Depth of Field

[iND]

When I shoot groups I am very sensitive to the depth of field as I dont want to have anyone out of focus.


I am able to calculate dept of field for any given focal length, subjaect distance, and f stop.


This is cumbersome and not readily done on the spot.


So I usually WAY over estimate my f stop and don't get the image I was planning.


Does anyone have method to determine DOF that can be done on the spot, or is there a chart to carry.
Would it not be nice if canon built this into the on camera info screen?

[luck101]

same dillema as you. what i do tho, i just shoot at f5 thru f8. normally resloves the best quality, and of all the people are lined up side to side, it should be enough to get all of them. but it depends what lenses you use too. this applies to my 50mm 1.8.





what lense you use for that tho?

[Keith B]

I usually shoot <35mm and usually aim for 5.6 or higher. I have actually gotten away with 4.0 before but it depends on how staggered the subjects are too.

[hotsecretary]

This? ("http://www.dofmaster.com/iphone.html) :)

[hotsecretary]

Or you could always print this ("http://www.dofmaster.com/charts.html). :)

[Rodger]

I was going to reccomend the DOF Master APP for iPhone/iPod too. Its a great little tool. I haven't found any practical use for it as I typically don't shoot things where I neeed to know the DOF. But its a cool thing to have should I need it.

[Daniel Browning]

When I shoot groups I am very sensitive to the depth of field as I dont want to have anyone out of focus.


It's easy with live view. Stop down, zoom in 10X on the back row, pull focus as far forward as possible without getting them out of focus, then check front row. If they're not in focus, stop down more. To simulate smaller print sizes, use 5X instead of 10X.

[kenbennedy]

Does anyone have method to determine DOF that can be done on the spot, or is there a chart to carry.


Would it not be nice if canon built this into the on camera info screen?






Or the lens? Depending on what lens you use, you may be able to read the the depth of field markings on the focus ring of the lens. Many (all?) of the newer Canon lenses, however, no longer have them.


There are plenty of online calculators/chart generators you can use though.


http://www.dofmaster.com/doftable.html ("http://www.dofmaster.com/doftable.html)





Also, does your camera have A-DEP mode? Not the best option, but maybe give that a try?

[Stephen Probert]

Or if you don't have liveview (I have the 5d and XTi), try the depth of field preview button?

[lculpin]

Or if you don't have liveview (I have the 5d and XTi), try the depth of field preview button?
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Lol good call

[iND]

I was really looking for some type of quick rule of thumb formula






<table border="0" width="100%" cellpadding="0" cellspacing="0"]
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<td width="4%" valign="top"]<span style="font-size: x-small; font-family: Arial;"]1.</td>
<td width="96%"]<span style="font-size: x-small; font-family: Arial;"]Larger F-numbers give greater depth of field. . </td>
</tr>
<tr>
<td width="4%" valign="top"]<span style="font-size: x-small; font-family: Arial;"]2.</td>
<td width="96%"]<span style="font-size: x-small; font-family: Arial;"]Shorter focal lengths give greater depth of field. </td>
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<td width="4%" valign="top"]<span style="font-size: x-small; font-family: Arial;"]3.</td>
<td width="96%"]


<span style="font-size: x-small; font-family: Arial;"]Greater subject distance gives greater depth of field.


<span style="font-size: x-small; font-family: Arial;"]
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<td width="4%" valign="top"]<span style="font-size: x-small; font-family: Arial;"]4.</td>
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<span style="font-size: x-small; font-family: Arial;"]Depth of field is greater behind the subject than in front


<span style="font-size: x-small; font-family: Arial;"]


<span style="font-size: x-small; font-family: Arial;"]eg. 50mm f/4 25 feet depth of field = 12 ft (standard)


<span style="font-size: x-small; font-family: Arial;"] 50mm f/8 25 feet depth of field =29 feet(2x f stop)


<span style="font-size: x-small; font-family: Arial;"] 25mm f/4 25 feet depth of field = 314 feet (1/2 focal lenght)


<span style="font-size: x-small; font-family: Arial;"]<span style="font-size: x-small; font-family: Arial;"] 50 mm f/4 50 feet depth of field =58 feet (2x distance)


<span style="font-size: x-small; font-family: Arial;"]If we look at the factors thatchangefocal lenght it appears that the F stop has the greatest affect


<span style="font-size: x-small; font-family: Arial;"]I was looking for something like:


<span style="font-size: x-small; font-family: Arial;"]double the F stop squares the distance (approx) 12 squared = 144


<span style="font-size: x-small; font-family: Arial;"]do we have a calculus expert out there?


<span style="font-size: x-small; font-family: Arial;"]


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[iND]

Sorry I should have stated that the focal lenght of the lens appears to have the largest affect on the depth of field, followed by the F stop


Surely there is a quick rule of thumb here.

[Stephen Probert]

Wikipedia has some formulas, but they do not condense well to rules of thumb. That is probably why people carry tables with depth of field on them. I printed out 4 tables on 2 notecards with common focal lengths. My idea is to reference these, or study them while shooting in non-pressure situations until I just get more familiar with what focal length/aperture/subject distance give what kind of depth of field. I haven't spent much time on it and it will probably be difficult and take many years. I would think if someone like a wedding photographer who primarily shot with a 35mm and 85mm lens or something like that, might be able to almost memorize the depth of field characteristics for those two lenses, but for zooms.....?


http://en.wikipedia.org/wiki/Depth_of_field ("http://en.wikipedia.org/wiki/Depth_of_field)

[asmodai]

Your best bet for quickies is to commit a few common conditions to memory. As in: "My 50mm at Xpaces at f/x.x provides Xfeet of in focus area, and Xfeet at x+2 paces", for each of your lenses. Once you know those you can wiggle around each memorized point with a few degrees of freedom.








Maybe one day each camera will have a little range-finder and an in-viewfinder display of present DOF size.