What an absolutely brilliant description! I have never properly understood this topic before. Now it all makes sense! Thank you!!

Great presentation. Especially the last slide shows a perfect calibration overview.

These informational/instructional videos you have put out, Adam, are phenomenal! Not only did you teach us to use WBPP, you thoroughly explained the whole calibration process and why we do what we do with calibration frames, why we take them, etc. You explain it very well making it much easier to understand. Thank you very much for taking time of your own to help other astrophotographers make the best of theirs! Thank you!

@AdamBlock

2 жыл бұрын

Thanks for watching. It takes a bit of patience to get through everything...

WOW This is an amazing series of tutorials/explanations. Which not only clearly explain the tool but the science behind it. Well worth the time. I did experience one issue as some of the brighter stars ended up badly blown out.

This is one of the best illustrations and explanations I have seen on this topic

@AdamBlock

3 жыл бұрын

THANK YOU! I did try very hard on this!! :)

You are an amazing instructor. Thank you for spending the time and energy to produce these fabulous videos that take a fairly technical subject and eloquently explain the processes in terms and diagrams that even a layman can understand.

@AdamBlock

2 жыл бұрын

That is a nice bit of kind feedback. Thank you.

This is really well put together. Many thanks.

@AdamBlock

3 жыл бұрын

Thank you!

This is probably the best explanation I have yet seen about how calibration truly work. No opinion, just the math. Thanks!

@AdamBlock

2 жыл бұрын

Thank you. I did work very hard on this... much more rigorously than other projects because I knew it had to be referential in order to be useful and far reaching.

Thanks Adam. What a totally good video. Explains the process of calibration frames and their use in the clearest explanation I have seen. The diagrams really helped getting the concept over. Time to watch the next video in the series - I have just started watching your new WBPP videos and you recommended coming back to this one first to really understand calibration frames.

@AdamBlock

Жыл бұрын

Great job in checking these out. Due to the new developements of PixInsight...I will be creating a Patreon page in order to garner support. Quality videos like these time much effort to create. I hope you will consider joining me once I launch it.

What an EXCELLENT presentation on this subject, and specifically, the steps within PI itself! I have searched KZread and the Internet over for basic answers to my issues using a DSLR as a rookie astrophotographer, and preprocessing in PI, and this answers all my questions, and explains the logic behind the steps the script takes! A millions thanks!

@AdamBlock

Жыл бұрын

As Lady Gaga would say... givin' you a Million Reasons... to become a member of AdamBlockStudios.com :)

Great! Thank you for the precise presentation!

@AdamBlock

3 жыл бұрын

Glad it was helpful!

Excellent presentation and easy to understand the concept.

@AdamBlock

3 жыл бұрын

Thank you very much. I worked hard to get across some nuances of what is otherwise a straightforward demonstration.

very helpful. thanks

Love your synopsis of Flat Darks. Doesn't hurt to use them over Bias. Thanks again for another great video!

@AdamBlock

3 жыл бұрын

YES! Thank you ... that is what I am trying to say. :)

@andyweeks2216

3 жыл бұрын

@@AdamBlock You said it perfectly!!!

Very informative and enlightening...

@AdamBlock

Жыл бұрын

Right? :) Thank you.

Great presentatiom. Thanks a lot. You might want to add that darkflats are also a remedy for problems with not so well behaved cameras, eg the ASI 294 MC Pro, even with relatively short exposures.

@AdamBlock

Жыл бұрын

Watch the next video in this series... :)

@MartinJunius

Жыл бұрын

@@AdamBlock yeah, did so, thanks. 😎

So for my SX-694 mono CCD camera I usually take 3 minute subs, I might wind up taking flats (depending on the filter) of 3 to 10 seconds. It sounds like to be exactly calibrated with my flats that I should match darks per filter as well as having a master dark of 3 minutes also. Thanks for making this video to explain WBPP 2.0. Tim

@AdamBlock

3 жыл бұрын

Darks with matched exposure times to data is certainly the safest way to go.

Great video. I'm new to astrophotography and this cleared up some fine points. Also, in seeing it described in this fashion, it makes it easier to go thru PixInsight to make sure all the files are properly entered. I'm a Adam Block Studios subscriber and the videos on there as well as KZread are all fantastic. Question: Can Flat-Darks be taken off site? Obviously, Flats have to be taken just before, during or after an imaging session to account for anomolies in the imaging light path. Since Flat-Darks are accounting for the Dark current, can theses frames be taken off site? Typically I take Master Darks at different temps and times and Bias frames at different temps, both to line up with my imaging temp and time, indoors. I usually remove the camera from the telescope and set up the sensor temperature with the sensor covered completely.

@AdamBlock

2 жыл бұрын

Yes. Darks and biases are photonless images. Doesn't matter where the sensor is- so long as the temperature is the same and there are no photons getting into the system. This where many people fall down- they think they have "covered" the sensor good enough...but light leaks happen! I always recommend taking biases and darks AT NIGHT and in complete darkness.

