Tuesday, March 4, 2008

Digiscoping: Taking that picture

Take that Picture! Many digiscopers emphasize the benefits and need for a cable release to take quality images. I don't have the setup to support a cable release, thus I have to resort to hand-held shooting, or self-timer shooting. I don't feel like I'm missing out at all, since I'm not convinced that a cable release system is necessary. Reason? A cable release helps minimize vibration to a camera when depressing the shutter button, however, it does nothing to alleviate vibration that is inherent to a scope sitting atop a tripod and exposed to wind. Unless you're shooting in a vacuum or on a dead-calm, windless day, the scope is going to see much more vibration than the camera will. So I prefer to use long-lens technique perfected by many of today's top nature photographers. The key to vibration damping is 'weight'! And our bodies can make great vibration-damping tools if used properly. So my recommendations are as follows:  

Stable tripod – add weight A good, solid tripod is a must for digiscoping. I was shopping for a tripod last year and wanted to get a mag-fiber, light-weight tripod that everyone was raving about. Half the weight of the more traditional aluminum tripods (and twice the cost), and extremely sturdy, I thought it would be a joy to carry in the field. Unfortunately, I could also imagine the setup easily blown over by the wind, especially with a backpack attached to it to act as a sail or windcatcher. So I opted instead for a heavier tripod (Manfrotto 3021BPRO). I carry my scope/tripod attached to a backpack so that my hands are free to use binocs and my Nikon D7100 and 300mm f/2.8 VRII. I wanted to be able to pop open the legs and extend the feet instantly, which the Manfrotto does very nicely. The mag-fiber tripods require that you unscrew each leg individually and pull to extend the legs. This is too much time when you have only moments to setup and shoot. The flip-open leg locks on the Manfrotto allow the legs to slide out freely to their full length, and can be locked by just pressing the levers back down. The bottom feet are already extended approximately 6" to put the system at the right height for my profile when the top legs are extended full length. Bottom line: carry the heaviest system your frame can stand; it will provide more support for your digiscoping setup than a light-weight system will. And don't skimp on a video head. The digiscoping rig must be stable, so professional ball head / video / fluid head system is of utmost importance. I use the Manfrotto 501HDV Pro video head.

Long-lens technique - brace scope and shoot continuous - stay low to subject- keep sun to your back - depress shutter half-way, focus w/ scope - hold breath, fire away Many photographers will use their bodies to help add weight to their system and to reduce vibration. I 'lean' into my scope with my arm draped over the scope and finger on the focus-wheel. Once my focus confirmation is 'green', I depress the shutter and fire in Continuous Mode (10 fps on the Nikon V1). The first image may be blurry from the initial press of the shutter button, but the 2nd and 3rd images will be sharp since the camera is shooting faster than I can move. 

Self-timer (5-10 seconds or less) The 'Twilight Snowy Owl' photo I took in March of 2006 was taken under heavy overcast skies and at sunset. With the self-timer set to 2-seconds I was able to capture images at speeds of 1/8 to 1/30 sec. at magnifications of up to 180X. When the subject permits, by all means use the self-timer function on your camera.

Lower magnifications = more keepers! Self-explanatory. Vibration increases with magnification as light-gathering capabilities drop and longer shutter speeds are required. You'll see better results by photographing your subject at 60X and then cropping your image afterward than trying to get a full-frame 180X image. Check out my article about Limitations.

Overcast days? – expect the grainies! Compact, P&S cameras are generally criticized by film-buffs for their poor white-balance capabilities, especially under cloudy conditions. This is because the sensor will mix blue and red pixels to make white colors. So, when you blow up an image taken on a cloudy day, you'll see lots of grain. Don't expect too many award-winning images on cloudy days. You might even consider leaving your camera at home when its cloudy and overcast, and just enjoy the view through your scope's eyepiece.

Best distances ~ 30 – 100 ft Image quality degrades exponentially with distance. The best digiscoped images are taken when the subject is closer to the scope. Longer distances mean that you're increasing the amount of air that light has to travel through to get to your scope, resulting in more light-scatter caused by thermal currents and humidity. Remember, however, to keep your subject's well-being your first priority. Digiscoping is meant to reduce stress on birds by being able to photograph them at longer distances and thus minimize direct interaction with them.

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