Kodak KAF8300 v's Sony ICX814 *Noise comparison*

[MattJenko]

1 minute ago, gnomus said:

 Both had been calibrated.  Since calibration is standard, 

This is the crux. Is it standard? If we are saying that despite worse paper specs, the Kodak calibrates noise out better, then we have a winner according to yours, mine and Saras criteria about sheer end result. I have a cooled cmos and it is wonderfully clean, but long exposures do give some glow which doesn't 'easily' calibrate out, so in effect, it is not better under those circumstances etc, although the sensor is a modern marvel. I do agree with the point of the thread though about Kodak chips and the fascination with low level technicalities which appear to have nothing to do with end result. I also have a tiny sony chip and it is ace, but my new big cmos blows it away for <5min exposure imaging.

[swag72]

I guess that the calibration is as standard as can be..... let me explain.

The same white wall of the observatory was used, through the same equipment, using the same software for capture and using the same ADU for the flats and lastly, perhaps more importantly taken by the same person..... so if my flats are wrong for any reason due to my process of taking flats, it will be the same for both... does that make sense?

[ChrisLX200]

I don't know for sure but I would guess (given the huge number of 8300-based cameras in use) that this sensor is responsible for more APODs and published images than any other, and it's still creating them today. CMOS sensors are a fascinating development but they have a long way to go yet before the 8300 could be considered 'retired'. I don't think there are going to be any larger Sony sensors to be seen in the astro camera market either. CMOS sensors also require callibration frames so by the time you reach the finished image there's no less work involved in using them - and given the large number of frames used (with their shorter subs) actually more work So if you want a large(er) format sensor then the 8300 is still a great choice.

ChrisH

[MattJenko]

It does, I'm just betraying my lack of success with darks in particular in my own calibration with both a Sony chip and now a cooled cmos. Maybe I should get a Kodak  

I rely on vast numbers of subs for my cmos imaging anyway, as the chip is only 14 bit to begin with.

 

[gnomus]

1 minute ago, ChrisLX200 said:

........ CMOS sensors also require callibration frames so by the time you reach the finished image there's no less work involved in using them - and given the large number of frames used (with their shorter subs) actually more work  ......

An extremely good point Chris.  The better CMOS pictures I have seen are the ones with longer total integration times - equal to the total times typically amassed in the good CCD images.  The number of frames required is therefore very high and, with download times factored in, I wonder if it actually takes longer to get (say) 5 hours worth of data with short-exposure CMOS frames than with long-exposure CCD.  Must be harder work for the processor too.

[MattJenko]

14 minutes ago, gnomus said:

An extremely good point Chris.  The better CMOS pictures I have seen are the ones with longer total integration times - equal to the total times typically amassed in the good CCD images.  The number of frames required is therefore very high and, with download times factored in, I wonder if it actually takes longer to get (say) 5 hours worth of data with short-exposure CMOS frames than with long-exposure CCD.  Must be harder work for the processor too.

The cooled cmos chips don't have the same dynamic range as the existing CCDs (my asi1600 is 14bit for isntance), so more subs, and many more subs, are required to get that range to the level of the good CCDs. Why they work at all, is that they excel at clean, shorter exposures. I have found that a good image takes time, no matter what. Neither tech, nor different CCD makes, has more more photons that the other to deal with