IR blocking and modded DSLR's

[Daniel-K]

should i have a IR blocking filter in my imaging train if i have a modded camera ? i still cant find a straight answer anywhere so i have turned to you fellow members here at SGL, currently my imaging train is- SCOPE-"2 SW LPfilter-0.8 reducer-Modded 450d

many thanks

[Steve Ward]

Depends on the Mod , details and explanation here ... http://www.astronomiser.co.uk/eosmod.htm

[russellhq]

Have you taken any images with the set-up? If you post one then maybe someone will be able to advise?

[Merlin66]

In the Canon there are two filters - the colour correction ( removed to increase the ha respnse, and usually this is the "mod"), then there's the front anti-alias/ dust shake filter.

This filter also acts as a UV-IR blocking filter and is removed to give a FULL full spectrum mod.

To answer your question: If it's just the "normal" mod then the remaining filter will do a good job as a IR blocker.

[lensman57]

should i have a IR blocking filter in my imaging train if i have a modded camera ? i still cant find a straight answer anywhere so i have turned to you fellow members here at SGL, currently my imaging train is- SCOPE-"2 SW LPfilter-0.8 reducer-Modded 450d

many thanks

Hi Daniel,

If you have removed all the filters ( full spectrum mod ) then you'd need an IR blocking filter otherwise you may get star bloat or that dreaded magenta halo round the stars with ED dublets.

A.G

[Daniel-K]

Thanks I done the mod my self a few weeks ago. Single filter removal. im getting the halo on the bright stars but not on thw smaller ones. Am I asking to much from my ed80?

[Merlin66]

Are the halo's blue or red?

Any other filters in the optical train which could cause reflections?

The ED80 is a well corrected refractor and shows little chromatic aberration....

EDIT: Ok I see you have a LPR and reducer in the optical path - my bet's on internal reflections....do a trial exposure with just the camera - not filter no reducer..