Lunatiki
Pooh-Bah
Reged: 08/07/05
Posts: 1252
Loc: Amarillo, TX
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Larry Owens took these fine images. Used the same exact set up. Looks like the Lumenera people might want to consider lowering their prices.
web page
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Mars Watch
All images taken with:
Celestron NexStar 8i SCT
DBK 21AF04.AS
K3ccd/Registax4/PSP8
ALPO Member #4287
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Sean McDaniel
sage
Reged: 10/17/05
Posts: 425
Loc: ashburn, va
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i just saw the posting on the marsobservers list. i pre-ordered the usb2 dmk 21 today. apparently TIS is receiving an order for these on monday with another order coming shortly later. i feel real secure with my decsion now...not that i had the spare bucks for a sky-nyx.
now if i can find out what filters larry is using.
Edited by Sean McDaniel (10/10/07 09:11 PM)
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Lunatiki
Pooh-Bah
Reged: 08/07/05
Posts: 1252
Loc: Amarillo, TX
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I sure don't see $700.00 difference.
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Mars Watch
All images taken with:
Celestron NexStar 8i SCT
DBK 21AF04.AS
K3ccd/Registax4/PSP8
ALPO Member #4287
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Sean McDaniel
sage
Reged: 10/17/05
Posts: 425
Loc: ashburn, va
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i see a $700 savings.
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sean mcdaniel
ns11
toucam pro ii
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Lunatiki
Pooh-Bah
Reged: 08/07/05
Posts: 1252
Loc: Amarillo, TX
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I'm seriously considering ordering a DMK or another DBK, just to have as a back-up.
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Mars Watch
All images taken with:
Celestron NexStar 8i SCT
DBK 21AF04.AS
K3ccd/Registax4/PSP8
ALPO Member #4287
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Sean McDaniel
sage
Reged: 10/17/05
Posts: 425
Loc: ashburn, va
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joel, do you still have your toucam? i sold mine on amart to fund the dmk. just shipped it today but thinking i should have kept it.
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sean mcdaniel
ns11
toucam pro ii
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Lunatiki
Pooh-Bah
Reged: 08/07/05
Posts: 1252
Loc: Amarillo, TX
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I do still have it. I'm going to make it available to the local astronomy club for people who want to give it a try.
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Mars Watch
All images taken with:
Celestron NexStar 8i SCT
DBK 21AF04.AS
K3ccd/Registax4/PSP8
ALPO Member #4287
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Ron B[ee]
Tyro
Reged: 04/27/03
Posts: 4719
Loc: CA
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Thanks Joel for posting this very interesting comparison!
Can someone explain how the C14 operates at f/48 with the Skynyx and only at f/24 (like 1/2) with the DMK and yet the images have the same scale?
Thanks,
Ron B[ee]
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5-inch Tele Vue NP127 APO 
4-inch Tele Vue TV-102 APO 
8-inch f/6 Discovery PDHQ Dob 
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wes
scholastic sledgehammer
Reged: 11/13/03
Posts: 978
Loc: Oklahoma
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Hi Ron,
Most likely it’s the difference in pixel sizes between the cameras.
Wes Higgins
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Lunatiki
Pooh-Bah
Reged: 08/07/05
Posts: 1252
Loc: Amarillo, TX
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Larry said....
Well I took these comparison images, same scope, same filters, same glass (barlow) using extensions to get the same scale (different chip sizes) with both a DMK21AF04 and a Skynyx2-0M
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Mars Watch
All images taken with:
Celestron NexStar 8i SCT
DBK 21AF04.AS
K3ccd/Registax4/PSP8
ALPO Member #4287
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Ron B[ee]
Tyro
Reged: 04/27/03
Posts: 4719
Loc: CA
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Thanks Wes.
Wanting to learn more, may I ask another question. Does this mean then that smaller pixel size is better? For example, assuming we shoot the C14 at prime focus. The smaller pixel size will result in more pixel per sq area of the object. Thus in theory, the more pixel that covers the same area, the better the resolution in the image right?
Another question if I may  . But smaller pixel means smaller image scale which I now understand why f/48 versus f/24. Assume for the moment in the future we have a camera that is 1/4 the pixel size of the Skynyx today. Would that mean someone would have to pile on powermates/barlows at f/192 just to get the same image scale as the other camera? In other words, is there a limit to how small the pixel should be in order to be real-world practical?
Thanks,
Ron B[ee]
PS - Wes, I'm so glad you have a website now. I love going there to consult some features in great depth of details on your website 
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5-inch Tele Vue NP127 APO
4-inch Tele Vue TV-102 APO
8-inch f/6 Discovery PDHQ Dob
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Bird
Carpal Tunnel
Reged: 08/07/03
Posts: 2621
Loc: Canberra, Australia
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Ron, it's the other way around - smaller pixels make the image larger, increasing the effective image scale.
There's also the issue of noise, traditionally smaller pixels mean an increase in noise levels. Some cameras have a pixel size around 4.5 microns, which is about as small as you'd practically want to go.
The Toucam and DMK21AF04, and all other cameras using the sony ixc098bl sensor have a pixel size of 5.6 microns.
The Dragonfly2 / Dragonfly Express and some other SkyNyx models have pixel sizes of 7.4 microns.
