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I think you won't get it with a GoPro. Blade Blur is dependent on a slower shutter speed, not a faster framerate.

 

Film/Video requires a 180* shutter speed, which means that if you're shooting at 24fps, your shutter speed is double the reciprocal, or 1/48 of a second. 30fps, 1/60th, 60fps, 1/120th. Etc. The higher the framerate, the shorter duration your shutter speed is to avoid judder or choppy motion.

 

In still photos, I usually aim for less than 1/125 shutter speed depending on the rotor rpm of the machine to ensure blurred blades. If you can shoot at 24fps, you're going to have more blade blur, but your next challenge is the rolling shutter that a GoPro has.

 

Rolling shutter means that the blades will appear warped and rubbery because they'll be at one position at the top of the frame, and by the time the sensor has scanned to the bottom, they'll be at another location. Because of this, the blades won't get a chance to blur as they're moving.

 

If you want to shoot artistic video of a heli, I'd recommend a DSLR like the Canon 70D with a good image-stabilized zoom lens, and then slap on a variable-ND filter to control the amount of light at wide apertures.

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I think you won't get it with a GoPro. Blade Blur is dependent on a slower shutter speed, not a faster framerate.

 

Film/Video requires a 180* shutter speed, which means that if you're shooting at 24fps, your shutter speed is double the reciprocal, or 1/48 of a second. 30fps, 1/60th, 60fps, 1/120th. Etc. The higher the framerate, the shorter duration your shutter speed is to avoid judder or choppy motion.

 

In still photos, I usually aim for less than 1/125 shutter speed depending on the rotor rpm of the machine to ensure blurred blades. If you can shoot at 24fps, you're going to have more blade blur, but your next challenge is the rolling shutter that a GoPro has.

 

Rolling shutter means that the blades will appear warped and rubbery because they'll be at one position at the top of the frame, and by the time the sensor has scanned to the bottom, they'll be at another location. Because of this, the blades won't get a chance to blur as they're moving.

 

If you want to shoot artistic video of a heli, I'd recommend a DSLR like the Canon 70D with a good image-stabilized zoom lens, and then slap on a variable-ND filter to control the amount of light at wide apertures.

Excellent description of the differamce between shutter speed, video vs stills, and rolling shutter. You saved this thread from going to a very bad place.

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Have used the go pro installed on external loads for a few years,,,works fine although not really interested in what the helicopter looks like. Everything else is awesome. Be very careful about installing willy nilly on aircraft externally, simply put it is illegal. Anything in aircraft airflow has to be approved. Whereas on the load is simply an external load. My little quad copter won't lift it though,,,,,;(

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I've had GoPros installed inside the cargo basket on an Astar and the footage is awsome. If you have an Aero Design basket, there's that big opening at the front of the basket. As long as it's inside the basket you're "legal"...

 

I've also seen guys install it in the belly pan in Astars while long-lining as well (no window in the floor, which is illegal in of itself)...

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@whippersnapr

 

Thank you for the excellent explanation! That is precisely the information I was trying to satisfy before committing to purchase a Go Pro. As well, I've often wondered why in-flight photos of rotors and props looked warped and "rubbery" - your explanation satisfies that question as well.

 

Do I take it from your explanation there is no way to tame that rolling shutter on the Go Pro? I had plans to invest in a good photo/video DSLR in the future but was hoping first for something small and powerful like the Go Pro or other alternate (suggestions?) that a person could fit easily in a pocket and/or strap to a helmet - and ideally interface with a smart phone and/or remote for more capability "on the fly" so to speak.

 

Or maybe technology is not yet ready for my demands? LOL

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Do I take it from your explanation there is no way to tame that rolling shutter on the Go Pro? I had plans to invest in a good photo/video DSLR in the future but was hoping first for something small and powerful like the Go Pro or other alternate (suggestions?) that a person could fit easily in a pocket and/or strap to a helmet - and ideally interface with a smart phone and/or remote for more capability "on the fly" so to speak.

 

Or maybe technology is not yet ready for my demands? LOL

 

 

Unfortunately the rolling shutter on GoPros are directly linked to the framerate. The higher the framerate, the higher the scan rate of the sensor, the less chance of distortion. Fine for other situations, but counter to what you want. The GoPro uses a CMOS sensor, which uses a progressive-scan sensor.

 

A video camera with a CCD sensor will scan the entire frame similar to a film camera, but not many consumer-level cameras use CCD's these days, as most CMOS cameras have increased their scan-rates high enough for rolling shutter to not be a concern.

 

I'd recommend checking out the Canon 70D. I use a Canon 60D for my aviation stills and for some videography. The 70D has improved on a lot of the limitations of the 60D. It has full-time video autofocus, more low-light sensitivity, more megapixels, and a faster still autofocus sytem. It's not a cheap camera, but it truly is a jack-of-all-trades if you're looking for both photo and video capabilities.

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