SX50 and CHDK - Built-in ND filter

A couple days ago I grabbed the alpha port of CHDK for the SX50 and started playing. Having used CHDK with my little SX150IS, I am comfortable with it. While reading the CHDK forum about the SX50 port, I noticed that someone found that the SX50 has a built-in neutral density filter. Their experiments showed that with the ND filter "In", a +3 exp. comp. was necessary to obtain the same brightness as without the ND filter. To me, that means 3 stops - a ND3 filter. So, I tried a couple shots, 24mm fl, ISO 80, manual mode, f8.0, at 1/50 sec. with ND "In" and at 1/100, 1/200, and 1/400 sec. with ND off. Lo and behold, the 1/400 sec. shot without the ND filter was of nearly equal brightness to the 1/50 sec. shot with the ND filter. So to my satisfaction, the presence of a built-in ND3 filter is confirmed.

Now I just have to go find a running stream to see if this is really as useful as I hope!

Take care,

Al