Full well depth for dslr?

DSLR Acquisition Deep Sky Help Needed
4 replies•220 views
Menelaos avatar
Menelaos avatar
Hi guys
So i’ve been looking around and i couldn’t find any information about the full well depth of my dslr camera (canon 250D).
I started thinking about this because the stars in my images are always white in the centre and they have colour around them so i thought maybe the pixels are saturated. I assume this is the reason? Anywhere i can find info about this? 
thank you.
Shopaholic avatar
Shopaholic avatar
https://www.lightvortexastronomy.com/measuring-your-camera-sensor-parameters-automatically-with-pixinsight.html

i think there’s a script in Pixinsight. Check this out
Wei-Hao Wang avatar
Wei-Hao Wang avatar
https://www.photonstophotos.net/Charts/Sensor_Characteristics.htm

250D is not listed.  But you can look at the data for other similar cameras, like 200D, 300D, 350D, etc.  It won't be difficult to guess.

The situation you described could be saturation, or just a consequence of your processing workflow.  It's hard to tell just based on your description.
Arun H avatar
Arun H avatar
Wei-Hao sent you a great link that I have used many times. Apart from Full Well Depth, Bill Claff's site has a wealth of information on noise and dynamic range.

Your available full well depth will depend on ISO. Each doubling of ISO will halve the available full well depth.
Well written Concise
Björn Arnold avatar
Björn Arnold avatar
Hi guys
So i’ve been looking around and i couldn’t find any information about the full well depth of my dslr camera (canon 250D).
I started thinking about this because the stars in my images are always white in the centre and they have colour around them so i thought maybe the pixels are saturated. I assume this is the reason? Anywhere i can find info about this? 
thank you.

Hi,

I am using this camera as well. The brightest stars usually saturate with sufficiently long exposure times. I don’t know if you refer to those only or fainter stars as well.
For completeness sake: are they saturated already on the light frames or after integration?

If you could provide some more detail on your imaging settings, we could provide more detailed advice.

Björn
Well written Respectful Concise