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Posts Made By: Roland Christen

December 15, 2004 02:32 PM Forum: Astro-Physics

14 inch Mak-Newt on 1200 mount

Posted By Roland Christen

Hi all,

Here is a picture of a 14" Mak-Newt on our 1200 mount. This instrument, made in Germany with Russian optics will be going to Chile for remote imaging of the southern hemisphere. I've had fun doing a bit of imaging with it these last two days. It is impressive what you can capture in 10 seconds, and even in 1 second.

Roland Christen

December 20, 2004 03:04 PM Forum: CCD Imaging and Processing/Solar System

Horsehead by Chris Hetlage

Posted By Roland Christen

This one is just too good to not post:

I shot this from Chiefland last weekend. A tough one to process, I
hope I haven't over-done it!

AP130 f6 - AP Field Flattener
AP 900 GTO Mount on ATS Portable Pier
SBIG STL-11000 with SBIG Research Filter Set Custom Scientific 4.5nm Ha Filter with AR Coatings

Ha - 10x20min
Red - 10x5min
Green - 10x4min
Blue - 10x6min

http://www.hetlage.com/images/hh_ha_hargb_ps_xlarge.jpg

A work in progress - Comments-tips-insults welcome....

Chris Hetlage
http://hetlage.com

December 20, 2004 03:05 PM Forum: Astro-Physics

Horsehead by Chris Hetlage

Posted By Roland Christen

This one is just too good to not post:

I shot this from Chiefland last weekend. A tough one to process, I
hope I haven't over-done it!

AP130 f6 - AP Field Flattener
AP 900 GTO Mount on ATS Portable Pier
SBIG STL-11000 with SBIG Research Filter Set Custom Scientific 4.5nm Ha Filter with AR Coatings

Ha - 10x20min
Red - 10x5min
Green - 10x4min
Blue - 10x6min

http://www.hetlage.com/images/hh_ha_hargb_ps_xlarge.jpg

A work in progress - Comments-tips-insults welcome....

Chris Hetlage
http://hetlage.com


February 2, 2005 10:18 AM Forum: Equipment Talk

Re: diagonals is there a differance

Posted By Roland Christen

The main difference is not in the reflectivity. This is not what's important about diagonals, because you will not see the brightness difference visually between a normal aluminum 88% diagonal, and enhanced 92% aluminum diagonal or a 99% dielectric.

There are two reasons for a dielectric 99% diagonal, aside from the high reflectivity:
1) the surface is cleanable without danger of introducing sleeks which can affect planetary contrast. A full dielectric is made from 50+ alternating layers of hard oxide materials. These have very good abrasion resistance because they are similar to thin layers of quartz. A diagonal using aluminum, even when overcoated with a protective dielectric layer, is vulnerable to scratching and sleeking when repeatedly cleaned.
Why does a diagonal need to be cleaned? Dust and dirt will accumulate quickly on a star diagonal as you insert and remove eyepieces, and this is the number one reason for poor planetary contrast. To get the best planetary performance, you need a clean diagonal surface.

2)An all-dielectric diagonal does not have a metal layer, so the overall light scatter is very much lower with the dielectric. Any time you apply a metal layer to a glass surface, you produce a scatter layer. You can see this easily enough if you compare an aluminized surface with a dielectric surface under full sun illumination. If you look through the diagonals, without any telescope, as they are pointed nearer and nearer to the sun, you will see the aluminized diagonal surface grow in brightness very much faster than the dielectric version. The bottom line again is higher planetary contrast. A good clean dielectric is the closest thing to having nothing but air between the eyepiece and the telescope objective.

Is the difference big? It is to dedicated planetary observer, and small or non-existent to the deep sky observer.

Roland Christen

February 4, 2005 08:09 AM Forum: CCD Imaging and Processing/Deep Sky

Trapezium closeup

Posted By Roland Christen

For those who have not seen this image before - it was taken down at the Florida Star Party on Summerland Key in 2003. Scope was my AP 10" Mak-Cass with ST10XE camera. The image is a combination of 60 exposures ranging from 1 second to 20 seconds.

Roland Christen

February 17, 2005 06:44 PM Forum: CCD Imaging and Processing/Solar System

Saturn last week

Posted By Roland Christen

My latest image taken at F22 with 10" AP Mak-Cass, SBIG ST10Xe, CFW. Approx 400 images processed in Maxim and Photoshop.

Roland Christen

April 1, 2005 08:08 PM Forum: CCD Imaging and Processing/Solar System

Dance of the Moons

Posted By Roland Christen

This image was taken with my 10" AP Mak-Cass on the evening of March 28, 05. ST10XE camera 2x Barcon 7500mm focal length, F36. The image was processed to bring out the faint Moons. First set of exposures taken at 7pm, second set 20 minutes later.

I think there are 5 Moons shown for sure and one faint star (upper, to the left of Titan). A 6th Moon seems to be showing very close to the rings on the upper right of Saturn, but it could be noise.

Roland Christen

April 13, 2005 12:05 PM Forum: CCD Imaging and Processing/Solar System

Sunset on Maui

Posted By Roland Christen

Took some images with my 92mm F5 Stowaway using afocal projection. Olympus digital camera shooting into a 34mm Zeiss Abbe eyepiece.

Roland Christen

April 27, 2005 07:41 AM Forum: CCD Imaging and Processing/Solar System

Jupiter from France

Posted By Roland Christen

Image was taken by Gilles Cohen with 155EDF refractor, Baader FFC at F28, using Toucam Pro.
Stack of 1200 images with Registax 3, color enhanced in Photoshop.

RC

May 4, 2005 06:29 PM Forum: CCD Imaging and Processing/Deep Sky

NGC4631 Whale

Posted By Roland Christen

Finally cleared last night for the first time in about 3 weeks. Tried my hand at the Whale using 160F7.5 EDF refractor, ST10XE camera on a 600 mount. 3x5 minute exposure. The image is 1/2 size.

Roland Christen