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  #61  
Old 27-03-2008, 04:14 AM
Arp
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Hi!
I hope you still follow this thread, as I stand before the same choice as Matt.
As far as I read here, the DBK produces the better quality as the other color camera. But I dont think this is because of the filter, but maybe because of another design of the bayer sensor. Anyway, I already tried the spc900 which gave some good results, but nothing compared to the great images shot with the D*K cameras.
So, I think I will purchase the DBK... Im still not sure if it will be the 21, or 31. Depends on the price

But I still got a big question. Right now I am using a 90/910 refractor as a guidingtelescope and the spc900, not modified, as the guidecam. As you can imagine, the amount of guidestars is limited. Will a DBK perform much better? I always wanted to do a good M51... would this camera on this guidingscope find any guidestars? My SPC900 did not.
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  #62  
Old 27-03-2008, 04:22 AM
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Hi Arp and to IceInSpace!

I use a DMK21AU04 as a guide camera and it picks up enough stars for me to choose when guiding. The will also be fine if you plan on getting the one-shot colour camera.

I look forward to seeing that shot of M51!
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  #63  
Old 27-03-2008, 04:30 AM
Arp
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sounds good.
Now, I need to think about money... do you know any resellers which ship to germany? I could imagine that because of the low value of the USD compared to the Euro, I could save some money. Is there a chance?
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  #64  
Old 27-03-2008, 04:34 AM
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No, i'm not sure. I guess you could simply ask them.

Good idea to shop around though.. even locally here there are price differences which can make it worthwhile to shop around.
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  #65  
Old 27-03-2008, 04:36 AM
Arp
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Since I never shoped outside of germany, do you have any links to some shops?

I got another question popped up, and I think you know the answer since you use the dmk for guiding. Do you know the program guidemaster? Does it work with a DMK/DBK?
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  #66  
Old 27-03-2008, 04:41 AM
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I'm pretty sure guidemaster works with the D*K cameras. I personally use PHD guiding and love it. Very simple and easy to use.
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  #67  
Old 28-03-2008, 12:04 AM
Arp
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Hi!

I just realized that a D(F)(B)K and the SPC900 have the same sensor, the Sony ICX098BL. So, if they use the same sensor, how comes that the D*K has better quality and costs so much more?
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  #68  
Old 28-03-2008, 04:18 AM
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I'm guessing the chipset is better, giving better/lower noise - and of course uncompressed transfer through USB2/firewire instead of compressed USB1.1
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  #69  
Old 28-03-2008, 05:14 AM
Arp
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Thanks. I will purchase the DBK 21 in about two weeks. Thank you for your help.

I got a quick question. It seems that the clouds over my head are vanishing so I'm prepping another session for tonight. I will use for Mars and Saturn the spc900, not modified. Do you know what codec is best suited? I420 or YUY2?
thx
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  #70  
Old 28-03-2008, 05:59 AM
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I used YUY2, it was slightly less compressed.

Do you definitely want to get a colour cam? Why not mono?
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  #71  
Old 28-03-2008, 08:50 AM
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I know that the monochrome version would have better quality, but right now I cant afford to buy the camera and a filterwheel and a set of filters. And If I got all things, I think its very hectic to rapidly change the filters to get another colorchannel. And I am not sure if the additional work justifies the better quality.
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  #72  
Old 28-03-2008, 10:15 AM
Dennis
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Hello, Arp

I have a DMK21AF04 (mono) and a DBK21AF04 (colour), both Firewire and there appears to be a big difference in “sensitivity” between the two units that you may want to consider in your purchasing decision.

When I was recently imaging the Trapezium stars in M42 with the mono DMK I was able to capture at up to 60fps with the gain (0-1024) set at around 500, whereas when I switched to the colour DBK, I had to drop the settings to 15fps with a gain of around 950 and the images were noisier. Unfortunately, I did not try the DBK with a mono codec to see what affect that would have on the image.

At the time, I was using a Tak Mewlon 180 F12 with a Televue x2.5 Powermate which is obviously not a typical auto guiding set up, so if you are planning to auto guide with a typical 80mm F7 refractor this may not be an issue.

Cheers

Dennis
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  #73  
Old 29-03-2008, 08:00 AM
Arp
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Thanks Guys.
My Decision is now final... Next Week Im going on hollidays for some days, and after that Im gonna order the DMK21. To get colorimages I will use the SPC900 as a camera for the colorinformation, and the DMK for luminance information.. hopefully this will give some nice results, at least until I buy a filterwheel and filters some months later.
Thanks again, I will show you my results
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  #74  
Old 29-03-2008, 10:53 AM
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Excellent, Arp. Great decision. Are you getting the USB version or the firewire?

