View Full Version : ND Filter Problem


Todd Clark
March 19th, 2007, 08:41 AM
Has anyone experienced your ND filter turning off on it's own? If so, were you able to fix it? Thanks!

Graham Bernard
March 19th, 2007, 11:40 AM
Has anyone experienced your ND filter turning off on it's own? If so, were you able to fix it? Thanks!

Nope, can't say I have. Sorry! Sounds a nightmare. Just tried it myself and in both easy mode and full manual nothing will budge the ND. OK, I DO get a flashing warning in easy mode - but that's about it.

Can you reproduce this and tell us how you achieve it? Sounds like a visit to the Canon Garage!

Todd Clark
March 19th, 2007, 12:56 PM
I first noticed it when I was adjusting the white balance.

I had it outside and the camera told me to turn on the ND Filter and then I adjusted the white balance and the Camera started to blink the ND Filter to tell me to turn it on again. Very strange.

Thanks for the quick response.

Bradley D Barber
March 21st, 2007, 05:12 AM
I have had the same happen in Auto but never in manual and it always happened outdoors while balancing.

Good luck if it happened in manual mode, let us know how it sorts out.

Todd Clark
March 22nd, 2007, 06:52 AM
Bradley,

Did yours stop doing it or do you still have the problem in auto?

Don Palomaki
March 22nd, 2007, 08:16 AM
Are you talking about the ND warning turning on/off after white balancing whiithout changing the ND filter position?

White balance operates by adjusting the gain of the analog amplifiers in CCD outputs before teh signal reaches the the A/D converters. This action has a similar effect to changing the exposure or gain in a color channel. The ND wrning will appear if the signal is outside the acceptable range of input for the color channels and a change in the ND state will bring the signal closer to the acceptable range. Changing from indoor to outdoor WB is a significant change in signal level in the red or blue channels. (Consider it interms of the corresponding tungston-to-daylight (80A) photo filter exposure factor - about 2 stops)

If the light level is near the threshold for a ND warning, adjusting the WB can cause the signal from the CCD to cross that threshold and trigger the warning.

Todd Clark
March 22nd, 2007, 09:14 AM
Not the warning. The actual ND Filter. What happens is the warning will flash and then I will turn on the ND Filter. Then I will adjust my white balance and then the warning will flash telling me to turn on the ND Filter again.