Broadband astrophotography with your Canon full-frame DSLR
The Optolong L-Pro UT EOS-FF is an ultra-thin clip-in light pollution filter for compatible Canon EOS full-frame DSLR cameras. It combines the L-Pro multi-bandpass response with Optolong's UT design, intended to reduce the edge-image effects that some wide-angle lenses can show when a filter is placed behind the lens.
Why choose the L-Pro UT?
- Ultra-thin optical design: intended to reduce the image-edge effects associated with using clip-in filters behind some wide-angle, ultra-wide-angle and fisheye lenses.
- Broadband target coverage: the L-Pro response suits subjects such as galaxies, reflection nebulae and globular clusters.
- Selective light pollution reduction: suppresses selected wavelengths from sodium and mercury-vapour lighting and atmospheric skyglow.
- Balanced spectral transmission: retains broad transmission regions alongside important nebular emission lines.
- Canon EOS-FF fit: a dedicated in-camera clip format for the compatible DSLR bodies listed below.
Camera compatibility — check before ordering
| Camera or system | Compatibility |
|---|---|
| Canon EOS 6D | Compatible |
| Canon EOS 5D Mark II | Compatible |
| Canon EOS 5D Mark III | Compatible |
| Canon EOS 6D Mark II | Not compatible |
| Canon EOS 5D Mark IV | Not compatible |
| Canon EOS R mirrorless / EOS-C APS-C | Require their own camera-specific filter format |
Use with compatible Canon EF lenses on the supported full-frame DSLR bodies. If your camera is not listed above, please check with Dark Clear Skies before ordering.
Live View is required: Optolong's EOS-FF clip-in design holds the DSLR mirror raised, affecting the optical viewfinder. Compose and focus using Live View with the filter installed.
What the L-Pro response does
The L-Pro selectively reduces unwanted wavelengths while transmitting broad portions of the visible spectrum. This makes it useful for broadband subjects as well as nebular emission, with colour balance forming part of the filter's design.
Important transmitted emission lines include H-beta, OIII, H-alpha, NII and SII. The benefit is improved contrast against the sky background where the unwanted light falls within the filter's rejection bands. It does not increase the object's brightness or remove all light pollution.
Optolong L-Pro reference transmission curve. This illustrates the L-Pro family's spectral response; it is not an individual test certificate for the supplied UT filter.
Specifications
| Brand | Optolong |
|---|---|
| Model | L-Pro UT EOS-FF |
| Filter design | Ultra-thin, multi-bandpass light pollution filter |
| Mounting format | Canon EOS full-frame DSLR clip-in |
| Confirmed camera bodies | EOS 6D, EOS 5D Mark II, EOS 5D Mark III |
| Lens system | Canon EF on compatible DSLR bodies |
| Shooting method | Live View |
Using your filter
Handle the filter carefully by its frame and follow Optolong's fitting guidance. Lens designs vary, so the ultra-thin construction should not be taken as a guarantee of identical corner performance with every lens. Check focus and the edges of your first test exposure before beginning an imaging session.
Not a solar filter. Do not use this filter to observe or photograph the Sun.
Choosing the right Optolong filter
Explore our Optolong camera clip filters or browse the Optolong range at Dark Clear Skies. For the manufacturer's body-fit information, see the Optolong camera compatibility guide.
