View Full Version : DBK21 Exposure settings.

September 1, 2008, 10:27:10
I'm helping someone with their DBK21 usb camera (I have the firewire) and I don't understand the exposure setting with the DBK. When I try to adjust the exposure I find settings of -8, -7, -6, ......0, 1, 2, 3, etc. Nothing that equates to the normal exposure settings.

Can anyone explain what is happening?

Stefan Geissler
September 1, 2008, 11:09:59

The camera has three exposure interfaces:

Register values:
From 4000 to 1, where the exposure time is calculated as 1/n = seconds, e.g. n=30 => 1/30 seconds

Physical values (DirectShow standard):
-11 to 4, where the exposure time is calculated as 2^n = seconds, e.g n=-6 =>2^-6 = 1/64 seconds

Absolute values:
This is the interface with the widest range from 0.0001 to 30.0, resp. 0.0001 to 3600.0 for the astronomy cameras. The exposure time is give as float value, e.g 0.3333 = 1/33 seconds.

The ranges of the interfaces depend on the camera model.

I guess, the program you use, uses the standard DirectShow interface.

Sascha Schmidt
September 1, 2008, 11:16:15
Hallo 1ponders,

This issue mostly results from a wrong 'uvc_driver.vda'.

So, I have some questions in order to narrow down the problem:
- which IC Imaging Control version do you use?
- does this problem also occur with IC Capture?

Maybe just a driver update will suffice to solve the problem.
You can download the latest usb driver from:

September 1, 2008, 11:26:51
Thanks for the quick reply folks.

Stefan, I'm using the astronomy version of the camera and the exposure settings were the same (Physical by the look of it) in both
IC Capture 2.0 and K3CCDTools. I don't have the camera here atm so how do I go about changing from Physical to Absolute or Register values.

Sasha, I thought this might have been the problem as I'm sure windows loaded the default windows driver when I connected the camera. How can I prevent this, or change the driver to the correct one (assuming the correct one doesn't load now if I connect the camera). I did load the driver from the disk after the computer recognised the camera, so it is on the machine.


September 1, 2008, 11:29:30
Oh and btw Stefan, fwiw my version of K3CCDTools (latest version from memory) locks up using Vfw, should I be using WDM instead do you think?

Stefan Geissler
September 1, 2008, 12:26:54

In order to use the absolute values in IC Capture, our driver must be installed. Same for k3CCDTools (WDM) as far as I know.

September 1, 2008, 22:05:17
Stefan, how do I go about ensuring I have the correct driver installed? ie removing the windows default driver first and finding and installing the TIS driver?

Stefan Geissler
September 2, 2008, 08:40:19
You do not need to uninstall or remove the standard Windows. Simply install our driver from the CD ROM. You can check in the Device Manager, which driver is installed.

IC Capture should display the absolute values immediately. As far as I know, K3CCDTools too.

September 6, 2008, 02:24:24
All fixed. Thanks for the help Stefan and Sascha

March 26, 2009, 11:44:47
Sorry to resurrect an old thread Stefan but I am having the same problem only this time with a DBK31. I've installed the driver from the disk but still receive exposures in Physical Values. Any suggestions? BTW this is a USB camera

Stefan Geissler
March 27, 2009, 09:38:02
You installed the driver for this camera correctly and IC Capture shows the values for exposure as absolute values?

April 17, 2009, 07:39:30
Yes I've installed the driver correctly ( a couple of times, even used the latest driver from the site) but I'm getting physical values (-9,-8, etc). I don't seem to be able to get absolute values.

Stefan Geissler
April 17, 2009, 09:08:12
In which program? Also can you show a screenshot?

April 17, 2009, 11:28:21
In both IC Capture and K3CCDTools

Stefan Geissler
April 17, 2009, 14:56:45
Did you update IC Capture from the CD ROM that came with your camera?

April 19, 2009, 07:38:16
No I didn't I used my existing IC Capture. But it does the same thing with K3CCDTools as well.

Stefan Geissler
April 20, 2009, 11:56:41
And what about IC Capture? In K3CCDTools all things are different. I am not sure, whether you can use an ASCOM driver for image acquistion in it.

April 22, 2009, 09:20:53
Hello Stefan. I have been using the IC capture that came with my original Firewire camera (
DMK21AF.AS. I didn't bother loading the version that came with the DBK. I have now loaded that version and the IC Capture shows the exposure in the correct units.

I have also managed to find a work around for K3 as well, though it still shows the exposures as -2, -1, 1 etc, but I can live with that. Thanks for your time.

Stefan Geissler
April 22, 2009, 16:42:39
If the K3 software works with the IC Imaging Control SDK (I am not sure about, but there is an ASCOM thingy available), then copy the *.VDA file into the K3 directory. May be this helps.