Calculators Effects >>> Field Depth.


		<script 
		language="javascript"
		type="text/javascript">

		/* Visit http://www.yaldex.com/ 
		for full source code

		and get more free JavaScript, CSS and DHTML scripts! */

		<!-- Begin

		function 
		doField(form)
		{

		distance 
		=
		(form.distance.value)*1000;

		CoC 
		=
		(document.form.format.options[document.form.format.selectedIndex].value);

		aperture 
		=
		(document.form.aperture.options[document.form.aperture.selectedIndex].value);

		focal 
		=
		(document.form.focal.options[document.form.focal.selectedIndex].value);

		if
		(isNaN(distance)) 
		{

		alert('Please 
		enter a numerical value for subject distance.');

		document.form.distance.focus();

		document.form.distance.select();

		}

		else
		{

		hyperFocal 
		=
		(focal
		* 
		focal)
		/
		(aperture
		* 
		CoC);

		form.hyperFocal.value 
		=
		Math.round(hyperFocal)
		/
		1000
		+
		" m";

		dofNear 
		=
		(hyperFocal
		* 
		distance)
		/
		(hyperFocal
		+
		(distance
		- 
		focal));

		form.dofNear.value
		=
		Math.round(dofNear)
		/
		1000
		+
		" m";

		dofFar 
		=
		(hyperFocal
		* 
		distance)
		/
		(hyperFocal
		-
		(distance
		- 
		focal));

		if
		(dofFar
		<
		0)
		{

		form.dofFar.value 
		=
		"Infinity.";

		}

		else
		{

		form.dofFar.value 
		=
		Math.round(dofFar)/1000+" 
		m";

		}

		dofTotal 
		=
		Math.round(dofFar
		- 
		dofNear);

		if
		(dofTotal
		<
		0)
		{

		form.dofTotal.value 
		=
		"Infinite.";

		}

		else
		{

		if
		(dofTotal
		>=
		0
		&& 
		dofTotal <
		0.001)
		{

		form.dofTotal.value 
		=
		">1 mm "; 
		

		}

		else
		{

		form.dofTotal.value
		= 
		dofTotal /
		1000
		+
		" m"; 
		

		         }

		      
		}

		   
		}

		}

		//  End -->

		</script>

		<form
		method=post
		name=form>

		<table
		border=3
		cellpadding=10
		cellspacing=0
		width=500>

		<tr>

		<td 
		align=center
		colspan=2>

		Depth of Field Calculator

		</td>

		</tr>

		<tr>

		<td 
		align=left>

		Negative Format

		</td>

		<td 
		align=left>

		<select
		name=format>

		<option 
		value=0.033>35 
		mm

		<option
		value=0.025>APS

		<option
		value=0.05>6x45 
		cm  

		<option
		value=0.06>6x6 
		cm

		<option
		value=0.065>6x7 
		cm

		<option
		value=0.15>5x4 
		inch

		<option
		value=0.3>10x8 
		inch

		</select>

		</td>

		</tr>

		<tr>

		<td 
		align=left>

		Lens focal length

		</td>

		<td 
		align=left>

		<select
		name=focal>

		<option 
		value=17>17 
		mm

		<option
		value=20>20 
		mm

		<option
		value=24>24 
		mm

		<option
		value=28>28 
		mm

		<option
		value=35>35 
		mm

		<option
		value=50>50 
		mm 

		<option
		value=70>70 
		mm

		<option
		value=80>80 
		mm

		<option
		value=100>100 
		mm

		<option
		value=135>135 
		mm

		<option
		value=150>150 
		mm 

		<option
		value=200>200 
		mm

		<option
		value=210>210 
		mm

		<option
		value=300>300 
		mm

		<option
		value=350>350 
		mm

		<option
		value=400>400 
		mm

		</select>

		</td>

		</tr>

		<tr>

		<td 
		align=left>

		Selected aperture

		</td>

		<td 
		align=left>

		<select
		name=aperture>

		<option 
		value=1.4>F 
		1.4

		<option
		value=1.8>F 
		1.8

		<option
		value=2>F 
		2

		<option
		value=2.8>F 
		2.8

		<option
		value=4>F 
		4

		<option
		value=5.6>F 
		5.6

		<option
		value=8> 
		F 8

		<option
		value=11>F 
		11

		<option
		value=16>F 
		16

		<option
		value=22>F 
		22

		<option
		value=32>F 
		32

		<option
		value=45>F 
		45

		<option
		value=64>F 
		64

		<option
		value=90>F 
		90

		</select>

		</td>

		</tr>

		<tr>

		<td 
		align=left>

		Subject distance (Meters)

		</td>

		<td 
		align=left>

		<input
		type=text
		name=distance
		value=""
		size=6>

		</td>

		</tr>

		<tr>

		<td 
		colspan=2
		align=left>

		<br>

		<center><input
		type=button
		value="Calculate."
		onclick="doField(this.form)"></center>

		<br>

		<input
		name=hyperFocal
		type=text
		value=""
		size=6> 
		Hyperfocal distance for this lens/aperture combination.

		<BR>

		<input
		name=dofNear
		type=text
		value=""
		size=6> 
		Near limit of acceptable sharpness.

		<BR>

		<input
		name=dofFar
		type=text
		value=""
		size=6> 
		Far limit of acceptable sharpness.

		<BR>

		<input
		name=dofTotal
		type=text
		value=""
		size=6> 
		Total depth of field.

		<BR>

		<br>

		</td></tr>

		</form>

		</table>