What's Shot is History...

Monday, 25th March 2013

'What's hit is history. What's missed is mystery.'

So goes the old saying with regards to sightings of potentially rare birds. It's amazing how history repeats itself though: the shooting still goes on, and we ornithologists are still collecting - photos not skins nowadays, thankfully!

The camera has replaced the gun, to me it has also replaced the scope. There is no way I am ever going to lug a scope and tripod around for three hours along the Weares. The Weares may be one place where many might feel a scope is 'necessary', but I simply can't be bothered. The camera is a different story for it has a further use than for conventional photos. See the example below. 

During our survey we spot (through binoculars), a very distant, smallish gull, with somewhat buoyant flight. The bird is so far off in fact that we don't notice it has a black head until the photos taken here are enlarged! Indeed the very act of finding the bird in the camera viewfinder frame proves very difficult at such a range - even when using a lens with an image magnification of approximately 630mm (35mm equivalent focal length).

Eventually, and not before time, the 'spec' is in sight and I shoot: on high speed servo at 1/1250 sec, f7.1, ISO 2000. Within seven seconds a dozen or so frames are 'in the can' (as we said in the days of film). Got it! Our mystery bird is recorded for posterity. You can see it here in a full frame image - right between the yellow spots that I have added to help!

Mystery gull at 630mm (35mm equivalent focal length).

On examination by enlargement it transpires that about five images are potentially useful for ID purposes. The first image below is a blow up from the uncropped photo above.

and yes, it's my favourite bird - the Med. Gull! The first one for the Weares this year. Had it been an adult Franklin's, we would have clinched a record for history that would have been 'lost' through using a scope.

One thing I have learned here for certain is that it's the combination of photos that render the bird identifiable at this sort of distance. In most cases, because we can only get an image of appalling quality, many of the individual photos can appear quite misleading.  

Some artifacts have crept in on several frames, notably some dark pixeling on the gull's belly on frame one, and the same on the underwing on frames four and five. Also in the first frame the leading edge of the right wing looks as if it's dark; this proves however to be a trick of the light. Shots one and two were taken at less than one second apart.

Reducing the ISO in the hope of obtaining a cleaner image at this enlargement may have worked, but under these dull conditions dropping either shutter speed or opening the aperture any wider may well have resulted in poorer results instead. Whichever way one chooses to go when working at these limits is a bit of a gamble. Let's just hope I get right for the Pterodroma!

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