POV-Ray : Newsgroups : povray.advanced-users : About camera focal lengh, Urgent!!!!!!!!!!!!! Server Time
8 Jul 2024 18:43:29 EDT (-0400)
  About camera focal lengh, Urgent!!!!!!!!!!!!! (Message 1 to 10 of 10)  
From: sitha
Subject: About camera focal lengh, Urgent!!!!!!!!!!!!!
Date: 28 Nov 2006 22:45:00
Message: <web.456d0183a79d3b284ac3566b0@news.povray.org>
Hi Everybody,
I am willing to do image analsis using pov-ray. Here I have a small problem
aboyt focal length of camera used in pov-ray. when we set the camera we
have,
1.location
2.direction
3.angle

above three parametrs but dont have focal length. Is there anyway to define
focal length? Pls help me as soon as possible. If we dont have focal length
in POV-ray camera, I should go for other options.........

Thanks lot in advance.

Regards,
Sitha.


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From: Charles C
Subject: Re: About camera focal lengh, Urgent!!!!!!!!!!!!!
Date: 28 Nov 2006 23:10:00
Message: <web.456d073ba8eb71432869ae640@news.povray.org>
Try here for focal_point:
http://www.povray.org/documentation/view/3.6.1/248/

"sitha" <nsi### [at] excitecom> wrote:
> Hi Everybody,
> I am willing to do image analsis using pov-ray. Here I have a small problem
> aboyt focal length of camera used in pov-ray. when we set the camera we
> have,
> 1.location
> 2.direction
> 3.angle
>
> above three parametrs but dont have focal length. Is there anyway to define
> focal length? Pls help me as soon as possible. If we dont have focal length
> in POV-ray camera, I should go for other options.........
>
> Thanks lot in advance.
>
> Regards,
> Sitha.


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From: sitha
Subject: Re: About camera focal lengh, Urgent!!!!!!!!!!!!!
Date: 29 Nov 2006 00:45:00
Message: <web.456d1e0ba8eb71434ac3566b0@news.povray.org>
Dear Charles,
I tired with focal_point vector. But it did not work as real camera. If I
change focal point vector it should give different picture depending on
focal_point. But it gives same picture for any value of vector. Pls help
me..

Is it possible to get a similar distorted picture in pov ray like real
distorted photo taking by camera?

Regards,
Sitha.


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From: sitha
Subject: Re: About camera focal lengh, Urgent!!!!!!!!!!!!!
Date: 29 Nov 2006 01:15:00
Message: <web.456d24cfa8eb71434ac3566b0@news.povray.org>
Hi Charles,

I am  very thankful for your help. By using focalblur camera I could make
distorted camera. So I hope I can continue my image analysis in POV-ray.

Regards,
Sitha.


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From: Charles C
Subject: Re: About camera focal lengh, Urgent!!!!!!!!!!!!!
Date: 29 Nov 2006 01:25:01
Message: <web.456d26b4a8eb7143ee21010a0@news.povray.org>
Hmm, I'm not any kind of expert with camera effects in POV-Ray.  There are a
lot of people on here who know way more than me about this.  But anyway, are
you getting any blur effect at all?  You need to tell it how many
blur_samples to use or it won't give you any focal blur.  Take a look at
scenes/camera/focalblur.pov and play with the focal_point on that one & see
if it's what you want.  In that case it definitely does change the picture
when adding *5 to the focal_point.  Good luck.

Charles


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From: Charles C
Subject: Re: About camera focal lengh, Urgent!!!!!!!!!!!!!
Date: 29 Nov 2006 01:25:01
Message: <web.456d2785a8eb7143ee21010a0@news.povray.org>
OK good.  I just replied to your other post, but it sounds like you got it
:-)

"sitha" <nsi### [at] excitecom> wrote:
> Hi Charles,
>
> I am  very thankful for your help. By using focalblur camera I could make
> distorted camera. So I hope I can continue my image analysis in POV-ray.
>
> Regards,
> Sitha.


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From: KEBman
Subject: Re: About camera focal lengh, Urgent!!!!!!!!!!!!!
Date: 29 Nov 2006 19:45:00
Message: <web.456e2894a8eb7143a26cbdf80@news.povray.org>
Hm, just wondering. Would it be possible to do Nyquist-Shannon sampling
tests with those? Or Raleigh scattering stuff regarding Raleigh's Law with
them? If I'm not mistaken, real focal lenghts and things like that would
then be
required.


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From: Alain
Subject: Re: About camera focal lengh, Urgent!!!!!!!!!!!!!
Date: 29 Nov 2006 21:00:19
Message: <456e3b33@news.povray.org>
sitha nous apporta ses lumieres en ce 28/11/2006 22:41:
> Hi Everybody,
> I am willing to do image analsis using pov-ray. Here I have a small problem
> aboyt focal length of camera used in pov-ray. when we set the camera we
> have,
> 1.location
> 2.direction
> 3.angle

> above three parametrs but dont have focal length. Is there anyway to define
> focal length? Pls help me as soon as possible. If we dont have focal length
> in POV-ray camera, I should go for other options.........

> Thanks lot in advance.

> Regards,
> Sitha.


Strictly speaking, the POV-Ray camera is an ideal pinpoint camera: an infinitely 
small aperture.
There is no real focal lenght. You can simulate focal blur, but it still only a 
simulation.

-- 
Alain
-------------------------------------------------
Hinduism: This shit has happened before.


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From: sitha
Subject: Re: About camera focal lengh, Urgent!!!!!!!!!!!!!
Date: 30 Nov 2006 00:00:00
Message: <web.456e648da8eb71434ac3566b0@news.povray.org>
>
> Strictly speaking, the POV-Ray camera is an ideal pinpoint camera: an infinitely
> small aperture.
> There is no real focal lenght. You can simulate focal blur, but it still only a
> simulation.
>
> --
> Alain


Dear Alain,
Thanks a lot for your information. If this camera doesn't have real focal
length, Is there any realtionship made for focal blur with focal length or
with some other parameters like aperture, sampling and etc.
Pls give me some idea about it.

Regards,
Sitha.


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From: Gilles Tran
Subject: Re: About camera focal lengh, Urgent!!!!!!!!!!!!!
Date: 30 Nov 2006 03:47:08
Message: <456e9a8c@news.povray.org>

web.456e648da8eb71434ac3566b0@news.povray.org...
> Dear Alain,
> Thanks a lot for your information. If this camera doesn't have real focal
> length, Is there any realtionship made for focal blur with focal length or
> with some other parameters like aperture, sampling and etc.
> Pls give me some idea about it.

You can try this:
http://www.wozzeck.net/images/DoF.html

G.


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