Product Review for the Dual Speed Crayford Focuser for Synta Refractors made by William Optics
by David Milone


I’m very excited about my new dual speed focuser from William Optics. I put it on my old Orion 80ED and let me tell you, it looks and feels almost like an entirely new telescope. Finding perfect focus is now much easier than before. I’ve had many nights of planetary observing, struggling with my old focuser, shaking the scope with every turn. I would try with my glasses on, my glasses off, rubbing my eyes, rack in, rack out, constantly tweaking, never satisfied with my focus. Attaching a camera to the old focuser could be even more frustrating. So I was very excited when I stumbled across this new dual speed focuser on the internet. It seemed like a perfect fit for my 80.


Although it is made by William Optics, it is designed to fit virtually any Synta refractor, (i.e. Celestron, Orion). It is a simple, elegant design that is light-years ahead of the old stock focuser. It has a black anodized finish, it’s fully rotatable, it has a 1 to 10 ratio between the fine focus knob and the main focus knob, and it has a 2 inch draw tube and a 1.25″ adapter both with brass compression rings. All the parts are precision machined rather than die-cast like the old stock focuser.

Installation on the telescope is very simple. Though for me, it was the removal of the old focuser that was the most difficult task. The old Orion focuser refused to come off. I pulled on it, I yanked it, I tried to wiggle it out, but my little Orion 80ED would not let go. I ended up having to use a small amount of WD40, being careful not to let any run into the tube of the telescope. I then wrestled with it for a while longer until it finally popped off. I actually got a couple of bruises on my forearm in this struggle.


This is the old focuser removed. The housing is made of die-cast metal, and the inside surfaces are simply spray painted with flat black enamel paint. It’s pretty cheap.


In addition to the new focuser, I also purchased a finder scope bracket made by William Optics. There is none included with the new focuser. On each side of the focuser body there are two screws, one flat head toward the front, and one allen head toward the rear. All I could do was take a guess at which one was for mounting the finder bracket. There are no instructions included with the focuser or the finder bracket. There wasn’t a single piece of paper. I invariably chose the wrong one, picking the allen head toward the rear. I think I managed to put it back in without anything moving, shifting, or falling off. The correct screw for the finder is the flat head towards the front. It is really just a plug. Here you can see the bracket installed.


This focuser is beautifully crafted with a high degree of precision, and is solidly build and sturdy. The gold colored fine focus knob operates very smoothly and precisely. It’s like butter. However there was some sticking at first here and there when turning the silver colored main focus knob. Fortunately, this has smoothed out almost completely after racking the draw tube all the way out and all the way back in again several times. This might sound bad, but it really isn’t. I suppose it just needs some breaking in like a new pair of shoes.



The draw tube only has one tightening thumb screw. Even though there is a brass compression ring, I feel it could use a set of three. I was getting some slippage. When using heavy eyepieces on a diagonal, the diagonal would slip around when it was in a near horizontal position.

Although this focuser is heavier than the old stock focuser, I don’t believe it is as heavy as a Moonlite focuser. I have a Moonlite focuser on another one of my scopes, but I’ll save that for a future article. I’ll just tell you for now that the Moonlite is a real work of art. But for my Orion 80ED, I felt that the William Optics focuser would work a little better. It looked lighter in the pictures, and I think I guessed right.


Excessive weight at the back end of the short tube of the Orion 80ED tends to throw off the balance on the declination axis. The center of gravity it too far to the rear of the scope. With the new William Optics focuser, finder bracket, finder scope, diagonal, and a large eyepiece, I have to push the tube as far forward as my mount will allow. Surprisingly, it balances OK like this. Having all of those items at the back may be pushing the limits of balance, but it works.

Upgrading from my original stock focuser to the William Optics Dual speed focuser has improved the functionality and ease of use of my Orion 80ED by a huge margin. I’m very pleased. The task of focusing is now much easier. It operates silky smooth. Even if the seeing conditions aren’t the best and I feel need to futz with the focus of an object, it’s not a problem. I can lightly touch the knob, making fine adjustments very smoothly and easily, without all that telescope shake. It is very luxurious.



Cons: (mostly minor quirks)

Leave a Reply

Your email address will not be published. Required fields are marked *