When dark frames or bias frames are applied during a live stack, the picture is highlighted in red.
If you don't do pre-processing, the red, green, and blue channels will naturally blend into natural colors. However, applying dark or bias frames to improve the quality of the image highlights the red channel. Is there any way to solve this problem?

I experimented with LPRO filter and UV/IR cut filter, but all of them have the same problem.
Is this a problem with the stack algorithms?

I ran it with 533mc pro camera and asi 2.0 application.

I found an article written by someone who has experienced similar problems with me before here.
Unfortunately, he's using the same camera as me.

https://bbs.astronomy-imaging-camera.com/d/14111-red-tinted-images-with-asi533-asiair-pro/9


(not subtrackt Dark, Bias)


(subtracked Dark, Bias)

    LovelyNights Forward to the team. Cloud you share your Lights (two frames would be ok) and the calibration frames thru Google Drive?

      @ASIAIR@ZWO#60352 Unfortunately, all I have now is the original stacked file. I deleted the calibration files while organizing them. In the near future, I will shoot again to solve this problem and provide you with the file. Even so, please check this problem on zwo even if my file is not provided. I think red channels are highlighted when processing dark frames and bias frames. Or this could be a setup problem only for 533mc pro.

      @ASIAIR@ZWO#60352 I found a video with a similar histogram on the YouTube QUIV channel. He also used 533mc pro, and the histogram of the image shows that only the red channel is acting separately.
      https://youtu.be/kTdlJebOnXk?t=787


      I'm not 100% sure that this case is the same as mine, but this histogram shape is similar to what I saw and it's similar to the picture that was posted by a user who had the same experience before.

        @ASIAIR@ZWO#60356 Here's the test of tonight.
        Shooted VEGA as It's one of the most famous BULE STAR.


        (This is a stacked image Light only)


        (This is a stacked image with a Master Dark)

        as you can see above, If you subtract a master dark, the stacked image has red tint.
        I provide the original file for your team's analysis. Please go to the link below and download the files.

        https://drive.google.com/drive/folders/1dY47T4hWPyWgLiKUeYb1IisyKJmg0u7t?usp=sharing

          @ASIAIR@ZWO#60356

          I've tried this out many times to find out.
          The results are as shown below.

          1. When applying the master dark made by ASI AIR or ASISTUDIO, the picture turns red. Even if it is a blue star, it turns red.

          2. If the master dark made by SHARP CAP is moved to AIR and applied, the color is natural.


          (MasterDark taken by ASI AIR)


          (Master Dark taken by SHARP CAP)

          I have attached RAW files for your review below. Please visit and analyze it.

          In my opinion, the master dark that you make seems to cause something to malfunction in the case of the 533MC PRO. This may be a problem with the AIR program or at the firmware level of the 533MC.
          I'm tired of experimenting with this. I just hope that you will identify the cause and resolve it as soon as possible.

          https://drive.google.com/drive/folders/1dY47T4hWPyWgLiKUeYb1IisyKJmg0u7t?usp=sharing

          P.S : Because I want to do EAA by performing full calibration on the field. Using the dark taken by SHARP CAP, the correction is not properly achieved when applying FALT and BIAS. This is probably due to something else I don't know about image processing. But if I use the darks from the AIR, the correction is done properly, but I have to see the red distorted image.

          • w7ay replied to this.

            I have not done any recent darks for my ASI533MC. Still using older ones but I need to make some new ones. The red tint does not show with the older darks using v1 ASIAIR software and v9 firmware. It looks like I need to sit on installing v2/10 until this is fixed.

            JohnD

            LovelyNights The results are as shown below.

            I am curious... since you have two sets of master dark frames, what if you process the data by using one of the master dark as the "light" frame, and using the other master dark as the "dark" frame?

            There is something very suspicious with the ZWO master darks. With Vega, the histograms of the three components track one another quite well using the SharpCap master dark, as one would expect. But look at the red channel histogram-- but there are some extraneous bumps in the red histogram with the ZWO darks, in addition to overall larger red response everywhere. It would be interesting to see what the dark frames them selves look by comparing them (using one as light frame and the other one as dark frame).

            Q: I take it the two sets of dark frames are taken under the same exact conditions right? I.e., no chance that there is some extra light leak in the IR side of of the spectrum when taking the ZWO dark frames versus when you took the dark frames using SharpCap?

            Chen

                w7ay
                The probability that the IR channel has affected is 0. Because if I make a dark in the field, make a dark in the drawer of the house, or use ASI's dark, the red channel is unconditionally emphasized. (All AIR/ASISTIDIO are the same)

                I made a lot of dark frames and experimented with them. They all got the same results.
                I think 533MC feels something is wrong when it relates to the ASI program in its hardware setting

                  @ASIAIR@ZWO#60356 What would also be helpful is with live stacking to have the ability to change the red and blue channels like you can in Video mode and not just rely on auto white balance.

                  Is it possible to add a mid tone slider to the histogram?
                  I used livestack for test and the result wasn’t great but then I opened the fit it created and just a stretch and green removal with pi
                  and the result was good

                  2 months later
                  2 months later
                  2 years later

                  Hello. I know this is a old thread... but in my system is happening the same problem.
                  Live stacking using dark library I did with Asiair results in very reddish images.
                  Asiair Mini updated to the last version, iOS app updated to the last version, ASI533MC as the camera.
                  Has this nasty problem ever been solved? How?
                  Thanks...

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