Thats great, well explained my ASI294MC various amp glove, not bias only flat dark. Questions: after calibration light still got some red ring visible, specific when due band or narrow band. Any idea to calibrate it?

so I am right in thinking that whether you need to use bias frames or darkflats just depends on which sensor you have? I have the IMX571, so what calibration frames would I need for that? Biases or darkflats (currently I shoot both!)

Great video series so far, thanks for taking the time to explain it. I have a question which you may or may not have answered in one of the remaining videos in this series. During manual stacking I like to use SubframeSelector and Blink to filter out bad subs based on eccentricity and/or FWHM of stars. Does the WBPP 2.0 script include this type of feature or should I screen the subs before using WBPP?

@AdamBlock

3 жыл бұрын

Yes, you should screen your subframes before WBPP. This script is a form of automation that works best with data that is self-similar. Although it has been hardened against some forms of failure (weighting, registration... etc) by skipping offending frames- it can't avoid nonsensical output in all cases- so don't give it nonsense to begin with and it will work just fine!

@IcedReaver

3 жыл бұрын

@@AdamBlock Thanks for the prompt response. As a newbie, so far I have been following the manual stacking approach laid out by Kayron Mercieca (Light Vortex Astronomy). The tutorial said to use subframe selector between cosmetic correction and registering subs for the purpose of applying weights and for defining acceptance criteria for subs (like I said, eccentricity, FWHM etc). With my OSC camera and WBPP 2.0 in mind, when is the opportune time to use subframe selector in my work flow if I decide to use the script? I didn't think subframe selector worked on non-debayered images.

@AdamBlock

3 жыл бұрын

There are errors in that (calibration) procedure that cause "newbies" all kinds of problems.

@IcedReaver

3 жыл бұрын

@@AdamBlock Understood! I'll continue watching the rest of this series and will compare the differences to the procedure I've been following until now.

@AdamBlock

3 жыл бұрын

@@IcedReaver I have some tutorials on my site that explain the manual method and where the issues are. In particular, Kayron instructs you to create bias subtracted master darks. *THIS* causes all kinds of issues. These are called thermal frames and are used to scale darks for calibration purposes...but this comes with caveats AND many CMOS sensors do not permit this kind of thing due to their electronic signature.

Adam, thank you. This is interesting. So by going this tutorial, is it fair to say that with the newer CMOS sensors that don't have any amp glow (IMX455, IMX571, etc.) we can follow a more traditional CCD-styled workflow of using bias calibrations, whilst for the older/legacy CMOSes (like the 1600 or 294) that suffered with amp glow, that they leverage on the flat-dark approach? Are there any repercussions in using the flat-dark approach on the newer "amp glow'"-free CMOS sensors?

@AdamBlock

3 жыл бұрын

Hmm... that isn't quite what I said. :) I would say you can always match dark frames for all sensors and not have an issue. So that is why I so strongly recommend it. Even without an amp-glow I do not assume that a sensor doesn't have a variable bias (electronic signature). In fact, I have evidence of some sensors that change their signatures (no amp glow) on short timescales (a few weeks). But, I do think you are right that the most egregious examples do have the amp glow. So I don't trust any sensor until it is determined to be "stable." Once that happens... then taking advantage of what a bias provides is great (calibrating a range of flat exposures and dark frame optimization).

@markmuratore413

3 жыл бұрын

@@AdamBlock If I can follow up...I have the 294MC Pro which has amp glow. I have also read the this particular sensor does not do well with bias frames and most users of this sensor do not use bias frames but instead use flat-darks. Just so I understand what you are saying, as long as I match my lights to my darks and flats to flat-darks, I don't need bias frames? Am I correct? Thank you. Great videos by the way! Thanks for doing them.

@AdamBlock

3 жыл бұрын

@@markmuratore413 Yes, I agree. AND... unfortunately, you cannot take advantage of the bias benefits (including dark frame optimization)...so do not do this as well.

@markmuratore413

3 жыл бұрын

@@AdamBlock Thank you. It's all starting to make sense.

Hi Adam. I'm just taking your Fundamentals course and it's excellent so thank you. Loved the FastTrack course as well. Maybe I missed it but I'm using the 294MM so I take flat and flat dark frames. I know where to load the Flat frames in WBPP. Do I load the FlatDark frames in with the Dark frames and exclude the Bias frames al together? I probably missed this point in one of your WBPP videos. Thanks!

@AdamBlock

2 жыл бұрын

Yes sir! That sounds right to me.

@AstroVagabond

2 жыл бұрын

@@AdamBlock%22%22 Thank you for the quick reply Adam. Much appreciated and keep up the excellent work.

Is the MasterDark file that is saved off by WBPP calibrated? i.e. If I were to reuse that MasterDark in the ImageCalibration process and use dark-frame optimization in that process would I need to leave the Calibrate option unchecked (while the Optimize option is checked)?

@AdamBlock

2 жыл бұрын

The MasterDark that WBPP creates is NOT calibrated (it contains the bias). I suggest that if you want to manually calibrate- you keep the bias in the dark as well. The *only* reason to calibrate the dark when doing manual calibration is to take advantage of optimization (and you should know what you doing... i.e. have very good reason to do this). So if you are doing optimization you *do* calibrate the dark... and then you need to subtract both the scaled thermal frame and the bias from the light frame.

At approx. 12:15 in the video, a master flat-dark is shown in the calibration diagram as being applied to the flats. But if you look at the Flat section of the control panel, there is no check mark showing a dark is being applied. When darks are applied to lights, the control panel shows the check mark, consistent with the calibration diagram. Maybe an error in the script?

