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Meade 56mm plossl, Japan/China, 4 or 5 element

Started by NB, 09/16/2012 08:02AM
Posted 09/16/2012 08:02AM Opening Post
I have a Meade 56mm Super Plossl, Japan.

Externally there are 3 varieties of these.
1. Smoothside, Japan
2. Rubber cup and rubber grip bands, Japan
3. Rubber cup and rubber grip bands, China

Internally there are 2 varieties.
1. 5 element, Japan
2. 4 element

I have the intermediate type of Rubber cup and rubber grip bands, JAPAN.

How can I tell if mine is a 4 element or 5 element?
Are all of the Japan versions a 5 element design, reguarless of external variety?
Are ONLY the smoothside versions a 5 element?

Please state your source of information, or qualifications. I've researched this a little and found too much indeterminate responses, mostly questions.

Thanks!

Posted 09/16/2012 11:39AM #1
Hi,

As far as I know the Smoothie(japan) is the only 5-element version. I am not quite sure about the difference between the Chinese and Japanese rubber-cups, but they are all the conventional 4-element PLs.

The Smoothie has much better performance but unfortunately are not longer available.

Neil Barnett said:

I have a Meade 56mm Super Plossl, Japan.

Externally there are 3 varieties of these.
1. Smoothside, Japan
2. Rubber cup and rubber grip bands, Japan
3. Rubber cup and rubber grip bands, China

Internally there are 2 varieties.
1. 5 element, Japan
2. 4 element

I have the intermediate type of Rubber cup and rubber grip bands, JAPAN.

How can I tell if mine is a 4 element or 5 element?
Are all of the Japan versions a 5 element design, reguarless of external variety?
Are ONLY the smoothside versions a 5 element?

Please state your source of information, or qualifications. I've researched this a little and found too much indeterminate responses, mostly questions.

Thanks!

Posted 09/16/2012 07:10PM #2
Supposedly you can determine the number of elements by shining a small light through and counting reflections. Mike Hosea has a post on CloudyNights (Feb 2010) on the details. 6 reflections for a 2-2 plossl, 8 reflections for a 2-1-2 design. Mike says they can be tricky to see, but if you get 7, then the 4 element design can be ruled out.
Mike R