[Terry B]

Originally Posted by Zuts

Hi,

I am not sure if i am reading the graph correctly but the following suggests that an unmodded 40D has a much worse response to Ha than an unmodded 350D.

Less than 10% Ha is let through? If this is true then its like shooting at F50 for Ha so I would agree with bassnut and say mod it.

http://www.astrosurf.org/buil/eos40d2/filter.htm

Paul

Edit.. Actually the graph is relative response but i still reckon mod it

The graph demonstrates that the unmodded 40d is worse than a modded 350d as expected. The modded versions are essentially equal.