Equipment

The images you see on this website were produced through several very different telescopes and camera/filter systems.  Following is a brief summary of the equipment I currently use.


In November 2015 I added a Sky-Watcher Esprit 120 apochromatic refractor to the observatory.  With a focal length of 840mm and a focal ratio of f/7 it fills the "void" between my smaller William Optics Star71 and the Vixen VC200L.  The first image I took with this telescope is the Bubble Nebula through a hydrogen alpha filter. 

 

My largest telescope is the Vixen Visac VC200L - an 8 inch (mirror dia.) aspherical cassegrain.  It was designed for astrophotography.  It has a native focal length of 1800mm (f/9) but I normally use a focal reducer which results in the focal length being shortened to 1280mm (f.6.4).  This allows me to gather more light in a given amount of time thereby allowing me to shorten my exposure time.  The Vixen's longer focal length makes it my telescope of choice for galaxies and for zooming in on the smaller details within nebulae.


A recent addition to the observatory is a William Optics f/4.9 Star71 refractor.  This telescope was designed specifically for astrophotography and its "fast" optics allow me to gather more data in a shorter period of time.  It also has a flat field - which simply means stars remain pinpoints of light all the way out into the corners of the image.  Many telescopes, due to their optical design, do not provide a flat field.  My first image with the Star71 was taken very recently.  This telescope has basically replaced the AT65EDQ for wide field imaging.


My other wide field telescope is an Astronomy Technologies AT65EDQ - a 65mm refractor.  It's smaller size results in a much wider field of view so it is normally used to image nebulae and open star clusters.  Since obtaining the William Optics Star 71 (see below) the AT65EDQ will be used exclusively for autoguiding - not imaging.

 

Until the fall of 2013 a Canon 500D (DSLR) was used for all my imaging - with the exception of lunar photography.  The standard IR (infrared) filter was modified resulting in increased sensitivity to the reds - the main color in emission nebulae resulting from excited hydrogen ions... :-)  This camera served me well but I always thought I could produce better results with a different system.  The other type of camera used by astrophotographers is called a CCD (charged couple device).  Great strides have been made over the past several years in their development so in October, 2013, I made the switch - or as my astrophotographer friend Scott Rosen says, I went to the dark side... :-)

 

The camera/filter system I chose was the Atik 460EX and EFW2 filter wheel.  This system has proven to be everything I hoped it would be - very sensitive and reliable.  Atik makes superb astro-imaging systems.

 

I purchased the mono (black and white) version of the 460 for several reasons, one of which was that this allows me to do narrowband imaging.  This is a fascinating field of astrophotography which allows capturing light in very small band of the spectrum.  A couple of my images were done in hydrogen alpha - the California Nebula and the Cone Nebula region.  Exposure times need to be increased dramatically to capture this data but when done correctly the image will show much more of the fainter nebulosity than standard (broadband) filters. 

 

The filters are manufactured by Astrodon.  I use their Tru Balance LRGB broadband filters and the Ha (hydrogen alpha), OIII (oxygen 3) and SII (sulfur 2) 3 nanometer narrowband filters.

 

Finally, for lunar imaging, I use a Point Grey Chameleon camera.  It captures about 18 frames per second.  A typical sequence would involve taking 500 - 2000 frames in AVI format and then "stacking" them with software such as AutoStakkert! 2.  My procedure is to use only the best 20% of these frames.  This image is then taken to PhotoShop for finishing work.  In the spring of 2015 a ZWO ASI120MC camera was added.  It is a color camera and will be used for planetary, lunar and solar imaging.

 

When you ask an astrophotographer to name the most important piece of equipment in their systems most will tell you it is the mount.  If the mount is not tracking the movement of the stars precisely a high quality image cannot be obtained.  Therefore, in the fall of 2014 I upgraded my mount.  Until then I was using a Celestron CGEM DX mount which had been hypertuned by Deep Space Products in Phoenix.  It was a good mount but not what those in the hobby would call a great mount.  I wanted something that would help me produce images with crisper details and, most importantly, pinpoint stars.  To that end I purchased an Astro Physics Mach1 GTO mount.  It is a highly engineered system that is well respected in the astrophotography community. 

 

Below are photos of how the systems are configured.

 

 

Wide field setup
Wide field setup
Esprit 120
Esprit 120

 The observatory's most recent addition is a Sky-Watcher Esprit 120 ED triplet refractor.  It has a focal ratio of f/7 and a focal length of 840mm.  This fills the gap between my William Optics Star71 (350mm focal length) and the VC200L (1280mm focal length).  This scope was put into service in November of 2015. 

 

The camera, filter wheel, off axis guider and guiding camera are mounted on the Esprit - this is the typical imaging configuration.


The system also has a dedicated doublet field flattener which provides a flat field and minimizes aberration and distortion.  The flattener was designed specifically for this telescope.

Esprit 120 lens and baffles
Esprit 120 lens and baffles

The business end of the Esprit showing the lens and baffle system.  It is an apochromatic system with a three element objective lens.  The light baffles are designed to reduce stray light which is very undesirable when imaging.



WO f/4.9 Star71
WO f/4.9 Star71

Here is a recent addition to the observatory - the William Optics Star71 refractor.  A beautifully crafted telescope, it provides widefield views and will replace my AT65EDQ.

Baffles
Baffles

This view shows the baffling (ridges) inside the optical tube.  These are designed to minimize the amount of stray light entering the telescope.

Another view showing the back of the telescope.  The connections are threaded (instead of compression fittings) allowing for a more rigid connection between the telescope and filter wheel/camera system.  This means there is less chance for unwanted movement while imaging.

Imaging with the VC200L
Imaging with the VC200L

This is the configuration when I am imaging with the VC200L and autoguiding with the AT65EDQ.  The Starshoot autoguider's purpose is to lock on a star and send commands to the mount allowing the telescope to precisely follow the imaging target.  When autoguiding is not functioning correctly the stars in the image will appear oblong (or worse).  Stars are points of light and that is how we want them to look in our final images.

Imaging with the AT65EDQ
Imaging with the AT65EDQ

And this is the configuration when I am imaging with the AT65EDQ and autoguiding with the VC200L.

Adapters and more adapters
Adapters and more adapters

This is an image I made for myself that I have on the wall of my observatory so I can remember how to put things back together... :-)  The marks on the focus tube indicate the proper focus positions for the various configurations.


Meadowlark Ridge Observatory
Meadowlark Ridge Observatory