distance estimate ... is this math correct ?

DoityBoid — Thu, 24 Sep 2009 17:33:48 GMT

If by knowing the FOV of my glasses and the average wingspan of the bird in question, would I be able to get a reasonable estimate of distance away from me by using the following calculations ?

Let's use a hypothetical FOV of 300 ft/1000 yds and a bird with a wingspan of 3 feet. If the bird fills my field of view, then I would estimate that he would be 1/100 (3 ft / 300 ft) of the 1000-yd distance, or 10 yds, away from me.

Also, let's say the bird is far enough away that I guess-timate that 20 of them would fill my field of view. At 3 feet each, that would be 60 feet (3 ft x 20 images) of bird-span. That works out to 1/5 (60/300) of the 1000-yd distance or 200 yds away.

Does this sound right ?

What Binoculars Would You Recommend to a Newbie?

rrecovery — Sun, 25 May 2008 20:33:56 GMT

I am brand new to all this and the binoculars I am using are great for viewing a concert not so much for watching birds. Any suggestions?

Does anyone own a pair of 10x50 Bushnell's???

MoJoWaxSwinger — Wed, 01 Oct 2008 14:39:32 GMT

I bought a great pair of 10x50mm Bushnell binoculars about 5-6 months ago. They have that triangle shaped focus system that allows only one stroke/movement to focus on an object. They call it 'Insta-focus'.... I think.

Anyway, the reason I ask is because something very strange happened the other day. I went for a day trip up to a great birding area in Northwestern CT... when I was leaving, I packed up all my stuff in the same duffle bag, the same way I always do. I packed my camera and lenses, large binoculars, tri-pod, hiking boots, field guides, empty drink bottles, and the smaller binocs. I know for a fact that they were fine when I put them in there because on the ride out on the dirt road I had to stop and pull them out to watch a Black Vulture soaring over the Housatonic River. They worked great, as usualy, when I put them back in the duffle bag.

After I put them in there I drove to McDonalds, then home.... about a 2 hour ride. The whole time, the bag was sitting on my passenger seat, with no stress on it, and not jammed in or being pressed on or anything.

When I got home, I put the duffel bag in the same place it always goes. Maybe 2-3 days later, there were 3 flycatchers perched along the picket fence in my backyard..... so I run downstairs to grab my binocs, run back upstairs and sloooowly open the back door... and the focus is broken.

They still work, but I have to manually move the eyepiece part back and forth to focus. To see what was wrong, I pulled out the eyepiece part... the part that comes out is the 2 eyepieces connected to a bar that slides down into the main part. On this bar there is a hole/slit where a pin or something needs to go. And, inside the shaft on the main part, where the bar fits into, there is another hole/slit where the pin form the bar would be inserted. There is no pin.... the hole/slit on the inside of the shaft is on the inside of the 'Insta-focus' triangle. So, if the pin was in there, it would be inserted in the hole/slit on the bar that is connected to the eyepiece part, and in the hole/slit that is inside the shaft on the main part that is controlled by the triangle focus knob.

So.... I know what the problem is. I do not know how it happened. And, I do not know how I would go about fixing it. Its not like the binocs were hundreds of dollars, they were only about $70. But, 70 bux is 70 bux and I can't afford to buy another pair.

Has this happened to anyone before?? Any suggestiong about how I can go about fixing them?? Obviously the best course of action would be to buy another pair... but as of now, that is not in the cards. As far as I know, there is no warrenty any more.

Binoculars vs Monocular

purplepain — Sat, 29 Mar 2008 04:57:03 GMT

I am curious what people here feel about this. I recently dropped my binoculars on the sidewalk (not a huge loss, there were a $25 pair from Sport Authority, but it was sad, they were a nice little pair) and I am looking for something as a replacement. Any opinions are wanted!