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I am hoping someone might be able to help with a possible way to shoot dark and bias frames on a DSLR (canon 700D) without the need to cover the scope or camera, ideally using APT scripts
My thinking is that the camera, has a noise reduction mode where it will take the light shot, then with the shutter closed it will take a dark frame and subtract it from the light. So could you take a series of dark frames on ATP and lock the shutter down?
If anyone knows I would love to know. Would be great to automate the lights, park the scope and have it run darks and bias, without the need to go out to it and cap up at 3.-4 in the morn
New to forum help needed. I have had this problem a couple of times now over the last few weeks. I hope someone can help.
I am seeing a black band at the bottom of some of my imaged. They are all 10min light frames. At first I thought it was my filter wheel out of position but it seems to be on every other image. I used the same setup the night before with no issues.
I'm using a Explorer scienific Apochromatic 102. ZWO Optical ASI 120mm-S (CMOS). ZWO Electronic Filter Wheel 1.25inch with R,G,B filters and ASIAIR
Any ideas would be helpfull.
By Matt Hayden
What with all this locking down business and home schooling my ten year old son, I have dusted off my TAL-1 and created a slightly less than ideal setup in his room. The westward facing window has been providing great views of the moon and venus over the past week. Obviously doing this indoors is not great (the floor is pretty solid, as is the TAL stand!) but it does mean we get to use the scope every evening, rather than going through the process of carrying the whole rig outside every day.
I have a T-mount converter for my old-ish Pentax k-M DSLR, but have quite disappointing results with the camera, when compared to the observed image using the eye. The eyeball view is nothing less than banging - crystal clear detail with a 25mm eyepiece, strong contrast - it's spectacular. I add the camera with an eyepiece inside a tube, and can't replicate the same result, or anything like it. It's OK, but not good enough.
I've cleaned the eyepiece today and collimated the scope. The primary mirror looks fine other than a couple of tiny dust particles, no scratches or weirdness on the coating. The camera is working pretty well as far as I can tell. Apart from a little clumsy-ness with the adjustments, the clarity in the eyepiece suggests it's all working fairly well. Photo attached of best result from last night.
My question is: is this a focusing issue or some sort of aberration? Should I expect focusing to be difficult in the camera eyepiece? What's going on?! Does anyone have any other tips I can try to get this working better?
I am wondering if anyone has a suggestion that might help me
My imaging set up is an RC reflector with an FLI proline 16803 camera and 50mm Astrodon filters (LRGB + 5nm narrow band)
I have had a string of issues...everything from my mount had mechanical problems to my telescope had issues with the mirror cell to some family distractions...but at long last I seem to have everything working with the exception of the Astrodon Ha filter.
Attached are representative 30minute subframes of the horse head and Pacman nebulae in Ha, SII, and OIII. I get similar results with different objects although for bright, broad spectrum targets like M42, I will get data from the Ha filter (much as the stars shine thru on the HH and Pacman) although even that data does not comport with other imager’s Ha images of those objects. The LRGB performance appears to be normal. My hypothesis is that this Ha filter is defective, perhaps not centered on 656.3nm
I have contacted Astrodon and exchanged a couple of emails with Cary Chleborad seeking some help. At first he claimed there was no issue because with enough manipulation some data could be extracted from the Ha. Later, when confronted with the other narrowband frames and the obvious difference to the Ha, at first he ghosted me, but when I said I would ask other imagers for help, he responded with a new position stating that because of the way the filters are made and their robust quality processes, it is impossible for the filter to be defective and therefore something else must be at issue. He does not offer a suggestion of what might be the problem, nor is he interested in having me send the filter back for evaluation. Frankly, I’m more than disappointed given the premium I paid for Astrodon filters
All that aside, and taking Cary’s position at face value, does anyone have an idea of what might cause this behavior other than the filter? In a perfect world, does anyone live in the Austin, Texas area who would be willing to try my filter one night and see what they get with their equipment?
The attached link is to the raw, uncalibrated files right off the camera. I think a simple blink process in PixInsight will show what I’m talking about.
I’m a little at my wits end, please help!
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)