Shutter speed with telephoto lens

[Joytek]

I have a 70-200 f4 L lens and and a 10D and am wondering if the multiplier (x1.6 for the 10D) comes into play with the 1/focal lenght of lens rule of thumb hand held.

So if I am shooting at 200mm (hand held) (10D at 320mm) should I aim for 1/200sec or more like 1/320sec?

w.

[Webster]

Yes, the focal length "Multiplier" must be taken into consideration, since the effect of camera motion becomes more pronounced as smaller portions of the frame are used. And, other than resolution and diffraction issues, there is very little difference between zooming with the lens and zooming by using a smaller part of the frame.

[CyberDyneSystems]

On the other hand, a monopod or tripod helps tremendously. On overcast days I have been able to get some surprisingly sharp photos at 1/60 second through my 500mm f/6.3 by simply using a monopod.

...but those are usually the lucky shots,. maybe one out of 4 at that shutter speed is really sharp.

[Joytek]

Thank you for the answers.

So with a zoom lens as one chnages the zoom one can lower the shutter speed too? Like 1/320+ at 200mm (320mm effective) and 1/125+ at the 70mm (112mm effective)?

w.