My Commercial Equipment.

Despite making much of my equipment there are still some bits that need more resources than a single amateur can muster. Indeed, that is one aspect of my hobby that has changed significantly in recent years. While commercial optics (certainly the cheaper, mass produced ones) are still generally marginal, the expensive ones can be very good and offer designs that are hard for an amateur to better. Eyepieces are something I'd probably not consider making myself, and the newer designs are great. The mechanical quality of both mounts and telescopes has improved significantly - but at a price. You really get the quality for which you are prepared to pay. It is with electronics that the biggest changes have occurred. In the 1970s there were a couple of professional "goto" telescopes - now mass-produced toy telescopes have a computer attached and goto capability.

The better of my toys - in no particular order - are discussed here:

A brace of commercial telescopes

What's the collective noun for a group of telescopes?
My Takahashi FSQ-106N with a William Optics Megrez 90 APO mounted on it,
next to an Astrophysics 130-EDF triplet with a Borg 100mm mounted on it;
all mounted on a Paramount ME.

Eyepieces Eyepieces

Eyepiece and other things to look through

Eyepieces have improved considerably since Al Nagler came on the scene. Prior to the 1980s, the best eyepieces were based on designs from the previous century. Plössls, orthoscopics and Erfles were the best available - and they weren't great. Al changed all that, and now there are some great eyepieces out there.

I have mostly Naglers in my eyepiece collection - a 26mm, 16mm, 9mm, 7mm and 4.8mm. I used to have a 32mm Widefield (a modified Erfle design - one of Al's earliest successes) but I sold that with my 31-cm Newtonian and bought the 26mm Nagler. I love the wide field of the Nagler eyepiece and sharp images.

I recently had the opportunity to use a William Optics 28mm UWAN eyepiece and found it to perform equally well to the Nagler - and the price is much kinder to ones budget. I recommend these as well as the Naglers.

I also have a binoviewer. I think binocular viewing is the most comfortable way to observe the moon and planets and some bright objects. Using both eyes means your not straining one eye and it just feels better.

Newtonian telescopes and binoviewers don't get on well together due to the very large backfocus needed - 110mm in my case - but with a suitable Barlow lens focus can be achieved. This necessarily makes them high powered, but since I mostly use it for viewing the moon and planets that's fine. Few refractors can achieve focus with binoviewers either, so the Barlow comes in handy there, too. The above image shows the binoviewer attached to my FSQ and observing the transit of Mercury in November 2006 (which I imaged with an AP-130).

The binoviewer came with a pair of 17mm wide angle eyepieces which work adequately, especially when they have to be used with at least a 2×Barlow lens so the focal ratio is much kinder. The binoviewer I bought came with both 2× and 3× Barlow nosepieces. The 2× works well, but the 3× isn't perfect, showing a bit of false colour.

I also have a TeleVue 4× Powermate for those times when you need the extra magnification, especially on a short-focus refractor. I also have the T-thread adapter for it, which is great for taking moon images with a DSLR.


optical correctors

Optical correctors

I have the Baader coma corrector for my Newtonians (although it's an old one sold under the Celestron brand). This essentially eliminates the coma in my f/4·5 and f/5 Newtonians - at least in the field of my Canon 350D DSLR. It seemed to do a pretty good job on a 5D, too. The above picture also shows the spacer I had made to allow the use of the coma corrector on the ST-10 CCD.

I also have the Williams Optics 0·8× reducer/corrector for their refractors. I have both the old R/C II for the SD66 (which couples with an SCT thread or an SCT-to-2-inch nosepiece) and the newer R/C III which covers a larger unvignetted field. I measure 0·81× reduction from both correctors. The R/C III still uses a T-thread output connector which vignets larger cameras (like the 5D) but does at least make sure the spacing is correct for the system.


30cm telescope on Paramount ME

Software Bisque Paramount ME

What is there to say about the Paramount that hasn't already been said? It's not mine, but it lives in the skyshed and I get to use it. It's the single reason my imaging improved. No longer do I have to worry about finding objects, nor whether the image will be trailed. The Paramount is one of the few products I've ever seen that lives up to the hype. It just works. It has enough capacity to carry my 30-cm Newtonian (it's harder to carry long loads like a Newtonian than short, heavier loads like an SCT). I know I sound like a paid advertisement, but if you struggle with your mount for imaging, then just get a Paramount. I love the Paramount and I don't know how I'll cope when John wants to take it away. They're very expensive - but as I said - you get what you pay for.

Sure, there are problems with it, but they can be dealt with. It doesn't like the cold; I don't like the software you have to use to operate it (TheSky); it doesn't track far through the meridian. But for the most part, the pointing and tracking are superb and more than compensates; and being able to pass most of the cables through the mount so they don't get in the way is well worth the limitation it introduces. (It doesn't have a USB passthrough, which is a pain these days. If it had a USB hub built in it would be wonderful, as would having several USB to serial ports. That would really be great.)


