The 40.5mm UV/IR Cut Hot Mirror Lens Filter from Kolari Vision is designed to normalize your camera when it has either a full spectrum or two-spectrum modification. In either case, it allows light to pass normally to the sensor, so you can shoot normal photos. The filter is designed with coated glass optics and an aluminum filter ring threaded on both sides. (The optional pro version has a knurled brass ring.)

The filter can only be used with a modified camera. A spectrum-modified camera is one in which the camera's native low-pass filter was removed in order to support certain IR filters for IR photography. If you have such a camera, this hot mirror filter will let you take normal photos without having to make any changes to the spectrum modification. The filter blocks IR light and some UV light, the same way the native low-pass filter that was removed from the camera during modification would have. The filter requires no exposure compensation.

Normalizes Spectrum Modified Cameras    Works with Full and Two-Spectrum Cameras    Functions Like Native Low-Pass Filter    Coated Glass Optics with Aluminum Ring    Dual-Side Threading

Related Questions and Answers

Q: 1. Will it fit a canon AE-1 35mm film camera?

A: Opteka 500mm f/6.3 Mirror Lens for T Mount is compatible with the Canon AE1 but you also need to get this FD to T mount adapter. https://www.bhphotovideo.com/c/product/116734-REG/General_Brand_ATC_T_Mount_SLR_Camera_Adapter.html

Q: 2. 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: 3. Does this lens have any noticeable chromatic aberration?

A: Yes Opteka 500mm f/6.3 Mirror Lens for T Mount does have noticeable chromatic aberration in an area of high contrast where a bright light meets a dark shadow.

Q: 4. 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: 5. I would like to try this lens for deep sky photography. What light pollution filter should I use?

A: A couple of very good choices for a light pollution filter, (depending in many ways on the amount of pollution and the type of pollution an individual is experiencing), would be the NiSi 95mm Natural Night Filter https://bhpho.to/2WRqS6R or the B+W 95mm UV/IR Cut MRC 486M Filter: https://bhpho.to/31Mv4IP. It is important to keep in mind that the artificial light-blocking power of these filters also affects the natural colors found in the night sky.

Q: 6. 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: 7. 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: 8. What is the country of origin? It's not written on the box or lens.

A: The Opteka 500mm f/6.3 Mirror Lens for T Mount is made in China.

Q: 9. Will this work with a Nikon D3500?

A: It is a manual lens so it will work. You will need one of these adapters https://bhpho.to/2ZSLj53.

Q: 10. Will I need an adaptor to use this lens with my Nikon D3500?

A: Yes you would just need a T-Mount to F-Mount adapter.