moving cars and background

[Rob Wilton]

Dear all,

 

Im shooting using a car rig, on 35mm. Im not sure I have the money or time to test it out properly, with film.

 

Im especially interested in the fuzziness of the background once the car gets to a certain speed.

 

I understand there are factors such as lens, distance from camera and the speed of the car but does anyone have any tips, or rules of thumb from their own experience shooting from out of moving cars?

 

much appreciated!!

 

Rob Wilton

[G McMahon]

I am not sure by what you mean. Are you shooting into a car at actors and you have your bg behind them, or you have a camera mounted on a car shooting away at objects passing by?

 

What fuzziness are you referring too? Out of focus? Surely thats not effected by the speed.

[Rob Wilton]

I am not sure by what you mean. Are you shooting into a car at actors and you have your bg behind them, or you have a camera mounted on a car shooting away at objects passing by?

 

What fuzziness are you referring too? Out of focus? Surely thats not effected by the speed.

 

 

I was thinking of shooting out of a car, actors not in frame.

I just have no idea how much the background will blur with a moving car.

 

Say for example you want to film a shop you pass by, from the POV of the car

How fast can you go before the details of the shop (for example the sign) becomes too blurred to read?

 

I cant imagine people knowing this by heart, but any tips are extremely welcome :)

 

thanks!

 

Rob Wilton

[Jon Kukla]

Well, it's a function of motion blur, so it is determined by the speed at which the object is crossing the frame and the exposure time. (This is assuming that focus and framing is already fine.)

 

Your speed of frame crossing will be primarily factored by the speed of the object or camera and the size of the object (ie your distance and focal length). Exposure-wise, your frame rate and shutter angle will matter.

 

How fast are you supposed to be going and how fast do you think you are going to go? What are you shooting and how are you planning to frame it?

[Alessandro Machi]

This is the kind of experimenting before the actual 35mm shoot that may be best suited for Super-8, especially if you don't have the money to rent the 35mm for your test. You could do a series of tests with a Super-8 camera that would involve different frame speed rates, shutter angles, film stocks and f-stops. The primary thing you can't emulate well with a Super-8 test camera would be depth of field, other than that, you could learn a ton by just doing such a test once or twice, provided you have the right Super-8 camera for your test.

[Rob Wilton]

This is the kind of experimenting before the actual 35mm shoot that may be best suited for Super-8, especially if you don't have the money to rent the 35mm for your test. You could do a series of tests with a Super-8 camera that would involve different frame speed rates, shutter angles, film stocks and f-stops. The primary thing you can't emulate well with a Super-8 test camera would be depth of field, other than that, you could learn a ton by just doing such a test once or twice, provided you have the right Super-8 camera for your test.

 

Thanks for the replies!

 

Dear Jon

Say for example you want to film a shop you pass by, from the POV of the car

You're shooting 24fps, and the shop is 30ft away. How fast would the car go before the details of the shop (for example the sign) becomes too blurred to read?

 

cheers

Rob Wilton

[Alessandro Machi]

If the sign is large and you shoot wide angle, you will have a bit of flexibility. If the sign is small and you have to zoom in, then it becomes more difficult to predict, especially if you do or do not have control over the shutter angle. You probably should view the shot prior to filming to get a feel for what you need. Even if you don't shoot any super-8 film, just putting a super-8 camera up to your eyes and looking through it and playing around with the zoom magnification may give you some ideas moreso than using a video camera because you are looking through a true optical device rather than an electronic one. A directors viewfinder would actually be better but they are more expensive.

 

Sometimes you can find a 10-1 super-8 camera for 20 bucks or less on Ebay, I think older Elmos can be found this cheaply, something like the Elmo 110??? For your purposes it doesn't matter if the camera works as long as the viewfinder and lens does work. Of course you'll have to convert the settings to match either 16mm or 35mm.

[Jon Kukla]

I'd hazard to say that one of the key things will be being able to keep the sign framed as static as possible (considering the moving car) - in other words, trying to keep it in the same place in frame during the immediate approach and passing. Ultimately it comes down to how fast the object is crossing the frame and it's exposure time, so I'd suggest framing more on the wide end and closing down your shutter angle maybe to 90 degrees (enough to help but not enough to be too noticeable, unless you're all for that, in which case, keep going!)

 

What time of day are you shooting, what stock speed, and which camera?