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Is close focusing ability in a binocular REALLY necessary (1 Viewer)

42za

Well-known member
Hello All,

I cannot really understand why some people insist that a binocular focus below a certain distance.
If a binocular has a minimum focus distance of say 8 or so meters this should be ok , after all binoculars were originally designed to observe distant objects.

If one must look at nearby objects , play at being Sherlock Holmes and use a hand magnifier.

o:D o:D o:D

Cheers.
 
Being able to focus to 3m or so enables you to look at butterflies and other small stuff that’s not far off. Though being able to get too close risks them getting spooked and flying off. I have an old pair of bins that can’t focus on the bird feeder on my back fence (?4-5m off) and it’s annoying, but that’s the only time I’ve had a near focus issue.
If I want to go on a mini beast safari then nothing beats the Papilios.

Peter
 
If you are an extreme specialist and only look at, for example, birds, then a close focus distance of 1.5 metres or so is probably not necessary for you.
If you are interested in all aspects of nature then close focusing binoculars open up many wonderful worlds including dragonflies, butterflies, moths, reptiles, life in pools and rivers, life in sea-side rock pools, not to mention flowers and lichens and fungi.
Have you ever watched a nature show on the television or on-line? Did you ever see a fantastic close-up of a butterfly on a flower and say to yourself: you never get views like that in real life? Because if you did, you are mistaken. Views like that are easily obtainable through close focusing binoculars.

Lee
 
If a binocular has a minimum focus distance of say 8 or so meters this should be ok, after all binoculars were originally designed to observe distant objects.
It also depends on the magnification. A 25x binocular that focuses 8m, is like an 8x focusing 2.5m or a 10x focusing 3.2m.
And of course it also depends on what you observe.
One day I was photographing ducks and behind me a squirrel was looking for food. I tried to photograph it, but the lens couldn't focus it. So I took the binoculars and I watched it easily with beautiful close-ups.
 
Another '' I don't need it / want it, why should you?'' thread...

I think it's perfectly legitimate to question what is essentially marketing-driven inflation of specification numbers. It may be a niche requirement for some but a close focus of 1 m in a roof-prism binocular would preclude merging the images, even at reduced IPD.

Such extreme close focus either demands stronger focussing elements or increased travel thereof, which in both cases could be detrimental to correction of spherical and chromatic aberration.

John
 
I think it's perfectly legitimate to question what is essentially marketing-driven inflation of specification numbers. It may be a niche requirement for some but a close focus of 1 m in a roof-prism binocular would preclude merging the images, even at reduced IPD.

Such extreme close focus either demands stronger focussing elements or increased travel thereof, which in both cases could be detrimental to correction of spherical and chromatic aberration.

John

That's not at all how the OP framed the question though....and a CF of 8m would be of little use to most birdwatchers, let alone those of us that like to observe insects etc.

The ''why we have CF bins'' has been done to death here and the questions asked have been answered dozens of times. The OP's premise is flawed off the trot - that bins are for looking at distant objects - not always true - we often want medium close objects brought much closer.
 
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For me, yes it's a necessity.

I once went to Norfolk in the hope of seeing, among other species, my first Yellow-browed Warbler. Someone pointed to a thicket and said "There's at least one in there". I carefully edged my way in, and in front of me was a warbler. The bins I had at that time focused no closer than about 5 or 6 metres, and the bird was only 3 or 4 metres away. I saw the features just about well enough for a positive ID, but thoroughly blurred. Yes, got a tick, but there was little pleasure in the sighting, and I made my mind up to get ones that focused much closer at the next upgrade.

Also, it's a joy watching dragonflies in superb detail from very close quarters.
 
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The OP's premise is flawed off the trot - that bins are for looking at distant objects
I would say that it is understandable, since it is paradoxical that binoculars made to zoom in and to bring distant objects closer, is used to see objects at 2 or 3m.

However, I am certain that once some micro-observation experiences have been made, the OP might think again and accept this function as sought after.
 
I think it's perfectly legitimate to question what is essentially marketing-driven inflation of specification numbers. It may be a niche requirement for some

John

Since this is called Birdforum and is visited by birders it is understandable that the impression can be gained that binoculars are only used to look at birds, which are frequently distant objects.

However a few minutes viewing any nature show on the tv will reveal there is more to nature than only birds and many of these fascinating subjects are amenable to being studied using close-focusing binoculars.

As I posted earlier: if you are a specialist in bird observation you may not need a close focus, but if you are interested in a wide variety of nature observation subjects you will find a close-focus extremely rewarding.

In terms of the breadth and depth of the world of nature, an interest only in birds is a very narrow niche. By providing close-focus capabilities, binocular manufacturers are clearly hoping to attract buyers from the world of nature-observers as well as birders, and also providing a capability for birders who dare to 'spread their wings' and take an interest in other subjects, instead of remaining confined to the niche-world of birds-only.


Lee
 
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However a few minutes viewing any nature show on the tv will reveal there is more to nature than only birds and many of these fascinating subjects are amenable to being studied using close-focusing binoculars.

However, what is often overlooked is that there is a price to pay for the close-focusing ability: The focuser needs more travel and gets quite a lot more complicated and thus more prone to failure - remember the problems quite a few close-focusing binoculars had a few years ago? Also these binoculars typically require more complex optics, with a focusing lens between the objective and the prisms.

The situation is similar to having eyepieces on virtually all quality binoculars that can can be used by eyeglass wearers. There is also a price to pay, like a smaller field of view, larger and heavier and more complex eyepieces and so on.

I wish there were some simple, wideangle binoculars without a close-focusing ability, and not only binoculars that try to do it all.

Hermann

What I forgot to write: I'm not talking here about a focusing distance of 8m, more something like 2-3m which IMO is quite reasonable for birdwatching. I need binoculars, if I need a field microscope I use one.
 
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Lee,

I did say a niche product and I think Arthur's, Canip's and Hermann's comments substantiate this. For butterfly watchers there are specialist products (reverse Porro) with a very narrow objective spacing, but I think the perceived pressure on manufacturers to offer close focussing of 1,5 m or less on roof prism binoculars is senseless, not only because of design, reliability and price considerations.

I have occasionally used my 8x33 Kowa Genesis for watching butterflies and have just tried it at its minimum focussing distance of 1,5 m. I had to reduce the IPD from 63 mm to 58 mm but it was nevertheless very uncomfortable trying to merge the images. As others have pointed out, I think the vast majority is well served by a close focus of 3 m as on the latest Swarovski CLs and SLCs. In 15 years of use of a 7x42 SLC (4 m Close focus) I could count the situations on the fingers of one hand in which I would have wished for less.

John
 
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