Settings for ASI183MC?

[AstroViking (Steve)]

Hi again,

Another interesting 'quirk' of the '183MC-Pro is the default (in camera) white balance settings.

There are 2 settings - WB_R and WB_B, which default to 52 and 95, respectively. WB_R is the RED balance, whilst WB_B is the BLUE balance.

With the default values in place, can anyone guess why all my images had a massive blue tint to them?

I've since dropped the WB_B value to 50, and the images look a lot, lot better. I saw a forum post that gave some reasonable values for WB_R and WB_B which I will post below.

Of course, your software may be over-riding this setting, so if you are not getting horrible blue images, then you can ignore this update!

Cheers,
V

The reason for this question is info I found in 'Bernd Landmann: Guide to Preprocessing of Raw Data with PixInsight (revised on September 18, 2022)':

If you use an OSC camera of make ZWO, caution is advised when the 'native' camera driver is used: the ZWO Software Development Kit (SDK) enables the user in the image acquisition software to control settings that influence the white balance of a displayed color image. This is achieved by two parameters, WB_R and WB_B, data range 1 to 100, the default values are WB_R = 52 and WB_B = 95. The intensities of the red channel will be multiplied by WB_R/50 and the intensities of the blue channel by WB_B/50. Unfortunately the results of this multiplication are also written to disk in the FITS file. So it is important to set the values of both parameters to 50 and subsequently apply 'Save Config'; only in this way, the real raw intensities will be saved to disk in the FITS files, see [5]. Since the data coming from the camera are saved in FITS files which usually have the data format '16-bit integer', otherwise rounding errors and clipping of high values will arise. Such a complication is generally avoided when the ASCOM camera driver is used instead of the 'native' camera driver.

[Drac0 (Mark)]

Interesting. So with OSC either change the settings to bring it back to about a 1:1:1 RGB ratio, or use the ASCOM driver. Will have to remember that if I get an OSC, which is still a possibility later.

Thanks Steve for the info.

[Crater101 (Warren)]

Originally Posted by AstroViking

Hi again,

Another interesting 'quirk' of the '183MC-Pro is the default (in camera) white balance settings.

There are 2 settings - WB_R and WB_B, which default to 52 and 95, respectively. WB_R is the RED balance, whilst WB_B is the BLUE balance.

With the default values in place, can anyone guess why all my images had a massive blue tint to them?

I've since dropped the WB_B value to 50, and the images look a lot, lot better. I saw a forum post that gave some reasonable values for WB_R and WB_B which I will post below.

Of course, your software may be over-riding this setting, so if you are not getting horrible blue images, then you can ignore this update!

Cheers,
V

You know, after years of owning digital cameras and getting used to their varying oddities, it never occurred to me to check the white balance settings on the 183MC. Thank You for the jog to my obviously useless brain. At this rate I'll be able to post something that doesn't look like something from a kindergarten painting class shortly!

[AstroViking (Steve)]

Mark and Warren - you're very welcome! I'm glad I could help in some small way.

[ZL4PLM (Simon)]

Originally Posted by AstroViking

Hi all,



2) How do I take bias frames? What are the recommended camera settings for taking flats?

3) Is there anything I can do to get rid of the vignetting? I had to crop the outer quarters off the image, and even then corners were still a lot darker than the centre.

4) How much different will my post-processing workflow be when compared to the DSLR? I am using SiriL to stack and do the base processing, then Affinity Photo for the 'beautification' steps.

Many thanks!
V

You should def watch this

https://youtu.be/nl_LQDmkg2o

the comments here are relevant for the 183 as much as the 1600/183/294 etc

anything with amp glow this process will help with

thanks

Simon

[SB (Chris)]

Originally Posted by ZL4PLM

You should def watch this

https://youtu.be/nl_LQDmkg2o

the comments here are relevant for the 183 as much as the 1600/183/294 etc

anything with amp glow this process will help with

thanks

Simon

Hi Simon,
Thanks for drawing attention to this video. Very helpful.

Chris

[ZL4PLM (Simon)]

no problem- hope it helps

thanks
Simon

[Drac0 (Mark)]

Originally Posted by ZL4PLM

no problem- hope it helps

thanks
Simon

Good video & the CN post is an interesting read - especially interesting to me was the idea of putting a short exposure between long exposures when doing darks. Got me wondering now whether that would also make a difference with normal imaging, not just darks, the write up seems to suggest it does...

Cheers,
Mark

[AstroViking (Steve)]

Hi Simon,

Thanks very much for the link to the video. Aside from the "keep your exposures over 3 seconds", most of your tips/suggestions I am already doing. Moving from bias to dark-flats was a major improvement.

I just need to get a proper light source for taking the flats now.

Cheers,
V

Originally Posted by ZL4PLM

You should def watch this
https://youtu.be/nl_LQDmkg2o
the comments here are relevant for the 183 as much as the 1600/183/294 etc
anything with amp glow this process will help with
thanks
Simon

[ZL4PLM (Simon)]

The flat panel is a must - It's been one of the most used items in my kit - I use it so often for my own gear and testing others. It's a def need to have IMHO