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Posts Made By: Roland Christen

February 17, 2010 04:12 PM Forum: Astro-Physics

Pictures from Dome C in Antarctica

Posted By Roland Christen
French research facility at Dome C doing extra-solar planet research:

http://e.bondoux.free.fr/imagesforum/PAIX.JPG

3600 mount with heavy equipment package. This one is definitely not carry-on size:

http://e.bondoux.free.fr/imagesforum/t300.JPG

March 4, 2010 04:00 PM Forum: Equipment Talk

Re: 2 inch ap diagonal vs tv diagonal

Posted By Roland Christen
The overall wavefront error of a diagonal has less meaning than that of a primary mirror. In a primary mirror every image must pass thru the entire aperture, therefore the entire aperture must have high wavefront error rating in order for the image to not be distorted at the focal plane. In the case of a diagonal, the overall wavefront error can be much lower, yet the effect on the image as far as distorting it, will be negligeable. That is because the diagonal mirror is so close to the focus point that only a very small portion of the surface is used to form the image. In the case of a 2" diagonal, only about 1/10 inch to 1/4 inch diameter is used to form the actual image of any star or planet. Therefore, a diagonal with as low as 1/4 wave surface can have an effective 1/40 wave error at the focus point.

Rolando

April 6, 2010 10:06 PM Forum: CCD Imaging and Processing/Deep Sky

NGC4565 with QSI583 camera

Posted By Roland Christen
Gilles Cohen image:
NGC4565, AP155EDF with flattener, QSI583 at 0.99" per pixel, poor seeing, 2.5 to 3.2 pixels...mag 3.5 sky. 24x5 minutes with Baader L filter.


April 6, 2010 10:09 PM Forum: Astro-Physics

Re: 130EDF Notifications?

Posted By Roland Christen
>>Has the notification process ceased for the current production run? When will the next production run start? >>

It is ongoing. I am still finishing up more lenses and will do so for the next 4 months.

May 17, 2010 08:04 PM Forum: CCD Imaging and Processing/Deep Sky

Deep Leo

Posted By Roland Christen
Hi All,

for those who haven't seen Tony Hallas' images lately, here is a link to his leo Trio taken with a 206EDF refractor: http://www.astrophoto.com/Leotrio.htm

Rolando

May 17, 2010 08:05 PM Forum: Astro-Physics

Deep Leo

Posted By Roland Christen
Hi All,

for those who haven't seen Tony Hallas' images lately, here is a link to his leo Trio taken with a 206EDF refractor: http://www.astrophoto.com/Leotrio.htm

Rolando

July 21, 2010 01:13 AM Forum: Astro-Physics

Production Honders test

Posted By Roland Christen
First of 4 Honders production astrographs now undergoing sky testing. This first image of M27 was made with 2 x 10 minute exposures each of RGB. The night unfortunately was very hazy so it is not as deep as it should be. Seeing was also not the best.

This first image shows the entire field of the STL11K camera with the astrograph's 1160mm focal length.

I will be testing each of the scopes over the next week or so, finalizing all the details as needed. I am very delighted by this first test, being that it is the culmination of a lot of work on everyone's part in our team.

Rolando

July 22, 2010 07:53 PM Forum: CCD Imaging and Processing/Deep Sky

M27 narrow band

Posted By Roland Christen
Recently was testing our new 305MMF3.8 Honders Astrograph under hazy Illinois skies. Tried RGB but with our heavy light pollution I was not able to get a very good result. Narrow band cuts thru most of that so here is the result.

2nd night of testing on M27. The air was still somewhat moist and hazy, but the seeing was much better. Switched from RGB to H-a, OIII and B.

Details:
Equipment - 305 Honders F3.8 astrograph, STL11K camera, 7nm Baader H-a, 7nm OIII Baader, Blue Baader filters, 3600 mount.

Exposure times - R = 1.5 hours H-a, G = 1.3 hours OIII, B = 10 minutes Blue.

Cropped image at full resolution

Rolando

July 29, 2010 10:02 PM Forum: CCD Imaging and Processing/Deep Sky

Abel 71

Posted By Roland Christen
Very faint object (mag17) in Cygnus. 40 minute exposure with 12" F3.8 Astrograph and STL11K camera.

Rolando

August 9, 2010 04:45 PM Forum: CCD Imaging and Processing/Deep Sky

Veil complex

Posted By Roland Christen
The Veil is always a tempting target for narrowband. I had a short window of opportunity lasting about 3 hours.

Scope - AP305mm F3.8 astrograph
Camera - SBIG STL11K
Filter - Baader 7nm H-a
Exposure - 6x10 minutes (1 hour total)

Full frame image reduced to appro. 1/3 size

Rolando

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