The S1747 turns a Canon EF or EF-S SLR lens into an upright-viewing telescope. Pair it with a telephoto lens to observe distant subjects between shots and put an existing lens to another use.
Compatibility: Canon EF/EF-S SLR lenses only. Canon EOS R-system RF/RF-S lenses, EF-M lenses and other mirrorless lenses are not supported.
Another way to look while out shooting
Keep one lens on your camera and turn a spare compatible telephoto lens into a monocular to observe distant subjects and find your next composition. The compact converter takes up only a small corner of your camera bag, adding a second use to a lens you already carry without packing a separate telescope.
A new purpose for a familiar lens
Moving to a mirrorless camera need not leave your SLR telephoto lens sitting on a shelf. Fit the converter for its mount and bring it back into use for distant observation—another reason to take a familiar lens on your next outing.
A considered optical path
Our offset optical design uses a total-internal-reflection prism system to erect the image, without reflective coatings on the reflecting faces. The intermediate image forms in air rather than inside glass. No additional focal-extending lens group is needed, reducing the influence of added optics and helping preserve the lens's imaging performance.
A 10mm eyepiece with its own focus adjustment
Divide the lens focal length by 10mm to calculate magnification: a 70–200mm zoom becomes a 7–20x telescope. The adjustable eyepiece works with the lens's focus ring for fine adjustment. A macro lens or suitable close-up accessories also enables close-range observation.
Effective light acceptance is limited to f/4, including with faster lenses, to control the effect of marginal rays on image quality. Slower lenses remain limited by their own aperture.
Specifications
| Mount | Canon EF/EF-S lenses; not for Canon mirrorless lenses |
| Eyepiece focal length | 10mm |
| Optical construction | 7 elements in 3 groups |
| Field of view | approximately 55° |
| Construction | precision-machined metal body; optical glass with MC broadband anti-reflection coatings |
| Dimensions | 55 × 65mm |
| Weight | 145g |
Included
Converter, front and rear protective caps, and a thick padded protective pouch.
Use
Mount as you would a camera body. Slide the release button toward the eyepiece to detach. Set the lens to MF where required for manual focusing. Never look directly at the sun through the lens or converter.