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So...a question...let's say you want to shoot in a slightly light polluted area...but you also want to use the IR/UV cut filter...how can you use both then? You can only apply one filter at a time...so are is this a sort of 'pick your poison'? So you can't have IR/UV filtered along with Light pollution as well?
For example here:
There's a ton of great filters...but how is it possible if you need a light pollution filter because of the area you're in..but you also want to cut IR/UV ? It seems like you can only do one at a time.
I made an acquisition and processing tutorial a while back (3 years ago? Yikes!) and it is fairly dated in terms of what I'm doing these days. I've been asked for a long time to make a new one showing what I'm doing these days. Specifically how I'm processing a single shot image for both the surface and prominences and how to process them together to show prominences and the surface at once. I've abandoned doing split images and composites and strictly work from one image using layers. Acquisition does not use gamma at all anymore. Nothing terribly fancy, but it's not exactly intuitive so hopefully this new video will illustrate most of the fundamentals to get you started. Instead of an hour, this time it's only 18 minutes. It's real time from start to finish. I'm sorry for the long "waiting periods" where I'm just waiting for the software to finish its routine, it lasts 1.5 minutes and 30 seconds tops typically at first. The first 4 minutes is literally just stacking & alignment in AS!3. I typically will go faster than this, but wanted to slow down enough to try to talk through what I'm doing as I do it. Hopefully you can see each action on the screen. I may have made a few mistakes or said a few incorrect things or terms, forgive me for that, this is not my day job. I really hope it helps folk get more into processing as its not difficult or intimidating when you see a simple process with only a few things that are used. The key is good data to begin with and a good exposure value. Today's data came from a 100mm F10 achromatic refractor and an ASI290MM camera with an HA filter. I used FireCapture to acquire the data with a defocused flat frame. No gamma is used. I target anywhere from 65% to 72% histogram fill. That's it! The processing is fast and simple. I have a few presets that I use, but they are all defaults in Photoshop. A lot of the numbers I use for parameters are based on image scale, so keep that in mind, experiment with your own values. The only preset I use that is not a default is my coloring scheme. I color with levels in Photoshop, and my values are Red: 1.6, Green 0.8, Blue 0.2 (these are mid-point values).
Processing Tutorial Video (18 minutes):
RAW (.TIF) files available here to practice on (the same images you will see below as RAW TIFs):
Video for Acquisition, Focus, Flat Calibration and Exposure (20 minutes):
(Please let me know if any links do not work)
Results from today using this work flow method.
SSM data (sampled during 1.5~2 arc-second seeing conditions):
Equipment for today:
100mm F10 Frac (Omni XLT 120mm F8.3 masked to 4")
Baader Red CCD-IR Block Filter (ERF)
PST etalon + BF10mm
SSM (for fun, no automation)
THIS ITEM HAS NOW BEEN SOLD.
This listing is for my personal narrowband filters (Kayron from Light Vortex Astronomy). They are the Astrodon Hydrogen-Alpha (HA), Oxygen-III (OIII) and Sulphur-II (SII) 3nm 1.25" narrowband set. These are considered the highest-end narrowband filters money can buy, able to produce images of exceptional quality and incredible sharpness, cutting through a vast amount of light pollution. The 3nm variants featured here are fantastic for pulling out fine nebulous structures clearly above background. For more information, please see Astrodon's website:
Please note that these three filters together currently retail at just over £1,710 from UK suppliers, €2,180 from European suppliers or $1,690 from US suppliers. Payment is preferred via bank transfer but PayPal is OK with an extra 2.9% to cover PayPal fees. I'll cover postage to you via tracked Courier.
I welcome any questions you may have regarding this listing. Thank you for looking.
The other night, I got a rather weird thing happen using Sharpcap. In live-stacking, the first image arrived and it was full of stars. So, without changing any settings, I did a "platesolve" (which also realigns the scope) to centralise my target. It did its single frame capture and I got a practically blank screen and a message saying it could only detect 3 stars. I tried reducing the "sigma" setting, as advised by the on-screen message, with little effect. What gets me is that the same settings produced a whole mass of stars in each of the subs that were being live-stacked. Never had this happen to me before, and no, of course I didn't do anything intelligent like saving the log file!
I can always try to replicate this next time (although I always find trying to replicate something that isn't working to be a weird activity in itself!), but on the off-chance that anyone can see what was happening without the log file, I thought I would ask.