Do you really need Dark Frames for your ZWO ASI2600 / QHYCCD 268 cameras ??
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- เผยแพร่เมื่อ 29 มี.ค. 2022
- In this video, I talk about the hot topic of whether dark frames are needed to calibrate images taken with camera's based on the Sony IMX 571 sensor, namley the ZWO ASI2600 and the QHYCCD 268
I go through two sets of data I've personally captured and compare the results with and without Dark Frames integrated during the calibration process.
Don't forget to watch the video at the maximum resolution (4K) for the best overall experience.
#astrophotography #astronomy #zwo #qhy #deepspace #sky-watcher #celestron
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Twitter: @hogarthUK
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Email: youtube@alien10.com
I'm always open to providing impartial and fair product reviews - วิทยาศาสตร์และเทคโนโลยี
Wow, for a beginner, that’s one of the cleanest most concise video explanations I’ve watched so thanks. Just about to take delivery of my 2600 and still the debate goes on, but as a beginner this just lets me know “darks” not 100% needed (at least to start)
Great video, thanks for sharing! I only use Flats and Bias frames with my 2600MC Pro and get great results...Love that camera! Keep up the great work and best wishes from north of the border! :)
Hey thanks for the feedback, I do appreciate it.
Excellent info and perfect timing since I have an ASI2600MM on the way. Thanks Hogarth.
Hey thanks Chuck.
I've heard the discussions about not using dark frames but it's good to see it in reality so thanks for doing this video demonstration.
Interesting review Glen! Thank you for sharing.
Glen ? Hey thanks Darren..
🤣
Thank you for sharing this video! With my cooled ZWO camera I don’t need dark frames. It was something always needed with my DSLR.
I don’t have a backyard set up. I have to go out to a dark sky site to shoot, so I cannot be out there for hours on end.
I know that in the Astro photography “religion”, dark frames, and every other type of calibration frames, are always needed no matter what.
Thank you for this video. I am a new owner of the asi2600MC-P and I have read conflicting remarks on if darks are needed with this camera. I think since I am new to astrophotography, I will do some darks just to be safe, but I will probably stop doing them once I get more proficient in processing my images.
Interesting review! I had the same thoughts on this with my 2600mc, so I stopped using darks! But I have actually started using them again now! Couldn’t really see the difference but it didn’t feel right not adding all my calibration frames🤣 Clear skies!
Thanks Simon, I know what you mean, feels dirty not doing it.
@@HogarthsAstrophotography 😂 lol
I have a ASI294MC Pro and for that I *obviously* use darks. But since I have my second rig in mono, which uses the ASI2600MM Pro I have not taken the 'trouble' of creating a dark library. The only calibrating I do on that mono data is using flats and I bias. I had a video idea for it too on my todo list. You've covered the "does shooting darks matter" part quite nicely.
Hey thanks Martin. Its still seems a widely debated subject. often citing what about hot pixels, but those can also be removed during stacking without darks if you have enough..Glad you enjoyed it and found it useful
Cheers !, I've never used darks with my 2600mc so good to see this.
Thanks Ollie, I’ve no idea why everyone is calling me Glenn though 🤣
@@HogarthsAstrophotography lol 🤣 oh. no I saw one person and followed suit !!
Interesting video Hogarth I think I saw you at the PAS in Kettering a couple of weeks ago so apologies for not recognising you & saying hello as I've been subscribed to your channel for a while now, I've got the Altair Astro 269C which has the SONY IMX chip so I might do a stack with & without darks at some point just to see if there is a difference between the two.
Hello. Thanks for watching, you did indeed. I was with Luke and Ben a lot of the time. Would be interesting to see the results from the Altair camera
@@HogarthsAstrophotography myself and the other half came down and said hello by the Pulsar dome Ben, Chloe and Luke were there plus yourself and a couple of others I believe. I'll have a mess around with some more data soon after I get the RASA sorted.
@@dumpydalekobservatory Yes I do recall the moment, I'm also on your video of PAS as you pan around the TH-camrs.. but with no tag for me... hahaha. I'll definetly say hello if your at IAS in October
Well I do apologise let me introduce myself I'm Tich from the Dumpy Dalek observatory & to my left is my better half Nicky lol, I shall update the video description & put in other folks channels on it, I'm not sure if I can add a tag to you in the video but I'll have a look anyway cheers.
