[danehower]

Well I am prety much a forrest guy with regards to birding , however at my lunch break I have been frequenting a local hawk watch migration. There a few dudes with sworo scopes and I was privaliged enough to look through them . I guess I was just wondering what is the advantage of having a scope over a good pair of giant bins. Wouldn't you get a better FOV and is this not an untapped market . I am new to the long distance viewing and I would like to hear any ideas from those that would oblige . Thanks -dave

[jcwings]

Once you learn to pick out distant objects with a scope (sort of like learning how to properly use binoculars when you first start birding) then the ability to see a bird in detail without the bouncing around you would encounter with binocs is a better way to go. To each his own though. I think most people would find it more "comfortable" and the stability of a scope in that situation is best. There are times when a scope is useless however. My first pelagic trip I thought it would be a great idea to bring my scope- utter stupidity. You can't pick out a distant bird on the water or in flight when the boat goes up and down. This is a time when you need powerful binoculars. Sort of the opposite of the hawk watch situation.

[Pinewood]

Dave,

I am not too familiar with giant binoculars but they are generally made for the amateur astronomy market. Therefore three concerns arise about large binoculars:
Are they center focus or individual focus? I know that some of the best are IF.
What is the minimal focussing distance compared to 'scopes?
The maority of astronomical binoculars are not made for the most demanding bird watchers. At the very least, astronomical binoculars are not made for wet weather.

A quick and unrepresentative comparison of the 16x70 Fujinon, a rather well made IF binocular, and the 65 mm Swarovski scope with a 20 power eyepiece shows the Swarovski has a ten foot minimum focus and a 180 feet FOV at 1,000 yards, while the Fujinon has a close focus of 36 feet and a 210 feet FoV at 1,000 yards. In this case the Swarovski is on a par in FOV considering the higher power and is rather more useful for close work.

Even the discontinued Zeiss 15x60 had a close focussing distance of nearly fifty feet and an FOV of 248 feet. The current Swarovski 15x56 WB has a close focussing of 26 feet and an FOV of 231 feet. [Typically, the Zeiss Porro beats the Swarovski roof in FOV, while the Swarovski roof beats the Zeiss Porro in FOV]

I do not know what how big is a giant, nor the price points which you have in mind. I am also not making a truly informed contribution but I hope that I am being helpful.

All data was gathered at dealers' web sites.

Happy bird watching,
Arthur

[RAH]

I have a pair of Pentax 16x60 binocs and also a Pentax PF-65 scope. So, I can tell you that I use my scope for birding, instead of the binocs for several reasons. But first, it should be pointed out that binocs can be mounted on a tripod just like a scope, so I think the most meaningful comparison would be tripod and scope vs tripod and binocs.

The binocs are center focus and waterproof, so that is not a concern.

In this case, the binocs are much more cumbersome and unwieldy to carry around. Also, the max mag is quite a bit lower (my zoom eyepiece gets my scope up to 48 power). These are my main reasons, and the stereo view you get with binocs doesn't seem enough reason to argue for their use.

Also, I think the field of view with the scope is better at low power (although I'm not sure of the specs), so it seems faster to quickly locate an object. The entry above has better info about FOVs.

As far as handheld use, binocs are better of course, but this can get pretty tiresome very quickly. And again, the field of view seems less with the binocs, so it makes it hard to find something in a hurry.

Having said all this, however, I think I should also admit that part of the reason is fashion - i.e. you just about never see someone using large binocs on a tripod for birding. I'll admit I'm a little reluctant to expose myself to more than the normal amount of ridicule I get. ;-)

[henry link]

With a few expensive exceptions giant binoculars make poor substitites for spotting scopes because the optics of most giant binoculars are not very good. They use f/4 achromatic doublets as objective lenses and have huge amounts of chromatic and spherical aberrations. Spotting scopes generally have objectives with focal ratios between f/5.5 and f/7 and the best of them use ED glass or Fluorite and triplet objective designs. There is a world of difference between the image quality of an f/4 achromatic doublet and an f/6 APO triplet.