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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)
I first came across the term ‘Solargraphy’ on this forum and was directed to website dedicated to the art of Solargraphy.
This is a basic photographic method of recording the path of the Sun as the year progresses. This image commenced on 22 June 2019, the day after the Summer Solstice when the Sun was at its highest altitude in the noon day sky and finished on 22 December 2019, the Winter Solstice when the Sun is at its lowest point at noon. The silhouette of the neighbouring properties can also be made out in the picture.
Using a basic pinhole camera I was able to record every clear day the track of the Sun across the southern sky, each day the Sun’s altitude was getting slightly lower.
Whilst the camera is basic, the main challenge is to avoid water damage and as you can see from the image some rain has managed to find its way inside. However, the pinhole camera is cheap to make with the following purchases made via Amazon;
100 cable ties £5.49
20 35mm plastic film canisters £8.88
100 sheets of Ilford Multigrade 4 glossy photographic paper £25.98
The remaining items were already in the house (drill bit, tinfoil, electrical and duct tape).
Given the potential for disaster I made two pinhole camera’s and one of them provided this image, the other was washed out due to rain water getting in. Making more than one camera certainly improves the chances of success. The camera's themselves were attached with cable ties to the down pipe of the guttering and facing South.
Anyone wishing to learn more about Solargraphy and how to construct the pinhole camera should check out Tarja Trygg's website http://www.solargraphy.com/index.php .
Just bagged 10 minutes between the clouds and got to see the Mercury shadow transit!
Its so long since I used the Lunt that I took a few seconds to get back into the groove of tuning the double stack and letting some air into the tuner as it was flat.
Not much else on the disc - 3 x sets of proms, 3 tiny filaments, saw one small bright flux patch briefly.
But the Mercury shadow was nice and clear and a decent sized patch too.
Just got back inside before it started spotting with rain! Fingers crossed for another clear patch later ...