@@dumpydalekobservatory Hey Tich, good to meet you. I was only messing about the youtube tag btw... I also have another half called Nikki.. must be an astro thing! :-)
That is an interesting result. No question about using dark frames with my 183 sensors, lol.
Hey thanks.. Absolutly right about the other ZWO/QHY cams... I did have a set of data taken with my now sold 071MC, but thought the video was going on a bit to go through it as well.. they cleared benefited from darks
Great test Nigel! I love this kind of stuff. So when you do your flats, are you taking flat-darks then? I tried stacking some 2600MM lights without darks, but with flats taken with flat-darks and my images came out looking like the flats were over-exposed (which is impossible). So I took some light-darks and then the images came out perfect. I can only assume that the stacking software I was using (APP) was subtracting the electronic signature from the flat-darks and didn't have an electronic signature from the lights so it was adding that in to the final image. When I added the light-darks it then correctly subtracted the electronic signature (I'm assuming). I didn't try using PI to stack with or not using the flat-darks, but wished I would have to test with. What are your thoughts.
Thanks for the comments Joe. Interesting outcome you had.. The images I processed in PI, were with Flat-Darks. Im not an APP user so I can only guess, maybe the way they are integrating is slightly different, as the results should be the same (or there abouts). I did have a video planned comparing 4 stacking programs, but never got around to doing it.. maybe I'll re-submit for a trial APP and do some more tests
@@HogarthsAstrophotography That would be a really cool video if you did that. I'd love to see how they all compare, I've used all the usual stacking programs before but never tried all 4 with the same stack to just compare them before. That's a great idea.
Great review. Idid a similar experiment with my ASI2600mc. I tried to convince myself that there was slightly more contrast in the darks version but the difference, if any was negligible. One thing Ive been concerned about, is that my calibrated individual light frames (corrected with flats etc) appear noisier than the corresponding raw light frames.
Hey thanks Cliff, I’m pretty sure I was doing the same, I wanted to convince myself the difference was greater. I will do some more tests offline, as right now I’m processing my images with and without darks and starting with what I think is the best out of the two.
What’s blown me a bit, is it’s quite clear on the TH-cam video there is a larger difference on the Heart Nebula data pair, that I couldn’t see on my monitor whilst I was recording, but on my iPad watching the video, it’s a little more apparent. Maybe I need to calibrate my monitor, or my eyes 🤣
I usually try and find two faint stars close together and try and assess how well they are defined in each image. Aldo, if the stretch of the image is slightly different it’s hard to make objective comparisons.
One question re using the WBP script, do you ever use the optimise master dark option?
No, I remember reading somewhere about its use cases, I must re-visit it to see if its more relevant now.. as it was a long time ago..
In my opinion this is an insane question to even ask. Why would anyone spend 20-50 hours on meticulously-crafted project, using thousands of dollars of gear, only to NOT use the easiest and most trivial of all calibration frames. Why risk it? You've already invested so much time and money, it takes literally one cloudy evening to build a darks library that will last for years. In the worst case you get a small improvement, in the best case you get a dramatic improvement, for almost no investment in effort. It blows my mind that anyone wouldn't calibrate correctly.
Thanks for the feedback
True one probably doesn’t need darks with these cameras but easy enough to build a library all on auto with NINA taking darks over your usual exposure times. Saturday afternoon would probably do it. Even if only 1% gain, why not?
Excellent video
To me , the picture without dark had more colors
So if darks are not used how do you guys cope with the Hot and cold pixels, and if you don’t dither, as I don’t, how do you deal with walking noise, Darks stops all these issues….?
Dithering is the key along with the low read noise of the cameras. this is the way when stacking using something like PI, it can remove the H/C pixels very easily.
without dithering the noise will be low, but yes you could have some walking noise.
@@HogarthsAstrophotography so for people like me then who don’t dither, dark frames are a must…the reason I don’t dither, is I have an EQ8 mount, that has DEC backlash, and so I guide in just one direction, which makes the lash moot, then I use dark frames, as it gets rid of any hot and cold pixels, and also any walking noise, so it’s far easier for me to use darks, than try and deal with dithering…👍🏻
You didn't mention if you used bias frames and/or flat frames.
For these tests I don't think I used flats.. I've never used bias frames for my astro cams, but tend to always use flats for correcting dust motes and vignetting
Great video
Question
I have 2600mc
Do I need flats biases etc ?