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Originally Posted by Startrek
Alex,
Finally back in Terra Australis after 7 weeks abroad
Great to be back in the best country in the world
You have captured an excellent M16 there and have exposed some really nice detail around the pillars
Colour looks good too !!
Well done indeed !!
A few questions if I may -
In Startools , did you load your Mono data set via Compose and select “Linear” ? If not, this maybe the reason why you have to back off the Green Bias so much. Using my OSC 2600MC I usually have to back off the Green Bias significantly due to the OSC matrix having RGGB.
In regard to using “Drizzle” to improve resolution, your Askar 130 at native focal length is 1000mm ( correct me if I’m wrong ) So using either your 2600MC or 2600MM would result in a pixel or image scale of 0.77 arc sec per pixel which is Oversampled. Drizzle only benefits from “Undersampled” data or above say 1.5 arc sec per pixel. Using “Drizzle with Oversampled” data just introduces more noise in the image and no improvement in resolution.
Oversampled data greatly benefits from Binning as we all know ( as in Startools)
If you’re using a focal reducer in the Askar 130 resulting in a new reduced focal length of 600mm or less , then Drizzle may help when using the 2600 series cameras.
I did pixel peep and notice some fine grain noise mottle in the image which is typical of using Drizzle on oversampled data ( correct me if I’m wrong )
When I get some time I’ll send you some more info on Startools Colour ( as promised )
Hope the above all makes sense
Best always
Martin
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Great to hear that you are back home safe and sound Martin.
Yes as to over sampled etc but I only read about that yesterday.
My experience with drizzle was very favourable in the past but that was with different gear.
I use compose and select linear there is no room for stuff ups there really..but mapping Ha to green is just a red flag.. that is green...I have started to calibrate and things seem much better ( see Swan thread.. before and after calibration)..plus I have given up mapping HA to green ..I map Ha to red instead and now I dont even load the green data into " green"...not ideal but I see it this way..if you cant solve a problem manage it tbe best way you can...and really green has not been bothering me since my new approach..
I am a painter, water colours preferred but while it is just so difficult and so taxing I go for oils to relax where managing colour is actually easy for me..but in that game you mix red, blue and yellow so just going with red, blue and green I dont get...so the old dog wants to learn new tricks.
I am noticing more noise than ever before so I am going to test at different exposures...it is there well before stacking...once I found the cooler was at 15 + not 15- so I must check that each session as I have no idea how that happened...Maybe 100 gain rather than zero...heck I got less noise with 30 seconds at 350 gain...I did learn the theory but I forgot most of it so I need to ,learn it again....just so busy and so much to do.
However I do find drizzled images are generally better even recently but I will do some comparison tests...
Thanks so much for your interest and help.
I really do appreciate any help I can get...
Alex
