Bike over an air release...really dumb?

[dadsm3]

Hi : I remember reading somewhere that you can drive your bike over one of those 20' air releases to get a shot of yourself. I have one since I needed family shots for xmas with the M6.
Since I'm taking photo1 I have to do one of those exposure tests of cars going by, setting the camera at various speeds....I was thinking of getting junior to ride his bike over it a bunch of times instead. Not only will it allow me to get him at the same spot in the frame every time, it will save me looking like a dweeb with a tripod on a major street.
Anybody done this? Am I asking for it?
Thanks,
Mike

 

[dr.kollig]

What kind of bike is Junior riding? It could be difficult to hit the ball with race bike, I guess the ball would rather jump away. (My release ball is rather stiff) with low pressure MTB tires it could work. To be honest I would rather go for pre-focus and use a longer lens, with a M6 you can see the target moving in...Based on an calculation of juniors speed, your shutter delay and the speed of light for the focused distance this is very easy ;-)

Wolfram

 

[remrf]

Is enough pressure generated by running the bike over the cable or hose to trigger the shutter? If so then I guess you are all set. If not I would suggest using a long flat piece of plywood over the bulb. Something about 3' long and 6" wide and about 3/8" thick. Place the bulb under one long end of the plywood so the the bulb is farthest away from the direction the bike will be coming from. As the bike hits about the center of the board it should be compressing the bulb enough to fire the shutter. This way I think you can get your shot without destroying the air shutter release in the process.

 

[BrianShaw]

I don't know about this idea... but I'll keep tuned to "America's funniest home videos" to see how it worked out. 🙂

 

[dadsm3]

Yeah, I had dreams of the cable getting caught in the spokes and my M6 dragged along the ground for 20 feet.....
Think I'll try it with remrf's idea.....
Thanks guys,
Mike

 

[remrf]

Lets us know how it turns out.

I'm going to try a somewhat similar experiment in the near future. I was thinking about some old (early 1900's) photos of race cars and the distortion of the wheels in them. The wheels appear as ovals leaning forward. I remembered reading the explanation for this years ago but could not recall what it was now. I asked about it on another forum and got the answer (which I probably should have been able to figure out myself but did not) The answer:

Focal plane shutter running vertically.

I am going to try to duplicate the effect in both 35mm and medium format but I have a feeling that the focal plane shutters of today move quick enough to lessen if not remove this effect. We'll see.

 

[ch1]

Lets us know how it turns out.

I'm going to try a somewhat similar experiment in the near future. I was thinking about some old (early 1900's) photos of race cars and the distortion of the wheels in them. The wheels appear as ovals leaning forward. I remembered reading the explanation for this years ago but could not recall what it was now. I asked about it on another forum and got the answer (which I probably should have been able to figure out myself but did not) The answer:

Focal plane shutter running vertically.

I am going to try to duplicate the effect in both 35mm and medium format but I have a feeling that the focal plane shutters of today move quick enough to lessen if not remove this effect. We'll see.

I can remember images of those oval wheels - they seem to be taken at an angle to the wheel rather than horizonatally straight on.