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15% obstruction
October 23, 2010, 15:45:18
Hello, I'm new on this forum and I live in the Netherlands, so please don't shoot me if my English isn't perfect.

I have a question about the difference between the DBK and DFK camera.
I already know that the DFK has a build in IR-filter.
But is this the only difference?
A topic on "Cloudy Nights" makes me assume there are more differences.

http://www.cloudynights.com/ubbarchive/showflat.php/Cat/0/Board/Imaging/Number/1830440/page/0/view/collapsed/sb/5/o/all/fpart/2

Especially the post by Oliver P. on 09/10/07.

Another reason to believe that it's not only the IR-filter what makes the difference are the descriptions by the company "Astroshop.de".

Hopefully you understand German.
This is what they write on their webshop:

DBK:

"Die von Farb-CCDs gelieferten rohen Daten (8 Bit/Pixel, RAW-Format) bedürfen der Aufarbeitung. Diesem Zweck dient eine Farb-Interpolation. Sie wandelt die rohen Daten in eines der üblichen Farb-Formate. Diese benötigen 16 oder mehr Bit/Pixel und damit ein hohe Bandbreite bei der Übertragung. Die Farb-Interpolation der Astro-CCD-Kamera DBK 21AU04.AS können Sie ausschalten und so 60 Farb-Bilder/s übertragen. Die Farb-Interpolation führt dann IC Capture.AS auf dem Rechner durch. Selbstverständlich können Sie auch ganz auf die Farb-Interpolation verzichten und die AVI-Dateien mit Bildern im RAW-Format erzeugen."

DFK:

"IC Capture.AS übernimmt außerdem die Farb-Interpolation der von der CCD-Kamera gelieferten Farb-Rohdaten (RAW-Format) und entlastet damit den Prozessor der Kamera. muss hingegen der PC entlastet werden, kann auch die Teleskop-Kamera die Farb-Interpolation übernehmen. In diesem Fall ist die maximale Bildwiederholrate 30 Bilder/s. Selbstverständlich können Sie auch ganz auf die Farb-Interpolation verzichten und die AVI-Dateien mit Bildern im RAW-Format erzeugen."

So now I'm confused.:confused:
Is the IR-filter the only difference or not?
I will buy one of the two types.
But which one is best suited for mainly planetary imaging?
Hopefully someone can help me in this puzzle.

bwallan
October 23, 2010, 18:44:58
But which one is best suited for mainly planetary imaging? Hopefully someone can help me in this puzzle.

The IS camera best suited for (professional) planetary imaging is the DMK21 with filter wheel, if you're into mono imaging.

However, my one-shot color IS camera of choice for planetary would be the DBK21 or DBK31. I'm not too sure why anyone would buy the DFK, which locks you into using an IR filter?

Now that I've said all of the above, realize that I don't own either a DMK21 or DBK21. After much research and testing I purchased a USB DBK41 (almost went with the DBK31). Not ideal for planetary; too slow a frame rate. But much larger FOV; great for lunar, solar, (some) planetary, some potential for deep space objects and wildlife imaging; my optimum camera.

Some samples of DBK41 solar and planetary images @ http://tinyurl.com/bwaSun & http://tinyurl.com/bwaPlanets . Wildlife example with astro-telescope @ http://tinyurl.com/bwaDBK41Squirrel .

My best planetary image to this point is still one of Saturn taken with a QHY8 CCD. I'm beginning to believe planetary imaging is totally dependent upon atmosphere... the camera doesn't really matter!

Hope the above helps in your decision.

bwa

Emil
October 26, 2010, 12:59:39
I think '15% obstruction' is more interested in if there is an actual difference between the two camera's (DBK vs. DFK) apart from the the IR-block filter.

Can both camera's give the same kinds of output (e.g. Raw Y8 and RGB), or is one of the camera's more limited in one way or the other APART from the IR-block filter..?

And another question from me: what does the B and F stand for in DBK and DFK?

Stefan Geissler
October 26, 2010, 13:23:32
Hello:

"B" means color without IR cut filter, "F" means color with IR cut filter.

Emil
October 28, 2010, 16:14:33
I was more looking for what the letters B and F actually stand for.. why a B and an F, and not just use A and B, or C and X, or two other random letters?

But more importantly: how about the first part of my question?

"Can both camera's give the same kinds of output (e.g. Raw Y8 and RGB), or is one of the camera's more limited in one way or the other APART from the IR-block filter..?"

I think I know the answer, but I'd like to be 100% sure about this.

Stefan Geissler
October 29, 2010, 12:10:47
Well, that is simple:
"B" = "Bayer"
"F" = "Farbe" (which is "Color" in English. Please do not ask, why we used "F" instead of "C" when the names were created years ago :-) )

Emil
October 30, 2010, 00:55:07
I give up....

bwallan
November 2, 2010, 19:01:00
I give up....
Emil,

Don't give up. Post your question to the Yahoo DMKCCD-imaging forum @ http://tech.groups.yahoo.com/group/DMKCCD-imaging/ . I'm sure you'll get a response.

However, as far as I know from research I did prior to purchase, the DBK and DFK are the same except for the IR filter option.

I've been using my DBK41 for some solar imaging lately and still love it. I plan on configuring a C11 for Hyperstar and will try it in this configuration for some deep space imaging... should be fun!

bwa