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Rainer
May 8, 2007, 23:59:41
Hi,

Do you have data about how sensitiv the DBK cameras are in regard to UV and IR ?

Thank you

profjohn
May 9, 2007, 17:39:12
Rainer,

Since we do not use any optical filters in our cameras the CCD's "pure spectral behavior" is exibited. Please find Sonys specifications as a PDF file on the "Specification" pages of the cameras:

http://www.astronomycameras.com/en/products/firewire-cameras/color/dbk21af04as/

Unfortunately, Sony does not provide any "official" information concerning the UV and IR sensitivity. In industrial image processing we often use IR leds and from this practical experience we know that the IR sensitivity of the color CCDs is similar to that of the monchrome model.

CCDs are sensitive down to about 250 nm, but since the CCD's protection glass blocks UV light, we cannot use this part of the spectrum.

Rainer
May 9, 2007, 20:17:17
Hi,

Thanks for the data of 250nm.

Well if that would be true that no UV is detected then what is my DMK 21AF04.AS detecting then ?

The used UV Filter is a pass Filter at around 300nm to 400nm. Here is the result

http://www.rainerehlert.com/DMK/DMK-BUV-SUV-FR-03-01.jpg

Let me explain what all those images mean.

The left column was made using the Baader Venus Filter and the right column was made with a Schüler UV filter.

The imaging was done on a lamp illuminating a soccer field in fronm of my house.

I used a DMK 21AF04.AS and a filter wheel equipped with LRGB + H-Alpha + OIII + SII filters. From measurements of the transmission curve we know what passes through each filter. The interesting filters are the H-Alpha OIII and SII which have a leak in the UV spectrum being the leak aroubd 300 to 400nm.

As you can see the camera does a good Job capturing UV.