The lowest noise / highest sensitivity camera that I personally have seen and used is the Dragonfly2 from www.ptgrey.com. I bought one last year, and it's the camera I used for the June 22 Jupiter image posted elsewhere.
cheers, Bird
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Deep Sky Optics 13.1" f/5.5 newtonian,
PGR Dragonfly Express, PGR Dragonfly 2
RedHat Linux + Coriander
http://www.acquerra.com.au/astro/
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novbabies
Postmaster
Reged: 06/05/05
Posts: 15678
Loc: Northern Georgia!
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....wow, great pix on the link page!
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Good Seeing!
Mark
Orion 12" XTi f/4.9
VERY old Edmund 6" f/8 reflector
Assorted binoculars
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Dobermann
member
Reged: 08/06/07
Posts: 71
Loc: Minsk, Belarus
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Quote:
The lowest noise / highest sensitivity camera that I personally have seen and used is the Dragonfly2 from www.ptgrey.com. I bought one last year, and it's the camera I used for the June 22 Jupiter image posted elsewhere.
cheers, Bird
Sorry for off-topic  . Anthony, is there any difference in sensivity and noise level between Dragonfly 2 and Dragonfly Express?
Thank you.
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Our team: Konstantin Morozov, Yuri Goryachko (Yuri_18),Mikhail Abgarian (Dobermann) .
http://objectstyle.org/astronominsk/index_en.htm
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iceman
Post Laureate
Reged: 03/07/04
Posts: 4357
Loc: Gosford, Australia
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Very interesting comparison, and bodes well for the little DMK. Sean came to a similar conclusion in his recent S&T review of the DMK.
For the price, it really is the best astronomy camera around.
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Mike
. mikesalway.com.au - Astronomy and Photography by Mike Salway
. IceInSpace - The Australian Amateur Astronomy Community
. My Bio | My Jupiter 2007 Gallery | My Image Gallery
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jonbosley
professor emeritus
Reged: 10/19/05
Posts: 540
Loc: Texas
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Sure looks like the DMK has it in this test - I was reading a write up on a new imager, which was hinting that firewire produces more noise then USB2. Has anyone heard of this before?
I guess a side by side test of a DMK firewire & a new DMK USB2 would shine light on it.
Jon
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C11 XLT Celestron
Atlas Goto Mount on Concrete Pier
WO 66 SD Doublet APO Refractor
Philips SNC900NC Webcam
Faymax FC-1000m Webcam with cooling fan
Orion Star Shoot Deep-Space CCD
POD Observatory
www.whitedwarfobservatory.com
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rumples riot
Carpal Tunnel
Reged: 07/01/04
Posts: 2295
Loc: South Australia
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Hmmm, well I got to say the Skynyx is better. I have owned both and the differences I found remarkable. For a start the noise is so much greater in the DMK just in raw frames. Now this image is done with Mars. I would be interested to see what he gets on Jupiter. With a short time to take the frames I reckon the difference would be more remarkable. You can take frames for over 5 minutes with Mars.
The other difference is that you can use 12 bit on the Skynyx; its not available on the DMK.
I reckon the larger pixel size makes a large difference too. With a larger well depth the larger pixels can take in more information before they discharge than the smaller versions.
The DMK is good, but it is not the same as the Skynyx. More tests of differing planets would be needed to convince me otherwise.
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EARTH AND COSMOS
My Solar System Imaging BLOG
How to peltier cool a C14 SCT
SOUTH CELESTIAL POLE
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iceman
Post Laureate
Reged: 03/07/04
Posts: 4357
Loc: Gosford, Australia
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I don't think the comparison states any conclusions - and I don't think there's anyone in this thread saying the DMK is a better camera.
When you compare price for performance, I believe that's where the DMK comes out tops.
At more than twice the price, you certainly don't get more than twice the performance. For some people, price isn't a consideration and so if spending more money means an extra 5-10% improvement in their images, then it could be worth it.
As Bird points out, the ptgrey cameras are probably a step up again from the Skynyx. But again they are more expensive. For most people, the trade-off between price and performance is a very big factor in their decision. For others, they'll just buy the best even if it delivers only a small % of improvement. There's no right or wrong. It depends on their budget etc.
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Mike
. mikesalway.com.au - Astronomy and Photography by Mike Salway
. IceInSpace - The Australian Amateur Astronomy Community
. My Bio | My Jupiter 2007 Gallery | My Image Gallery
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Lunatiki
Pooh-Bah
Reged: 08/07/05
Posts: 1252
Loc: Amarillo, TX
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Well, in the comparison the DMK sure doesn't appear to have more noise in my opinion. They were imaged minutes apart, same set up, same processing.
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Mars Watch
All images taken with:
Celestron NexStar 8i SCT
DBK 21AF04.AS
K3ccd/Registax4/PSP8
ALPO Member #4287
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rumples riot
Carpal Tunnel
Reged: 07/01/04
Posts: 2295
Loc: South Australia
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I was not stating that the tests say one way or another Mike. I am telling you my opinion as I have owned both. I know what both are capable of. I guess that counts for nothing though these days. So many people make assessments without actually using the equipment.
Yes the price difference does not yeld a 50% increase in performance, but there is in my mind at least a 20% increase in performance.
Luna, the images while taken minutes apart could have been taken for several minutes. I think the imaging runs where over 30 odd minutes.
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EARTH AND COSMOS
My Solar System Imaging BLOG
How to peltier cool a C14 SCT
SOUTH CELESTIAL POLE
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