This page contains some collected notes about the equipment I have been using. It consist mostly of information that had no place left after my website was redesigned. Some of this information is about equipment I no longer have.

My Telescopes

Celestron C8 Schmidt Cassegrain

The Celestron C8 was my first ‘large’ telescope. I bought it used from e-bay. It's made in 1992, and has the Starbright coatings that were optional then. The Celestron C8, despite its age, keeps on being a great, versatile instrument with a good light gathering ability, while still being portable. The Schmidt-Cassegrain telescope design has many qualities, as well as a few disadvantages. All in all, my C8 has never let me down and has travelled with me to many interesting locations.

External link:

http://skywatch.brainiac.com/collimation.pdf Uncle Rod's guide to SCT collimation, by Rod Mollise

This telescope came with a fully motorized Vixen Super Polaris DX mount that's really suitable for the C8 OTA. It came equipped with a Celestron 8x50 Polaris right-angle finder that I find very convenient to use. In addition to the regular finder, I've added a Celestron 'red-dot' reflex finder, later replaced by a Telrad finder. This combination of finders makes finding even faint objects quick and easy.

The Vixen Super Polaris DX equatorial mount has motorized Right Ascension and Declination axes and is controlled by the DMD-2 hand-controller. I currently use a 12 Volt, 17Ah sealed lead-acid battery that can power the drives for many nights. This battery is also powering my JMI NGC-MAX computer and encoders (DSCs).

In 2005, my Super Polaris mount and JMI NGC-Max Digital Setting Circles have been replaced by a Vixen Sphinx GoTo mount.

When I acquired the C8, it was mounted on a steel pier instead of a tripod. While this is an extremely stable platform, I wanted something that was a bit more portable. So I started looking for a sturdy tripod. Eventually I found this in the form of a Vixen wooden tripod with a GP-DX tripod head. To attach my Super Polaris to this tripod head, I had a mold made by a local metalworking company. With this, I have a good and stable, but still transportable tripod. The tripod for my new Vixen Sphinx mount is a Vixen HAL110 high quality aluminium tripod.

Orion StarMax 127 Maksutov Cassegrain

After having owned the C8 for some time, it became clear that I was thoroughly addicted to the hobby. I started looking for a scope that was more portable than the C8, and which I could easily take to a dark spot, the observatory, or on holiday. After comparing the many options, I decided on a small 5 inch Maksutov-Cassegrain made by Orion. I consider 5 inches the minimum to see many deep sky objects, so a small refractor would not do. This Maksutov-Cassegrain is still compact enough to easily take with me. The Orion StarMax 127 EQ, which includes the StarMax 127 and an EQ3 mount, has received favourable reviews and is (reasonably) affordable. The entire scope (OTA, mount and tripod) weighs only 16 kilograms and so is easily transportable. This telescope is also sold under the SkyWatcher brand.

When I received this telescope, I immediately found a problem with the EQ3 mount it came with: The declination axis was stuck when a piece of metal from the clamping mechanism got displaced. This was immediately fixed by the dealer however, and I have not had any problems since. After some tweaking of the bolts around the worm drive mechanisms of the RA and declination drives, it is now a really smooth running mount (although there is still some backlash).

I later added a Right-Ascension motor drive to the EQ3 mount. Although it functions well, I have a few remarks on its design:

1. •The way the RA drive is attached to the mount is fragile and not very solid. It looks ugly.
   

2. •When it's connected to the mount, the manual RA fine adjustment cannot be used anymore without loosening a very small bolt (something which is next to impossible when you're at a dark site). A clutch design such as found on other mounts would have been a much better idea.
   

3. •Its maximum speed is only 8x sidereal, which is slow, especially when considering the manual fine adjustment cannot be used anymore.
   

4. •The hand controller LED is a very bright green. This is extremely annoying and disastrous for your dark adaptation one option is to put black tape over it. I've gone for the option of rotating the two-color LED 180° so the hand controller on/off LED shines a friendly dim red (this will void warranty!).
   

