Another newbie question concerning Modded cameras (canon 550d)

[Erik1988]

Hi, so I have a modded 550d canon camera, I understand I either need a uv/ir clip in filter or external in order to obtain image clarity in a refractor telescope. However, these filters are not needed in a regular reflector due to the way light is emitted. My question is, do I need a external uv/ir filter for the canon efs lens since the astronomik clip in filter I intend to buy does not work on the efs lens? Or can I simply use the modded 550d canon with efs 18-55mm 55-250 lens on regular tripod for images of the mily way, maybe a few lower magnitude clusters , constellations , etc, ? I would imagine the uv/ir filter is only a necessity for refractors.

[Knight of Clear Skies]

This frequently gets confusing. It depends on how it was modded, most recent DSLRs have two UV/IR filters in them and typically only one is removed as part of the modding process, making them fine to use with refractors or camera lenses. Here are some more details on the Cheap Astrophotography site.

[michael8554]

The star-bloating problem occurs with anything with lenses in - refractors and camera lenses.

Reflectors don't work by refracting the light, so aren't affected.

If your 550D has had both filters removed - a "Full Spectrum" mod - watch out for bloating with refractors.

If it's only had the "Infrared Cut Filter" removed, you're good to go with anything.

Michael