Stephen Ingraham, field rep for Zeiss Sport Optics, about a new digiscoping adapter that Zeiss is starting to market for their DiaScope spotting scopes and Vario D 15-56X/20-75X Zoom Eyepiece. He had asked me if I'd be willing to field test the new Digidapter™ digiscoping adapter, and I immediately said, "How soon?!" I contacted Paul Sayegh, inventor of new adapter, and he sent me a unit to evaluate.
Things didn't quite start out on the best foot, though. When Paul asked me what I was shooting with, he informed me that the new Digidapter™ would not work with my 'older' Vario D 15-45X/20-60X Zoom eyepiece - the eyepiece barrel diameter is smaller than the new 20-75X eyepiece, so the connector sleeve of the Digidapter™ would not fit it (too large). He also informed me that the Nikon 1 V1 w/ 10-30 mm lens would not fit the Digidapter™, either, because the lens is too large for the adapter assembly. Undaunted, Paul contacted Stephen, and he and Zeiss were gracious enough to send me a new 20-75X Zoom Eyepiece to evaluate the Digidapter™ with the Nikon 1 18.5 mm lens I had (and would fit). Long story short, I received the new eyepiece, the Digidapter™, and was able to make it work like a champ using both the 18.5 mm lens AND the 10-30 mm lens of the Nikon 1 V1 camera system. Initial results have me HOOKED on both the new eyepiece and Digidapter™!
here. I unscrewed the eyecup assembly from the Zeiss 20-75X Zoom eyepiece and slid the inner sleeve of the Digidapter™onto the eyepiece. The sleeve went on with a little bit of pressure, and fit snugly over the eyepiece barrel thanks to a nicely-designed inner O-ring inside the sleeve. I then screwed the eyecup assembly back on.
|Underside of platform with Nikon 1 V1 camera and 10-30mm lens|
Initial tests w/ 1 Nikon 18.5 mm f/1.8 lens
I printed an ISO 12233 Photography resolution chart on Epson Photo Paper and mounted it on a flat surface for testing the Digidapter™, the eyepiece, and the Nikon 1 V1 camera system. Since I was told that the 10-30 mm lens on the V1 would not fit, I first concentrated on the Nikon 1 18.5 mm f/1.8 lens.
I found that the V1 and 18.5 mm lens mounted on the platform had to be butted up against the rubber eyecup in order to get a sharp vignette circle at the extreme edge of the viewfinder. I photographed the test chart from about 20' away using ISO 100, +0.7 Exposure Compensation, at f/1.8, and auto-timer (10 seconds) using Aperture-priority.
|18.5 mm/f1.8 and 20-75X eyepiece|
|18.5 mm f/1.8 and 20-60X eyepiece|
So, if it is the lens, then how would adjusting aperture perform? At f/8 both the older and newer eyepieces showed much improved sharpness across the FOV, so if this lens is to be usable it'll need to be stopped down for optimum digiscoping efficiency (at the cost of an f-stop or two of shutter speed).
|18.5 mm f/8 and 20-75X eyepiece|
|18.5 mm f/8 and 20-60X eyepiece|
The next question begs, how does the lens perform throughout the eyepiece magnification range? As I soon discovered, the amount of vignetting that one experiences while zooming the eyepiece from 20X (none-to-slight) to 30X (minimal) to 40X (worst) to 50X (minimal-slight) to 60X (slight) to 75X (none) DEPENDS ON OPTIMAL LENS/EYEPIECE PLACEMENT. With this setup I have the 18.5 mm lens butted up against the rubber eyecup of the zoom eyepiece on the Digidapter™. With the rubber eyecup screwed back on over the inner sleeve of the Digidapter™the eyecup does not completely tighten to a closed position, thus it sticks out from the eyepiece lens a fraction of a millimeter or so. This results in more vignetting than if the lens/eyepiece were perfectly aligned. So this is what I saw through the camera when digiscoping the test pattern:
|f/1.8 at 30X|
|f/1.8 at 40X|
|f/1.8 at 50X|
|f/1.8 at 60X (disregard soft focus - my bad/not lens)|
|f/1.8 at 75X|
Modifications make a huge difference!
Success w/ the 10-30 mm f/4.5-6 lens!
With the eyecup removed it is now possible to mount the V1 with the 10-30mm lens on the platform and extend the lens throughout the entire focal length. The lens rests agains the eyepiece, but there's no concern w/ glass-on-glass. At 10mm there is significant vignetting, and it isn't eliminated until the lens is zoomed past 18mm. But I've found that the 10-30mm lens is actually sharper than the 18.5mm lens at all focal lengths, so I am thrilled that I'm able to get it to work with the Digidapter™and 20-75X Zoom eyepiece!
With the eyepiece at 20X this is the FOV allowed by the 20-75X Zoom eyepiece at the following focal lengths provided by the lens: 10mm, 14mm, 18mm, 24mm and 30mm.
With the 10-30mm lens at 24mm or 30mm its possible to zoom the eyepiece throughout the entire magnification range without vignetting. Here I have the 10-30mm lens set at 30mm and have taken images with the 20-75X Zoom eyepiece at 30X, 40X, 50X, 60X and 75X.
Thanks to Stephen Ingraham, Zeiss Sport Optics, and Paul Sayegh for a top-of-the-line digiscoping rig that should be fast, functional, and versatile in the field. Now to go chase some birds!