Time to be with your loved ones

Time to be with loved ones

by sat

submit your photo


Hall of Fame
View past winners from this year

Please participate in Meta
and help us grow.

Take the 2-minute tour ×
Photography Stack Exchange is a question and answer site for professional, enthusiast and amateur photographers. It's 100% free, no registration required.

How many cameras apart from the iPhone have a gyroscope for orientation?

Am I right to assume that there is a standard way to “tag” an image with the direction the camera was pointing in, as well as the GPS position?

Do any cameras have positional tracking better then a GPS?

I am thinking about a method to join photos when the subject does not have enough “random” detail for the current software.

share|improve this question
3  
I believe what the devices have are accelerometers and not gyros. By measuring the gravity vector along 3 axes, and with the addition of a compass, the device can resolve its orientation. Theoretically, you could do this with gyros, but calibration would be required each time you turn on the device. If there are gyros in the iPhone, my guess is that they only sense angular motion (e.g., for games) but not the orientation itself. Again, one can calculate this using accelerometers. –  ysap May 16 '11 at 21:33
1  
@ysap: you should add your comment as an answer. –  Paul Hadfield May 16 '11 at 21:55
    
@PaulHadfield - technically, it does not answer the question, since I don't know for sure that no cameras have gyros. –  ysap May 16 '11 at 23:15
add comment

3 Answers

The gyroscope in an iPhone doesn't actually let you track the direction the camera was facing at the time of a shot. All it does it track motion--it has no frame of reference to determine what point of the compass the camera is actually facing.

The "digital compass" in the iPhone 3G S onwards can give some idea of that, except that it's designed to be used when the iPhone is more or less flat. It would thus require a mirror to be fitted to the camera lens to be useful, and in any case compass data isn't included in the EXIF info. I would expect that any camera providing directional capabilities would be using an equivalent "digital compass" using a magnetometer.

share|improve this answer
add comment

To have "positional tracking better than a GPS" you will need an INS (Inertial Navigation System) of the kind that exists in cruise missiles... The on-board sensors you get in your camera/smartphone merely tell you the orientation and motion, but not the position.

share|improve this answer
    
Itai's comment implies that the Casio does use a sort of dead-reckoning to use sensors to estimate position. –  Henry Jackson May 16 '11 at 23:36
    
@HenryJackson - What it means is probably that the camera have a GPS for tracking its position, but uses the accelerometers for local tracking, originating at the last reliable GPS recorded location. Continuous position estimates based on a $2 sensor set is guaranteed to drift in amounts that will render it useless for geotagging. –  ysap May 16 '11 at 23:42
add comment

Among the current cameras with GPS you will notice that more than half also record orientation. Just look at the row towards the bottom of the table that says GPS at the above link.

Now, I have no idea if they use accelerometer or gyroscopes but all those record the orientation of the camera. At least the Casio H20G, which is also among the digital cameras to include a built-in GPS with orientation, is known to use accelerometers because it actually tracks your position indoors (or other places where GPS do not reach) too by measuring direction and speed from the last known GPS location. They call this Hybrid GPS.

share|improve this answer
    
How heck the the camera can know your direction and speed without GPS?! Man, the future is so awesome! –  Andres May 17 '11 at 1:31
    
Sorry I was not clear enough I guess. It measures from the last known GPS location, so it has to get a GPS lock at some point and keeps calculating from there until the next GPS lock. The H20G is among the list of cameras with GPS. –  Itai May 17 '11 at 1:44
    
But it really can detect your movements or it just traces a straight line from the last gps lock to the new one? (BTW, may be I sounded ironic, but i was really amazed about the tracking thingy) –  Andres May 17 '11 at 2:10
2  
Yes, it tracks movements using 3-way sensors for direction and rotation. It has to since it geotags BEFORE reaching the next GPS lock: casio.com/products/Cameras/Hybrid-GPS/EX-H20G –  Itai May 17 '11 at 2:51
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.