ST10 on FSQ

SBIG CCD Cameras

I've had access to several SBIG CCD cameras over the years. An ST-6 many years ago (painfully slow download through the serial port); an ST-4 autoguider (still gets used occasionally); an STV video CCD system (fun, but very poor sensitivity - but still makes a useful autoguider); an ST-8 (parallel port, so again slow downloads) and currently an ST-10 (USB upgrade and bigger guide chip). I've not owned any of them, but I get to use them. They've been responsible for most of my images so I can at least say that they work well.

SBIG made their name with the ST-4 autoguider. It is a stand-alone unit with a small head for the CCD (making it very easy to attach to a guidescope and didn't load it down) and the electronics were mounted in a separate box. This is a good way to make a CCD system (and the Cookbook CCD camera did much the same). It's a shame that they didn't keep using this approach as the biggest problem I have with them is that they are so heavy. Their weight, combined with their asymmetric design make them an unhappy attachment to a telescope. There is an opening for a large CCD camera where the bit that attaches to the telescope doesn't weigh more than a heavy eyepiece! I just don't see why most current CCD cameras are so physically large and heavy.


Takahashi FSQ-106N

Takahashi FSQ-106N

The best imaging telescope in the world - at least for short focal lengths. The FSQ is 106mm aperture and f/5 (530mm focal length), with a large (88mm, accoding to the manual) flat focal surface. Well colour corrected (the adverts for the new-Q one say that the colour correction is slightly better than the old one) with not too severe vignetting. I bought one of the last of the old 106Ns, just before the New-Q was introduced. Mechanically it may be a little sturdier in the focuser department as the new one has more overhang to allow for the increased back focus. While it means my one has difficulty reaching focus visually for some big diagonals and eyepieces, it is better for imaging. I've had a 16803 chip camera (37mm square, 52mm diagonal) on my FSQ and the images were pinpoint right across the whole field.

I've fitted a stepper motor to the focuser (like a Robofocus but home-made) and a similarly controlled rotator. It is usual to buy these things, but it's more fun to make them.


William Optics Megrez 90mm

William Optics Megrez 90mm

It's a long story how I came by this telescope, but all I need to say is that I'm very pleased that I did. It's a nice size - 90mm f/6·2 (don't believe the advertising or lens cell which says it's f/6·9 - it's focal length is very close to 559mm, which makes it f/6·2) - and not too heavy. An ideal portable telescope, or just for imaging anywhere. Coupled with the WO 0·8× focal reducer and you get a decent field at f/5.

Mechanically quite nicely made. The sliding dew-shield on the tube is a decent length and does a good job. It also has an in-built rotation mechanism on the focuser. The focuser itself is very smooth, especially with the 10:1 (more like 11:1 actually!) two-speed reducer, but lacks holding power for heavy cameras. Tightening up the adjustments does allow heavy cameras to be held in place, but takes the edge off the smoothness. One thing I have done on this focuser is to try out an idea I've had for years - that of attaching a stepper motor directly to the reducer shaft. It looks like this and works brilliantly.

I first fitted a reducer like this to a focuser back in 1996, to my simple 6-inch telescope. At the time I'd not seen it done before and thought that this trick might catch on (I think it has!). But the reducer on the WO telescope is very nice, much better than the 6:1 unit I originally used. It's much smoother, for a start, and with almost twice the reduction well suited to being driven with a stepper motor. Unlike the motors used on the Robofocus (which have gears, hence backlash leading to uncertainty in their absolute position) this style of reducer has no backlash - perfect for focusers (and telescope drives - my next experiment).

I use my freefocus controller which drives in half-step mode for a smooth motion with enough holding torque to stop the focuser from slipping.

Having finally got a telescope light enough to be portable, and good enough to be worth it, I needed a mount. Because I live under dark skies and have my telescopes in an observatory, I've no real need for a portable telescope. But I decided I wanted one for this. My friend Colin came to the rescue with the old Vixen SP mount shown in the above picture. It had some bits missing and needs a bit of work, but it's basically a decent mount.


William Optics SD66

William Optics SD66

After the success of the Megrez 90mm above, I decided to splash out and get an even smaller telescope - the William Optics SD66. Another f/6 doublet with good performance. It shares many of the same features of the Megrez 90 - well made, nice focuser, in-built dewcap, light etc. I intended to use it mostly as a guidescope, but it works very nicely to look, and image through. I've taken some nice images with this 'scope. With the WO 0·8× focal reducer you get a decent field at f/5 and a 322mm focal length.


Canon 10x42 IS binoculars

Canon 10×42 Image Stabilised Binoculars

I've always liked binoculars. I made a stand some years ago so that I could hold my 12×50s steady, but these Canon 10×42 image stabilised binoculars beat them hands down.

