AI Servo 'tricks' and Sigma 70-300 APO

[sf_1857]

Will the AI Servo "tricks" for the 300D work with the Sigma 70-300mm APO lens?

I am thinking about buying the lens but from reading the posts I see that USM is required on the Sigma for the AI Servo tricks to work.

Is the Sigma 70-300 APO a USM lens? I don't think it is.

[Jon]

If I read them correctly, what's required for one of the tricks was full-time manual, not just USM (micro USM doesn't generally support full-time manual). And the other two didn't require playing directly with the focus, but either zooming or moving the camera to fake it out. So, if you can get methods 2 & 3 to work, the lens shouldn't matter.

[spin180]

I just took possession of my new Sigma 70-300 APO today. Sigma's version of USM is called HSM, but this lens doesn't have it.

However, the AI Servo tricks do work with this lens; by moving the focus point and by changing the focal length, with the shutter half pressed.

;)