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Evaluating Antique Binoculars


It is a daily occurrence that we are asked to tell them what their item is worth, and for the appraiser, one that is simply impossible to correctly evaluate for each and every situation.

There are a lot of variables that go into appraising and evaluating an item. As a

general overview, these considerations are the product maker, age, condition including any restoration to fix or enhance an item, rarity, proven provenance (not here say) and general interest in a product at any given time, and of course that will most likely change with time.

Appraisals are written for a number of purposes. Insurance, to correctly appraise for replacement considerations, fair market value for resale, tax donations, inheritance and equitable distribution of an estate to heirs to name a few. These values range in number, for instance an insurance appraisal is its highest price evaluation for replacing an item similar in quality, age, manufacturer or maker, provenance, condition, rarity etc. from a source that offers these items for sale.

But, these are not the same value as one would expect to typically receive since most people selling items, even on web sites like ebay, are not specialized retail dealers. Also, if one is offering an item to a dealer, do not expect them to buy it at retail value nor anywhere close to it, since they are in the business of buying for resale and need to make a reasonable return on their time, overhead and financial investment.

Also, appraisers have to physically see an item to appraise it and cannot give you that information over the phone! Appraisal services are NOT free and are typically charged by the item or on an hourly basis.

I’ll have to add here, the dollar value of an old item should be to a collector its least interesting aspect. However, the value does play an important part of the appraisal evaluation, as shown above, but I do recommend that you consider first and foremost the desire to own an item and what that item is worth to you.

BINOCULARS

There are a number of styles of binoculars, and the description used to refer to them can vary. Typically, 'field glasses' or ‘binocular telescopes’ are a pair of identical or mirror-symmetrical telescopes mounted side-by-side and aligned to point accurately in the same direction, allowing the viewer to use both eyes (binocular vision) when viewing distant objects. Most are sized to be held using both hands, although sizes vary widely from opera glasses to large pedestal mounted military models.


Prism binoculars. Optical prisms added to the design are another way to turn the image right way up, usually in a Porro prism or roof-prisms design.

Porro Prism Binoculars

Porro prism binoculars are named after Italian optician Ignazio Porro who patented this image erecting system in 1854, which was later refined by makers like the Carl Zeiss Company in the 1890s. Binoculars of this type use a Porro prism in a double prism Z-shaped configuration to erect the image. This feature results in binoculars that are wide, with objective lenses that are well separated but offset from the eyepieces. Porro prism designs have the added benefit of folding the optical path so that the physical length of the binoculars is less than the focal length of the objective and wider spacing of the objectives gives a better sensation of depth. Thus, the size of binoculars is reduced.

Roof-Prisms Binoculars

Binoculars using roof prisms may have appeared as early as the 1870s in a design by Achille Victor Emile Daubresse. Most roof prism binoculars use either the Abbe-Koenig prism (named after Ernst Karl Abbe and Albert Koenig and patented by Carl Zeiss in 1905) or the Schmidt-Pechan prism (invented in 1899) designs to erect the image and fold the optical path. They have objective lenses that are approximately in line with the eyepieces.

Roof-prisms designs create an instrument that is narrower and more compact than Porro prisms. There is also a difference in image brightness. Porro-prism binoculars will inherently produce a brighter image than roof-prism binoculars of the same magnification, objective size, and optical quality, because the roof-prism design employs silvered surfaces that reduce light transmission by 12% to 15%. Roof-prisms designs also require tighter tolerances for alignment of their optical elements (collimation). This adds to their expense since the design requires them to use fixed elements that need to be set at a high degree of collimation at the factory. Porro prisms binoculars occasionally need their prism sets to be re-aligned to bring them into collimation. The fixed alignment in roof-prism designs means the binoculars normally will not need re-collimation.

As a general rule of thumb, German binoculars are considered the most sought after, followed by American, English; and French, which are typically good quality but are more common unless of unusual design. Some of the best names in Japanese optics of WWII or before are often of very high quality.

Some binoculars are center focus, with one central wheel that focuses both sides at once. Individual focus binoculars are adjusted by rotating each eyepiece. Each style is desired by different collectors. Very large binoculars are always sought after. Most binoculars are numbered according to their magnifying power and the diameter of the objective in mm. 12 x 30 optics magnify twelve times and have 30 mm objectives. Some of the older Paris made binoculars lack this information. Personally, I love the old Parisian binoculars, these classic heirlooms are usually quite affordable, fun to use and are a great product for tabletop and bookshelf décor.

 

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