For a start, they're portable. They're not exactly light weight, especially when you consider that they're only 42mm aperture, but they're light enough to hold for a while, and very easy if you can support your arms somehow. The optics are superb. They have a 4-element objective and 7-element wide-field eyepieces, resulting in a 6·5° true field of pinpoint stars. The view is surprisingly bright, again considering the 42mm aperture and 4·2mm exit pupil. They are considerably better than my old 12×50s.

The big thing I enjoy is the wide field - that's what binocular viewing is about, for me. Large portions of constellations are visible in one view, and at the same time great detail and faint objects can be discerned because of the image stabilisation. Dust lanes in the milky way that show on photographs now show in real time through the binoculars. Subtle open clusters stand out against the background glow in the milky way. I love these binoculars.


Canon 350D

Canon 350D DSLR

People have been using DSLRs for a few years now, but I'd never bothered with them as the objects I image tend to be very faint, and only seen in H-alpha light for which DSLRs aren't suitable. But in early 2007 when Comet McNaught spectacularly appeared in the sky I realised I had no way of taking a picture of it. It was too low to be seen from my place (trees along the western side) and I had no portable mount or even power supplies to take anything to a place with a better horizon, nor could I do really wide fields. The best I could do was this (with the crescent moon and Venus at lower right), or this image with my ordinary digital camera and a few seconds exposure.

I couldn't help notice that the best images of the comet were with DSLRs - and Canon ones at that. After lengthy investigation I decided that buying a second-hand Canon 350D was the best option for me. I couldn't afford a 5D and there was little difference between a 20D or 30D and a 350D, and the 350D was smaller, lighter and easier to control and so may well be better. Only the 20Da had anything better to offer, and again they were too expensive.

I used it for a while before deciding it was worth modifying for better H-alpha response. Well worth doing. Some images with this camera (and some other DSLRs I've borrowed) can be found here.


William Optics FLT-110

William Optics FLT-110

What a fantastic telescope. I was made an offer I found hard to refuse on this telescope. While I already had the FSQ, it was difficult to use visually. The FLT is an f/7 triplet and the colour correction is superb - amongst the best I've seen. Tri-colour imaging requires no focus shift between RGB filters (the FSQ does!) so it's a great imaging 'scope, too. The above image was taken right after I got the telescope and had to quickly mount it for its first use on the total lunar eclipse that night. The picture shows the Paramount loaded up with the FSQ carrying my SD66 (and a WO UWAN 28mm eyepiece giving 14× and a 5¾° field) with the FLT mounted along side and the 350D attached to the FLT flattener. A fun night trying out new telescopes and cameras on the eclipse. See some of the pictures of the eclipse here.

In common with the other William Optics telescopes I now have, I can say that the FLT-110 is well made, with a decent length retractable dew shield and has a very nice rotating focuser. Again, it requires careful adjustment of the focuser to keep the smooth feel and have enough grip to hold a heavy camera or eyepiece from slipping. The special field flattener for this telescope works very well, providing a flat field and pinpoint stars across the full frame of a Canon 5D - although there is vignetting at the edge of the frame due to the use of T-threads on the adapter. (It comes with another, larger threaded adapter but I've nothing that fits it.) The WO 0·8× reducer/corrector also works well with this telescope.


Lunt LS50

Lunt 50mm H-alpha solar filter

I ordered one of the first ones as soon as I saw the price and who was making them, and eventually received serial number 17 (2008017, which I assume means number 17 made in 2008). Naturally, as soon as I received it the clouds rolled in. It took ages for me to discover that the filter had been damaged in transit (despite appearing to be well packed) and wasn't working properly. Lunt took it back and repaired it and now I have a superb H-alpha solar filter.

I have it mounted on my William Optics Megrez 90. I had a holder made for the filter which slips over the dewcap and is secured by 6 nylon screws. I also made a sun finder which slips in place of the red-dot finder I have mounted on this telescope. The front has a small hole in an aluminium plate which is fitted to a piece of scrap 25mm aluminium tube (an off-cut from a truss pole) about 50mm long. An image is produced at the back end onto a piece of frosted sticky tape. Simple, but effective. I need to find something to replace the tape, but it works nicely as it is.

The diagonal has a very long 2-inch nosepiece. I'm not sure why it is this long, but it is. I'm glad I'd decided to use it on the M90 and not my FSQ as it would never have worked. Unfortunately, the eyepiece end is only 1¼-inches and is a bit of a limitation as I have few eyepieces (and no barlows) of this size. Fortunately, my binoviewer (with its 2x relay lens) does fit and produces an excellent view. I had to slightly modify the diagonal for it to focus in this telescope - I trimmed 1·5mm from the bottom of the eyepiece tube (fortunately the threaded section was long enough that it causes no problems) - and now it's my favourite for solar observing.

I really need to finish making my heliostat - it's bad for you to be standing out in the summer sun for so long. You really need to observe the sun from inside an observatory, not standing outside being baked.


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Page last updated 2008/11/13
Steven Lee