How loud is the ultrasound of USM ?

[ulrich_brandl]

We all appreciate the silent focussing with USM. But in the last days

I took some pictures from kittens and dog puppies with a 28-135mm IS

USM. Some animals showed (reproducable) panic reactions as soon I

pressed the shutter half-way down. The problem was fixed using manual

focussing (I learned this after some trials). The only plausible

explanation is that the animals hear the focussing motor's ultrasound

and find it very annoying.

 

Is there anyone who has made similar observations ?

 

Ulrich

[ronald_smith2]

I guess Canon wasn't targetting dogs and cats to be owners of EF lenses that featured USM when the idea was first launched over 10 years ago. LOL.

[jean_jacques_lemaire]

if so much (sound) energy is going out of your lens, it's really badly ingeneered. I guess that either your lens has a problem or the panic of these animals comes from something else... (Well, it's only a supposition)

[Greg M]

Yes, my cat carries on about it- he can hear it from across the room and gives me grief all the time. Now I do it more to annoy him than anything!

 

Fortunately, most of my subjects are not animals.

[myrjola]

My two cats do not seem to care about the use of USM lenses in any noticeable way. But this might be a matter of invidual cat behavior, I guess.

[jon_austin]

My dogs get pissed if I just point the camera in their direction, before I even have a chance to engage the USM-driven AF. Probably conditioned to avoid the bright flash.

[pturton]

Some time ago I was photgraphing a pair of wild swans and every time the USM was activated they looked right at me even though I was well hidden from their view. They were browsing in my creek and were disturbed at a distance up to 30 meters. But, Canada Geese and various ducks have ignored the USM.

My dog has given up on being annoyed - he knows he's a prime target.

[athinkle]

Also bear in mind that, while I'm not sure about USM, most animals can hear the sound of a flash capacitor charging. While I've never had an animal freak out at the sound of my 200mm 2.8L, all kinds of critters freak out to the sound of my 220EX charging.

[PuppyDigs]

Hmm, I've shot lots of critters--cats, dogs, wildlife & zoo animals--and none seemmed to

care or notice my USM lenses. I had to yell at my cat to keep him from falling asleep

during portrait sessions!

[graham_sheppard1]

I thought my dog was just camera shy until I switched to manual! Now she is fine. But, she is also much older and going a bit deaf so maybe that's the reason.

 

She didn't panic though, more she would just turn and keep walking away.

[bellavance]

My dog reacts to the sound of the 580EX from the other end of the house...

 

Pierre

[ronald_smith2]

I think some animals are just plain deaf.