Silver 20mm GSO Plossl Mystery

[Nightspore]

I very recently acquired a 20mm Guan Sheng Optical Plossl. This was primarily to complete the entire set. GSO manufacture Plossls in nine focal lengths: 40, 32, 25, 20, 15, 12, 9, 6 and 4mm. They are all made in Taiwan. My 40mm and 32mm are actually badged as ‘Revelation Astro’.

 

 

GSO all have distinctive 30mm aluminium barrels that are either smooth or have undercuts with bevelled lower lips. GSO are gradually phasing out their undercuts. The distinctive white plastic end caps are also peculiar to GSO.

 

 

The housings are usually black aluminium with a rolled down rubber eyeguard that can be flipped up when needed or necessary. 

 

 

However, my 20mm has a silver housing and the eyeguard is of a different type. It is more like the rubber eyeguards on the GSO SuperView series and is not rolled down. Although it can be.

 

 

I was a bit surprised when I opened the box. I thought the retailer had sent me a 20mm Celestron Omni by mistake. 

 

 

What’s interesting is that it resembles the silver finish of the Celestron Omni Plossl series. The Omni Plossls have been manufactured in Japan and by GSO in the past. 

 

 

The 15mm GSO and Omni Plossls are quite different. My 15mm Omni above now has a chromed brass barrel. Originally it had a standard 22mm aluminium barrel with an undercut. My Omni was manufactured in China, although I'm pretty sure they are actually produced by Barsta. Does anyone else have a silver GSO Plossl?

Edited July 31, 2021 by Nightspore

[MarkAR]

Could be they got the parts batches mixed up or decided it was easier to use wha they had in stock that wait for more of the right parts to be made.

Also it could just be a design change to make them look higher quality.

[Nightspore]

2 minutes ago, MarkAR said:

Could be they got the parts batches mixed up or decided it was easier to use wha they had in stock that wait for more of the right parts to be made.

Also it could just be a design change to make them look higher quality.

 

I honestly don't know. I suspect the pandemic has interfered with supply chains or production in Taiwan. It may be that they had an amount of the old Omni housings left over. At some point Synta switched to a Chinese mainland source for the Omni series. GSO may have had a stock of housings left over. Either way, it's a nice looking Plossl. Maybe they will be a limited edition and known as the silver GSO 'Pandemic Plossl' lol.

[MarkAR]

As long as the Limited Edition "Pandemic" doesn't come with Covid FOC.

[Nightspore]

Just now, MarkAR said:

As long as the Limited Edition "Pandemic" doesn't come with Covid FOC.

 

I'm sure it's had its jabs!

[Nightspore]

 

That's better!

[Nightspore]

As this has been moved to 'Visual observing at night' it would be probably be apposite to state that I had first light with the silver-blue GSO Plossl last night. Overall it performed excellently in my 72ED for 22x and a 3.4mm exit pupil. I even tried it in the 2x GSO short Barlow for 42x. Apart from slight vignetting it was fine and I had a great view of M57, M 29, the Double Cluster and the Owl Cluster. Without the Barlow I saw M27 and the Western and Eastern Veil Nebulae. Although afterwards I swapped the eyeguard from a borked 4mm GSO Plossl. I'm not over keen on the sticky-up sort.

Edited August 3, 2021 by Nightspore