This is the third different brand 50mm guide scope I have tried, trying to find decent optical quality all over a full 1/3" ccd sensor. This is the best so far and is just acceptable, although I would say it isn't brilliant. It seems manufacturers have decided we dont need top quality for guiding, but that means plate-solving images taken with them can be less than ideal.

This scope is mechanically robust and once the camera and focus element are locked up, it is very stable. The dovetail seems to be cast as part of the tube and is very strong and stable (hence also not removable).

Achieving focus isn't easy though. The focus adjustment (on the front objective assembly) has only a couple of millimetres of travel. There is none at the back. Coarse adjustment is achieved by simply locking the camera in the draw tube at whatever depth is needed. Fortunately I already had a 1 1/4" par focal spacer ring so I could use this to 'set' the camera position and remove the camera without losing position. Otherwise this is a scope that once focussed is best left assembled. Although they recommend 'cylinder' type ccd's, my ZWOASI 120MM-S and a RaspberryPi HQ ccd both were able to focus with room to spare.

The paint finish is good, except at the edges both near the dovetail and focus adjustment. It seems poor masking was applied when they sprayed the main tube. The bad edge is exposed at the focus adjustment as soon as the lens is wound away from the end stop. Not what I expected from William Optics.

Ordered this, and being a beginner in this world not knowing what to expect, but had read great reviews on the product. I was very surprised at the great quality of the scope. Setting it up to get the camera in exactly the right place took a bit of playing round (probably more from us not knowing what we were doing) but now we know how it works it is nice and quick.

We will be using this as a guide scope but are using it for polar alignment in the southern hemisphere as it is near impossible to do otherwise and it has been amazing - we can get the mount polar aligned in a matter of minutes. Even tried photographing the moon with some nice results

As for FLO - I have been spending months firing questions back and forth about how best for my son to get into astrophography and they have been nothing but amazingly helpful. Order was place and shipped within 24 hours and arrived to New Zealand within two weeks (after being stuck in our customs for a week). Package arrived well wrapped and protected and the experience buying from FLO has just been awesome ... have already placed orders for more equipment with them - keep up the amazing work

Works well with the ASI 120MM mini for guiding. It was with some trepidation, having read of people having issues with back focus, that I tried this combination, first in daylight and then with stars. Either the extension nosepiece supplied with the camera or the extension supplied with the scope need to be used - I'm using both to perhaps give more stability. The rotolock grips the camera well and at the other end the rotating dew cap (with lock ring) gives precise focus control. The base is permanently fixed to the scope - ultimately, I'm planning on using this in a WO saddle handle on top of an Esprit 100. But for now, this combination will be guiding my DSLR / lens combination in a side-by-side mount – once I get a suitable clamp for the narrow finder base; tests so far have been with this scope only (no imaging camera) directly clamped to my HEQ5.

Well engineered, easy to use and focus. The rotolock piece securely holds any 1.25" eyepiece or camera you may use the scope with.