From: Milton Aupperle <milton@outcastsoft.com>
Date: September 30, 2007 1:28:14 PM MDT
To: Astro_IIDC@yahoogroups.com
Subject: Re: [Astro_IIDC] Imaging Source DMK31AF03.AS
Hi Alberto;
On 30-Sep-07, at 6:16 AM, richter1956 wrote:
Hi Milton, hi all!
I hope you remember of me and my long correspondence with Unibrain.
I'd been silent because for many reasons i couldn't enjoy with Astrophoto for a while.
I just uploaded the Luna i did the past May using a "black" IR-filter:
070520-Moon-InfraRED-3700x2200.jpg
It seems better than other similar images I did before.
Very nice image
http://groups.yahoo.com/group/Astro_IIDC/files/Lunar/070520-Moon-InfraRED-3700x2200.jpg
Using an IR Pass filter or narrow band helps get better details with mono cameras.
I'm writing this post because i contacted the Italian dealer of Imaging Source in order to
buy the 640 x 480 BW camera but since they sold out the whole stock during a Astronomy
fair, they proposed me the 1024 x 768 version with a good (fair...price!) discount so
before saying Yes or No i would hear your opinion.
The dealer told me that the pixels are a bit smaller (a little advantage for autoguiding too)
and using my C8 with the focal reducer f.3 could be funny in order to grab good deep sky
images grabbing multiple unguided exposure time about 45 sec - 1 minute under polluted
sky.
The only somewhat negative things about the 1024x768 versus 640x480 are:
1) 20% less light gathering (640x480 have 5.6 micron pixels / 1024x768 4.5 micron pixels) because of smaller pixels.
2) Slower frame rates of 60 fps max versus 30 fps max.
3) More pixels means slower image processing and more storage space on your hard drive.
The generally positives aspects for the 1024x768 you:
1) You now have a larger field of view and larger CCD (1/3" CCD versus 1/4" CCD).
2) There will be a magnification increase by about 20%.
Check M16 and M27 by Bradaschia Filippo that were taken using that way:
http://www.otticasanmarco.it/ImagingSource_fotografie.htm
So what is your opinion? The 1024 x 768 worth ?
Regarding the BW, Color RAW and Color version do you suggest always to choose BW
version?
The B&W versus Color (Bayer RAW or just Color) camera choice has been debated here several times by multiple people:
http://tech.groups.yahoo.com/group/Astro_IIDC/message/985
http://tech.groups.yahoo.com/group/Astro_IIDC/message/987
http://tech.groups.yahoo.com/group/Astro_IIDC/message/382
Also, scroll down to the bottom of each of these messages and check out the message thread, which has more information.
Basically it comes down to resolution versus convenience. Bayer cameras have lower color resolution than shooting with a mono camera with filters. However they are super convenient because you shoot one movie, process one movie and see result from one movie. With filters, you have to shoot 3 (R G B) or 4 (L R G B) movies as quickly as possible (to prevent rotation of features on planetary disks) with each filter, have to process each movie, then take the 3 (R G B) or 4 (L R G B) image results and synthesize the resulting RGB image afterwards. If you have turbulent skies (I live directly under the jet stream, i can count the nights of good seeing per year on half a hand hand) the Filter wheel will likely give you no better results than a Color Camera will.
The other thing is that for photometric Astronomy (in to Astro IIDC 4), you pretty much need a Monochrome camera.
A final question: would you allow my AstroII DC to change the activation code from
Unibrain to Imaging Source?
No, you we don't allow that.
Our policy has been that the only times we allow people to switch are if the camera or Mac has been replaced because it was stolen, it was lost and replaced by insurance, it was replaced by manufacturer because of defects etc for the same model or similar model. For similar model or obsolescent cases, if you had an ADS Pyro or an iBot camera we would allow you to switch to another manufacturer because they don't make those cameras anymore. The same would apply if Apple would not repair a G5 Desktop and then replaces it with a x86 Mac Pro or if they replace the Mac mother board, such that Astro IIDC won't recognize that Mac.
You can purchase a second copy of Astro IIDC at $35 USD (1/2 price) though:
http://www.outcastsoft.com/SecondCopyAstroIIDC.html
and the second copy can be registered for either a Mac or Camera too - your choice.
Hope That Helps.
Milton J. Aupperle
President
ASC - Aupperle Services and Contracting
Mac Software (Drivers, Components and Application) Specialist
#1005 - 815 14th Avenue. S.W.
Calgary Alberta T2R0N5
1-(403)-229-9456
www.outcastsoft.com
Proud Supporter of the "Party of Alberta"
http://www.partyofalberta.org/
