DSLR Mod and white balance

[mackiedlm]

One of my Canon EOS1100Ds is of for Modification (Cut IR Removal) and I've been reading up about how to do Custom White Balance on it when it is back.

Everything I've read says to take the CWB image "under a clear noon sky". Where I am in the West of Ireland "clear noon sky's" are a bit like hens teeth. Particularly in October. Even less common than the "moonless clear night sky".

So I'm wondering if setting up the pic with the 18% grey card under a daylight lamp would be effective. Anyone with any experience of this?

Thanks

 

David

[WanderingEye]

Whatever you do take the image with the grey card outdoors on a bright day, with the sun behind you, don’t use any sort of false light...if no sun then Even on a cloudy day outside is better than a false light...

Also if you use any sort of filter for LP and plan on using the white balance for astro images, then make sure the filter is in the camera when you shoot the white balance image.. 

I personally find the astronomik CLS filter superb as it was designed for use with a modded DSLR and so it corrects the WB really well without using a custom WB with you images...

 

 

Edited October 10, 2019 by WanderingEye

[michael8554]

Are you applying a CWB so that you can shoot daytime?

Then take the CWB on the day with your grey card under whatever passes for light on your subject.

But be aware that your Canon Autofocus won't be correct because of the missing filter.

If you're shooting DSOs in RAW then you usually have a choice when processing whether to apply the CWB or not.

Whatever CWB you choose will be a compromise, so you will probably have to adjust levels during processing to suit your taste.

So I don't believe a CWB makes any difference to the finished processed image.

Michael

[almcl]

12 minutes ago, michael8554 said:

But be aware that your Canon Autofocus won't be correct because of the missing filter.

Not necessarily so.

If it's one of Juan Fieros's modifications it will still autofocus because Juan re-shims the sensor to achieve this.  

(Halfway down the page here: https://www.cheapastrophotography.com)

[michael8554]

17 minutes ago, almcl said:

Juan re-shims the sensor

Yes, most of the modders (and myself) do that so I should have qualified my warning with that.

Michael