The Iphone and some video camera's capture this weird bent blurry prop which ruins most good videos and pictures. Does anyone know if changing the frame rate will fix this. I use my Iphone 5 a lot because it takes great pictures but I can photograph anything off the nose which is annoying. Any suggestions would be awesome.

Thanks!

Frame rate has very little to do with why fast moving, reciprocating/rotating objects in HD video appear distorted. I mean, it does, but it's not an effectively adjustment in dealing with something like a rotating propeller.

The CMOS sensors from modern, cheap HD cameras build the image for each frame as a progressive write of horizontal lines. The trouble with shooting propellers is that they spin so fast that the prop is in a different position by the time the line-writing get near the bottom.

The only solution to this is to force the camera to use a slower "shutter speed" which is a familiar camera term, but not exactly applicable to a digital sensor that doesn't really have a shutter. In CMOS sensors, the "shutter speed" is accomplished by setting the rate at which the sensor senses and then writes, and is reset, cyclically. A better term would be "scan rate." In photography, keeping the shutter open longer has the effect of blurring fast-moving objects, almost to the point where they can't be seen. The same concept can help a little GoPro or Drift shoot a prop-free video. Here's an example of one I recently shot on a Hero3:



This is accomplished by reducing the amount of light that gets to the sensor with a Neutral Density filter. The camera's software compensates to get a good exposure by slowing down the "shutter speed." The result is the same exposure but with any fast-moving objects blurred out. The downside is that some vibration frequencies can affect the image quality, because stuff that's moving in the frame has the potential to be blurred. I'd only use this technique for shooting through the prop.

Where to get a Neutral Density filter? If you're shooting with an SLR, you don't really need one. Just use manual exposure mode and dial down your shutter speed until prop disappears. For a GoPro, Nflightcam makes a filter kit. Maybe they make one for the Drift as well? For the iPhone, you'll have to be a little more creative and find an app that lets you control those parameters, or use the same concept of reducing light to the sensor with something like this.

If you're not thrilled with paying $80 for that, you can always find some ND filter sheets and cut a piece small enough to fit inside the housing.

A slower frame rate (longer exposure per frame) definitely helps, as it blurs the prop. Some people put a neutral density filter on the lens to force the camera to use a longer exposure / slower frame rate if their camera doesn't allow easily setting it.

I used a #4 Neutral Density filter on my Drift. Killed the prop artifacts.

MTV

mtv wrote:I used a #4 Neutral Density filter on my Drift. Killed the prop artifacts.

MTV

Where did you get this filter?
Did you cut a sheet?
I can't find one made for the Drift.

Thanks

ZPilot wrote:

mtv wrote:I used a #4 Neutral Density filter on my Drift. Killed the prop artifacts.

MTV

Where did you get this filter?
Did you cut a sheet?
I can't find one made for the Drift.

Thanks

I ordered one for a standard lens, and, with a little electrical tape, I affixed it to the front of the lens. Been on there for over a year now.....

MTV

Rube Goldberg wrote:I ordered one for a standard lens, and, with a little electrical tape, I affixed it to the front of the lens. Been on there for over a year now.....

MTV

That's funny Mike!!

NimpoCub wrote:

Rube Goldberg wrote:I ordered one for a standard lens, and, with a little electrical tape, I affixed it to the front of the lens. Been on there for over a year now.....

MTV

That's funny Mike!!

Not funny....it's PMA'd electrical tape.

MTV

I use 2 layers of .6 ND filter film on my Drift Ghost and the effect is great.

The vendor I found is:

filmandvideolighting.com

Barn Door Lighting
232 Branford Rd
Branford, CT 06471

Here is a link to the .6ND filter film.

http://www.filmandvideolighting.com/lee ... hting.html

This place is about 1/3 the price of other vendors I found. i.e., around $7-8 per 20x24 sheet.