View Full Version : How to ...

May 26, 2007, 19:50:51
... calculate the bandwidth for a TIS camera


How do you calculate the needed bandwidth for a TIS camera ?

Thank you

Stefan Geissler
May 29, 2007, 11:54:38
Hi Rainer,

The bandwidth calculation is a little bit complicated, because you have not only the image data, but also an header overhead. Thus we created a table with the bandwidth allocations of the different video formats. It can be downloaded at:


May 30, 2007, 16:56:37
Hallo Stefan,

Danke. I made some tests running several TIS cameras at the same time in IC Capture.

Here is the posting I made in the Yahoo group:
************************************************** ********

Here is the test. 2 TIS cameras running in IC Capture. A DBK
21AF04.AS and a DBK 41AF02.AS


The 41 was running at 15 frames per second in BY8 and the 21 running
at 30 fps also in BY8.

Here another test.


The 41 running in IC Capture and the 21 running in K3CCD Tools.

Here you can see 3 TIS cameras running in IC Capture e.g. DFK
21AF04.AS, DBK 21AF04.AS and a DBK 41AF02.AS


and here 2 cameras in IC Capture and 1 camera in K3CCD Tools


as I have no more Firewire ports I can not connect more cameras to my
PC :-))

I hope you can see now the power of Firewire as well as IC Capture.

saludos Rainer
************************************************** ******

If I use your white paper data and the fps I achieved with 2 cameras then I get together 96% which covers then my Firewire speed.

Interesting again is, in order to confuse the enemy :p , that you do not list the BY8 color format as that is what I was using when making the test.

Why do you make to us amateur astronomers the life so hard by not having a common standard or compare things with what your cameras work with ?

Is BY8 in color the same as Y800 in B&W ?

How much can the header in total influence the speed ? Is the header that big that is has to be taken into account ?

Stefan Geissler
May 30, 2007, 17:19:45
Hi Rainer,

At least, I guess, the BY8 is newer than the document. But I tell the marketing to add this. BY8 is the same as Y800, just to be complete.

The header is specified in DCAM 1.3 and FireWire specification. I do not know how big it is. But the header guarantees that all connected devices receive the blocks, that are for them. I know protocols with bigger headers, e.g. CORBA, which is used in simulators.