We are frequently asked if we can supply eyepieces for older telescopes that have a 0.96" focuser.  While we have adapters that can let 1.25" eyepieces be used the cost sometimes seems prohibitive compared to the value of the scope.  So, we are supplying a range of 0.96" diameter eyepieces purely to meet that need.

The eyepiece is supplied in a plastic storage container.

The Ramsden eyepiece comprises two plano convex lenses of the same glass and similar focal lengths, placed less than one eye-lens focal length apart, a design created by astronomical and scientific instrument maker Jesse Ramsden in 1782.  The design is slightly better than Huygens but still not up to today’s standards. (Wikipedia)

Remember that a 4mm eyepiece is going to be powerful and consequently difficult to use on many telescopes so calculate the magnification carefully before buying one of these eyepieces.

"So yes, carry on telling people that such a small scope can be very good for a beginner – great for looking at the moon, the phase of Venus, the rings of Saturn, the moons of Jupiter and the sun.

Good news on the eyepieces that you sent! I tried them out last night by looking at Saturn, and they worked very well. As I hoped, the 20mm was good for locating it very quickly to start with (the other advantage of a small, simple scope – it is about 5 minutes from picking it up to looking at your target).

And I was also able to use the 4mm perfectly well too, even though at 150x it is above the 100x theoretical maximum for the telescope.

The image was understandably a bit dimmer but the slightly larger size was good to see." - Alan Dobie - client June 2013

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