Fullerscope eyepieces

[Alfian]

I have just bought a "vintage"  16mm Fullerscope 1.25"wide angle EP (thanks Dave) but so far have not had opportunity to try it out. In appearance it looks like a very  nice plossl  but I'm guessing the internals will not be a standard plossl configuration. In trying to find out a little more about the Fullerscope eyepiece(s) I can find quite a lot of mention of Fullerscope telescopes and the history of the company and the link with Telescope House, but nothing specifically about the eyepieces. I'm guessing they were imported, rebadged, from Japan but would like to know who made them. Are there any other similar eyepieces marketed with a different name that might give some idea of their construction etc l but I'm really looking forward to a first light when I can assess the performance for myself. Anybody on SGL have any experience of or  information about the Fullerscope EPs?

[Peter Drew]

I have a pair of 20mm eyepieces of the same design and period.  I use them on my 300mm reflecting binoscope giving 50x.  The centre definition is excellent but falls away rapidly towards the edge, much less noticeable with binocular vision.  The 84 degree apparent field is largely due to opening the field stop to the maximum possible.  They seem to need more IN focus than my other eyepieces.

One of them is branded "Fullerscopes" and the other "Mirador".      🙂

[Alfian]

Thanks Peter, good to hear that your 20mm works well for you, and the Mirador info is useful.  I know Dave (f15) was pleased with the 16mm and I'm hoping that using it with F10 + refractors and maks the wide field fall off will not be so bad though 84 degrees is asking a lot. I had read somewhere of your connection of sorts with Fullerscope so it didn't surprise me that you chipped in.

[John]

I've owned a few of those, some branded Fullerscope and some under other branding (University Optics). Their performance is just as Peter says. Great at F/10 or slower but flocks of seagull shaped stars star to show at the edges of the field of view in faster scopes. This I found very disctracting when I tried these eyepieces in my F/6.5 refractor so I didn't use them in that scope.

At one time there were a range of focal lengths available including a 30mm in the 2 inch fitting.

They originate from the manufacturer Kokusai Kohki in Japan. There was a later version of the design with improved coatings which were called the Widescan III range. They have also been copied by chinese manufacturers eg:

https://www.365astronomy.com/16mm-Columbus-UWA-Ultra-Wide-Angle-Eyepiece-with-80-degree-field-of-view.html

[Alfian]

Many thanks John,  just what I was looking for.

[F15Rules]

1 hour ago, John said:

They have also been copied by chinese manufacturers eg:

https://www.365astronomy.com/16mm-Columbus-UWA-Ultra-Wide-Angle-Eyepiece-with-80-degree-field-of-view.html

That's interesting John..I have seen one of these (and looked through it, although an unbranded version and not the 16mm that Ian bought from me)..I didn't realise that it might have similar optics to the Fullerscopes eyepiece, but what I do recall is that the build quality was not a patch on the Fullerscopes Japan unit, although the optics seemed pretty good.

I'm sure I read somewhere that, back in the 1980s/90s, these eyepieces were quite expensive to buy new (like most Astro kit from Japan in those days?)

Dave

[John]

1 hour ago, F15Rules said:

That's interesting John..I have seen one of these (and looked through it, although an unbranded version and not the 16mm that Ian bought from me)..I didn't realise that it might have similar optics to the Fullerscopes eyepiece, but what I do recall is that the build quality was not a patch on the Fullerscopes Japan unit, although the optics seemed pretty good.

I'm sure I read somewhere that, back in the 1980s/90s, these eyepieces were quite expensive to buy new (like most Astro kit from Japan in those days?)

Dave

I have a BC&F brochure from 1990 which prices the Fullerscopes wide angle "plossls" as they called them at £150 apiece. The KK Widescan III's were originally priced at £160 for the  1.25 inchers and £200 plus for the 2 inch one. So they were expensive eyepieces.

The chinese clones of them don't have the build or optical quality really.