Using the SPC900 for colour data can certainly work, you'll just need to do your best to focus quickly and try and match the camera rotation angle as quickly as possible, although you can always rotate in post processing to match them up.

I did a few shots like this back in 2006 before I got my filterwheel as well.
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  #75  
Old 29-03-2008, 11:21 AM
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I will get the USB version, because I only work with a laptop in the field which doesnt have a firewire port. And I am too lazy to build a connection for the power supply

Interesting pictures! This is the thing I want to try in the future.
Could you give a few pointers on how you do this in Photoshop?

I just experimented with it... I took a RGB picture, converted it to grey and used this as luminance and the original as RGB, to simulate my future projects
I used the LAB colormode in photoshop, but after realigning the pictures, I didnt have the same colors... anything I did wrong?
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  #76  
Old 29-03-2008, 11:24 AM
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Quote:
Originally Posted by Arp View Post
Interesting pictures! This is the thing I want to try in the future.
Could you give a few pointers on how you do this in Photoshop?

I just experimented with it... I took a RGB picture, converted it to grey and used this as luminance and the original as RGB, to simulate my future projects
I used the LAB colormode in photoshop, but after realigning the pictures, I didnt have the same colors... anything I did wrong?
Funny you should mention that.. Here's some reading for you.

RGB Planetary Imaging with a Monochrome Camera
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  #77  
Old 18-04-2008, 07:35 AM
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One question, regarding your setup at the page you linked. great reading btw.
If you have the setup: Telescope - Barlow - Filterwheel - Camera, and assuming you use the 5x powermate, you should have more then 5x magnification, right? Because the ccd chip is further away then without the filterwheel.
Its the same setup I have in mind, though I need some tubes to move the barow further away, since I got a new focuser and its smaller than the old one so it can not reach the focus point

As an alternative, I could have: Telescope - Filterwheel - Barlow - Camera. This way I would just have 5x magnification, the filterwheel is "long" enough so the Barlow gets into the focus point, but how to I connect the Barlow with the T2 "hole" in the filterwheel? (everything is exactly the same as on your instructionspage).
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  #78  
Old 18-04-2008, 07:51 AM
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Hi Arp

Yes, by having the filterwheel after the 5x, it gives me about 6.5x - which is fine with me, more focal length the better (this gives me about 10.5m).

When the seeing is really, really good, I also use an extension tube between the barlow and the filterwheel to give me about 13-14m focal length.
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  #79  
Old 06-05-2008, 10:39 PM
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DMK31AF03.AS and surrounding

Hello to all,
i'm new to this forum.
I was searching news about DBK-DFK sensitivity because i'm an happy user of a DMK31AF03.AS (1024 x 768) and i was wondering about "HOW MUCH" difference there is between BW and Color versions.
I bought the DMK it mainly for Guiding/Moon /Planets imaging but now i'm enjoying beginning with some unguided 45 seconds exposure DSO imaging from my town (i'm lazy so i stay on my terrace).

The results are pretty encouraging and i'm very happy i bought it.
Should i be disappointed by the color version? (i'd buy 640x480 for budget reasons).
I know that the 640x480 sensor has bigger pixels but they can't fully recover the loss of the bayer mask.
Could someone give me suggestions/opinion?

Regards
Alberto

my DMK31AF03.AS tests:
the DSO objects are all unguided exposition 45 seconds each one with a C8 + focal reducer 3.3

http://www.makina.it/Astro/080214-Th...-6353x4326.jpg
http://www.makina.it/Astro/M51-C8-f3.3-TIS-DMK.jpg
http://www.makina.it/Astro/NGC4565-C8-f3.3-TIS-DMK.jpg
http://www.makina.it/Astro/NGC3628-C...K.HalfSize.jpg
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  #80  
Old 07-05-2008, 04:10 AM
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Hi Alberto, Welcome to IceInSpace!

Those are some amazing DMK deep-space images, just beautiful. Probably the best i've seen from a DMK.

Why do you want to get a DBK? The DMK is much more sensitive as you'd know, because of the bayer filter. Can you not get a filter-wheel and colour filters for your DMK31?

Then you can use it for RGB planetary imaging as well as RGB deep-space imaging.
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