# Is there a formula for calculating shutter speeds?



## Skipster (Jun 18, 2005)

I'll be going to the World Cup of Snowmobile Grass Drags once again this summer. It's usually in August and very bright. What I'm wondering, is there a formula for calculating shutter speeds to freeze objects travelling at certain speeds. I fully understand how it affects exposure, but wondering if there is a guideline to follow. Last year I shot @ 1/500th and they were blurred. These sleds reach speeds of 110+mph in 500'. Any help is appreciated.


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## thebeginning (Jun 19, 2005)

what camera are you using?  it probably has an auto-shutterspeed setting where you choose the aperture and it chooses the corresponding shutter speed.  for such a bright scene i'm sure you can get faster than 1/500.  unless you are shooting at like f11 or so.


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## westman (Jun 19, 2005)

do u know Sunny16 ?


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## Ant (Jun 19, 2005)

I'm surprised they were blurred at 1/500.  The easiest answer is to get the fastest shutter speed you can get away with. 

You haven't said what camera you're using. I can quite easily get over 1/1000 @ f8 on a bright day with my D70 at ISO 200 but your camera may be more limited.......or it could be less limited


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## Skipster (Jun 19, 2005)

Ant said:
			
		

> I can quite easily get over 1/1000 @ f8 on a bright day with my D70 at ISO 200 but your camera may be more limited.......or it could be less limited



The Minolta I was using only goes to 1/1000 and F8 has too narrow of a DOF to capture all 4 lanes. Like a finish line shot. Can't remember what speed film I was using either. 

The camera I was going to use this year is a Nikon N80. Don't think aperature priority is the way to go here either because the camera doesn't know how fast the targets are moving. I was hoping to be able to run in shutter priority and let the camera body decide on aperature (hopefully with a good DOF).

Thanks all for the replies. Any more thoughts/ideas?


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## Mitica100 (Jun 19, 2005)

Have you tried panning? The technique is rather simple, when you have your moving subject in the VF move the camera in the same direction and with a constant speed so the subject is always in the same spot. Shoot while moving (speeds 1/250 and faster).


Good luck.


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## wharrison (Jun 20, 2005)

The "correct" shutter speed under such conditions is dependent upon the angle of view - from you to the subject.  If the subject is travelling across your field of view, you will need a 1/1000 of a shutter speed or higher - depending upon whether your camera has a shutter speed of 1/2000 or higher.

If, however, your field of view is such that the subject is coming at your camera diagonally, you should be able to make use of either 1/500 or 1/1000 shutter speeds.

If your field of view is such that the subject is coming at your camera nearly directly, you could even make use of 1/125 shutter speed.

Decades ago, one of our customers took photographs of motocycle races using Kodachrome 25, a Leicaflex SL II Mot (motorized) with the 400mm Telyt F/6.8.  Because of the angle of view, Bob was able to use 1/125 shutter speed with the lens wide open.  His slides were extraordinarly sharp and exhibited no blur or camera movement.

For your "homework" assignment, you might wish to take a look at some of the older, but still excellent books on photography, such as The Leica Way by Mathison or The Pentax Way by Keppler.  I am sure that there are other titles available at your local public library or bookstore.

A recent and excellent book on photography by the editors of National Geographic might have some useful information.  If you have a Border's or Barnes & Noble store nearby - check out this book and/or other titles.

Hope this is useful.

Bill


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## Skipster (Jun 20, 2005)

That's kinda what I was looking for. Thanks. Once I get the pics developed, I will post results. Gonna try to film @ 1/2000th and faster this year. Also gonna use iso400 and 800 and see if I can get some good snap-shots. These things are fast. Don't think panning is the answer as they start and finish 500' in around 3 seconds @ over 110MPH.


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