David's Astronomy Pages Telescope Accessories Telescope   Home Page   Observatory Use

This page describes the various telescope accessories I have. 
I've attempted to include some practical points and learning that may be of use to others.

Useful tips on using LX200 equipment can also be found in the the following
MAPUG Archives (Meade Advanced Product User Group). 
Doc G's Information Site
These external links will open in a separate window.

Eyepieces and Barlows

I have the following eyepieces  : 26mm,  9.7mm , 9mm Illuminated Reticule and a 13.8mm superwide, which I used extensively until 2003. Since then I use a CCD Camera for practically all my astronomical observations, the eyepieces are now hardly ever used, except for when using eyepiece projection and teleextender for taking closeup shots of planets. 

Meade 26 mm Plossel 4000 series (1.25")

This is my main 'workhorse' eyepiece, and came with my LX200 when I bought it in 1995. It carries the odd scare from when it was once dropped onto concrete paving. However it still performs reasonably well, but it tends to show show glaring sometimes.

Meade 9.7 mm Plossel 4000 series (1.25")

I used to use this eyepiece for higher magnification work on double stars and planets.  I don't particularly like this eyepiece as I find the ocular size too small. A larger angle of view would help or a lower mag eyepiece in conjunction with a Barlow lens (see 13.8mm Super Wide Angle below).

Orion 9mm Illuminated Reticule (1.25")

This eyepiece works well. The illuminated reticule is battery operated and is controlled by a switch on the end of the battery-containing side pod.  Whilst it is not par-focal with my other eyepieces I like the reticule shape and find the additional refocusing an acceptable limitation.  

Meade 13.8mm Super Wide Angle, Plossel 4000 series (1.25")

This eyepiece is fairly new (2000) and was purchased in 2000 with aim of adding a lens with reasonable high magnification (x145 for 8"/f10 LX200) but retaining reasonable eye relief. Combined with Barlow lens it provides a better combination than the 9.7mm lens alone.  I've used it in combination with my teleextender for close -up shots of planets. 

Meade 2x Short-Focus Barlow (1.25")

This Barlow is new and was purchased in 2000 with the aim for varying the magnification power of existing eyepiece lens and for using in combination with 13.8mm Super Wide Angle eyepiece in particular.  I will add more comments as I gain more experience with it.

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Barlow

I have a single Barlow purchased in 2000.

Meade 2x Short-Focus Barlow (1.25")

This Barlow was purchased in 2000 with the aim for varying the magnification power of existing eyepiece lens and for using in combination with 13.8mm Super Wide Angle eyepiece in particular.  It has worked well for me for visual observing, and I now use it occasionally for close up CCD imaging for Planets and the Moon.

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Meade 2" diagonal

This diagonal came with the LX200 telescope in 1995. I tended not to use the 2" diagonal much, preferring instead my 1.1/4" diagonal.  I tried the 2" again in 2000 and concluded that it gave no obvious optical benefits (none that I could easily perceive) and in fact had several practical disadvantages :

• when used with my JMI Focuser, the telescope can't approach Polaris without the eyepiece diagonal hitting the stand (Dec 72 to 76 deg N is the furthest that the telescope will safely go).
  
• 2" diagonal is more difficult to fit at start of observing session, as it involves screwing it on, as opposed to the bayonet style fit of my 1.1/4" diagonal (an adapter could make fitting easier. but would add to its length) 
  
• 2" diagonal is heavier (producing more strain on telescope bearings unless telescope tube is re-balanced)
  I also find that 2" diagonal makes the telescope slightly more susceptible to wind vibration.
  
• eyepieces are positioned higher than usual giving slightly more strain to back/neck (though a taller chair would of course help)

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Meade 1.1/4" diagonal

After using a 2" diagonal for a while, I purchased a 1.1/4" diagonal in 1996 for its compact size, which permits operation with the JMI focuser when aligning on Polaris or viewing any objects north of Dec 76 deg.

I subsequently use the 1.1/4" diagonal almost exclusively and the 2" diagonal was left sitting in its box.  Since moving to CCD imaging I no longer used a diagonal.

