Astrodon Clip-In UV/IR Filter for the Conversion of a Canon EOS Camera

Astrodon Clip-In UV/IR Filter for the Conversion of a Canon EOS Camera

Makes your camera extremely sensitive to Hydrogen Alpha (H-alpha) light.

This filter allows you to use your Canon DSLR for daylight AND astrophotography.

Why is it needed?

The DSLR camera provides the means for hobbyists to affordably enjoy astrophotography, but there is a catch. DSLR cameras were designed for daylight use. They were not designed to easily pick up the rich red colors common to astronomical objects. This deep red light comes from the excitation of hydrogen atoms in space at 656 nm. We call this hydrogen-alpha, or H-a light.

Canon and other cameras have an internal filter to provide good daylight color balance, but this filter decreases the sensitivity to H-a light to about 20%. This low red sensitivity makes astrophotography with stock DSLRs problematic.

Therefore Astrodon provides a replacement filter for Canon DSLR cameras that regains H-a sensitivity to 99% - about a factor of 5 improvement in sensitivity. The original Canon filter (first image left) has a blue-green color, whereas the Astrodon Inside replacement (first image right) is totally clear, yet it also blocks all UV and near-Infrared light.

You can see the difference in the second image, where the transmission of light through each filter as a function of wavelength is compared:

The Canon filter passes only 20% of the H-a light to the sensor whereas the Astrodon Inside passes ~99%. You can also see that the Astrodon Inside filter blocks all UV and Near-IR light. In the Near-IR, the Astrodon filter only transmits 0.003%, whereas a competitor´s filter lets 6% Near-IR light pass to the sensor. That´s 2000 times less for the Astrodon Inside filter.

Filter properties:

Use your Canon EOS for daylight AND astrophotography

Increase the H-a sensitivity by 5x to ~99%

Uses the highest quality, striae-free, fused silica substrates for distortion-free images

The substrates have 1/4 wave transmitted wavefront or better prior to coating

Rigorous filter thickness control for proper EOS focusing

100% coated to the edge of the filter with built-in anti-reflective coatings

Hard, durable coatings that do not require sealing at the edge

Thousands are in use as Astrodon´s luminance (L) CCD filter

Blocks UV and Near-IR light to better than 0.003% for no leakage

You do not need a separate filter to block UV or NIR light on your lens

Best performance for a replacement filter for your Canon EOS

Inventory maintained to avoid long waits

Proudly made in the U.S.A.

Suitable cameras:

Digital Rebel 400D/XTi, Digital Rebel 450D/XSi, Digital Rebel 1000D/XS, Digital Rebel 500D/T1i, Digital Rebel 550D/T2i, Digital Rebel 600D/T3i, Digital Rebel 650D/T4i, Digital Rebel 700D/T5i, Digital Rebel 1100D/T3, Digital Rebel 1200D/T5, 7D, 40D, 50D, 60D

Working with this filter:

The Canon filter must be removed and replaced by the Astrodon Inside filter. For daylight use, you will use a custom white point, often shot with an 18% gray card. Thus, the modification allows you to enjoy daylight photography while using your Canon camera at night for astrophotography.

PLEASE NOTE: When doing your own camera modifications, you void any remaining warranty on your camera and you take full responsibility for any damage done during the modification. Of prime importance when doing your own mod is to return the sensor platform via its three adjustment screws to within 0.001" of its factory set position or your autofocus will not be calibrated, and worse, your sensor may be tilted.

Safety informations: PDF Download