View Full Version : Canon servo lenses explained?


Simon Duncan
June 12th, 2007, 12:33 AM
If someone has the time and patience????

Could someone explain to me what actually is a servo lens compared to other types of lenses? EG Full manual lens.

Why did Canon decide to put this type of lens on the XL1 and XL2?

Thanks

Chris Hurd
June 12th, 2007, 01:11 AM
I'm not sure what you mean by "why did Canon decide to put this type of lens on the XL1 and XL2." Canon doesn't put a lens on the XL1 or XL2; instead these cameras are packaged with an auto servo lens and *you* can put it on, if you want. Or use a manual lens instead. It's up to you. These cameras have interchangeable lenses. You can use either type of lens (auto servo or manual); it's your choice.

The three advantages of the auto servo XL lens are its auto focus capability; optical image stabilization; and relatively low cost. The three advantages of the manual XL lens are its manual, geared focus ring; switchable manual / motorized zoom; and relatively low cost. Each lens is a different tool for a different type of shooting situation.

Simon Duncan
June 12th, 2007, 03:28 AM
Thanks Chris,

I guess what I was trying to ask is what is the difference between a servo lens and a manual lens?

I have a Canon XL1 with the packaged lens.
While I have been more than happy with the picture I have got from this camera what I haven't been too wrapped about is how the Servo Lens works when I use it in manual mode. But that could be more to do with my technique than problems with the lens.

Tom Hardwick
June 12th, 2007, 05:19 AM
The servo lens has the ability to be used in the manual mode of course, but your manual twisting action of the zoom and focus rings is converted into electrical pulses which are sent to drive micro-motors. If you zoom or focus very slowly you'll find that nothing happens - you're not generating enough electricity.

A manual lens has mechanical connections between the lens elements and the rings themselves, so turning the rings however slowly moves the internal elements. This needs more horsepower input on your part, but usually gives a better feel and of course gives natural end stops to the ring movement.

tom.

Chris Hurd
June 12th, 2007, 06:35 AM
...what I haven't been too wrapped about is how the Servo Lens works when I use it in manual mode. But that could be more to do with my technique than problems with the lens.Hi Simon, no doubt about it, the way the auto servo lens works takes a bit of getting familiar with, especially if you've come from a pro video background and "real" broadcast video lenses. Try this article for some pointers, it might help:

http://www.dvinfo.net/canon/articles/article12.php

Best regards,

Alfred Diaz
June 12th, 2007, 07:20 AM
You should know that not all lense/camera systems with servos work like the XLs. I use an XL2 with the 20x lense. I am curious if your 16x or 3x lense operates the same. Here is what I mean.

Some nicer cameras offer offer a servo button to zoom in and out, and they offer a full manual option.

What I mean by the full manual is that you can zoom from full-wide to full narrow in a fraction of a second just by quickly turning the zoom ring with your hand. This is not possible with my 20X lense because when I turn the zoom ring I am really just activating the servo. Is this how your 16X or 3X lense works?

Here is why a full manual zoom ring is helpful: When you you are trying to shoot sequenced cutaways with wide, medium and narrow shots, you can just quickly turn the ring and and be fully zoomed in less than one second.
It frustrates me that I cannot do this on my XL2. But that being said, I still really like my camera a lot.

Chris Hurd
June 12th, 2007, 07:39 AM
I use an XL2 with the 20x lense. I am curious if your 16x or 3x lense operates the same. Yes. All of the "white lenses," that is, the stock 20x auto lens for the XL2, both stock 16x lenses for the XL1 series (there were two variants of this lens) and the 3x wide lens all work the same way.

my 20X lense... because when I turn the zoom ring I am really just activating the servo. Is this how your 16X or 3X lense works?Yes, they are all the same in that regard.