Gx8
 

Hi,
Have played around with the new toy a bit now but can't seem to find a way of getting decent footage of propeller aircraft. The blades appear to be turning at 5 rpm & that simply does not look right at both 4 K @25p & 1920 @ 50p. Is this a problem that can be overcome ?
Thanks for any advise

Re: Gx8
 

At what shutterspeed are you shooting?

Re: Gx8
 

Hi Noa,
thank you for replying. It's at 60.

Re: Gx8
 

If you shoot at 50fps your shutter should normally be at 1/100, if you shoot at 25fps it should be 1/50 for normal motion blur. That is not an obligation because sometimes you need to adjust the shutter if you get horizontal stripes in your shot caused by indoor lights, cheap lights can often force you to deviate from the general rule just to get the banding away. Higher shutter also freezes motion more, like when you shoot a fountain of water where you can see every single waterdrop fall at high shutter speeds.

I"m not sure as I have not tested it but you also might get rolling shutter distortion and using a "normal shutter" might not have the effect you are after, I found below video with more info about this and maybe a solution to your problem:

Re: Gx8
 

Hi Noa,
Thank you for this very interesting & informative reply. I will be flying in the morning & will experiment with what I just learnt.
kindest regards

Re: Gx8
 

Hi Noa,
I just checked some footage & found that the helicopter blades are just perfect at 25p 4K 60 as is the propeller of a C208 however, on a Dash 8 it looks like the propellers are at standstill. On the smaller piston AC the blades go backwards & forward.
I tried to attach pics but it doesn't work.

Re: Gx8
 

This is one of those examples where the general shutter rules don't apply for whatever reason, it's like when I shoot under cheap led lights and I get horizontal banding eventhough I am at the "right" shutter, I sometimes have to go from 1/50 to 1/40 or 1/60 to get rid of the stripes.

The only thing you can do is to try different shutterspeeds on the spot and check in your viewfinder when the propellor appears to be turning at a normal speed.

Re: Gx8
 

This will also be dependent on the speed of the propeller - hence why you're getting mixed results from different aircraft.

Record the propeller as the ignition starts and it throttles up to full speed and you'll see this effect clearly - the propeller will seem to speed up, slow down, stand still and even reverse direction when in reality it should be speeding up the whole time.

Re: Gx8
 

Hi John,
I did exactly that today. I shot up through the top panels of the chopper during cruise & the blades showed that perfect hint of movement at 100 shutterspeed & 50p. The main rotors are doing 360 rpm & the tail rotor a hell of a lot more. All show up as they should. Will ask my friend to gradually wind up the fan of the Dash 8 & see how the varying rpm show up at different shutter speeds.
Once I learn how to post pics on DVinfonet I will.