The tube of this Mak-Cass is entirely made of metal and feels very solid. There are no complaints about the quality and finish of the OTA. On the rear cell of the primary mirror is a thread that looks remarkably like a standard SCT thread, but the thread is actually NOT compatible. There are also 6 screws to adjust collimation (the collimation procedure can be found on the Orion website or here). The standard Visual Back that comes with this scope, is 1¼ inch which is T-threaded on the outside, so SLR cameras can be directly attached needing only a suitable T-adapter for the camera. The focuser is a bit stiff, with varying resistance, but it's tolerable, and there is only slight image shift. There is a quick-release finder bracket so the finder can be removed withoud losing alignment. I have traded the standard 6x26 finder for an Orion EZFinder II red dot reflex finder. Later I've added a SkyWatcher 9x50 finder that fits the Orion quick-release finder bracket.

To test this scope's abilities in practice, I have looked at Saturn, Jupiter and M42 during a short observing session. Before looking through the StarMax i have left it outside for 45 minutes to cool down. During this session the temperature outside was around -1°C. I did not use the supplied Orion mirror diagonal, but my own Celestron mirror diagonal.

The first object to be viewed is Saturn. The Cassini division is clearly visible with a 90x magnification, as well as Saturn's largest moon Titan. Three other moons can be made out, but are fainter. Some contrasting bands on the planet's surface can be made out. Jupiter is beautiful and shows quite some detail; unfortunately the Great Red Spot is behind the planet's surface, so it can not be made out. The seeing is not too good, but that's not this scopes' fault. Jupiters' Gallilean moons are 4 bright dots of light in line with the planet's bands.

M42 in the constellation of Orion unfortunately was in the direction of some street lighting, which is noticeable by the orange glow in the image. The C8 is clearly not as sensitive to this, which I attribute to the dew shield I use with the C8. Still M42 shows very nice in this 5 inch Mak-Cass. The contrast is excellent and the boundaries of the 'bat' shape, as well as the internal structure inside the nebula can clearly be made out. The stars of the Trapezium (I can see 4) are brilliant and sharply defined points of light embedded inside the nebulosity.

This scope does not disappoint, and it brings a lot of observing fun for such a small instrument. I sold this scope and the EQ3 mount in 2007.

StarMax 127 links:

Inst_makcasscollim.pdf    Collimation procedure for the Orion StarMax 127

William Optics Megrez 80-II ED Triplet Apochromat

I've owned this telescope since january 2006. This is a high quality instrument that is finished to a very high standard. It has a triplet 80mm objective lens with one or more elements made out of ED (Extra low Dispersion) glass, which produces very good color correction. This is an f/7 scope (560mm focal length). It has a retractable dew shield. It is equipped with a smooth Crayford focuser.

The William Optics Megrez 80-II ED came together with a 2" dielectric (99% transmission) mirror diagonal and a nice backpack for the scope and its accessories. Together with the scope, I also bought a very well crafted William Optics Red Dot (unity) finder. Some time after I decided to enhance the scope with an aftermarket William Optics dual speed focuser.

The Megrez 80-II ED is a joy to use and quick to set up. This telescope has been discontinued by William Optics and it has been superceded by the f/6.8 ZenithStar 80 II ED APO Doublet.

SkyWatcher ShortTube 80 Achromat

In 2005 I acquired a used SkyWatcher Short Tube 80mm Achromat. This is a "rich field" f/5 telescope that has a focal length of 400mm. It has a simple rack-and-pinion focuser that nevertheless has a good feel to it. This scope is very quick to set up and can be placed on a simple camera tripod. It shows great views of the milky way, the moon, open clusters and some of the brighter nebulae. It is limited to low magnifications, so it's not a very suitable planetary scope. This is a truly portable instrument, and a favourite of my children.

The ShortTube 80 makes a great "super finder" piggy backed on my C8. I use an Antares quick-release finder bracket (see http://www.teleskop-service.de/Selbstbau/Sucher/sucher.htm#AnSucherhalter).