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Meade F/6.3 Focal Reducer (Teleconvertor)

I purchased this Meade F/6.3 Teleconvertor at the same time as my LX200 telescope. I didn't often use it for visual observing, though when I did it performed very well for viewing extended sky objects like open clusters and the milky-way. 

After getting my JMI NGS-S focuser,  using the F/6.3 focal reducer entailed taking off the JMI focuser, which meant that I would tend to not use it or positioning it after the diagonal (I need to check it again but I believe that the Focuser tube could 'crash' into the F6.3 Focal Reducer Lens if they placed next to each other. 

I began CCD imaging with telescope set up in original focal ratio of F/10, however over time I tended to use the telescope almost exclusively with F/6.3 focal reducer in order to obtain a larger field of view thereby increasing my chance of having sufficient stars in view to achieve plate solution/linking in areas away from the milky way.

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JMI NGF-S Focusser

The LX200 telescope inherently suffers from image shift when its own focuser is used. It is worse on some LX200s than others.  The amount of shift was initially very bad on the scope when I bought it.  Even after the telescope went off for adjustment back at BCF it still displayed some image shifting through not as much as before.  In the end I decided I would get a JMI NGF-S focuser and it has proven to eliminate most of the image shift problems I was experiencing.

The JMI focuser screws to the visual back of the scope and button controls a little handset (which contains a battery) is used to move the focuser and attached diagonal & eyepieces back and forth.  The focuser is perfect for getting the very best focus whilst having the object/star stay rock solid in the centre of the eyepiece.

The JMI focusing range is limited however and the main LX200 focuser still needed to be used when changing optics and even when swapping between 26mm eyepiece and my 9mm illuminated reticule eyepiece. 

Use of the JMI NGF-S Focusser on 8" LX200, requires use of 1.1/4" diagonal if access to sky areas above Dec 74 deg N is needed - as a 2" diagonal will hit the telescope stand if an attempt is made to slew to Polaris with the focusser installed.   

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JMI DFC (Digital Focus Counter)

I acquired a Digital Focus Counter in 2001 with the aim of making mirror focusing easier when changing equipment (e.g. eyepiece to ST7).  Initially it didn't work, since the DFC tends to slip on the LX200 focus knob (This is in part related to the stiffness on the mirror focus knob which as been stiff since 1996 when I had the mirror focus adjusted to help reduce image shift).  I subsequently put in a grub screw to form a stronger connection between the DFC and the Meade Focus knob. This fix has been reasonably satisfactory. 

Telrad Sight

I purchased my Telrad sight in April 1996 and have since found it to be an indispensable tool for quickly bringing the telescope to bear on alignment stars.  I used to have my Telrad fitted on the lower surface of the LX200's tube, however it has now moved to the upper right surface of the LX200 due to installation of a 3D counterweight system below the tube.

The Telrad is highly practical and comfortable to use. With the eye(s) someway distant from the device it is easy to move the telescope so that an object or star is brought to the centre of the Telrad's sight. The smallest circle is 1/2 deg in diameter and guarantees that the object/star is placed within view of 26 mm eyepiece, though not necessarily within the view of my 9mm reticule eyepiece.

In certain telescope positions, the Telrad - as positioned on my telescope - does not permit sighting of object/star  (e.g. this occurs when looking at Polaris at some times of the year, directly overhead objects/stars and objects in NNW or N sky ).   These occasions are relatively rare and I then switch over to using the Meade Finder.  A Telrad positioned on the upper surface of the tube would also suffer restricted viewing in certain telescope positions.

Even nowadays with CCD imaging I use the Telrad at the very start of each session in order to align the telescope on a bright star.  The Telrad is sufficienctly well aligned with my scope that I can place a bright star onto a 16 x 11 arc min field of view of my CCD camera nearly every time.

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Tele-extender

I have an Orion Teleextender which I have used on occasions for taking photos through the LX200.

My first attempts of using the Teleextender where for taking pictures of Mars, M31 Galaxy, M42 Nebula and the Moon. The attempts were frustrating and none of the picture results where very good. I put this down to poor alignment, (I was using Tripod based Alt-Azimuth alignment in those early days), poor telescope stability, the severe image shift on Meade focuser and lack of experience.  My experience taking photos is still fairly limited, but now that my scope is permanently installed on a pier, and consequently more stable and more reliably aligned I got better results.

