My colleagues in the Support Department asked be to write about how to capture colored RAW image data into uncompressed Y800 AVI with IC Capture.AS and then import it to RegiStax 4. They tell me they have at least two customers every day who need assistance on figuring out how to do this.

For the purpose of this mini-tutorial, a DFK 21AF04.AS camera will be used to generate the AVI file. The resulting file will be imported into RegiStax 4, in which the color calculation will take place.

Step #1: Setup the DFK 21AF04.AS in IC Capture

Start IC Capture.AS and open the camera, as described in the documentation. Set the video format to Y800, as illustrated in the following screenshot:

Step #2: Get Ready For AVI Capture

First of all, a filename and the AVI format must be specified. The AVI file format must be uncompressed Y800. This can be set up by opening the Record Video File dialog, which is activated by clicking on the button marked in the following screenshot:

The following dialog box should open. Proceed by clicking on the indicated button:

The following dialog should appear:

Check the radio button next to Uncompressed and select Y800 from the selection list. You can also specify further properties, such as the filename and number of frames to be captured.

To proceed, click the OK button. The dialog box will close.

Step #3: Capture The AVI File

The Record Video File dialog box should now look as follows:

You can start AVI capture by clicking on the red record button The black pause and stop buttons pause and stop AVI capture respectively.

Once you have finished capturing, you can close IC Capture.AS.

Step #4: Import Into RegiStax

Now start RegiStax and import the AVI file, which you have just captured. Then, click on Additional Options, as shown in the following screenshot:

Proceed, by clicking on Use Debayer and select G8 from the radio buttons:

And that is all there is to it - the image is now colored.

If you need any help with this mini-tutorial, please do not hesitate to contact our Support Department. Please do not forget, when you purchase an astronomy cameras, manufactured by The Imaging Source, you are not only getting the hardware, but an all-encompassing support package as well. All customers can contact the Support Department by telephone, e-mail and fax.

Oldfield So, over in Hong Kong, has published an interesting article about debayering techniques for the DBK and DFK series of astronomy cameras.

He discusses the following three techniques:

Case A: Debayer’ing is done at hardware level, and so the data coming from the camera is already in full color. [...]

Case B: By choosing Y800 for the device codec, the hardware sends original data which is not yet debayer’ed, that saves some Firewire bandwidth, and then the debayer’ing is done at software level by IC capture. [...]

Case C: We have chosen Y800 for the device as above, so the data coming from the camera is still not yet debayer’ed, and therefore, it uses less Firewire bandwidth. And Debayer’ing is also disabled in IC Capture, meaning that Debayer’ing is not done on-the-fly as well, and so it requires less CPU cycle.

He has published a screenshot for each technique, one of which that illustrates the third technique, is below:

You can read the full article, in Oldfield’s blog.

A great thanks goes out to Oldfield for sharing this information with The Imaging Source astronomy cameras community.

The question of whether FireWire or USB 2.0 is a better choice for an astronomy camera gets raised time and time again in our support and pre-sales departments.

One of our German reseller - Intercon Spacetec - has published a brief overview of how they see the situation. With their permission, I have translated the following from German into English for our global audience:

The speed at which data can be transferred across the FireWire bus and the USB bus is almost identical. In practice, FireWire seems to have a very slight edge. However, as the maximum frame rate of both the FireWire and USB series of astronomy cameras is identical, this advantage is purely academic.

Customers who are looking to run their astronomy cameras on Linux will have an easier time with the FireWire series, as the standard IEEE-1394 driver works fine. USB, on the other hand, requires a specialized driver [see these blog posts for details].

Users of Windows are better off using the USB series, as the cameras’ handling is easier than that of the FireWire astronomy cameras.

Power is also an issue to look at when debating whether FireWire or USB is better suited to the task. Normally, both FireWire and USB cameras draw their energy over the cable. An external power supply unit is, therefore, not necessary.

One (very important) exception is when running the cameras on laptops: The FireWire connectors on laptops typically have only four pins and thus cannot power the cameras. It is, therefore, necessary to power the cameras using an external power supply unit, which, out in the field, is often somewhat cumbersome.

Deploying USB cameras avoids this inconvenience.

German and French versions of this text are also available.

• What do you think?
• Which do you prefer?
• FireWire or USB?
• Why?

Please post your opinion in the comments section below. Thank you!

Joe Zawodny wrote to us recently talking about some of the difficulties that members of the astronomy cameras community had been experiencing focusing the DBK 31 series at long focal lengths. He writes:

Saturn is [...] a lot dimmer than either Jupiter of Mars. But then, so are the Saturnian moons. I managed to capture Saturn and 4 of its moons in [the following] image, using a Celestron 11 at f/20 and my DBK 31AF03.AS.

Later in his e-mail, he continues.

Two things I learned in the process. You need to increase the brightness control to bring the noise in the darkest parts of the image above zero counts (use the histogram function). Otherwise, stacking will not allow you to access the information lurking in those regions. In this case it was Enceladus that I was after. The second thing I learned is that the DBK’s noise level is still quite low even at very high gain setting. This image was shot with a gain of 880 and an exposure of 1/11 second (with a UV/IR blocking filter). It is a stack of 1600 of the best frames out of 2800. I used the ROI function in IC Capture to allow me to capture so many RGB24 encoded frames and keep the AVI under 1GB for compatibility with RegiStax. I nice challenge with an equally nice reward.

Below is the photo that he submitted:

Thank you Joe for sharing your wisdom with the rest of the astronomy cameras community!

Many users of The Imaging Source cameras have recently phoned, emailed, and even faxed what seems to be a most relevant question concerning the new USB models. Tom Ferraro of Melbourne, FL writes:

[...] the humidity here in Florida is just deadly no matter what time of year it is! Can I extend the USB connection from my laptop to my DMK 21AU04.AS so that I can stay cool while sipping a tasty beverage?

Good news Tom. I’ve purchased a few long USB cables and extension cables from a local electronics shop and tested The Imaging Source DMK 21AU04.AS (and its siblings) up to 10 meters! One note: buy good quality cables!

Have a Great Day,

profjohn