What binocular power?

To: Gregory Little <>, "'David Adams'" <>, "'Birding-Aus'" <>
Subject: What binocular power?
From: Denise Goodfellow <>
Date: Wed, 28 Mar 2007 13:22:04 +0930
Birding in the Top End wet season as I do, makes waterproof binoculars and
scope essential.  

Denise Lawungkurr Goodfellow
1/7 Songlark Street
Ph. 61 08 89 328306

On 28/3/07 10:28 AM, "Gregory Little" <> wrote:

> David 
> I agree. Was away with a fellow for a month recently, he had equal
> quality binoculars of 8x (mine are 10x) and he saw the detail in
> everything that I saw with no troubles what so ever. Matter of fact I
> reckon that because the 8x have the advantage of less
> "movement/vibration/camera shake" whatever, than the higher powers they
> see just as much detail. Of course if both were rested on a firm surface
> the 10x may have an advantage. Waterproof binoculars are good not only
> for the occasional rain showers and river dunkings but for dust,
> humidity and sweat etc.
> As regards costs, nobody thinks much of it if you spend thousands of
> dollars on a tinny and motor to go fishing or tens of thousands for a
> bigger boat. Nobody gets embarrassed by that. But when you tell people
> how much the binoculars cost they gasp. Why? Lots of pursuits are
> expensive to set up. For a couple of thousand dollars you get a superb
> optical instrument, that the kings and Packers cannot get better than,
> that "should" last many, many happy years and you will use a couple of
> times a week at least for the rest of your days. A good pair of
> binoculars, a good field guide, a note book and pen and your set up.
> Pretty cheap for your life long passion/obsession.
> Greg
> -----Original Message-----
> From: 
>  On Behalf Of David Adams
> Sent: Wednesday, 28 March 2007 7:37 AM
> To: Birding-Aus
> Subject: Re: [Birding-Aus] What binocular power?
> I've always used 8x binoculars but, as far as I can tell,
> magnification is not the single most important factor. Generally,
> you're going to get a smaller angle of view with higher power
> binoculars. It's easy to give too much weight to magnification when
> buying optics. Keep in mind that higher magnifications don't deliver
> as much benefit as you might think. As an example, imagine you're out
> looking at a Lesser Spotted Dingle-Dangle (or is it a Greater
> Spotted?) standing on a post 100m away. With the naked eye it looks
> 100m away, assuming you've got standard vision. Now imagine you're
> using a 2x binocular (if such a thing exists). The bird now appears to
> be 50m away. You've just moved 50m closer. Now imagine you've got a 4x
> binocular. The bird now appears to be 25m away. You've doubled the
> power but only halved the gain. At 10x, the bird seems to be 10m away.
> So, the 2x gains you 50m total and the 10x gains you only and addition
> 40m for 90m total. (My explanation here is off the top of the head and
> I've long found the subject a bit confusing. If someone who is smart
> about optics wants to post a correction or better explanation, I'd be
> grateful.)
> A couple of factors that may be more important to your satisfaction
> than magnification:
> * Quality of optics
> A high-quality 7x binocular will help you see and identify a lot more
> birds than a lower-quality 8x or 10x binocular.
> * Weight and comfort
> Binoculars don't do you any good unless you have them with you and, in
> a lot of cases, already around your neck. A $1,000 pair of binoculars
> aren't help much if they're in a drawer. I'm using an old pair of
> Pentax 8x42 binoculars and, when I bought them, was very tempted by
> the 7x pair. The 7x were much lighter, smaller, very nice in the hand,
> bright, and provided most of the magnification of an 8x. I got the 8x
> as they're within the size I'm willing to carry around with me all of
> fthe time.
> * Close focus
> Some binoculars can focus on objects 2m away, others need 4m. This
> doesn't matter all of the time but having binoculars with a short
> close focus ability turns out to to helpful surprisingly often.
> * Waterproofing
> If you don't mind getting wet, consider putting this feature on your
> list. It's reassuring to have binoculars that are designed to survive
> a soaking. (Although, as people have already reported, this isn't a
> feature that is guaranteed for life.)
> With all that said, if you get 8x binoculars you don't have to worry
> about the other kids laughing at you ;-) Just get the highest quality
> set you can reasonably afford and enjoy!
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