White balance settings for ASI224MC

tulloch

Hi there, I have been using an ASI224MC for a few months now to image the planets and it’s working really well, thank you for developing this product. One thing I’ve noticed while imaging is that I need to make significant changes to the colour balance after capturing and stacking the frames, in particular the raw images come out too green. I am using FireCapture to take the images and use the recommended white balance settings of Wred=52 and Wblue =95, but I always need to increase the blue and red levels and decrease the green level in order to make the final images “correct”.

You can see the effect in my posting on the Cloudy Nights website below for examples.

https://www.cloudynights.com/topic/685348-colour-correction-settings-for-asi224mc/

Christophe Pellier recommends setting the Wblue value to 99 (the maximum) and even then it’s not high enough.

https://www.planetary-astronomy-and-imaging.com/wp-content/uploads/2019/02/Planetary-imaging-with-a-colour-camera.pdf

I spoke with Torsten who writes the FireCapture program and he is unable to program a Wblue value higher than 99 since the ZWO SDK does not allow for values greater than 99. So to get to the point (finally);

Can you please create a new SDK file for the ZWO cameras where the maximum Wred and Wblue values are (say) 150?

This way I can set a better white balance for the camera straight out of the box, without having to rely on modifying the colour settings after capturing.

Thanks for your consideration in this matter.

Andrew

chad

Hi Andrew,

Sorry, we can not.

First, as we know, what our SDK provides is a general method. So for the white balance, when you set to the max, the pixel value will be doubled to the original value, otherwise the minimum value will be only half. It is enough for most of the applications.

Second, although this operation seems simple, it is actually closely related to our entire architecture. So it is not an easy job to change it.

Third, I think it should be easy to do it in the applications than SDK, You just need to capture the original data, then proceed it according to your needs.

Thanks

Chad

tulloch

Hi Chad, thanks for your reply.

It is a shame that the maximum setting cannot be (say) tripled instead of doubled, as this would enable us to set a more accurate white balance directly from the ASI224MC.

While this correction is relatively easy to apply in an application like FireCapture that uses the SDK, this would most likely introduce performance issues that would degrade the maximum capture rate which is a key feature of these cameras.

Thanks again,

Andrew

tulloch

The easiest way (I believe) to implement this would be a simple option to choose whether the multiple was 2 (giving min value of 0.5 and max of 2.0 which is the current setup) or 3 (giving a min value of 0.3333 and a max value of 3.0).

Just a suggestion

Thanks,

Andrew

chad

Hi Andrew，

If this operation is execuated in the application, it will not affect the camera, so the max framerate will not be reduced.

And for us, the resources are limited, so only the basic service can be provided. White balance is among them.

Hope you can understand.

Thanks

Chad