The following simple experiment was done to examine the differences in my digiscoping cameras, adapters and focus methods. The test target (above) is simply two 6" steel scales at right angles to each other. A few feathers were added to give some indication of what might be expected when focusing on birds. Colors and contrasts were muted to minimize contrasts, placing more demand on my aging eyes and camera focus systems. To get some indication of Depth of Field the vertical target is tilted (top to bottom) at a 45 degree angle. This tilt places the 5" and 1" marks 1.41" from the 3" (center focus point) mark.

Observations / Comments:

The magnification of the Canon 10D and CP5000  with Swarovski 20X-60X and plastic adapter is nearly identical. The magnification of the CP5000 with Maxview adapter is approximately 80% of the other combinations. Keep this in mind when comparing images. For both the Maxview and plastic adapter the CP5000 zoom was adjusted just to the point of vignetting.

In all cases I manually focused the scope by viewing through the camera viewfinder (10D) or LCD screen (CP5000) as best I could, then let the camera do the selected autofocus routine. After taking the picture I then defocused the scope and repeated the sequence for a total of 3 photos of each condition to get some indication of repeatability. To minimize image clutter only the best of the three is shown here. In many of the images the central focus point would often be skewed from the central 3" target point to the 2" or 4" mark (representing 0.7" in focal distance change). The primary observation of this simple experiment is that the repeatability of any of the methods is not good,  2 out of 3 photos were worse than the ones shown. Take as many pictures of the subject as you can!

The "expensive" solution (Canon 10D and Swarovski 800mm adapter) does not appear to be the best solution. Central image quality is no better than the CP5000 and Depth of Field is less than the CP5000 solutions. This confirms my real world, real bird experience. As expected, at an ISO of 400 the noise of the CP5000 is noticeably more than the 10D.

Which is best? I'll let you decide but as the plastic adapter is cheaper, smaller/lighter and permits rapid transition from photography to normal scope use I'll be using it more often. As far as the "best" CP5000 focus mode I'm afraid this limited experiment doesn't answer that question to my satisfaction.

Suggestions for further experiments? Advice ?

Combinations of cameras and adapters.

• Canon 10D with Swarovski 800mm adapter

• Nikon CP5000 Scopetronix Maxview 40 adapter
• Nikon CP5000 with  simple plastic adapter to Swarovski 20X-60X zoom lens
  • Zoom lens set at 20X for these tests

Equipment and Conditions:

• Swarovski 80HD

• Cannon 10D

• Swarovski 800mm camera adapter

• Nikon CP5000

• Scopetronix Maxview 40

• Swarovski 20X - 60X eyepiece with homemade camera adapter

• Electronic shutter release(s)

• Photosolve Xtend-a-View LCD viewer

• ISO of 400

• Distance from target to scope = 24'

• Cameras set for largest image and highest jpeg quality

  • The images are "actual pixels" crops of the original. The crops were compressed somewhat to make them practical for web download but not to the point where they misrepresented the original.

(click on images to enlarge)