My latest (used) EP purchase. Skywatcher UWA 58. 4mm

[Marmot]

Whilst browsing the used market I recently came across the following EP:

A Skywatcher UWA 58 degree 4mm. 

The most powerful EPs I have at the moment are a 6 and 5mm TMB clones. I was not particularly looking for a 4mm EP as I rarely use my 5 and 6mm, but I found the EP interesting for a few reasons: It seemed very similar to the TMB clones (with which I am very happy) and it was an unused EP being offered at less than half the price of a new one. Consequently I purchased the EP, probably more out of interest than actual need.

The EP is indeed similar to the TMB clones that I already possess although it also has certain obvious differences:

The EPs have the same 58deg FOV.

The body of the EP is similar in shape and size although it utilises an undercut to secure it in the diagonal rather than a taper.

The top of the EP has the same rotating, screw up and screw down housing to obtain a comfortable eye position, although the rubber eyecup is fixed whereas on the TMB clones it can be ‘flicked up’ or rolled back down. I also believe the rotation to be a little smoother on the Skywatcher. When the eyepiece was screwed all the way out/up there was a small amount of light grease on the exposed part of the barrel, something that I did not experience on the clones.

The clones both came with a noticeable rattle which was easily resolved thanks to instructions supplied by ‘Nightspore’. The Skywatcher had the same rattle, although not quite as noticeable. I took the top of the EP apart in exactly the same way as the clones and found that the same retaining collar required fractionally tightening.

 

So is the Skywatcher UWA actually another TMB clone or at least something very close? I would be interested to hear from anyone who can shed any light on this.

 

As to its performance I can’t actually say due to poor weather. I have tried in daylight and on the moon in twilight, but due to poor conditions I can’t make a judgement on its Performance. Time will tell.

[Nightspore]

These have been marketed under a few names. I'm pretty sure they were made by Barsta. They were sometimes bundled with some higher end Sky-Watcher refractors at one time.

 

 

AFAIK they are five element, and believe it or not, have even been marketed as a 'Plossl'.

 

 

Some of mine are toast now but IIRC they were as good as the TMB clones. The 'grease' problem is well known. 

Edited February 18, 2022 by Nightspore

[Marmot]

Thanks for info Nightspore. 

The box has a label on it stating they are a plossl! Strange.

The box also calls them SWA whereas on the EP housing it states UWA. Maybe Skywatcher just couldn’t decide exactly what they were or what to call them🤔. Either way, you have reassured me I haven’t bought a dud. Wether it’s a keeper or not only time will tell and I am sure I will have some fun trying it out.

[Nightspore]

57 minutes ago, Marmot said:

Thanks for info Nightspore. 

The box has a label on it stating they are a plossl! Strange.

The box also calls them SWA whereas on the EP housing it states UWA. Maybe Skywatcher just couldn’t decide exactly what they were or what to call them🤔. Either way, you have reassured me I haven’t bought a dud. Wether it’s a keeper or not only time will tell and I am sure I will have some fun trying it out.

 

They're definitely not duds. I use the 7mm for lunar with a 102mm Mak quite often. There is little or no ghosting. I'm guessing these have four elements with a Smyth like negative in the barrel. FLO still sell them. They're around £50 now. I don't think I paid 30 quid for any of mine lol.

 

 

At about 58° they're hardly ultra or super wide angle lol. 

 

 

Either way, my 7mm UWA and the 4mm TS Planetary (above) are still used quite a bit. I like the overall ergonomics and eye positioning of the UWA/SWA's. They are also dependable and relatively lightweight. I'm not over keen on the undercut but at least the barrel is brass. I find brass barrels with undercuts have less hang-up problems as a whole. 

Edited February 18, 2022 by Nightspore

[Galileo]

lovely