From: albe albo <richter1956@yahoo.com>
Date: January 18, 2010 1:22:45 PM MST
To: Astro_IIDC@yahoogroups.com
Subject: Re: [Astro_IIDC] Celestron C11 experiments & setup
Thank you Milton,
you are right about horizontal-vertical collimation but one day in the future (when i will see the stars again) i'll refine the collimation with a true star.
I got a certain experience in collimation after spending a whole day in learning the responses of the screws.
I noticed that SCT scopes are robust beasts and they keep the collimation very well unless you try to collimate keeping the 3 screws "delicately" loose: in my opinion they must be fairly in tension otherwise the collimation suffer every little shock.
In honor to your country we should call it a "Stampede Collimation"! LOL
It happened that after disassembling and reassembling the corrector plate the collimation remained almost perfect. I'm not talking about the rough collimation (short focals as the first or second step in my image) but i'm talking about the final hi-res collimation.
For this reason i'm not really worried about the horizontal/vertical collimation unless the chassis of the C11 will result less ridgid as the previous Meade LX10, that was solid and heavy like a military tank!
The C11 is 1 inch bigger but is almost 1Kg lighter than the Meade 10" so... i hope that Celestron made the OTA solid enough.
I'll be able to confirm it under a clear sky!
Unfortunately i'm "having" a clear sky... but invisible because of persisting fog.
That fog is so dense that doesn't allow me to aim the artificial star too.
About the star: for the moment it is not a extremely true star since the pin hole was made in a hurry. I didn't measure that hole but it is a bit large to be defined as "star".
Anyway, as you can see in the photos, the distance fromthe observer is enough in order to achieve some reliable result.
The next step is to try with the 50micron fiber optic (i already used it indoor) but i need an auxiliary led placed in the neighbor of the star in order to see "where" is the artificial star since 50microns are really difficult to find and to aim from 70meters.
The 50 micron hole at 70 meter can be considered as a true star.
I think that this C11 is good and i really hope in a magic night in order to capture some interesting picture at f. 46.6 (that's the sum of ocular projection + my extenders).
On the other side I'm curious to push the reducer to f. 2.8 or less in order to check if the very small DMK sensor allows a good correction at the borders too.
For the Moon i guess that i must place the black velvet into the OTA because the internal black(?) paint is really "reflective" and shiny if compared to the velvet.
Even without capturing the sky i find that some optical experiments are interesting too.
Perhaps i have already posted this image:
http://dl.dropbox.com/u/1094920/VARIE/Test-30Km.jpg
it was taken from my house to some people on a mountain 30 Km. far.
Consider that 30 km in horizontal suffer a lot of the warm-terrain seeing and the air is always thick, dense and dirty while when you aim to the zenith you have only a few kilometers dense.
Sorry if i was verbose but as you can see i like every kind of experiments...
TTYL
Alberto
Da: Milton Aupperle <milton@outcastsoft.com>
A: Astro_IIDC@yahoogroups.com
Inviato: Lun 18 gennaio 2010, 19:06:51
Oggetto: Re: [Astro_IIDC] Virtual Moon Atlas
Hi Alberto;
Very interesting, thanks for sharing.
What did you use as a light source for the collimation testing on the horizontal at 70 meters?
And aren't you afraid that the collimation will need to be re-done when you move the scope into a more normal near vertical orientation?
Or are you just interested in the optical properties of the C11 for the horizontal testing?
Also, in the zip focal test folder is the image "100116-Ir-ScarceSe eing-NotFullyCol limated.jpg" . That looks like a nice IR Mars shot.
TTYL..
Milton Aupperle
On 18-Jan-10, at 6:45 AM, albe albo wrote:
Thank you to all.
I installed the Moon Atlas on my iMac and it works fine.
I'm wondering if while installing on my MacBook i had the bad idea to change the path for the installation.
I often use a different folder for my applications in order to keep them separated from the Apple applications.
When i did so, i noticed a weird behaviour : the installer created a new "applications" folder inside my folder and i considered that a strange behaviour.
On the contrary while i installed on the iMac i left the default Applications folder and it worked fine.
Of course now i must do the same thing on the MacBook in order to confim such theory.
A quick test consisting in moving the Atlas folder to the Applications folder didn't work.
I'll try unistalling it and reinstalling in the default folder.
About the C11: it seems very good.
I did a intense set of collimation and testing on ground objects (the seeing was very bad) and i got a nice collimation at f. 46.6 (more than 13 meter focal length). It is the first time i get a very nice airy circle using an artificial star far approx 70 meters from my scope.
This is the resume of such collimation and testing:
http://dl.dropbox. com/u/1094920/ ASTRO/C11/ 100116-C11- Scheda-Collimazi one.jpg
i did a rough Ronchi test and it seems nice too:
http://dl.dropbox. com/u/1094920/ ASTRO/C11/ ronchi-C. avi
If someone is interested about the C11 test at f.46.6, f.21.6, f.10, f.7.83, f.3.97, f.2,88 this is the set of images of a building placed exactly at 1500 meters far from my house.
The pixels measurements have been done in order to calculate the resulting focals assuming that the "normal" C11 is 2800 mm.
http://dl.dropbox. com/u/1094920/ ASTRO/C11/ C11-FocalTest. zip
Cheers!
Alberto
Da: Willie Strickland <cwskas@earthlink. net>
A: Astro_IIDC@yahoogro ups.com
Inviato: Sab 16 gennaio 2010, 00:25:58
Oggetto: Re: [Astro_IIDC] Virtual Moon Atlas
I have everything downloaded now, all the options. Played with it a bit, but havent had a lot of time to spend on it today.
Willie
On Jan 15, 2010, at 3:25 PM, Mark Gaffney wrote:
>
>
> Hi Willie,
> Glad to hear someone`s having success with the Mac download!
>
> Mark.
> On 16/01/2010, at 4:40 AM, Willie Strickland wrote:
>
>> Alberto,
>>
>> I installed successfully on my MacBook, 10.6.2, 2GB ram, Intel GMA 950 graphics.
>>
>> I also have a CPC 11", but I couldnt say I know much about it other than point and look. :-)
>>
>> Willie
>>
>> On Jan 15, 2010, at 2:47 AM, albe albo wrote:
>>
>> > i didn't know about the mac porting.
>> > Unfortunately i installed it on my MacBook Pro (apparently successful) with OSX 10.5.8 but it refuse to start.
>> > The icon bounces for some seconds then close.
>> >
>> > I launched it logged as root but it's the same.... :-(((
>> >
