FotoSharp Telescope Focusing Adapter for Canon DSLR

FotoSharp Instructions
Telescope Focusing Adapter for Canon DSLRs

KW Telescope
100 Victoria Street North
Kitchener, ON Canada
N2H 6R5
519-745-5757

Your FotoSharp adapter can be used with any Canon digital single lens reflex (DSLR) camera attached to a telescope (with suitable optional adapters). It signals the user when precise focus is achieved. The signal is either a green light as seen through the viewfinder of the camera, or a beep if the beep option is turned on in the camera (see your user manual on how to turn the beep function on and off).

FotoSharp attaches to your camera the same way that an ordinary t-ring does. Looking at the rear of the adapter you will see a small circuit board and a red dot or notch. Align the dot/notch on the FotoSharp adapter with the red dot on the camera at the top of lens opening. Gently insert the adapter, and then turn the adapter clockwise about ¼ turn until it clicks into place.

The adapter is now properly seated. You can thread a nosepiece adapter into it and insert it in your focuser. Remove the adapter the same way you would remove a lens that is attached to the camera. YOU DO NOT NEED TO REMOVE THE ADAPTER TO TAKE PICTURES ONCE YOU HAVE FOCUSED. Just focus and leave it in place.

Attaching FotoSharp to your telescope

If your focuser has a built in T2 thread then all you need to do is thread your FotoSharp adapter to your focuser. If you find that the camera ends up in an oblique position behind the telescope you can adjust this by loosening the three setscrews around the perimeter of the T2 thread on the adapter. When these are loose, you can orient your camera anyway you please. Remember to tighten the setscrews when you are done.

If your focuser is not pre-threaded you can use a 2" or 1.25" nosepiece adapter, and then insert your camera into the focuser the same way you would an eyepiece.

If you have a 2" focuser we recommend a two-inch nosepiece adapter. Our 2" adapter (Part SI-DP2; $42 CA) is highly recommended. It can be separated into two components and can be used with an SCT focal reducer with good results on a wide variety of telescopes. With the SI-DP2 a 0.63 reducer operates at 0.69, giving you a significantly faster focal ratio and wider field of view.

If you only have a 1.25" focuser we offer the SI-DP1 optional accessory. The SI-DP1 fits any 1.25" focuser. You can screw a focal reducer into the end of the DP1 (Part SI-FR1) as well to achieve faster focal ratios and wider fields of view.

Please contact us if you have any questions.

In the above image the camera is attached to the focuser via the FotoSharp adapter along with our SI-DP2 2" nosepiece adapter.

The FotoSharp adapter fits your camera just like an ordinary t-ring.

To use it, just centre a bright star under the central focus sensor as seen through the viewfinder of your DSLR. While holding the shutter button half-down, adjust focus of your telescope. When you hit focus, the green light will appear in the viewfinder and/or the "beep" will sound to signal that you have achieved focus.

Once focus is established, you can start taking your images. You do not need to remove the adapter after using it. It stays in place, making it for more convenient than conventional knife-edge focusers.