butterfly spooked by autofocus motor

[LCPete]

Hi I have been visiting the butterfly house at Chester zoo lately to keep my hand in
I had a odd thing happen today one of the butterflies, a Glasswing, was spooked by the sound of the autofocus motor as soon as it started the butterfly shot off
It happened a couple of times always with the same species the others were not bothered ended up manaully focussing
This was with a Sigma 105 which has a motor driven autofocus.
Pete
Heres one of the Glasswings

[Lee Hurrell]

Cracking shot Pete

Cheers

Lee

[Chris Pickford]

Common experience! I've had it particularly with woodland butterflies like Speckled Woods with my Nikon D300, never with blues or whites. I've also noticed it with some other insects on occasions - for thius reason I generally switch to manual focus closer than 1:4.

Chris

[NickMorgan]

I get this a lot with my little compact. I was wondering if it was the infrared that the auto focus uses? I find that if I start of a few feet away from the butterfly it seems to get used to it and I can approach it, getting closer each time.

[LCPete]

Thanks
I have not noticed it before but do now think it must have happened before and I did not realise that it was the noise that spooked the butterfly
its odd that only certain species are bothered by the noise
pete

[EricY]

When using my "Bridge" cameras I have thought for a long time that birds are spooked by the infrared, so many seem to fly away when the button is pressed halfway down. Eric