Estimating distance of birds

[NoSpringChicken]

I'm not sure if this the correct section to post this question in but it is loosely connected to photography so I will post it here.

Sometimes it is required to state the distance that a bird was photographed from and I find this rather difficult to calculate. It normally goes along the lines: "The bird was approximately [insert hugely inflated wild guess at the distance] from me at the time."

I wonder if anyone can suggest any useful techniques or cheap bits of equipment which would help to make the process more accurate. I try to imagine how many six foot people lying head to toe it would take to cover the distance but that is difficult and far from accurate.

I thought something like range finders or the devices that estate agents use for measuring rooms might help but they seem to be too expensive. Apparently, some binoculars such as the Minox HG have distance scales incorporated, which would help, but I don't own a pair.

Any other suggestions?

Ron

[Ken Hall]

some camera lenses have a distance scale on them which you could use, but only for shorter distances. The scale on my Canon 400mm lens only goes up to 20m, thereafter infinity. A better way is to familiarise yourself with distances such the length of a 25m swimming pool, a football or rugby pitch, near enough 100m in length (as a goalie that's the only view I ever got). There are 100m posts on most motorways (eg 74.3, 74.4, 74.5). If it is feasible, you can measure the distance by counting your paces (after you have finished looking at the bird of course). Check your pace count against a known distance. Sometimes it is possible to measure the distance on an O.S. map if you know exactly where you are and where the bird is. It's just a case of practice. Hope this helps. I suspect a lot of people have little idea of distance unless they are accustomed to making such measurements.

[NoSpringChicken]

Thanks for those tips, Ken. Thinking about it, on television they always attempt to give an idea of the scale of things by how many footballs pitches or Olympic swimming pools could be fitted in. It used to be London double decker buses for distances. Perhaps I'll start imagining family saloon cars!

I use digiscoping for my bird photos so the camera lens scale doesn't apply to me unfortunately. I'm sure you're right: most of us have little idea of distance and there are some very wild guesses out there.

Ron