for the quality score ;-). At the moment this is a fixed formula and I will soon make this completely clear. The current formula contains: star density, star size & roundness = star shape, noise. Signal to Noise ratio is not used because it is known to give many false positives.
S1 - please check the batch modify tool in 9) tools, that provides the desired crop function. I intend to split that batch modify tool in separate tools, like a Batch Crop tool and will further improve it for more usability 😉
S2 - yes, great suggestion, I intend to load both the corrected data and the original input into the image viewer, so you can quickly flip between corrected and not corrected 😉
Main developer of Astro Pixel Processor and owner of Aries Productions
Thank you very much to both of you for all the clarifications that you bring to my questions and my suggestions.
Indeed my Q1 had a mathematical sense even if intuitively I saw this possibility of loading a channel more than once in the Combine RGB tool but without really knowing how the interface APP1.075 would deal with this situation or if it would be of improper use. Now it's very clear and it gives this tool superb power and ease of use! Thank you for that.
The more I learn to use APP, the more I enjoy performing the processing of my astrophotographs and making appropriate choices according to each situation that arises.
Thank you and have a nice day,