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BIRDWATCHING SEASON IS HERE! (03.03.2016)
Text and photos Triin Leetmaa
When starting with bird watching, it is enough to own decent binoculars but if you wish to watch birds that are a bit further away, you definitely need a fieldscope. You can choose between different producers and models. I decided on Nikon EDG Fieldscope 85-A and EDG 16-48x/20x-60x Zoom.
Since I became acquainted with birding through nature photography, for me, it is self-evident that I could also capture the scene that I am seeing through the fieldscope – the correct word for it is digiscoping. You can just put your camera (or even the smart phone) against the ocular of the fieldscope or use an adapter which has optical lenses. In both cases, the fieldscope is like a manual focus telescopic lens.
The first system is more universal – despite the brand, all fieldscopes are suitable for whatever cameras because basically you are photographing an image created by the ocular. Similarly, you can capture the image seen through the binoculars. There are special digiscoping brackets to fix the camera to the fieldscope. Nikon offers brackets for COOLPIX (FSB-UV Bracket) and also Nikon 1 (DSB-N1 Bracket) series cameras. Depending on the combination of camera, fieldscope and ocular and shooting settings, there could be strong vignetting, shadows and hot spots on the photos. To avoid the latter, you can cover the area between the ocular and camera lens with a black cloth. The biggest advantages of the system described are its price, universality and light weight, biggest disadvantages are the weak photo quality (mostly it is enough for “designation“ photos) and the danger that the moving front lens of the compact camera goes against the ocular and the lenses get damaged.
The other option is to use special adapters that can be placed between the fieldscope and camera and which are attached to the camera with a special mount. Nikon offers adapters for Nikon 1 and Nikon DSLR cameras.
Nikon 1 camera adapter DSA-N1 is attached to the fieldscope ocular with a screw thread mount. That is why, the camera is in an optimal position with regard to the fieldscope axle and no light can reach the camera sensor. You can also unattach the camera from the fieldscope fast if you wish to and just look through the ocular. Unfortunately you cannot use the adapter with the zoom ocular. You can shoot in a aperture priority mode and also in manual mode (centre-weighted metering). The magnification depends on the ocular in use and it cannot be changed smoothly. This is a complex solution and its price lands between the brackets and DSLR adapter FSA-L2 (the prices of the ocular and camera are not included)
My photography equipment includes Nikon D800 SLR camera; thus, I chose FSA-L2 SLR adapter (fits all Nikon F-Mount cameras) that needs to be replace the fieldscope ocular. EDG 85-A fieldscope has a weatherproof bayonet mount for that.
With the help of FSA-L2 adapter, fieldscope EDG 85-A becomes a 3.5X magnification 500-1750mm f/5,9-21 manual focus zoom lens in front of the full frame sensor DSLR camera. Unlike with a normal lens, you cannot change the aperture of the fieldscope – it depends on the magnification used. Focusing is enabled with the help of focus ring and zooming with the help of the ring on the adapter. You can shoot in aperture priority mode and also in manual shooting mode. Automatic exposure metering is centre-weighted metering. This adapter has a fixable screw mechanism for turning it from horizontal position to the vertical position. With an inclined fieldscope, this is the only way to shoot vertically.
At first, it took me some time to get used to the fact that irrespective to the real situation, the camera’s information screen and photo EXIF displays 800 mm f/13. The approximate parameters can be specified on the FSA-L2 adapter scale. The same problem occurs with all the other digiscoping systems because there is not electronical connection between the camera and the fieldscope. Generally, the 35mm equivalent focal length can be found through the formula of [ocular magnification] X [camera’s 35mm equivalent focal length]. With Nikon DSA-N1 adapter, the equivalent focal length [focal length of adapter (18 mm)] X [2.7]. The aperture can be calculated through dividing the focal length with the diameter of the front lens. If this information turns out to be necessary, it should be added to the photo file manually.
The biggest shortcoming of the FSA-L2 adapter is the fact that when you raise the magnification, the camera sensor receives less light and the image finder turns quite dark. This makes focusing quite difficult is low light conditions. Using Liveview helps to a certain extent but it is worth to check the sharpness of the frames from the camera right after the shooting. When using long shutter speeds, the remote shutter is irreplaceable to avoid the shaking of the camera.
With full frame cameras the image covers the whole sensor from 800mm with the FSA-L2 adapter. Later on, some vignetting is going to occur (this decreases „indoors“) which can quite easily be corrected in post-processing. Photo contrast and colour transfer are good, detailness decreases towards the angles of the photo. One needs to consider that every type of atmospheric phenomena (haze, fog, rain) affect the photo quality noticeably when shooting subjects that are far away.
In addition to still photos, fieldscope together with a suitable adapter also enables to capture videos. Without the adapter, it is complicated to hold the camera stabile with regard to the ocular of the fieldscope. If while photographing I would have preferred EDG 85 straight body; while filming, the tilted body of EDG-85A turned out to be an advantage as it enabled to set the frame more conveniently. For avoiding changes in the photo luminance, it is best to use the aperture priority mode. In low light conditions, higher ISO might become a problem. But the emotions derived from the moving picture compensate any shortcomings.
Summary
When choosing a fieldscope, it is important to consider the quality and ease of use of the optics in everyday usage; but at the same time, it is also important to think about the possibilities of capturing photos and videos. It is possible to take photos through the ocular even with a smart phone but if photo quality becomes very important or there is a need to film things seen, one should consider having an adapter. This definitely increases the possibilities and not just when birdwatching.
Some points
1) The magnification of the fieldscope amplifies any kind of camera movement. Even the quiver that occurs due to pressing the shutter might cause the image not to be sharp. Use a self-timer or a distance shutter release if possible (when it is a SDLR camera, use a mirror lock-up)
2) A decent tripod made of carbon fibre muffles all the quivers that occur to all of the external factors much better than a tripod made of aluminium alloy. The difference between different tripods of the same series made by the same producers could be huge. In one case, the image stabilises in 2-3 seconds after moving the fieldscope but it could take 10 seconds with another tripod.
3) The further away is the bird being watched the more air there is between the bird and its watcher and thus, all the atmospheric phenomena (haze, fog, rain) affects are amplified and the photo quality decreases.
Even the bird that seems motionless never actually is. The freeze the moment, you need to use as fast shutter speed as possible. Since it is not possible to change the aperture of the fieldscope, the only way is to raise ISO.