@AdamBlock

2 жыл бұрын

No...the script is fine. I shouldn't have shown masters calibration frames (I should have had the raws loaded). The Flat section should NOT have a check mark showing the dark is being applied because it is a MASTER FLAT! Master flats are already calibrated images. They can be used as is. My screen captures (taken with raw files loaded) to not reflect have masters loaded. A bit of a non-sequitur on my part.

@mikei.6294

2 жыл бұрын

@@AdamBlock Thanks Adam. Mike

I have read that if you use dithering for your lights, you don't need to use darks... but I'm confused about the impact on flats correction without the darks or bias frames.

@AdamBlock

Жыл бұрын

Usually in these instances... the bar to reach the level where darks are not "needed" (I am suspicious) is so high that it isn't reasonable and serves only to increase the misery of others.

@dr7615

Жыл бұрын

@@AdamBlock What if I took some darks and bias with the same temp on the sensor setting and the same gain, could I add them successfully to the existing calibration session? Although, since then I have cleaned the dust from the sensor cover filter. I spent hours trying different levels of flats. I use a light board with several layers of white paper and fogged plexiglass mounted on the front of my OTA, taking flats after each filtered 'lights' capture. Using the histogram in SharpCap, I have swung from 25% incrementing to 60% and none of the flats worked... 😟

@AdamBlock

Жыл бұрын

@@dr7615 the light level of the flats is the least important part of making them work. Typically a calibration error or scattered light are sources of flat errors.

Ok, I am somewhat confused here. First my camera is an ASI533MC and it has no amp glow so it seems to me from viewing your video on this that I should not have to use dark flats. Yet in numerous posts I find users of this camera quoting from this video that they use dark flats. Then in one reply to a comment in this video you say some amp glow free cameras can change over a period of weeks and you seem to be recommending agains using bias frames without dark flats. To make it simple, if I take bias frames in all my sessions with this camera do I need to worry about not having dark flats? Are my processed photos going to be of lesser quality not using dark flats? Thanks I find your videos to be quite instructive, but this issue has me quite confused.

@AdamBlock

2 жыл бұрын

Hi Jim- Did you watch the video previous to this one? (part 1). In order to understand what I am saying- you need to answer the following question,- What is the difference between a dark frame used to calibrate flat field images and a bias frame? Your question above implies they are always DIFFERENT things. You need to understand when they are the SAME thing. A bias frame is effectively a super short dark frame that contains only the bias level and fixed electronic signature. A dark frame, being longer than a bias, will contain some dark current. But appreciable dark current only occurs after many seconds (perhaps as much as 30 seconds or more) for many cameras. So you have to agree with me...here a dark frame of between 1-30 seconds is the same as a bias. This is the case for your camera- and I am clearly indicating you should use a Bias frame to calibrate your flats (which are shorter than 30 seconds in length). But Jim- are you certain your camera doesn't have an amp glow or any other kind of electronic signature? Perhaps NOW you are.. but many people don't know! If the camera has amp glow or other issues- you need to take matching dark frames to calibrate the flats. This is a minority of cameras. Can you see it now? I recommend to everyone to start by taking matching darks for flats since even if it is unnecessary in the first case above it DOES NO HARM since I just proved that a bias and a short dark are the SAME. Then these people learn... oh...look at that I can just take a bias. But if I made the other recommendation, to use biases in general- ALL of the people with these goofy sensors that need matched darks for flats will have an issue and I will look bad. So I say take matched darks until you understand you do not need to if you have a well=behaved sensor. Same sensors change (or users change software or gain/offset and screw themselves)... this is a different issue.

Does it matter if I check evaluate noise when integrating darks files?

@AdamBlock

Жыл бұрын

It is not required to do this calculation - it is for informational purposes so that you can compare integrations of the same data with different settings (rejection, weighting...etc). There isn't much overhead in the calculation though..it only takes a few seconds.

@Ben_Stewart

Жыл бұрын

@@AdamBlock Thanks Adam.

Kind of useless. An actual set of different exmple cases would be 100% better !

@AdamBlock

3 ай бұрын

I understand this is a critique... but I do not understand what the criticism is?

@Nick-we7lf

3 ай бұрын

@@AdamBlock You should run some actual examples of data. As someone who is an educator, the problem with theory is that many of the details remain unanswered. WBPP is not very forgiving when certain things don’t lineup. There doesn’t seem to be anyone capable of explaining these details. So this is not a criticism only of your presentation but in general, no one has a video or sets of videos that go over various examples in detail to show what happens if things work correctly and what happens when things don’t work correctly and explain why.

@AdamBlock

3 ай бұрын

@@Nick-we7lf I am quite capable of explaining. As you know, I do exactly this with examples and explain WHY at AdamBlockStudios.com . This is the free stuff here on KZread. Note, no other content creator- not even the developers- went to this degree of effort for free. And, based on your answer, I do not believe you have watched my entire KZread series on this. I certainly do give some examples especially in areas where there is some confusion. On a final note, as an educator, you will know that the more specific the lesson- the easier it is to become out-dated with changes in software or method. What you decry as too overly general is what has permitted this solid information to continue to be valid for years.

@Nick-we7lf

3 ай бұрын

@@AdamBlock Oh ! Now i got it. You want money for that. Sorry. I now realize you are a Car Salesman. 😒

@AdamBlock

3 ай бұрын

@@Nick-we7lf I would put some money you are from England or Europe where there is an expectation of "free knowledge" or some variation of that culture. The WBPP video you watched took a heck of a lot of time to create. I gave you value. I gave you more value on this topic then any other content creator. Not enough you say! Plenty of Monty Python skits with the right kinds of insults applicable to you. Give them a watch. :)