Align your camera perfectly with your calibration chart with this Magnetic Mirror Centering Aid from Pret a Tourner. The compact mirror has four magnets that allow you to strategically place it at the center of any magnetic calibration chart, so you can line up perfectly parallel with the image plane and achieve precise results in seconds. It has a diameter of 3.9".

For Centering Camera for Calibration    Mirror with Four Magnets    3.9" Diameter

Related Questions and Answers

Q: 1. Will this work with a Canon EOS T100 with the T-mount adapter for EF/EF-S mounts? I notice it's pretty large and I'm wondering if the flash protrusion which sticks out about 9/16 of an inch on the T100 would interfere with this fitting correctly.

A: Yes it will fit the T100. It is manual focus only and your camera will only work in manual or aperture priority exposure modes.

Q: 2. Does this lens require a rear filter to function correctly? Many do.

A: Mine came with a lens element already installed at the rear T-mount end. So I would say an additional rear filter is not needed.

Q: 3. Does it pose any problems when shooting with a non full frame camera like the Canon 70D?

A: No, there shouldn't be any issue when using this on a non full frame camera. Just keep in mind that there will be an effective crop factor of 1.6x on a camera like the Canon EOS 70D DSLR Camera, which would be an 800mm full frame equivalent. Also, in order to adapt the lens to a Canon EOS 70D, you will need an adapter such as this one: https://bhpho.to/3Pb8G63

Q: 4. Will the Opteka 500mm F/6.3 lens work with a crop sensor camera? Specifically, I have a Nikon DX camera (D7100).

A: Mine works fine with my Canon T3i with crop sensor. It may not cover a full frame sensor, but crop size is fine. I find my Opteka 500mm very easy to use and focus and resolution are better than expected.

Q: 5. Stopped down, on a tripod, does it get sharp?

A: The Opteka 500mm F/6.3 Mirror Lens has a fixed aperture of f6.3 which means it cannot be stopped down or opened up. All photos are shot at f6.3 due to the design of a mirror lens. Using a lens on a tripod will prevent camera hake blur which helps improve the sharpness in a photo.

Q: 6. What is the magnification factor at minimum focus distance?

A: Unfortunately, this information is not published by the manufacturer.

Q: 7. Is the T-mount included? Is there a hood that will fit?

A: T mount not included, but its inexpensive. And you can get the proper one for your camera.No hood that I know of...

Q: 8. What is the difference between this and the Bower 500 mm f/6.3 mirror lens that costs $199? They look like they come from the same factory.

A: The Opteka 500mm f/6.3 Mirror Lens for T Mount and the Bower 500mm f/6.3 Manual Focus Telephoto T-Mount Lens are very similar in design. There are a couple differences. The Opteka is currently made in China, whereas the Bower is currently made in South Korea. The Opteka comes with a Limited 10-Year Warranty, whereas the Bower comes with a Limited 1-Year Warranty

Q: 9. Good night: Will this Opteka 500mm f6.3 95mm mirror lens fit my Sony A390? I need T2 thread for Sony @390 DSLR camera (A390).

A: To use the Opteka 500mm f/6.3 Mirror Lens for T Mount on the Sony Alpha A390 Digital SLR Camera, you need the Vello T Mount Lens to Sony A-Mount Camera Adapter. Here is the link: https://bhpho.to/3lUBHao.

Q: 10. Is there a T mount adapter for this Opteka mirror lens that will fit an L mount FF camera?

A: Yes, there are T-mount adapters to adapt the Opteka 500mm f/6.3 Mirror Lens for T Mount to the L-mount. Currently we have the Leica T2 Digiscoping Adapter, BH #LEDAT2T (https://bhpho.to/3P0XHuW).