birding-aus

Low light bins

To: "'Rosemary Royle'" <>, "'Michael Hunter'" <>, <>
Subject: Low light bins
From: "Tony Russel" <>
Date: Wed, 9 Mar 2011 08:58:11 +1030
Hi all, yes I too found the article referenced by Dave Torr to be useful. In
particular the info about how age affects the optimum specification of bins
required per individual was something I hadn't heard before. I too am
thinking about some new bins "at some stage", and being an old bloke of
nearly 76 this has some importance in my choice.

 I am considering replacing my old Leica 10x42 BA's with either some new, as
I understand it, lighter BN Leicas, or some of the yet to be released
Swarovski EL 10x50's. My experience with the Leicas are that they are heavy
for their size and at one time the focussing mechanism jammed before getting
down to close focus. (This was subsequently repaired at great expense
because the local agent wouldn't cover the cost under warranty).

 When the Swarovski bins first came out I tried them and found them to be
much brighter ( and lighter) than my Leicas, and this comment also applies
to my Leica scope vs the corresponding Swarovski, much brighter in fact. 
 I have contacted Bintel about the EL's and they have given me a price with
availability in April, and I have Adelaide Optical on a similar request.
I'll advise you once the info comes to hand. In the meantime if anyone has
any further info which might influence my choice it would be most welcome.

On a different note, I too have just ordered a harness to take the weight
off my neck.

Cheers, 
Tony


-----Original Message-----
From: 
 On Behalf Of Rosemary Royle
Sent: Tuesday, 8 March 2011 10:37 PM
To: Michael Hunter; 
Subject: [Norton AntiSpam] Re: [Birding-Aus] Low light bins

I am always interested in communications on this list regarding binocular
magnifications. In the UK the most popular magnification is 8x40 or 8x42 and
10x are not much used. I realise that birding in Aus is a bit different to
birding in the UK but any delusions I had about you all being so fit and
macho that you could carry heavy 10x bins with ease has just been dispelled
by the recent "harness" thread!

Often 10x binoculars are so heavy that they are hard to hold steady enough
to get any advantage from the extra magnification.  A harness can help with
carrying but when actually using them you really need a tripod or a
Finnstick. (I have only ever seen the latter in Finland - it is a T shaped
piece of wood which you hold at waist height and use to support the
binoculars at eye height - it really works!) The only time I could see that
10x might be really useful is if you are, say, sea-watching, and do not have
a scope. In these kind of conditions, putting heavy bins on a tripod can be
quite a revelation - the world suddenly gets much sharper! Photographers use
a tripod for good reason. 

(Our first pair of "real" birdwatching binoculars were Swift Audubon 8x42
which were huge and heavy - a tripod or more usually, a handy fencepost or
rock, made a lot of difference to the sharpness of the image)

For gloomy forest conditions then it is the objective size rather then
magnification which is important, and also particularly the depth of field,
plus close focussing and number of turns to focus. 

However, the objective size of course also increases the weight, but it is
worth noting that due to improvements in technology the light gathering
power of bins has improved a lot over the last 20 years and it may no longer
be necessary to use x50 in low light. A modern 10x40 will be as bright as an
older 10x50.  

And unfortunately, the more you pay, the better the bins are in low light -
though the marginal benefit soon starts to get very costly!

And as a footnote, Nikons are often reckoned to be very "bright" - i.e.
gather a lot of light. 

The article referenced by Dave Torr is really very interesting and covers
material I have never seen before - however, it neglects to mentions depth
of field as an important characteristic. This is possibly because it is
rarely mentioned by manufacturers, so it is hard to find out how good a
particular model is, however good reviews will cover it. 

Peter and Rosemary Royle
Wales, UK







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