A Brief Introduction

ASIDeepStack is a deep sky stacking software (only supports 16-bit fits files for now). It offers many capabilities, including image preview, stack, histogram stretching and much more. It can process various types of files such as lights, darks, flats, bias, etc. and accordingly, after stack it will also improve the image signal-to-noise ratio (SNR).


How Does It Look Like?

ASIDeepStack interface1

ASIDeepStack interface2

Area A: Setting Bar. Including settings and help.

Area B: File List Area. Including Bias, Flat, Dark, Light four tabs, empty current tab button and so on.

Area C: Stack Area. Including open save path, start stacking, and switch single/stacked display.

Area D: Histogram Setting Area

Area E: Full-screen Button

Area F: Vertical Tool Bar

Area G: Capture Display Area

Area H: Status Bar. It shows current display image info and loading progress.

Area I: Image Processing Area

A Guide On How to Stack files

① Open ASIDeepStack. Let’s start stacking with lights files, so click the “Light” tab in File List Area (Area B).

② Click the ”Select Light” button, then select the Light files that need to be stacked in the pop-up dialog.

③ The files will be imported after you choose. You can watch the progress bar at the lower right corner of Status Bar (Area H). When the importing is finished, “Load Completed” will be prompted.

Select Light

The start stacking button in Stack Area (Area C) is now available. You can click the play icon to draw forth the stack window and then start stacking, but let’s just wait for a second.

④ If you need to re-select the Light files, you can click the sweep icon in the top right corner to remove all files under the current tab.

⑤ Import other calibration frames (darks, bias, flats).

Select Dark&Flat&Bias

⑥ When done importing all calibration frames, now you are free to start stacking. As mentioned in ③, a stacking window will pop up. After you complete stacking all files, it will automatically close and then show you the stacked image.



⑦ The main adjustment options in the “Image Processing” module are brightness, contrast and saturation. You can also stretch the upper “histogram” to further process the displayed image. When processing, if you think the result is over-processed, then you can click the “Reset” button to restart.

For beginners, we recommend you use “Auto”. For advanced astrophotography enthusiasts, you can adjust the brightness, contrast and saturation by yourselves. If the image still has much noise after processing, we recommend you check “Noise Reduction”. This would help.

When all work is done, don’t forget to save the image. The next step is about how to save it.

Image Processing


⑧ Click the setting button in Area A to set the file save path.

Save Path Set


Click the save button in Area F to save. By default, jpg and FIT format files are saved in the set path.

The saved path will also be displayed in the lower left corner of the software.

Image Saved

Click the folder button in Area C to find the image file just saved.

Here is the comparison before and after stacking:

Before Stacking

After Stacking

39 Responses to ASIDeepStack: What is it and how to use it to stack files for astrophotography
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    Comment Hi, I have problems using that application and I find a black image without any image. The data were taken with a 533MC Pro. I use the last version


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    I used the 1st time ASIDeepStack. I tried to load a light fits file which has been created by ASILive previously. However, ASIDeepStack reports an error: “Only support single channel”. My questions are:
    a) How can I configure ASILive to produce a fits file which is supported by ASIDeepStack
    b) What is the number of channels actually refering to?

    Thanks for any advice.


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    PLEASE release a version of this for the IPad Pro! The new M2 version should be able to handle this.


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    i tried to stack images from my asi585mc, and it just completely goes black, it doesn’t pick up on the images, it ignores them all. how do i fix this?


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    I’m trying to stack planetary images and keep getting the message “Not enough stars” for most of the images when stacking. Is there different software for planetary images or some other fix?


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    Just updated to ASIStudio v1.6 (on a Mac). Every time I try to stack a set of images, I just get a black screen. The bottom left of the screen says “0 stacked, 10 ignored”. The last version worked great and I’ve never seen this issue. Are there known issues?


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    The software currently only supports one-shot color pictures, correct. Have not found a way to process lrgb picture sets. Can you confirm?



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    I noticed that when I add Flats and Lights then click stack the software prompts for Bias, I can make them I know but if I do will the software then prompt me for Darks to? I was expecting the software to ignore the Bias and Darks if left empty but apparently not?


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    DeepSkyStack will only stack a single image. Says not enough stars and does not stack frames. Visually there are plenty of stars when in auto mode on the histogram (and in the files when open in FitsView). If I select reset on the histogram most of the stars disappear.


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    I am having the same problem as other users, I can open deepstack and load light frames. When I hit the begin stacks arrow, it begins stacking and then the program closes abruptly at 33% complete. I am using the latest release. Please hlep


  11. Avatar

    Hi, I am encountering issues stacking 800 fits. The program seems to load everything into primary memory for some reason and then crashes when it hit the limits of memory. Please utilize the secondary memory for caching or intermediate state storage. Why would you implement the stacking system purely using the primary memory?


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    I am using an ASI533MC and ASIDeepStack 1.5.5 on a Mac. It works very well. The default for saving the stacked file is .jpg. But the size of the file is rather small (less than 1 MB) so I assume it is compressed (?). Can I change the format and amount of compression for the saved file? In particular, can I change the format to .tif?


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    Is ASIDeepStack capable of stacking bin2 frames (e.g., RGB frames taken in bin2) to a bin1 (e.g., Lum frames) reference frame and perform upscaling like DeekSkyStacker?


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    Can’t find a link or place where to download the software.
    Please send me a link
    Thank sounding advance


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    I have the Problem, that bright stars are getting strange points and lines in the middle of them after stacking.
    The single exposures ar looking fine.
    The camera is a ASI2600MC-Pro.


  16. Avatar

    You say it only supports 16bit files. Does that mean it does not yet support lower bit files from 14bit cameras? This might affect my choice of new camera.


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    I can open deepstack and load light frames. When I hit the begin stacks arrow, it begins stacking and then the program closes abruptly at 33% complete. I am using the latest release. Also, Windows 10 is up to date with zero missing or corrupt files. What are the minimum hardware requirements? I.e. ram, processor speed, etc. what am I doing wrong. I really want this to work! Much invested in Zwo products. Than you! James


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    When it comes to stacking; it does stack the files but there’s no options for any type of quality control. It just stacks what you put in, unlike DSS which registers each file first and you can choose the quality of the subs you want to use. There is a noise reduction tick box, but this is an automatic setting and I’m not sure what it does because there was still noise on the completed image, as well as satellite trails. My conclusion from trying it; Handy to have but I won’t be using it as a replacement for DSS in it’s current form.


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      We have all adopted the form of automation. Users can do stacking without selecting any parameters. As for the option of image quality control, in fact, it is also made in the software. Bad images will be automatically eliminated.


  19. Avatar

    A couple of questions:

    If I want to export the raw staked image, am I right in thinking that I have to press reset on the histogram? What about contrast and brightness, should I zero them also?

    I’m new to astrophotography so have only just recently started stacking images but the initial results look surprisingly good. I took some dark frames with ASIAir and added them into the stack but they appeared to make no difference. Could this be because there is no noise in the Light frames? Looking at the darks I can see quite a bit of amp glow but I guess this is at a low level which is being amplified by viewer. The camera is ASI294MC-Pro.

    Overall this is an easy application to use and produces good results – I think!





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