From: Alan Friedman <alan@greatarrow.com>
Date: September 16, 2008 6:30:48 PM MDT
To: Astro_IIDC@yahoogroups.com
Subject: Re: [Astro_IIDC] New file uploaded to Astro_IIDC
Alberto,
You need to get off that comfortable terrace and onto a bus to some dark skies!
This is really a nice result with the DMK - I think you will be thrilled with the possibilities from a dark location.
The RGB Jupiter is very good too. I'm not sure what focal length you used to capture the raw data... f30 should be about right for Jupiter at its current low altitude. A smoother signal with more contrast will make image processing much easier. The "seeing" is dependent on many factors, wavelength included. The seeing progressively worsens as you move to the shorter wavelength filters - red will be your most detailed data and blue often looks like a mess. The theoretical story on wavelength vs. resolution is opposite, but the atmosphere overrules physics in all but the very best of seeing conditions. The sensitivity of your camera is higher in red and green, allowing a lower gain setting for these filters.
Your observation about the softness that can be tolerated in the RGB component of an LRGB image is quite true. You can have fun by applying a gaussian blur to the color data. You can blur the image to an almost unrecognizable blob and see virtually no change in the final result with the luminance layer applied on top. Magic!!
Thanks for sharing your work... look forward to seeing more.
steady skies,
Alan
On Sep 16, 2008, at 5:24 PM, albe albo wrote:
Thank you Alan and Milton.
Those words from you sound really pleasant!
I think that sometimes the "lazyness" represent a kind of advantage.
I'm pretty lazy... i often say that i 'd like to experiment dark skies but... i love my terrace, my music, my office, the heating (my wc..LOL) etc etc.
So until now i never did astrophoto at mountains or dark skies.
Because of this, i'm pushed to scavenge all the possible photons between the pollution and the electronic noise.
Now after a couple of years attempting from the terrace i'd really like to do a session under a black sky in order to check what i'm losing: i should find a terrace (with music etc etc) on the Alps (lol).
Anyway after doing many try on M27, M57, Triplet, etc. this year I attempted new objects and NGC 6992 is the first use of the 2x2 binning.
Some days before i did my first attempt with 6960 with no binning (i uploaded it) .
I was surprised by the details of the center of M20 and M16 even if that nebula passed at 20° and 30°.
I was amazed by coupling the new DMK luminance with older and blurr /noisy EOS color images!
If someone coud be interested i can post separately the Luma and chroma in order to understand what i mean for Lowww-res chroma.
These days i attempted some jupiter too (altitude 20°) but i guess that my Baader GB filters are too dark.
Do you know the way to understand if i own the type I or type II baader RGB filters?
In addition i get only a decent RED while seems that the Blue and Green are less detailed.
I'm a real newbie to RGB planetary assembling but even in this field i'm amazed by the amount of elementary information contained into dark, blurry and noisy movies.
For a mistake a recorded a jupiter very huge (almost 670 pixels diameter) and very dark ...at 7.5 frames/sec.
I was trashing the 3 movies but i processed them and i got something unexpected.
It is not a great Jupiter (Alan rules!) but considering the big-noisy captured frames and the low elevation of jupiter the final images shows unexpected details.
For curiosity i will post the 3 jpg of a typical frame of that movie into the planetary section.
080829-Jupi-Big-Blue-MAY.jpg 1024×768 pixel
080829-Jupi-Big-Green-MAY.jpg 1024×768 pixel
080829-Jupi-Big-Red-MAY.jpg 1024×768 pixel
Now i'm trying a quick NGC 6960 with full Moon: binning 2x2 20 seconds with the C8 at real f 3.3 (previously i thought i was at 3.3 but i was at f4.2).
I'm curious..
regards
Alberto
----- Original Message ----
From: Alan Friedman <alan@greatarrow.com>
To: Astro_IIDC@yahoogroups.com
Sent: Tuesday, September 16, 2008 3:58:03 PM
Subject: Re: [Astro_IIDC] New file uploaded to Astro_IIDC
That's a gorgeous result on the Veil with a webcam!
Alan
On Sep 16, 2008, at 9:32 AM, Astro_IIDC@yahoogro ups.comwrote:
Hello,
This email message is a notification to let you know that
a file has been uploaded to the Files area of the Astro_IIDC
group.
File : /DSO/080908- NGC6992-mosaic- test.jpg
Uploaded by : richter1956 <richter1956@ yahoo.com>
Description : NGC6992 - DMK mosaic + EOS chroma - 1st attempt
You can access this file at the URL:
http://groups. yahoo.com/ group/Astro_ IIDC/files/ DSO/080908- NGC6992-mosaic- test.jpg
To learn more about file sharing for your group, please visit:
http://help. yahoo.com/ l/us/yahoo/ groups/original/ members/web/ index.htmlfiles
Regards,
richter1956 <richter1956@ yahoo.com>
