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Archives of an email list on the history of binoculars. - page 8 / 150

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Stephen Sambrook

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  There are 'prism-lens' optical elements, for example a right angle reflecting prism with concave or convex faces, they have been used in telescopes.  Fabrication is quite difficult, as the curved face has be be centered as precisely as does a standard lens in a telescope.  If these exacting requirements are combined with the difficulties in fabricating a roof prism, the product would likely be an exercise for the idle virtuoso, rather than a viable commercial product.

  And there are achromatic prisms, with cemented crown & flint elements, though I'm not sure where they're used.

  And as noted, there are optical elements in some binoculars with a lens cemented to the prism.  No doubt, the glass types in those are carefully chosen, but whether they are crown / flint combinations is unknown to me.  These binoculars cement an eyepiece element to the prism, since if the objective is cemented, then the prism has to be much larger.

  However, the topic of such designs is of great interest, and the 1930s B & S or Zeiss models with cemented lens / prisms might not be the only examples.         --Peter

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Subject: Stabiscope

From: WIta057@___m

  I recently had the opportunity to handle a US military Fujinon 10X40 stabiscope.  It was being auctioned off as surplus inventory.  From the short demo, I could not see any apparent advantage over my Canon 10X30IS considering its weight and price.  It did come with extra objectives that would boost the magnification but I did not have the chance to install them.  It would seem that at 10X, the advantages of image stabilization with the added weight and cost are not really realized.  I noticed is that when panned horizontally, the image had a "rolling" effect similar to being at sea which might lead to motion sickness with prolonged usage.  I could not do a good test of the quality of the view because I was in a warehouse with limited sight distance for a 10X binocular and there were other bidders that wanted to try these.  The view seemed sharp but a little dark considering that these are reported to be light intensified.  I did a Google search and noticed that Fuji does not sell any current models in 10X40.  Anyone with more information on these gyro stabilized binoculars?

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As far as I can remember, the Stabiscopes have a very good reputation for image quality, they are not light intensified but are 'just glass', the stabilization is indeed for a 'lower frequency' of motion / vibration than the Canons, there is indeed a rolling effect as the image 'catches up' to your motion, and they're good for use in a boat.  But it has been a long while since I've seen these.

Image stabilization is an excellent, useful feature, though I have yet to purchase such a binocular.

The image delivered by the Canons is absolutely outstanding when stabilization is off, and it is generally felt that the stabilization works well.        --Peter

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Subject: binocular estate sale

From: "Mike" <mike@___heoptik.com>

  Attached is a list of binoculars we've  recently acquired through an estate sale here in the USA.  As you can see, the list includes some really exceptional items.  Prices are regrettably  high (in keeping with the market and what we had to pay), but we've built  in a significant cost advantage in buying them as-is (since our optical  shop is overloaded).  While prices are firm on individual units, I would be  happy to discuss a deal with anyone interested in multiple "as-is"  pieces.  

  s/ Mike Rivkin

April 8, 2003

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