QHY12 CCD Glass Transmission Data

[Eden]

QHY-CCD kindly provided me with the optical transmission data for the UV/IR blocking glass which covers the CCD sensor on their QHY12 camera. It's likely that the same glass is used on their other one-shot color models.

I am posting it here in case anyone is interested in the numbers. ;)

[Amaranthus]

Useful, thanks. I wonder what that resonance at around 320 nm
is?

(BTW, I'll answer your PM when I get back to my computer, too long to type on an iPhone!)

[Eden]

Hi Barry,

Thanks very much, I appreciate it. :thanx:

The UV/IR coverage on this glass allows some UV light from 320nm to 350nm and then from 380nm to 400nm to reach the sensor. I suspect that this can lead to star bloating in long exposures if it is not blocked by another filter.

Many of the light pollution and band-pass filters available are advertised with transmission graphs showing zero or near-zero transmission across the UV.

When these filters are tested by independent third-parties, the resulting transmission graphs often tell a very different story by showing that at least some UV light passes through, in varying quantities. I recently switched to an Astronomik CLS and found that it is definitely one filter that performs as advertised.