My Accessories

JMI's NGC-MAX Telescope Computer

With a family with small children, and a demanding job, my observing time is limited. It takes a significant amount of time to locate deep-sky objects in my non-ideal sky. This is the reason I decided to invest in some sort of electronic aid for quickly locating objects. For my Vixen Super Polaris mount, there are basically two options: The Vixen SkySensor 2000 Go-To system, and Digital Setting Circles (DSCs). The SkySensor 2000 is a highly-praised product, but I decided I did not need go-to functionality, just the ability to locate objects. JMI, with its NGC-MAX computer and corresponding encoders for the Super Polaris mount, had just the product I was looking for, for a price only half that of the SkySensor 2000. JMI was very quick and helpful but unfortunately Dutch customs were not, so it took some organizational skills to finally get the packet delivered to our home.

The computer, mount, encoders, cables and manuals were all neatly packed. Unfortunately the NGC-MAX computer's power switch was in the 'on' position, so the battery that had already been installed by JMI was empty (this could have been done by customs).

Installation of the encoders on the RA and Declination axis was simple. The RA encoder blocks the view through the mount's polar axis finder however. Fortunately, the NGC-MAX has a built-in facility to aid with accurate polar alignment. One small nitpick: the encoder housing is black while the rest of the mount is greenish-grey.

The entire alignment procedure consists of 3 steps:

    * Accurately setting the mount's DEC to 0 using the setting circles (while pointing the scope EAST!).

    * Selecting and aligning on the first alignment star.

    * Selecting and aligning on the second alignment star.

During the entire alignment procedure the telescope should stay on the west side of the mount, taking care not to cross the meridian. Star alignment is done by centering the alignment star in a medium-power eyepiece (I'm using a 10mm Plossl).

After aligning on the second star, the NGC-MAX computes a 'Warp factor' that indicates how much the the actual value returned by the mount's encoders differs from the actual value computed by the NGC-MAX. This value should be as low as possible. In my case it ranged from 0.0 to 0.3 between sessions, which are very acceptable values.

After completing the alignment procedure you can select an object from the NGC-MAX's database. There are more than 12,000 objects to choose from, spanning the entire Messier catalog (M), the entire NGC catalog (NGC), 2,800 objects from the IC catalog (IC), 928 single and multiple stars (ST), 386 Non-Stellar objects (NS), the 9 planets (P), and 28 user-definable objects (NEW). After selecting an object, the computer displays a brief description of it, including its size and magnitude.

After selecting an object from the NGC-MAX's database, you can select the Guide mode. In this mode, the computer's display will tell you how much you need to move the mount, and in which direction, to locate an object. I found that the guiding was quite accurate, and I always ended up with the object located somewhere near the middle of the field of view of a 23mm eyepiece. Since this is the main purpose of this system, I consider it a success.

Some tips:

1. •Pressing the Enter key in Guide mode will display the object's description on the NGC-MAX's display.
   

2. •In Guide mode, pressing the Up or Down key will select the next or previous item from the currently selected catalog.
   

3. •There is an "Identify" mode which will display the object the telescope is currently pointed at in real-time. This is great when panning through an interesting area of the sky.
   

Overall, I'm very pleased with the NGC-MAX, as it has very noticeably decreased the time I need to locate objects during observing sessions, allowing me to get as much as possible from this hobby in the limited time that I have available for it. It needs very little power, and has a very usable set of functions.

As I now have the Vixen Sphinx mount, I will not be using the NGC-MAX very often anymore.

My Eyepieces

A short list of my most-used eyepieces:

1. •Baader Hyperion 13mm; 2" / 1.25" Wide Angle (70° AFOV). Very well-made, large, very good optical quality;
   

2. •Burgess Optical 32mm SWA (Super Wide Angle, 70° AFOV); 2". Good optical quality. Nice wide-field eyepiece;
   

3. •Burgess Optical 16mm SWA (70° AFOV); 1.25". Good optical quality;
   

4. •Celestron Axiom 23mm (68° AFOV). Very well-made, very good optical quality;
   

5. •GTO 32mm Super Plössl;
   

6. •GTO 17mm Super Plössl;
   

7. •GTO 10mm "Silver Top" Plössl;
   

8. •GTO 7.5mm Super Plössl;
   

9. •Meade 6.4mm series 4000 Super Plössl;
   

10. •Orion Sirius 25mm Plössl. Good optical quality;
    

11. •ScopeTronix MaxView 40 Plössl with digital camera interface;
    

12. •TeleVue 9mm Orthoscopic with illuminated crosshair. Very good quality, useful for alignment.