I still occasionally use the tele-exender in combination with my CCD camera, when taking close up images of planets.  This is often also in combination with eyepiece projection.

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Filters

I have Orion Set 1 of Colour Filters (1.1/4"). Contains 4 colour filters. I used them occasionally when looking at Planets, when they can help increase the contrast between different surface or atmospheric features.

I also have an Orion Moon Filter. This is indispensable for glare reduction when attempting to look at the moon , which is incredibly bright (almost painfully so in fact) when viewed without the  filter in place.  [I would predict that a variable polarising filter would work better,  allowing the optimal amount of filtering to be set for the lunar phase and lunar feature being observed]

I haven't tried using a Broadband or Narrowband Nebular filter at all.

Since 2004 I also have a set of 1.1/4" Clear and RGB filters and a set of 1.1/4" UBVRI filters for use with a colour wheel for CCD Imaging.  I will typically work with one of the following filter wheel carousel  setups :

  1) Clear, 2) Red, 3) Green, 4) Blue, 5) Moon Filter

  1) Clear, 2) B-Band, 3) V-band, 4) R-band, 5) I-Band

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Camera Mount

I have a Camera Mount on the top of the LX200 which I can attach my 35mm Pentax Camera too. I've used it for  taking tracked photos of the night sky.   Photos of Hale Bopp are the best photos I've taken so far using it.

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Flexi Dew Cap

This is a black plastic sheet which folds into a cylinder and is secured with Veco, whereupon it can be fitted to the front of the telescope tube.

I fit it at the start of each observing session and it works fairly well in keeping dew off the LX200's front corrector plate. However whilst it certainly defers the onset of dew formation on the front lens, it is not a cure for dew - it can still end up terminating an observing session.

The black sheet is very shiny on the inside, which probably means it could have the unwanted effect of capturing unwanted light.

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Nightrite Pen

This pen has a built in light just behind the tip of the pen. I haven't used it for some time.  (I can't remember why -  as the pen performed ok in the first year I had it - it might be that the pen has run out of ink, however it may be due to my preference to use pencil rather than pen).

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TheSky Level IV (vn 5)

I purchased the astronomical software package called TheSky Level IV (vn5) in 1999 and have it installed on my home PC and on my laptop.

I currently use TheSky for preparing sky charts and examining past/future events. I used it for helping to locate the Asteroid Amphitrite and later on Herculina, Hebe & Irene

I've having begun using it for controlling the LX200 in the observatory since mid 2001 and have just begun using it in conjunction with CCDSoft for doing CCD Imaging - see Future Steps & CCD Imaging.

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Laptop

I bought a Compaq Presairo 1700 laptop in 2001 and combined with TheSky software I now use it in the observatory for controlling the LX200.  I take the laptop out to the observatory each session.  Setting up the laptop merely involves plugging in 2 USB cables (mouse and USB-Serial adapter) and switching on.

The Compaq doesn't have its own serial port,  instead I use a Belkin USB Serial Adapter. The adapter stays in the observatory and connects to an RS-232 cable which runs beneath the observatory floor, up the pier to the LX200.  All I need to do is plug the USB cable into the laptop (this by the way is slight easier to do in the dark than a serial cable). 

[ I initially bought a Belkin combined USB-Serial-Parallel Port Adapter, but returned it to the shop after finding that the Parallel Port doesn't allow true 2 way communication - and thus I wouldn't be able to use it with a CCD camera later on ]

Whilst I change the computer's colours to reds (via TheSky's Night Vision Mode), the LCD screen is still too bright and effects night vision & introduces excess light into the observatory whilst viewing.  I have made a screen which uses red film filter to reduce this problem. 

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ST-7E CCD Camera

After 3 years of planning I finally purchased a ST-7E CCD camera in September 2001.

LX200 Telescope  with ST-7 CCD camera

See Future Steps & CCD Imaging.

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Wish List of New Accessories

The following item would have been on my wish list for new accessories had a continued with visual observing

- 1.25" Variable Polarising Filter

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