Shutter Speed - the "math" 1/(FL x 1.6)

number six wrote in post #10198593
I have a 20 X 30 inch print over my desk, taken handheld with my 6.3 MP 300D. I would never have tried to print a 35mm film shot that large - in fact I think the largest print I ever did with film was 11 X 14.

Why? 35mm film did quite well printed large. Of course good glass and expert processing helped.

gjl711 wrote in post #10198752
Why? 35mm film did quite well printed large. Of course good glass and expert processing helped.

I agree with the above. I made several copies (which I sold) of one B&W shot I did back in the late 1960s that were a little over three feet wide - and that was a bit of a crop from the negative. They were quite nice to view in a living room.

The shot was done on good old Plus-X film and developed in Microdol X (1:3).

krb wrote in post #10198724
Perhaps you've misread some posts? 1.6x is a guideline for the minimum shutter speed when shooting hand held.

But what I'm saying is that with higher density sensors, that rule doesn't really work.

mikekelley wrote in post #10198936
But what I'm saying is that with higher density sensors, that rule doesn't really work.

Wasn't this hashed thoroughly enough in the other thread?

yes!

Shutter speed is to me one of those choices you have to make in less-than-optimal conditions, which is where I often find myself shooting, where there are tradeoffs whichever way you go. I've found myself shooting at way less than the 1/FLxwhatever plenty of times, and when I do I just need to concentrate on technique, which includes shooting short bursts of whatever to get one or two shots with a better chance of having less camera shake.

And, there are times when you want a relatively slow shutter speed, such as when you are panning a moving object and want to show motion blur or you are wanting to show prop spin/blur on a plane. Learning to handle various conditions with the right technique is a good thing! Not that the "rule of thumb" has not use, sure, I like to use a fast shutter speed when I can, but I also like to keep my options open and hopefully my skills up to speed.

number six wrote in post #10198593
Well, this "rule" is for minimum handheld shutter speeds. Personally, I don't think it's fast enough as a minimum and I try for 2X if I can. Not because I'm particularly shaky, but because we tend to print much larger than we used to in the 35mm film days, where that "rule" originated.

This is a prudent thing to do, especially if one has the insight that the 1/FL rule applied originally to medium format film cameras and was errantly NOT adjusted (it should have been!) for the 'miniature format', 135. So the safety factor was eaten up in trying apply the same formula to the smaller 35mm format.

I have a follow-up question on this "rule of thumb" --- If I put a Teleconvertor of length 1.4 on my 30D, would I normally multiply the previous "rule" by yet another 1.4 ? e.g., a FL of 100mm = 1/((100*1.6)*1.4) = 224 minimum SS?

Yep. The teleconverter makes the combination into a 140 mm lens.

-js

Thank you .. that's what I figured based on this discussion.

Just think of it as the inverse of the effective field of view. The math is the same but somehow seems less math like.