 | | | Camera FOV vs Focal Length | Camera FOV vs Focal Length 2005-05-09 - By Andre DeAngelis
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Thanks a lot for that Marc,
So for 35 mm camera the 3 values are properly set up then?
Andre
__ ____ ____ ____ ____ ____ ____
From: owner-xsi@(protected) [mailto:owner-xsi@(protected)] On Behalf
Of Marc Bourbonnais
Sent: Monday, May 09, 2005 11:51 AM
To: XSI@(protected)
Subject: Re: Camera FOV vs Focal Length
The relation between FoV, lens and aperture is correct in XSI. It's the
same trig relation between the 3 values.
The problem is the incorrect default aperture sizes for the HD cams, so
I can assume you are working with these types of plates.
The correct aperure size for high-end HD cams is 9.6mm x 5.4mm, roughly
0.37795" x 0.2126". Not the default XSI values.
The magic trig relation is :
f = (0.5*Ap) / tan(0.5*FoV)
where
f = lens
Ap = aperture
FoV = Field of view angle
of course keep track of mm vs. inches, and horizontal vs. vertical.
--
Marc Bourbonnais
3D TD
Hybride
(450)227-4245
-- -- Original Message -- --
From: Andre DeAngelis <mailto:andre.deangelis@(protected)>
To: XSI@(protected)
Sent: Monday, May 09, 2005 10:58 AM
Subject: Camera FOV vs Focal Length
Hello All,
Can anyone point me in the direction of a reference that
explains the formula for the relation between FOV, Focal Length and Film
Aperture used by XSI's camera?
The presets in XSI's camera don't seem to correlate to what the
table the director has given us and I want to put a script/plug-in to
reproduce the table he has provided.
AD
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<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'>Thanks a lot for that
Marc,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span><
/font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'>So for 35 mm camera the 3
values are properly set up then?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span><
/font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'>Andre<o:p></o:p></span><
/font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span><
/font></p>
<div>
<div class=MsoNormal align=center style='text-align:center'><font size=3
face="Times New Roman"><span lang=EN-US style='font-size:12.0pt'>
<hr size=2 width="100%" align=center tabindex=-1>
</span></font></div>
<p class=MsoNormal><b><font size=2 face=Tahoma><span lang=EN-US
style='font-size:10.0pt;font-family:Tahoma;font-weight:bold'>From:</span></font
></b><font
size=2 face=Tahoma><span lang=EN-US style='font-size:10.0pt;font-family:Tahoma'>
owner-xsi@(protected) [mailto:owner-xsi@(protected)] <b><span
style='font-weight:bold'>On Behalf Of </span></b>Marc Bourbonnais<br>
<b><span style='font-weight:bold'>Sent:</span></b> Monday, May 09, 2005 11:51
AM<br>
<b><span style='font-weight:bold'>To:</span></b> <st1:PersonName w:st="on">XSI
@(protected)</st1:PersonName><br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: Camera FOV vs Focal
Length</span></font><span lang=EN-US><o:p></o:p></span></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>The relation between FoV, lens and aperture is correct in
XSI. It's the same trig relation between the 3 values.</span></font><o:p></o:p>
</p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>The problem is the incorrect default aperture sizes for the
HD cams, so I can assume you are working with these types of plates.</span><
/font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>The correct aperure size for high-end HD cams is 9.6mm x
5.4mm, roughly 0.37795" x 0.2126". Not the default XSI values.</span>
</font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>The magic trig relation is :</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>f = (0.5*Ap) / tan(0.5*FoV)</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>where </span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>f = lens</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Ap = aperture</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>FoV = Field of view angle</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>of course keep track of mm vs. inches, and horizontal vs.
vertical.</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>--<br>
Marc Bourbonnais<br>
3D TD<br>
Hybride<br>
(450)227-4245<o:p></o:p></span></font></p>
</div>
<blockquote style='border:none;border-left:solid black 1.5pt;padding:0cm 0cm
0cm 4.0pt;
margin-left:3.75pt;margin-top:5.0pt;margin-right:0cm;margin-bottom:5.0pt'>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>-- -- Original Message -- -- <o:p></o:p></span></font></p>
</div>
<div style='font-color:black'>
<p class=MsoNormal style='background:#E4E4E4'><b><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial;font-weight:bold'>From:</span></font>
</b><font
size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> <a
href="mailto:andre.deangelis@(protected)" title="andre.deangelis@(protected)"
>Andre
DeAngelis</a> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><b><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial;font-weight:bold'>To:</span></font></b><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'> <a
href="mailto:XSI@(protected)" title="XSI@(protected)">XSI@(protected)</a>
<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><b><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial;font-weight:bold'>Sent:</span></font></b><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'> Monday, May 09,
2005 10:58 AM<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><b><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial;font-weight:bold'>Subject:</span></font></b><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'> Camera FOV vs
Focal Length<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-CA style='font-size:
10.0pt;font-family:Arial'>Hello All,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-CA style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-CA style='font-size:
10.0pt;font-family:Arial'>Can anyone point me in the direction of a reference
that explains the formula for the relation between FOV, Focal Length and Film
Aperture used by XSI’s camera?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-CA style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-CA style='font-size:
10.0pt;font-family:Arial'>The presets in XSI’s camera don’t seem to
correlate to what the table the director has given us and I want to put a
script/plug-in to reproduce the table he has provided.<o:p></o:p></span></font>
</p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-CA style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-CA style='font-size:
10.0pt;font-family:Arial'>AD<o:p></o:p></span></font></p>
</blockquote>
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