Kowa

Although I normally enjoy taking photographs by combining the PROMINAR 500mm F5.6 FL (referred to below as the PROMINAR 500mm) with a digital SLR camera, in this report I tried my hand at “digiscoping”, which means photographing using the PROMINAR 500mm with a compact digital camera. I previously tried a little digiscoping using a spotting scope manufactured by another company, but at the time I could not obtain the expected resolution, and also felt there were limitations imposed by the poor camera response, so I did not pursue this avenue further.
After I started using the Kowa TSN-884 as my main scope, I became highly interested in “videoscoping” using a video camera. This led in turn to me exclusively using the spotting scope for capturing moving images, and then retrying still image digiscoping. This means that I am still almost a beginner when it comes to digiscoping, but this time I was able to have the opportunity to try out the latest IXY210F digiscoping system through the kind cooperation of DIGISCO.com.

I thought it was amazing that I could carry out digiscoping even though the lens was originally for use with an SLR camera, but by removing the mount adapter at the back of the PROMINAR 500mm lens and replacing it with the TP-88EC1 prism unit, the lens was instantly transformed into a spotting scope. Although all of the eyepieces for TSN-880/770 Series scopes can be used, among these I would recommend use of the TE-17W 30 x WIDE eyepiece with its wide field of view and high resolution.

The combination of the PROMINAR 500mm, TP-88EC1, TE-17W with the BR-IXY210 and IXY210F enables photographing without vignetting at an angle of view equivalent to approximately 1300-3700mm (when converted to 35mm format effective focal length).
As the tripod used for mounting the complete PROMINAR 500mm digiscoping system, which weighs approximately 3kg, I used my favorite Gitzo Type 3, 4-stage carbon tripod (Current model name: GT3541LS), combining the Sachtler FSB6 as the video head. Even though it can be said that digiscoping is lighter than SLR camera systems, for a field of view greater than 1000mm a stable tripod and high-precision video head will be indispensable not only for preventing camera shake, but for quickly and easily introducing the subject to be photographed into the field of view and for framing. Note that the PROMINAR 500mm tripod mount allows mounting on some types of Manfrotto and Gitzo video heads and on Sachtler FSB Series heads without requiring the use of a quick shoe.

In addition, accessories that can be said to be essential for digiscoping are the sighting device and the LCD hood.
Digiscoping without using a sight will be difficult to introduce the subject for shooting into the field of view.
This will without doubt be an indispensable item when digiscoping using focal lengths of 1000-3000mm.

• Adapter 02 Sighting Device
• HD-30WMC LCD Hood

Further, the LCD hood will also be indispensable in order to enhance the visibility of the LCD display when using it outdoors.
When the hood is attached, it will enable photographs to be taken with the sensation of looking into an LCD viewfinder which I think can be appreciated by digital SLR camera users.
Naturally, this item is also configured to allow a cable release to be mounted on the bracket in order to lessen the shock caused when pressing the shutter button and is obviously an essential item.
Digiscoping is a method of taking photographs where the quality of the equipment in your system directly affects the outcome of your pictures. I would recommend that you prepare all of the required items before starting to take photographs.

Autofocus

As the merits of digiscoping, the greatest advantage is that it allows super-telephotography to be easily enjoyed using a simple system. The hardest part of photographing wild birds is coming within a distance close enough to the birds that the captured image is large enough to be satisfactory. The amazing compactness of the digiscoping system, which allows enjoyment of a world of focal lengths in excess of 1000mm, cannot be emulated by SLR cameras. In addition, the fact that autofocusing can be used in this world of 1000mm and greater focal lengths can also be counted as a major merit. After simply introducing the subject into the field of view and roughly focusing with the PROMINAR 500mm focusing ring, the fine focusing will be carried out by the camera’s autofocus.

Images without blur

In addition, the use of a compact digital camera makes it possible to almost totally ignore the sources of camera shake resulting from camera movement, including mirror shock. Even using the largest tripod or video head, if the effect of mirror shock cannot be suppressed, the photograph will certainly be blurred. In particular, when photographing small birds living in the forest at the slow shutter speeds which are often used, the majority of the failed images taken using digital SLR cameras are caused by blur arising from camera movement.
Digiscoping will be ideal in situations such as when photographing small birds chirping in the forest, where although the subjects for photographing are small, requiring a large focal length, the light amount will be insufficient so that the use of slow shutter speeds will be unavoidable.

Resolution

Regarding the resolution when digiscoping using the PROMINAR 500mm, which was my greatest concern, I was able to enjoy sharp images with good color reproduction and a feeling of high resolution with the clarity that was to be expected from Kowa’s fluorite crystal and XD lenses. In the same way as when using a digital SLR camera, since there was almost no appearance of chromatic aberration the resolution attained a satisfactory level.
However, even digiscoping, with its ability to capture supersuper-telephotographic images, cannot achieve a high picture quality if photographs are unreasonably taken by relying on the optical system when the photograph subject is 30m or further away. This is because there is fluctuation in the air between the camera and the subject. Although it will be a precondition that the photographer should take care of the conditions to avoid alarming the bird, in cases where high resolution is sought a favorable result will best be achieved by reducing the distance to less than 20m and taking the photograph at as wide an angle as possible. Because the highest possible resolution is achieved around 1 or 2 steps on the wide angle side after vignetting is no longer apparent, converting this to an angle of view will mean it will probably be best to keep within 1500mm as a rough guide.
I felt that it would be good to normally use the lens on the wide angle side without vignetting (up to 1500mm), and only to use focal lengths greater than this in situations where the distance to the subject is great or when you are intending to take extreme closeups.

Operability

Regarding the operability, perhaps it may only have been due to the IXY camera, but I was able to capture attractive pictures simply by pressing the shutter.
I had the impression that it was sufficient merely to press the shutter without bothering about more complicated matters.
Because the BR-IXY210 exclusive bracket has been released by DIGISCO.com, mounting on the scope is also a simple matter. The relatively low price of the bracket is also attractive.

This time, I was challenging digiscoping again after a period of five years. While there had obviously been an evolution in the cameras, I could really appreciate the great suitability of the PROMINAR 500mm for use in digiscoping. Although it is my own personal impression, I felt again that if it is possible to get very close to the subject for photographing, a digital SLR camera is undoubtedly going to take the better picture, but when the distance to the subject is far, digiscoping will definitely give a more favorable result.

The PROMINAR 500mm enables quick switching between digiscoping and digital SLR photographing according to the distance from the subject and the conditions.
It is probably advisable to separate the operation into utilizing the digital SLR for capturing subjects within a 15m distance that realize an adequate size and for moving objects, while using digiscoping for subjects that are more than 15m away. The PROMINAR 500mm, which allows enjoyment of both photographing styles using the one lens, is an ideal lens for the acquisitive birder.