Wonderful, details and easy understand. Question: when take flat frame, how long should we take said 3sec or 10 sec, are they different?( Flat panel maybe abit too bright) For RGB is hard to take long exposure. For SHO sometimes over 10sec. So is it RGB we don't need flat dark??

absolutely fantastic explanation. Is there any benefit to have a master superbias? thanks

@AdamBlock

3 жыл бұрын

My opinion, no. A superbias really can be approximated with lots of biases (50?). A superbias runs the risk of oversubtracting due to the averaging a columns. This can be an issue for low-signal work like NB. You asked my opinion.... But...if you do create a superbias... add the word "master" to the file name..and it will load in WBPP correctly as a master like you expect.

Excellent video for helping people reason through to answers to common questions about calibration frames, even if they don't use WBPP or even PI. One thing your video got me thinking about, however, I can't quite reason through and that regards dark current and cooled cameras. If dark current is predictable and removed by darks, why do people bother to try to cool their camera as much as possible (often to as low -20C) to reduce the dark current? I understand using a cooled camera to keep the temperature consistent and predictable, but it seems there's no good reason to make that consistent and predictable temperature *low*. What am I missing?

@AdamBlock

3 жыл бұрын

The dark current will be higher (a different and greater rate) for higher temperatures. This comes along with more noise... there is always noise! So the smaller the contribution, the less you have to subtract..the less noise.

@neverfox

3 жыл бұрын

@@AdamBlock Thanks. But are you saying that the higher the dark current, the less success the darks will have in removing it? Or is it just a matter of not wasting valuable dynamic range?

@AdamBlock

3 жыл бұрын

@@neverfox Not exactly. Anytime you have a signal (from light or in this case electrons) the fluctuations (noise) in that signal goes up with the amplitude of the signal. This is about the random fluctuations... so a dark subtracted image taken with a warmer chip will tend to be a noisier image.

Great video. In order to cover all bases, isn't better to use bias and flat darks all the time? Or can I just use one of those two?

@AdamBlock

Жыл бұрын

So... you only need to do one or the other. In general just using biases is proper for more cameras. There are some sensors that this is not true and you need to create matched dark frames all the time. Thus..I reccommend matched darks because then you can never be wrong...but you will waste time - until you figure out that biases are just fine.

@hael8680

Жыл бұрын

@@AdamBlockThank you for responding. I use cameras with the IMX571 sensor. Do you know what is best for that sensor?

Great video but I have a question. If I am using Darks and Flat Darks, why do I need a Bias? Won't the darks already include the Bias data? It feels like the Bias will get subtracted twice.

@AdamBlock

3 жыл бұрын

Great video BUT... lol There are two reasons to use a Bias frame. You can calibrate a Flat with a Bias and you can optimize a Master Dark using a Bias. If you are doing neither of these, the bias will not be used. So in your case, if you have matching Darks for your Flats, you are not using the Bias to calibrate the Flats (unless you turn off Darks:auto). You *could* (though I do not advise this for beginners) optimize master darks for light frames.. So there is a configuration that exists that a Bias could still be used even though YOU are not doing so. Developers of this kind of tool have to make available each configuration- even if someone of them are not commonly used. Using WBPP you cannot double subtract a bias without completely ignoring all of the Warnings (or worse) it tells you. Show me a configuration that you can double subtract- and I will show you all the warnings/errors in the configuration.

@midnightlightning1

3 жыл бұрын

@@AdamBlock Thanks Adam, makes sense. Enjoying your FastTrack, will go onto Fundamentals shortly.

Fab thanks. Has made me frown though with confusion. Why would I have a >30s flat? I was always told to do flats with a light source and usually sub 1s (Canon 7D DSLR) (around 17 min time)

@AdamBlock

3 жыл бұрын

Imagers that use narrowband filters will have long flat field exposure times. EL panels are not bright in H-alpha light. By the way, subsecond flats can cause a number of other problems. Whoever is advising you may not be doing so in your best interest. Some cameras behave differently (switching modes) with subsecond exposures. Non-uniform illumination due to shutter shadows can also be an issue. Safest times to avoid almost all problems are 3-5 seconds in length at a minimum.Tturn that frown upside down.

@MasseyLee

3 жыл бұрын

@@AdamBlock I love you video - I like to understand the "why" as well as the "how" and you seem to explain it very well - I may have to sign up for your courses ! .. To my question: This is the first time I've heard anyone say that flat's shouldn't be too short. Would you mind elaborating a little ? I have some ND filter film - should I add it to my EL panel to extend the flat times ? (my current Lum/colour flats for my ZWO1600MM pro are 14ms / 39ms)

@AdamBlock

3 жыл бұрын

@@MasseyLee There are a number of "gotchas" for short flat exposures. Some CMOS sensors have switching modes for fast times. Another issue, for certain cameras, is the shutter speed may cause the sensor not to be illuminated uniformly. There is also an issue with some sensors that the electronics warm up with many fast exposures in succession... and the list goes on. What is a few more seconds to save some hairs on the head? I did exactly as you describe..and got some ND film for my own EL panel. It was surprising how many layers I needed in order to cut down the light- these sensors are sensitive!

