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Dollond Antique Binoculars

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4 replies to this topic

#1
Izar

Izar

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Here we have a review of a pair of Victorian binoculars, but first
let me fill you in with a bit of background information.
For some time now I've been getting frustrated with the standard
7x50 finder on my scope. In the field I use Sky Atlas 2000.0
and the AAVSO star atlas for finding objects, and the inverted
view of the finder sometimes makes finding objects difficult
for me.

Going around car-boot sales and markets, I see many old Galilean
binoculars for sale at give away prices. As these instruments give
a correct view, I thought I would buy a cheap pair and mount the
optics into a turned wooden tube and then fit it to my scope using the
standard finder bracket.

Going around a local market, I had a choice of around 10 pairs ranging in
price from £5 to £30. One pair caught my eye, and taking a closer
look I could just make out the name of Dollond on the eyepieces.
The sum of £15 exchanged hands, and I went home happy.

Instead of using the optics for a finder I decided to completely overhaul
them, as Dollond had a good reputation for the quality of their optics.
After around 12 hours work, I now have a pair that now look
similar to the ones for sale on this web site: http://www.gjaltkemp.../telescope.html

Of course, doing up a pair up like I have done is purely down to personal tastes,
and many would like to keep them in the original condition.
I now have them on display in my living room, because they are simply
stunning in appearance with their brass, aluminium
and leather bodywork.
The build quality, fit and finish is staggeringly good.
The sliding sunshields simply glide over the brass lens barrels. When I stripped the
binoculars down I found that the method used by Dollonds for the retractable shades
is still being employed on some of the expensive APO refractors that are around
today.

The optics at both ends are held together in finely engineered brass cells,
and the attention to detail is amazing. The black paint used inside the binoculars
is as good as any that I've seen on the most expensive modern day optics. After 100
years, not one flake has dislodged itself from the tube walls.
Now for the review, which left me completely changing my mind about
Galilean optics. I thought it would be interesting to see how a pair of optics
made in the Victorian period would compare against modern instruments
with their multicoated optics.

The following were used, Takahashi 7x50 finder, Skywatcher 9x50, GSO 8x50
and a pair of excellent Zeiss Jena 8x30 binoculars.
As many will know, Galilean optics cannot match the wide field views given by the
finders and Zeiss, so instead I was looking at the actual quality of the views given.
The bridge on the Dollonds has x5 and 2 7/16" stamped into it. I took the x5 as meaning
5 times magnification.
During the day, various objects were looked at and the Dollonds gave an image that was every bit as sharp as the modern scopes.
The lenses on the Dollonds seem to be un-coated, and clearly show that they are reflecting more light
than the others , however, the Dollands give a wonderful image that is both bright, sharp and clear.
Also with Galilean optics you tend to get a drop off in image brightness at the outer edges.
In the Dollonds, this drop-off is very slight indeed and does not seem to affect the enjoyment
of the day/night image. Indeed, faint stars that were at the limit of the aperture, were still very
clearly seen when moved from the centre to the outer edges of the FOV.
Going head to head against the Zeiss binoculars, the Dollonds matched the Zeiss
for quality of image, and I actually found the Dollonds very nice to handle and use
for they have very good eye relief. The focus wheel is extremely smooth, and still working
as good as the day it was made. I like the simplicity of the optics, and not having prisms
means they are very lightweight.

At night, I could just fit Castor and Pollux into the Dollond field of view, meaning that
they were giving a FOV of around 5°, which I would find acceptable for a finder
scope, and locating objects was surprisingly very easy.
All the stars visible in the Zeiss, were also seen in the Victorian ones,
and several DSO's showed up very well. M35 was easily seen, in spite of it being low
down in the western sky. The limiting magnitude of both instruments
was the same at around magnitude 8.0., but I suspect that the Zeiss should reveal stars
a tad fainter from a dark observing site.
Both instruments produced views that are free from flaring and ghosting.
The only advantage that the Zeiss had over the Dollonds was the wider field of view, for everything else,
the two were evenly matched.

I was very impressed by the Dollonds, for they held their own against the modern instruments,
and in this day and age, where can you buy such a piece of history with such outstanding build
quality for so little money. Indeed only this morning, I picked -up a pair of Ross, London for £10
and a pair of very early C.P.Goerz (c.1900) German military binoculars for only £11. The Goerz have a very
interesting history, and I hope to post a review shortly if anyone is interested.
Interestingly, the Ross binoculars and my Dollonds are the same except for a different plate on the bridge,
all the various parts inter fit each other.
So it looks like they were produced by the same manufacture, and only the stamped name on the eyepiece barrel
was changed. Who this manufacturer was will probably remain un-known. In terms of optical performance, both the Ross
and Dollond are exactly the same.

Dollond Pros
Excellent optics giving clear, sharp and bright views.
Simply superb build quality.
Can be bought at very cheap prices.
A real piece of optical history.

Cons
Narrow field of view, typical of the limits of the optical design.

#2
argonaut

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Izar,

That was a very interesting read indeed. Thank you for taking the time to write it.

I suppose you can't really beat quality engineered equipment. Not all ideas are new,are they? I have seen the link before,but try not to look :)

More reviews with the history as well would be very nice.

Thank you again.

Glen.

#3
Brass n glass

Brass n glass

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Here's another good reason for buying old ones: they keep their value.
The old makers liked Galilean binoculars because the optics were much simpler and cheaper than in the more advanced prismatic glasses. The result is that you get incredible light transmission even with the uncoated lenses that were universal until after World War Two. The downside is the tiny field of view caused by the ferocious baffling needed to keep ghost images at bay - Hugh

#4
Izar

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Many thanks Glen and Hugh

Glen- a review on the Goerz will be up shortly.

Hugh - I noticed that when looking down the binocular tube on the Dollond, that the outer 10mm of the lens appears to steeply
slope inwards leaving a round clear aperture of around 30mm. The eyepiece tube then contains 2 baffles.

With the Ross, the lens just appears normal, but that unit contains 3 baffles in the eyepiece tube.

The quality of views is the same in both instruments.

#5
Brass n glass

Brass n glass

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The classic Galilean design as used by the great man himself in a telescope more than two feet long consisted of only two lenses, a double convex objective and a double concave eyepiece - hence your sloping lens. By the 19th century lens design had advanced so much that manufacturers could shorten the tube drastically. Then somebody joined two short tubes side-by-side creating the standard Galilean binocular that was made in large numbers up to World War One.
Apparently some of the most expensive today were made in France in the 1860s. A lot of them were sold originally to the USA and are now in demand by enthusiasts there who like to carry authentic equipment when they re-enact Civil War battles - Hugh.




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