If you have a SLR or DSLR camera and other maker/mount lenses, the Fotodiox Mount Adapters allow you to use your lenses on the film/digital camera body. Sharing lenses has some distinct advantages. Certain prime lens just can't be replaced, and you save cost of purchase lenses. Fotodiox offers a range of adapter from large format to smaller format digital adapters. Adapting larger format lens, i.e., large format - medium format, medium format - 35mm, excellent edge-to-edge sharpness; and the smaller 24x36 mm image field helps minimize the effects of lens distortion and aberration.
A T-Adapter allows you to attach your 35 mm SLR camera to the prime focus of your telescope or spotting scope. This arrangement is used for terrestrial photography and short exposure lunar and planetary photography. It can also be used for long exposure deep-sky photography when using a separate guidescope. Both a T-Adapter and T-Ring are required to mount a camera to your instrument.This universal 1?" T-Adapter fits (drop in style) any type of telescope that uses a 1?" focuser or visual back.
This adapter easily screws onto the front of the Canon G10 Digital Camera, allowing you to add 58mm lenses and filters.

This metal two piece lens adapter set with 58mm threads is an alternative to the one piece plastic Canon LA-DC58K with 58mm threads for the G10 and G11
The problem with Canon's LA-DC58K lens adapter is that its over all length is 51.56mm, which works with Canon's telephoto lens ONLY, it was not designed for used with filters. When the camera's lens is fully zoomed in, it will extend pass the lens adapter by approximately 1mm, which is too short and will cause the lens crash issue when trying to use a filter or a third party telephoto lens, where the camera lens will actually come in contact with the back of the add-on optics, causing a lens error.
This problem is solved with this third party lens adapter, its overall length is 54.62mm, which is long enough to use any 58mm filters or third party lenses without lens crash. When the G10 or G11 is fully zoomed in, this adapter has approximately 2.5 threads extending pass the camera's lens. With this adapter, you are now able to use any third party lenses or filters of your choosing.
When using a wide angle lens or filters while zoomed out, you want to use the first/bottom section of the lens adapter set. When you need to use telephoto, macro/close up or filters while zoomed in, then you just need to screw on the second section of the adapter set to extend the length
Canon LA-DC58K Conversion Lens Adapter for Canon G10 Digital Cameras. Required to connect the Tele Converter - TC-DC58D to your camera. Compatible Products: PowerShot G10
This lens adapter makes it possible to mount an OM system lens- a compact system lens used with our traditional SLR film cameras, onto the Olympus E-P1 Pen Digital Camera.
Allows you to use Nikon F Mount Lenses on Micro 4/3 cameras like the Panasonic G1 and Olympus EP-1
Product Features Description This adapter allow to use CANON FD mount lenses and macro accessories on Canon EOS cameras. The lens distance scale can be used as well as the focusing to infinity .The adapter has correction lens inside.
52-55mm Step-Up Ring connects 52mm lens filter thread to 55mm threaded filter conversion lens or attachment.