Taking bent prop pics? - Here's why!

Wonder what the next technology will be.
I keep thinking they should be refreshing individual pixels at some point versus scaning a row at a time.
 
What did pictures of a moving propeller look like in the old days with 35mm film? Just blurry? Or could the shutter be fast enough to actually see the blade?
 
Yea, what EdFred said. A good high speed film on a bright day and a high shutter speed (etc.), you can stop the prop - sometimes...

Most of the time, it is just a dim arc in the air. I have a good DSLR and that is what I get: a dim prop arc which to me is the better pic. (If the prop is stopped, I think the pilot should be at least sweating pretty good.)

By the way, most DSLRs seem to sample the data differently - maybe multiple times. But I'm only a DSLR pilot too - don't ask me too many technical questions there.
 
brian];1582390 said:
Yea, what EdFred said. A good high speed film on a bright day and a high shutter speed (etc.), you can stop the prop - sometimes...

Most of the time, it is just a dim arc in the air. I have a good DSLR and that is what I get: a dim prop arc which to me is the better pic. (If the prop is stopped, I think the pilot should be at least sweating pretty good.)

By the way, most DSLRs seem to sample the data differently - maybe multiple times. But I'm only a DSLR pilot too - don't ask me too many technical questions there.
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Yeah, DSLRs grab the entire sensor at once. Very different from the little cameras in phones and action cams. A DSLR and an old film camera will behave the same. A high shutter speed will freeze the prop, a low one will result in a pleasant blur.

For example, here's a shot I took a couple weeks ago with 1/60th of a second shutter speed:

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images

Same issue with vertical travel focal-plane shutters of old.
 
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rwellner98 said:
Yeah, DSLRs grab the entire sensor at once. Very different from the little cameras in phones and action cams. A DSLR and an old film camera will behave the same. A high shutter speed will freeze the prop, a low one will result in a pleasant blur.

For example, here's a shot I took a couple weeks ago with 1/60th of a second shutter speed:
Click to expand...

I'm surprised how sharp that was for 1/60, it's a good shot. My Cannon 7D can get up to 1/8000. I would love to see how that looks.
 
FredFenster said:
What did pictures of a moving propeller look like in the old days with 35mm film? Just blurry? Or could the shutter be fast enough to actually see the blade?
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Yes, at higher shutter speeds, the prop is 'frozen', call it faster than 1/250th of a second. As you would get slower you would get blurred arc segments where the prop turned during the exposure. Slower than 1/60th of a second on an engine running at speed and you pretty much had a fully blurred disk.
 
brian];1582379 said:
Pretty cool article showing why camera phone pics suck when taken through the prop arc:
http://jasmcole.com/2014/10/12/rolling-shutters/
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That article fails to point out that rolling shutter effects only apply to current CMOS camera sensors - while CCD camera sensors use a global shutter, so that effect doesn't occur on them.

So if you want to avoid that issue entirely, just make sure to use a camera with CCD sensors, not CMOS sensors. My Canon camera uses CCD and all my movies with moving props yield only the blur one would expect of a non-zero exposure time.
 
EagleKnievel said:
I'm surprised how sharp that was for 1/60, it's a good shot. My Cannon 7D can get up to 1/8000. I would love to see how that looks.
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You probably won't like it much. Prop will be complete frozen and it will look like an awkward plane that is in the air even though it isn't running.
 
Jim Logajan said:
That article fails to point out that rolling shutter effects only apply to current CMOS camera sensors - while CCD camera sensors use a global shutter, so that effect doesn't occur on them.

So if you want to avoid that issue entirely, just make sure to use a camera with CCD sensors, not CMOS sensors. My Canon camera uses CCD and all my movies with moving props yield only the blur one would expect of a non-zero exposure time.
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Ok, so what is the cheapest, compact HD video camera that uses CCD?
 
It's called global shutter when the sensor grabs the whole pic at once. It's coming (back, I should say, it's not a new process) more and more and that's when you get rid of all those anomalies. Problem is the processors haven't been able to process it in an effective way until now. It's also got to do with the architecture of the chip - today we use CMOS chips, whereas the older CCD's could handle global shutter pretty well. However, they were not good with resolution, colour management and latitude, so CMOS prevailed. Now CMOS sensors are starting to be enabled with global shutter. In the next 10 years you will see great improvements in this area. There will be no rolling shutters in the future.

This is what I do for a living, so I'm not talking out of my a*s.:)
 
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dans2992 said:
Ok, so what is the cheapest, compact HD video camera that uses CCD?
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I have no idea. Also not sure what resolution qualifies as HD.

But for reference, I bought a Canon PowerShot ELPH 115 IS (CCD) for about $120. (I think the ELPH 150 IS is the latest of that series.) I got it mostly because it can fit in a pocket and it is possible to shoot videos and still pictures with one hand. It is pretty much dedicated to the flight bag. I'm a novice at cameras so I'll let those who know the field give proper recommendations.

For some idea of what a moving prop looks like with video made with a CCD camera, here is a boring and shaky video (some resolution lost when uploaded) shot by me with the Canon while simultaneously taxiing over rough ground (note the prop isn't distorted; I also gave the auto-focus a work-out too):
https://vimeo.com/108028096
 
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