Math Is Fun Forum

model

Member

Registered: 2011-08-10

Posts: 142

distance from camera to object

Hy guys ,

I want to find distance from camera to object .
A picture is given in this link: http://i1069.photobucket.com/albums/u472/tina12354/anglefind.png

Could any one please help me how to find distance from camera to object .
thanks

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anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: distance from camera to object

Hi model

Does the star represent where the camera is?

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“Here lies the reader who will never open this book. He is forever dead.
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

model

Member

Registered: 2011-08-10

Posts: 142

Re: distance from camera to object

hmm yes you can say focal length .

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Maths is Doctor that make our life easy ..

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anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: distance from camera to object

Did you try trigonometry to solve this?

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“Here lies the reader who will never open this book. He is forever dead.
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,648

Re: distance from camera to object

hi model

Have a look at

http://www.mathsisfun.com/sine-cosine-tangent.html

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

model

Member

Registered: 2011-08-10

Posts: 142

Re: distance from camera to object

Hy thanks Bob:)

Well i tried to solve that.

if you see this figure :http://i1069.photobucket.com/albums/u472/tina12354/anglefind-1.png

then cos(60) = base /hypo
       1/2      = 100 / y
       y = 200 cm

and sin(60)     = perpendicular / gypo
      sqrt(3) /2 = x / 200
      sqrt(3)*100 = x
      x = 173 cm.

Is it correct ?
So in think distance from cam to object is 173 cm.
Please correct me if i am wrong .
thanks

---

Maths is Doctor that make our life easy ..

https://www.facebook.com/groups/Maths.GIS/

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: distance from camera to object

If the distance given is 10cm then those two answers you got must be divided by 10. Otherwise, your answers are correct.

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“Here lies the reader who will never open this book. He is forever dead.
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,648

Re: distance from camera to object

hi model

I agree with anonimnystefy.  You started with 10 cm.  200cm is impossibly large.  Did you mean 200 mm ?  Or 20 cm.

Same with 173.  17.3 cm or 173 mm.

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: distance from camera to object

Hi Bob

I guess another 0 just slipped in. No biggie.

What I am curious about is what this is for, because I know most model's questions have a practical application behind them.

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“Here lies the reader who will never open this book. He is forever dead.
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.