Posts Made By: Roland Christen

Saturn with ST10XE in planet mode. RGB image, 50 each with AP 10" Mak-Cass taken last weekend.

Roland Christen

Hi All,

I thought I might post a comparison of the 160 EDF color curves with that of an optimized achromat of the same size, in case anyone is interested. Later I may post a side by side image of the Airy disc at each color to show how these color curves translate into actual images at the eyepiece.

Roland Christen

I figure with the new scope we shoudl have a new paint job too. Here's idea #1

Rolando

here is a sample image taken with the 160. 5 second exposure LRGB with SBIG ST10XE

Roland Christen

We have made all the mechanics for all the sizes and are still awaiting the optics from Aries. Last word was that he was doing the QA on them. Meanwhile I am pursuing some other avenues to speed up the production.

Roland Christen

All achromats will have similar percent chromatic aberation. It amounts to a defocus of approximately .06% of the focal length. This means that for a 1000mm focal length, the blue and red will focus 0.6mm farther than the green. The longer the focal ratio, the closer this will be to the 1/4 wave limit of a diffraction limited image. For a 5" scope, this occurs around F16 for the three colors of red, green and blue. However, the visual spectrum continues beyond blue to violet, and this will lie outside the Airy disc by a substantial margin. The attached image shows the Airy disc at high power from a 5" F16 achromat.

For shorter focal ratios, the red, green and blue colors will not be within the Airy disc, so some of each color will hang outside the image, depending on the focus position. I will post some shorter ones next.

Hello,

A new optics design group is forming on Yahoo for anyone who is interested in discussions of optical design of all types of amateur optics from refractors to mirrors and Catadioptrics. I am reprinting the announcement by Chuck Taylor here:

For those who enjoy optics, there is a new optical design group at:
http://groups.yahoo.com/group/ATM_Optics_Software/

This will center on the use of ATMOS (ATM Optical design and analysis
Software). It is a place to swap ideas and questions about ray tracing,
optics and optical design and the ATMOS software.

For those who haven't tried ATMOS, it is a very powerful package, including
optimizing a design, tracing up to 30,000 rays at 6 wavelengths, outputs to
Aberrator software, Schott and Ohara glass catalogs and roughly 1.2475
zillion output graphs, all of which make sense. I have no connection to the
software, but it is fun to play with while learning more about optics. (I
have no connection to the software, other than enjoying it)

I invite you to the world of optical design, it's fun!

Clear Skies

Chuck Taylor

Hi folks,

One of our French dealers sent me this link showing the French research team
down under with two of our 900 mounts getting ready to track the Sun and stars
with a pair of specially made C11 scopes. These mounts already spent last
season down there in weather as cold as -60C doing research on seeing at Dome C.

Interesting that the platform and tripods were made from wood. I was told
that they resist the cold better than metal and won't twist with the temperature.

Some pictures:

http://pleiades.unice.fr/~agabi/galerie/Agabi_DSCN9206_m.jpg
http://pleiades.unice.fr/~agabi/galerie/Agabi_DSCN7818_m.jpg
http://pleiades.unice.fr/~agabi/galerie/Agabi_DSCN9370_m.jpg
http://pleiades.unice.fr/~agabi/galerie/Agabi_DSCN9219_m.jpg

Home page: http://pleiades.unice.fr/~agabi/

Roland Christen

PEMPro 1.10 available for all AP mounts with PEM

PEMPro is now available for download and purchase from CCDWare Publishing.

PEMPro is a Microsoft Windows application that will analyze the performance of any mount that is equipped with a CCD camera and compatible camera control software. No more exporting log files and Excel spreadsheets. PEMPro will reveal your mounts performance in real time regardless of seeing conditions.

PEMPro gives you powerful tools to program your mount's periodic error correction firmware to achieve the best possible performance. PEMPro dramatically improves guided and unguided imaging resulting in better images and fewer lost exposures.

* Acquires performance in real-time over multiple worm cycles.
* Analyzes the collected data to define mount performance.
* Creates a smoothed, fitted correction curve.
* Programs your mount's periodic error correction firmware.
* Allows simple comparison of before and after results.
* Provides advanced refinements to further fine tune your mount's performance.

This software is applicable to all current and past Astro-Physics German Equatorial mounts with PEM (permanent error memory). This includes the mounts with Quartz Micro-Drive controllers (QMD) and all versions of the GTO control box. The functionality of the program may vary, depending on which control system you have. The most recent GTOCP3 control box can take full advantage of all functions.

To find out more about PEMPro, take and interactive tour, and download a fully-functional 14 day trial version, visit http://www.astro-physics.com/products/accessories/ccdware/pempro.htm

A Special Edition of PEMPro (PEMProAP) will ship with all new Astro-Physics 1200GTO and AP900GTO mounts starting December 1, 2004. A demo version will be available to all 1200GTO mounts that were shipped earlier in 2004 and to all people who have purchased (or will purchase) the new GTOCP3 control box as an upgrade. For more information, please visit the above link.

For any questions or comments regarding PEMPro, feel free to join the CCDWare Yahoo Newsgroup at http://groups.yahoo.com/group/CCDWare/

Hi all,

I had a chance to do a bit of imaging with a 14" Mak-Newt the last couple of days. This impressive instrument will be set up in Chile for remote imaging. I had it on my 1200 mount in my observatory, checking it out for the owner before it gets sent down under.

This image is a combination of 1 sec, 6 sec, 10 sec and 30 sec RGB images placed on top of each other.

Roland Christen