Hand held rule - do we multiply focal length by 1.5

[stubbsy]

Ok. I'm confused (not hard really)

I've just read Matt K's new pdf on shutter speed assignment (linked to from the index page - and very good it is too!) and, to summarise, it says when shooting hand held with the D70 that the simple rule for hand held is that the shutter speed should be 1/focal length * 1.5 (the 1.5 allowing for the difference between 35mm film and the smaller CCD in the D70) so a 200 mm lens should have a shutter speed of 1/200*1.5 or 1/300th second

Elsewhere here I seem to recall reading that youd DIDN'T multiply by 1.5 for this (I think Gary said this, but don't quote me). The latter makes more sense to me since the shutter speed is to "cancel" shake which becomes more exaggerated the further away your target and I can't see how the size of the sensor would make any difference to the amount of relative shake.

If this wasn't written by someone as knowledgable as Matt I'd say he's just plain wrong, but I figure he isn't based on past experience so can someone please enlighten me.

TIA

[pippin88]

I follow your logic, it's a crop factor not a focal length factor.

Besides from personal experience, I get sharp images at 1/focal length (or slower) just fine.

[Greg B]

The muliplier has its effect in the field of view, that is to say that the area you can see through a 200mm lens on a d70 is the same as you would see through a 300mm lens on a 35mm camera.

The 1/focal length as minimum shutter speed idea is really just a guide. Some people can shoot slower shutter speeds, some may find that even this as a minimum is still too slow to get a sharp image.

I agree with Matt - I would also use the "multiplied" focal length to estimate what would be the minimum shutter speed for sharpness, after all the issue is the degree to which a given amount of movement in the camera is magnified at the subject. However it will vary between people, so just treat it as a rough starting point.

[Matt. K]

The reason I advocate this is because to make a print....the D70 image would have to be enlarged more than a 35mm image. In that sense it needs to be sharper so it would be prudent to go with the 1.5 factor. However, Greg B has put in nicely....these are only guides and individuals may find they can user lower speeds if they use sound camera holding techniques.

[stubbsy]

Greg B, Matt K

Thanks for your illumination. Matt I see now how this makes sense - didn't think about the printing aspect.