Stereo photos of model helicopters

handyandy55

11

« on: 20 / July / 2009, 19:43:33 »

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Hello All

Andy here, new to the site, I have found it very interesting so far.

I am looking to buy a pair a cameras to allow me to take photos of radio controlled helicopters in 3D i need to use a lens of around 200mm as you can't get to close to the heli as the blades do 2000 RPM and the blades are carbon fibre.

the seperation base will be around 15cm due to the lenght of the lens required

Is it possable to sync the two cameras with CHDK? the sync need to be spot on as the helis are always moving especialy the blades and control them both through USB connections or their sync socket if they have one.

Any info would be great, as i am itching to get the cameras and start playing with CHDK

Many Thanks

Andy

The normal shutter speed i use is around 1/300 to make sure a get some blade movement.

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an0n

152

Re: Stereo photos of model helicopters

« Reply #1 on: 20 / July / 2009, 21:22:42 »

Hi Andy,

It is possible to sync the cameras with CHDK, go to Main Menu>Miscellaneous stuff>Remote parameters,
for Enable Remote and synchable remote settings. I have not tried it so can't comment on accuracy etc.

The Stereo Data Maker site http://stereo.jpn.org/eng/index.html is going to be of interest to you,
SDM is a modified CHDK for stereo photography (in case you didn't know already).

Hope that helps a bit.

« Last Edit: 20 / July / 2009, 21:24:33 by an0n »

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A720IS.

Anaglyphic

129
Anaglyphic lives!

Re: Stereo photos of model helicopters

« Reply #2 on: 20 / July / 2009, 22:12:56 »

Welcome, you're in the right place.

Hey depending on the lift of said helicopters, you could put a pair of lightweight Canons on them and shoot in-flight stereo video.

Yes, sync is done via voltage detection on the USB +V pin(s).... sync with no additional hardware but a battery, a switch, and two hacked-up USB cables is around 1/8000th... and more!

Adding to an0n's suggestion, you'll find lots of useful info on the Yahoo! SDM group... perhaps even join the list?

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Since we cannot know all that there is to be known about anything,
we ought to know a little about everything. -- Blaise Pascal

Microfunguy

4037

Re: Stereo photos of model helicopters

« Reply #3 on: 21 / July / 2009, 09:00:36 »

Quote from: Anaglyphic on 20 / July / 2009, 22:12:56

you could put a pair of lightweight Canons on them and shoot in-flight stereo video.

Wow, that would be good (even though movie synch is nowhere near as good as still-image synch) !

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handyandy55

11

Re: Stereo photos of model helicopters

« Reply #4 on: 21 / July / 2009, 09:48:32 »

Thanks very much SDM looks like fun and i have joined the Yahoo group

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cybercom

268

Re: Stereo photos of model helicopters

« Reply #5 on: 22 / July / 2009, 16:27:30 »

One suggestion if you are somewhat photographically savvy:

If you allow the cameras to use too high (fast) a shutter speed, you will get a series of static images of the blades that will most likely never be in synch. By adjusting your ISO (I still call it ASA) speed higher - 400 or more if the noise floor is OK - and shutting down the aperture - f/8 or f/16 - you will slow the shutter speed and get blurring of the blades which will look much more natural.

You'll have to do tests to work out the best combinations.

Also, don't forget ND filters.

HTH,

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handyandy55

11

Re: Stereo photos of model helicopters

« Reply #6 on: 01 / August / 2009, 11:25:49 »

Yes i find that 1/320 work well to make sure that the blades have some blurred movement

How would ND Filiters help

They would cut down the light so making the camera use nF stop of 2.8 to 5.6 which would cut down the depth of field to much?

As you point out an F stop of F8-F16 works well

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cybercom

268

Re: Stereo photos of model helicopters

« Reply #7 on: 04 / August / 2009, 21:45:33 »

Sounds like f/8 @ 1/320th is the magic formula.

I was only mentioning ND filters because they might help if you couldn't get what you needed otherwise. Remember, an ND filter will let you change any of the shooting parameters - ISO, aperture or shutter speed, so, for example, if you wanted more blur, you could add an ND.3 and shoot at 1/160th at f/8 with the same ISO.

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