Thursday, September 3, 2009

Digiscoping 4 - when is "FAR", too far?!?...

Often while working the Leica booth at some consumer show, someone will look through one of my sample binoculars and ask, "How far can you see with these?" To which I invariably respond, 'How far you can see is really dictated by atmospheric conditions. A binocular or spotting scope doesn't make you see any farther than you can with your naked eye, it only makes the subjects appear larger and/or closer depending on the power of magnification.' Of course, quality of glass, coatings, and construction of any product can make a BIG difference in the ability to resolve fine details at comparable powers of magnification, but even the best glass can't make you see any farther.

With a digiscoping rig, it is much the same. These systems allow greater magnification than any other commercially available photographic equipment (often out to the equivalent of 6,000 mm or near 120x of magnification!) None-the-less, making full use of this magnification will always be greatly affected by atmospheric conditions that change from spot to spot and from one moment to the next. When you listen to weather reports you will often hear, "...visibility is limited to X miles..." (or km perhaps) as the atmosphere allows.

large bull Elk digiscoped @ ~500 yards, Rocky Mt. National Park, CO 8/5/09

The image of the large lounging Elk above was taken with the new Leica APO Televid 82 mm scope, D-Lux 4 camera, and matched digital adapter 4. Using a Geovid range-finding binocular I was able to determine this individual was ~500 yards away - a bit over 1/4 mile or just under 1/2 km for sake of reference. As you can see the system allowed me to capture this big boy well enough. He's in focus, well lit, colors are accurate, but at that distance near mid-day, under a hot sun (especially for high elevation tundra) this is the most detail I could muster even with the best equipment!
Elk digiscoped Rocky Mountain National Park, CO 8/5/09

The elk pictured above was taken at the same time from the same spot with the same equipment. The only difference here was the subject was considerably closer, between 250 & 300 yards or near half the distance as the group shown at top. You can see here, with all else being equal how much more detail is preserved on the closer subject. Individual details like the hairs on the velvet-covered antlers, and sinewy lines on the body are that much more apparent.

The lesson learned?!?... simple, while digiscoping allows you to "reach out and capture" a very distant subject, I'm certain all who digiscope will agree that your images will always be comparatively better if you are closer and using less zoom. How good or bad these images are is often dictated by a number of factors including:

1) the quality of your equipment - your system will only perform to the maximum capabilities of the weakest link in your system obviously. e.g. the highest quality camera in the world being shot through a low-quality/low-end lens (or scope in the case of digiscoping) can not offer premium quality images. Same is true of poor quality camera through great scope!

2) atmosphere - particles in the air from wind borne dust/dirt, to relative humidity, etc. will all affect overall imaging.

Let's consider atmospheric disturbances for a moment, my friend Bill Schmoker often refers as this as "bad air". When there is a lot of atmospheric disturbance this seems to manifest itself as "noise" the tiny 'off-colored pixels in images. Noise in digital photography is similar to what we would have could grain or graininess in film photography. These odd-colored pixels detract from the overall resolution of your subject making it appear less- sharply focused.

For sake of argument if we consider this disturbance as perhaps a dirty window pane between you and your subject. When we triple the distance to our subject lets consider that we've added an additional two planes of dirty glass. You see where I'm going here. There really is almost no way to correct this short of getting closer to the subject although this could change over minutes. Bill also suggested different angles but this is only going to be marginally effective.

a view of distant Little Tobago Island taken with a Leica D-Lux 4 camera 7/2009

I know some digiscopers who won't even bother taking a distant shot as their only goal is to get and take just the highest quality images. For me though, I'm interested in recording my memories, documenting different plumages on birds, and even in some extreme cases documenting a rare sighting. As such, I always "shoot first & ask questions later"! ;p Memory cards are cheap and deleting is an easy and painless process. Most of the time when I have low expectations that a distant shot will turn out, I find I'm right, but once in a while you'll be surprised! That's why I always take a shot anyway. The image above was a scenic shot taken near the Blue Waters Inn in Tobago showing distant Little Tobago Island, a well-known breeding colony for otherwise seldom seen seabirds! You can just make out the gleam of a light-colored house (a tiny white square in the photo) siting to the left of the pass between the two smaller, nearer islands in this photo.

Tobago island house digiscoped from Blue Waters Inn, Tobago.

As I viewed this distant, now abandoned, home I thought, "I wonder how that would look digiscoped?" It was late in the day, it was warm and I was shooting across water. My expectations were real low, but this was one of these instances where I was surprised at the results. It was not overly noisy, and the details are still QUITE noticeable, see where the roof has been damaged at the right corner?... the blinds are askew in the top right window on the near side, and hey is there someone looking back out at me here?!?... ;o Just kidding here, this house is vacant.

"Small Tortoiseshell" butterfly - digiscoped in Rutland Waters, UK - 8/09

The small butterfly I digiscoped from the Leica stand at the recent British Bird Fair in the UK (Small Tortoiseshell) was also through the APO Televid 82 mm spotting scope with the new kit - D-Lux 4 camera & matched digital adapter 4. This shot was taken @ minimal focus near 12 feet (4 meters) away. At this closest range one can actually make out individual powdery scales on the hind wing of this critter. This only requires a bit of light. I'd consider this "best case", the image below represents near the worst!

Scaly-naped Pigeon digiscoped on Little Tobago Island 7/09

Normally, this image would warrant an immediate move for the "delete" key. However, this image held special purpose. Scaly-naped Pigeon is a species that has been expanding it's range through the Caribbean islands and had been recorded only 4 times in Tobago since the first sighting in 2002 (still not recorded from Trinidad a bit further south). The bird was feeding on a distant ridge on the opposite side of a large cove. The bird was TOO distant for a good clear image, the light too poor, and atmospheric disturbance too high. None-the-less, even this horrible image was enough to show overall coloration of the bird, you can see albeit not clearly that the base of the bill is red with a yellow tip, and that there is a reddish ring around the eye. Enough to show this as a Scaly-naped Pigeon. As a result of my sending this to local bird experts in Trinidad & Tobago, locals were able to be assured that we had indeed seen this species and numerous locals were able to relocate this small flock which may well represent the first colonists of this rare bird in Trinidad & Tobago. So sometimes even a "bird too far" (sounds like a movie) can have its place!

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