Baader Protective Canon DSLR T-Ring with 7nm H-Alpha Nebular Filter

The Baader protective T-Ring has an integrated 7nm H-alpha filter with 50.4mm diameter and 3mm thickness. It reduces athmospheric stray light and allows longer exposure times for more contrast.

Fields of use:
Protects the sensor against dust. Especially useful for modified DSLR cameras with removed IR cut filter.

The Baader 7nm narrow band filter allows spectacular images of H-II regions (red gas nebulae) without being disturbed by artificial light sources.

The Protective T-Ring for Canon EOS DSLR cameras offers (beneath mechanical benefits) problem solvings. It accepts mounted 2" and unmounted 50.4 mm filtes and can be placed in front of the camera body without wasting optical length.

Advantages and fields of use of the Baader Protective T-ring:

versatile adaptation to telescopes and tele lenses with best mechanical quality

use filters directly in front of the camera without loosing valuable optical path

protect your camera sensor: the ring can always remain in front of the camera so no dust can intrude

expose free of vignetting, even with fast systems

Alternative to clip filters and camera retrofittings:
Baader´s Protective T-Ring is an alternative to camera conversions with special filters. Just remove the internal filter completely for maximum astro-performance and choose an interchangeable filter for your indivdidual needs. We also offer this service: Art.No. DSLRUmbauOF.

Instead of directly in front of the sensor, the IR filter is integrated into the T-ring. Or use the effective Baader UHC nebula filter.

Click on "reviews" and learn how to use the filter together with correctors with 55 mm working distance.

We offer the Baader Protective T-Ring with already installed filters, too. See the accessories section for more details.

1. Protective T-Ring for CANON EOS body
2. Baader 50.4mm x 3mm H-Alpha filter
3. Temperature compensation ring (to prevent filter damage at high temperatures)
4. S52/M48 adapter ring (M48 corresponds to the international 2" Astro filter thread)
5. M48/T-2 insert ring
6. S52/2" connector socket (with additional 2" M48 filter thread on the front side)

Baader Canon protective T-ring with filter - why does it shorten the optical length?
The mechanical length of the protective T-ring is 11.5 mm. This is slightly longer than the standard T-ring with 10 mm. But nevertheless the protective T-ring can be used instead of a standard T-ring. You maintain the required back focus of standard correctors even if the in-fact position is 1 mm farer away than a standard ring.

Why? The filter is the answer. Although it does not alter the focal length, it shortens the effective length by approx. 1/3 of its thickness. The optical rays follow a different path inside the filter. As the Baader filters are 3 mm thick, 1/3 of this amount is 1 mm. So the glass path of the filter shortens the optical length from 11.5 to 10.5 mm. You are inside the corrector´s tolerance with this value.

If you use the standard correctors designed for 55 mm back focus, you´ll have perfect stars with your DSLR camera. Baader´s protective T-ring as an alternative to Canon IR-cut filter retrofittings: Canon EOS cameras should be modified for astronomical use because their internal standard IR cut filter is not intended for astronomical objects. Often this filter is replaced by another IR filter with better H-alpha transmission or by a so-called clip-filter.

The alternative: The original filter can also be removed without replacement. We offer this service with the article "DSLRUmbauOF". Now you can place a filter of your choice directly in the Baader protective T-ring.

Advantages:

Benefit from the wide choice of 2" filters

Less internal reflections because the filter is farer away from the sensor

The camera body is protected against dus

Less vignetting, especially with full format sensors

Changing the filter is easier

Compared with clip-in-filter solutions, you gain further advantages:

The filter can be used for both APS-C and full format DSLR cameras

Optimal field illumination without T2-bottleneck

The whole internal room of the camera is protected, not only the sensor

The protective T-ring is filter holder AND camera adapter in one

Best mechanical adaptation possible

Mounted standard 2" filters and unmounted 50.4 mm filters can be used.