The Critical Error in My M81 Project: A Deep Dive into Astrophotography Troubleshooting
ฝัง
- เผยแพร่เมื่อ 12 มิ.ย. 2024
- Dive into the heart of astrophotography with me as I share a gripping tale from my latest adventure - imaging the mesmerizing M81 galaxy. 🌌✨ In this video, I reveal a simple yet critical mistake that nearly jeopardized the entire project. Join me on a diagnostic journey to uncover the rogue calibration frame that caused chaos, despite working for another image. 🛠️💡
Why was this frame an issue? How did I navigate through the troubleshooting steps to save my project? I'll break down the process into easy-to-understand steps, sharing valuable insights that every astrophotography enthusiast can learn from. Whether you're a beginner or an experienced stargazer, this video is packed with tips and tricks to enhance your astrophotography skills. 🚀🔭
Don't forget to hit like, comment with your thoughts or questions, and subscribe for more astrophotography insights and tutorials. Got a specific question? Drop a comment or send me an email at Tony@HiddenLight-Photography.com. Let's explore the universe together! 🌠📸
hiddenlight-photography.com/
00:00 Introduction
00:41 The Problem
02:47 Blink the Light Frames
04:16 Examine the Individual Frames
07:34 They Worked Fine for Another Image
08:26 Isolate the Issue
15:14 The Simple Oversight
18:30 The Difference
#m81galaxy
#astrophotography
#imageprocessing
#hiddenlightphotography
I just encountered a very similar issue after imaging M51 over multiple nights. In my case, there were 2 culprits: A flat frame mistakenly taken with the wrong filter and an ever changing light gradient thanks to a nearly full moon. Although retaking the flat really helped, I ended up having to throw out too many subs in order get a workable stacked image, even for gradient removal tools. I still have a lot to learn and a lot can always go wrong but in my opinion, astrophotography is a great hobby that's well worth the effort.
I’m sorry to hear about the trouble! What was the ADU of your flat frames and how did you take them? Also, did you use the same capture software as your light frames?
Yes, this hobby is worth the effort, especially when you have that final image in your hands knowing YOU did it!
Wow, well sleuthed! Half way through the video, I wondered if it was the 10/11 May aurora that was messing you up.
Thank you! I would have happily accepted that haha. Did you get any good shots of the Aurora?
@@Hidden.Light.Photography Hi Tony, yes I got some good shots with my Canon T3i. I spent a couple of hours just snapping away as I've never seen anything like it before. I'm based close to Oxford, UK
Very good! I would love to see some of you don’t mind.
Tony, this was a great video and an eye opener. There's not many troubleshooting videos out there and this one gives us a great way to do some problem solving.
Thank you! I plan on recording issues that I run into in hopes of helping someone who may be dealing with the same thing.
@@Hidden.Light.Photography Couple of quick questions. Both concern shooting multiple nights of data. I know I can stack together multiple nights even if the exposure times were different. Will WBPP automatically read the FitsHeader data and correctly match the corresponding dark frame exposure to match the light frame? I think I remember you mentioning that it would without any input from me.
If sensor temperature changes are different from night to night would that matter when stacking all the data together? For example, if Night 1 was 300sec exposure at 32 degrees, NIght 1 should have a Dark folder containing images at 300sec at 32 degrees. If Night 2 images were captured at 180sec at 10 degrees, Night 2 should have a Dark folder with 180 sec exposures taken at 10 degrees.
Or could every night just have a Dark folder, and Flat folder for that matter, containing all the different temps and exposure times and WBPP would automatically sort it out? Thank you.
I love this question! Here’s what I do. I have a separate dark library folder where I sort all of my dark frames so I can pick and choose. I have the sorted by camera, exposure time, gain, offset and temp so I can pick and choose what I need.
Next, I will have a folder called, let’s say for example, M81. Within that folder, I’ll have a folder or multiple folders if multiple nights; NIGHT 1, NIGHT 2, NIGHT 3 etc etc.
Now, within each night folder I have my captures for the associated nights LIGHT, DARKFLAT, FLAT and this is for whatever exposures I captured for the night plus the flats and darkflats for the night.
When I’m ready to process, I will browse my dark library and copy the DARK folder with matching dark frames and paste it in the appropriate night (paste in each NIGHT folder if all nights used the same exposure otherwise copy and paste the appropriate dark exposures in each folder).
Now when you get into WBPP, I always reset everything and clear cache, then I go to directory and choose, for this example, M81 and WBPP will put everything in the appropriate tab. From there I sort with grouping keywords on the right side of WBPP and enter the word NIGHT since that’s what my sub folders are called. This will have WBPP sort all of the frames to the correct groups. The last thing to do under the darks tab set exposure tolerance to 1 and in the lights tab set the exposure tolerance to 1. You will then see within each tab all of the frames sort with the different exposures.
I know this is kind of a long explanation and I hope it makes sense. If not, I can do a short video for you.
@@Hidden.Light.Photography Thanks Tony! So, if I'm using different filters and my Flat, Dark-Flat have different exposure times (due to the different filter used and ADU I want to achieve), I would do the same thing as what I do for my Dark 's: Set tolerance to 1 in the Flats tab and WBPP will sort it out, correct?
I don’t think there’s an exposure tolerance in the flats tab, at least none that I’ve seen. Are you referring to narrowband and broad band in the same set with WBPP?
Grax pert is a great tool.
Yes it is! What does your workflow look like and what part do you use GraXpert in?
I guess I didn't understand your solution. You stated your later lights were over exposed due to M81 moving close to the Phoenix light pollution. The cure was to take new flat frames at higher ADU and then restack the lights with the new flats?
If you had noticed the new position of M81 what would you expect the difference in exposure and gain be for the lights taken close to the light pollution vs the frame taken earlier when M81 was in darker skies?
Also, when you are in light pollution do you generally lessen the exposure lengths vs darker skies.
So in Sharpcap there is a tool that will help you decided how to chose the exposure length and gain? I'll have to read up on Sharpcap. Is that one of the Pro features? Clear skies are not frequent enough and now the days are longer I don't get started until 10 pm after setting, focus, polar alignment and getting through calibrating in my favorite program, PHD2 then moving to target, mostly the galaxies around Ursa Major.
Great questions! Yes, the cure to save this image was to take higher ADU flats and restack with the new flats instead of the original. I came to this by a test with a set of higher ADU flats from another project (25k ADU) and it started to smooth out the field. Basically this was a trial and error scenario and a demonstration to hopefully help someone who may have had the same thing happen.
In brighter skies, your exposure would be less than when in darker skies. My gain would have still been around 100, however, instead of 180s I would have gone with closer to 90-120s.
Yes, SharpCap has what they call a smart histogram which analyzes the sky and based off of your camera (through a sensor analysis) will recommend exposures. This is in the Pro version and very helpful. Here are two videos I have going over SharpCap:
th-cam.com/video/x5F3aoifzsM/w-d-xo.htmlsi=iM_b8TvzWW71ja-1
th-cam.com/video/xNE2QSj9OKk/w-d-xo.htmlsi=j5Gpdfsg0fjcIJHD
I hope this helps and makes sense.