Trusted National and Worldwide Supplier of Affordable DSLR Astro Cameras since 2013
Why is filter removal needed in astrophotography?
All DSLR cameras have sensors which are sensitive to infra-red light. Camera manufacturers install IR filters to keep most IR energy from reaching the imaging sensor in order to maintain a correct colour balance similar to what our eyes see. Unfortunately, these filters also attenuate hydrogen-alpha radiation which is very important for capturing the red nebulosity in astronomical photographs. A typical IR filter blocks as much as 75% of the light arriving to the chip in the H-alpha wavelength. By removing the stock IR filter or replacing it with a Baader IR filter that is transparent to hydrogen-alpha, the camera's sensitivity for astrophotography is greatly increased.
LP1 Filter. This filter is not removed.
This modification leaves the LP1 (front) filter in place and the sensor remains sealed and protected. Also the piezo vibrator which removes small dust particles from the front filter remains fully operational. This filter blocks UV and IR light with a very sharp cut off at the edges of the visible spectrum. The filter blocks UV and IR very effectively and is of very high quality.
Orion Nebula with the same camera after filter removal
As you can see, the camera's sensitivity to H-alpha radiation has increased noticeably. Nevertheless, some star bloating and halos are present. This is due to the fact that the Canon 350D model only has one filter in front of the sensor. By removing it, the sensor is exposed to IR and UV light which results in bloated stars as lenses don't bring IR and UV light into focus at the same point as visible light. For this camera model, a Baader filter replacement would have solved this problem. Later camera models such as the Canon 450D or 1000D come with two filters in their optical assembly, making it possible to remove the colour correction filter whilst still retaining the IR UV Cut filter to avoid star bloat
All the cameras have been checked for dead pixels both prior and after modification. Time and weather permitting, I make an effort to test them in prime focus with my telescopes.
SW200P reflector telescope (1000mm focal length) on a HEQ5Pro. Guiding with PHD through a Stellavue F50 finder and an Orion Starshoot Autoguider.
SW Evostar 80ED DS-pro with 0.85 SW focal reducer on a HEQ5 Pro. Guiding through a SW 9X50 finder scope and a Orion Starshoot Autoguider via an adapter from Modern Astronomy
Please fill in the form below to request any further information. I'll get back to you as soon as I can to let you know what cameras are available.
You can also contact me at
Cheap Astrophotography is an 'evening and weekend' enterprise because of the demands of my full-time employment. I'll do my best to fill orders and respond to emails promptly; however, please realise that there may be times when I cannot respond as quickly as I would like to. I appreciate your patience.Thank you for your custom.