Hi Adam. Near 1:55 you note that bias frame counts can be in the hundreds or a few thousand. When I capture bias frames with my ASI2600 and 6200 cameras I pretty much see read noise with counts of a few. What would give rise to the relatively huge counts you note (aside from large offsets)?

@AdamBlock

Жыл бұрын

CCDs and CMOS cameras have different electronics and settings. CMOS sensors in particular have offset and Gain settings you can control.

@paulsubject9003

Жыл бұрын

@@AdamBlock Interesting, thanks, I take that to mean that these high count levels are primarily an issue with CCD cameras

My CMOS camera has really heavy amp glow and I always take flat darks to match the exact time of the flats. But when I use WBPP and select use Flat Darks, it sometimes uses Bias only to calibrate the flats anyway. If not done exactly right I can get amp glow carrying through to the final light masters. Is there anyway to force WBPP to use Flat Darks instead of Bias? My only solution right now is to do the step by step Image Calibration and Integration. Thanks much for any comments :).

@AdamBlock

3 жыл бұрын

This is no longer an issue. You will be able to see exactly which files are being used before you press RUN. Please see the next section kzread.info/dash/bejne/ia550tugdqrIfpM.html . And there is also an example section as well! (keep going!)

@johnadastra1754

3 жыл бұрын

Thanks Adam! I just updated PixInsight but have not yet used the new Control Panel in WBPP. I will give it a try!

@dances_with_drones

3 жыл бұрын

I don't know what camera you are using but my Canon T5i has terrible amp glow when live view is on. I use live view to find and focus then turn it off when capturing data. Very little amp glow.

Adam, here's what I don't get about raw light frame calibration (WBPP episode 3, 20:35), please explain to me if I have this wrong: When the master dark is subtracted from the raw light frame, then doesn't the read noise on the light frame which has a gaussian distribution, get its lower half chopped off at zero? In other words, let's say my camera is set to have an offset of 100 counts with zero photons coming into it to make sure no statistical (think gaussian curve) signal is getting chopped off at zero. That results in the master dark frame histogram being shifted up from zero to 100. Great so far. Now then, during calibration, the uncalibrated light frame which also has gaussian read noise, has the Master dark subtracted from it. Seems to me this is going to result in half of the light frame read noise being eliminated (falsely)! I do not see how the math hangs together: - if people shift the camera offset up (to make sure they get all the low end sensitivity) and then it gets the offset (bias) subtracted, then what benefit does that have.?

@AdamBlock

Жыл бұрын

When you take a picture of the sky- there is a natural offset (a bias level in terms of signal). So during calibration, no values go negative. I think you will agree with this? Read noise is smaller than the natural sky bias. BUT... I know you are already going to complain- what if your sky is very dark. This is exactly what happens with Narrowband imagery. The sky is so dark that when you subtract you calibration frame- you *can* can negative values. So... you add a pedestal value (please see the video on this... later in this series). What happens is that in memory at calibration time, you DO HAVE NEGATIVE VALUES. But this is before the image is "created"... these are just numbers. And then the pedestal is added to this oversubtracted result so that no negative values remain. The pedestal is only added internally during the math process. I think this answers your question... but I am usually wrong and you can let me know. :)

@davedepagnier8601

Жыл бұрын

@@AdamBlock Great explanation. Thanks!

Hello! I have a doubt, yesterday I did a section at -10C° and yesterday I didn't realize that the temperature of the camera was at -5C°, is there a way to calibrate those darks to be able to integrate the two nights, the lights are with the same parameters and understanding that flats and darkflats are not affected. I await your response thank you very much.

@AdamBlock

4 ай бұрын

You can use this dark of a different temperature. It will not calibrate as well as one taken at the same temperature. There is an additional option, you can *try* to use the optimize dark...it might help as well. It might be better just to take some darks at -5C when you get a chance.

@alejandrohenriquez7316

4 ай бұрын

@@AdamBlock Thanks so much!

@alejandrohenriquez7316

4 ай бұрын

Hello! You know I stacked it in multi section with DSS and it generated a lot of color noise, but I'll do it again with the Pix. I'm not that expert in this hobby. Thanks again.

I know this is an older video, but why do you state Flat frames could have an exposure of 30 or more seconds? Seems everyone is preaching Flat frames should be just 3-4 seconds tops. HAs something changed since this video has come out?

@AdamBlock

2 ай бұрын

Nothing has changed. There is nothing wrong with longer exposures to achieve a particular light level. Narrowband filters sometimes require this- especially red ones since EL panels (for example) do not emit much red light. The point I was making is that the dark current is very low in exposures of even 30 seconds or more for many cameras. If this is the case, then you can just use a bias to calibrate for any time... even as "long" as 30 seconds.

@yervantparnagian5999

2 ай бұрын

Thank you Adam for the reply and all you do for the Astro community