Astrodon Premium DSLR Replacement UV/IR Filters
for the



If you are comfortable in working around microelectronics and expensive CMOS sensors, you may want to purchase just the replacement filter to modify your own Canon DSLR from any of the instructions that are available on the internet.  I am now proudly the North American supplier of premium quality Astrodon Inside DSLR replacement filters made here in the USA.  High end CCD imagers are well acquainted with the quality of Astrodon filters.  These DSLR filters are the same as the Luminance filters sold for CCD imaging...they block longwave IR and UV energy, but pass visible light and the all important Hydrogen-Alpha energy.

NEW! Astrodon now offers the AD40Clear filter for Full Spectrum Modifications.  Learn more about it HERE.


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 (below left) has a blue-green color, whereas the Astrodon Inside replacement (below right) is totally clear, yet it also blocks all UV and near-Infrared light.


You can see the difference in the following graph, where the transmission of light through each filter as a function of wavelength is compared.

You can see that 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, we only transmit 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.  We used the Canon filter spectrum from this reference.

The Canon filter must be removed and replaced by the Astrodon Inside filter. For daylight use, you will use a custom white balance, 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.  I have more information about using modified cameras for daylight work HERE.

Filter Characteristics
  • The AD40D is for the following cameras:

    Canon Camera AD40D
    Digital Rebel 300D No
    Digital Rebel 350XT No
    Digital Rebel 400D/XTi Yes
    Digital Rebel 450D/XSi Yes
    Digital Rebel 1000D/XS Yes
    Digital Rebel 500D/T1i Yes
    Digital Rebel 550D/T2i Yes
    Digital Rebel 600D/T3i Yes
    Digital Rebel 650D/T4i Yes
    Digital Rebel 700D/T5i Yes
    Digital Rebel 1100D/T3 Yes
    Digital Rebel 1200D/T5 Yes
    7D Yes
    10D No
    20D No
    30D No
    40D Yes
    50D Yes
    60D Yes


  • Use your Canon EOS for daylight AND astrophotography
  • Increase the H-a sensitivity by 5x to ~99%
  • We use the highest quality, straie-free, fused silica substrates for distortion-free images
  • Our 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.

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.  I will be happy to answer questions via e-mail but cannot be held responsible for any damages.  If you do not feel comfortable working on microelectronics, handling the expensive and fragile CMOS sensor, and making measurements of before and after sensor positions to within 0.001", I offer full modification service using quality Astrodon Inside filters.

Description Price
(inc. US shipping)
Part # AD 40D    Replacement UV/IR Filter (one per customer - no resellers) $105.00
Priority International Shipping for customers in Canada (price reflects 2014 USPS postal rate increase)  $20.55
Priority International Shipping for all other non-US customers (price reflects 2014 USPS postal rate increase) $24.75


Filter purchases are limited to one filter per type per customer.

Payment is accepted by PayPal to, or by money order.

My mailing address is Hap Griffin, 2740 Fenimore Drive, Sumter, SC 29150


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