Class 1 vs Class 2 16200

[matlud]

Hi,

Im about to order a KAF16200 before they are all gone rather than waiting for an APS-c mono CMOS. I have read a few various forums about whether class 1 sensors are worth the extra cost over class 2. Just wondering if anyone had an up to date perspective on this - do class 2 sensors develop more defects over time than the class 1? Has anyone had issues processing the column defects out?

[multiweb]

I'd say class 1 sensors have less hot pixels or defects out of the box than class 2. Having said that after let's say 10 years of use your CCD will have been bombarded copiously with cosmic rays depending on usage so the end result might be the same. It is very likely that when it develops column defects and hot pixels over time you will still be able to calibrate that out by dithering, dark frame subtraction or bad pixel map. In pratice I have a KAF8300 that is 11 years old. It has a lot of defects now but I calculated that it still well under 1% of the total sensor suface. And that's after over 10 years of use. So it is worth the extra money?

[matlud]

Thanks for the reply Marc. I'm thinking the Class 1 is probably not worth it, you could get a Class 1 and end up with a defect after 6 months or so and so not be any better off than with a Class 2 from the start. I see Class 2 are 'allowed' to have up to 15 column defects -does anyone know if getting this many is common or is it usually just one or two?

[multiweb]

I have numerous hot pixels but one defective column and one other in the making. For a new sensor it is very unlikely you'd get that many or any column defect at all. They say 15 but TBH I never heard of a brand new sensor having that many. I've seen STL11K with more than 15 column defects still fit for imaging. So I wouldn't worry.

[gregbradley]

My KAF16200 does not have any column defects like the earlier KAF sensors.
Others I have seen also don't have any. These are all class 2 sensors.
It seems the quality of these sensors improved over time.

Greg.

[Peter Ward]

I agree with Greg. As an SBIG dealer and owner I have seen the raw output from various grades of sensor.

The KAF16200 even at class 2, is still very clean and calibrates perfectly. You will also have to calibrate a class 1 sensor, hence there is minimal price/performance benefit for the added expense. That said, yes the class 1's are remarkably clean, making it a bit easier to push the boundaries with extremely dim objects.

[matlud]

Thanks for the helpful replies, looks like class 2 is the way to go which will help soften the blow of getting the NB filters 😳