Create your own customised DOF chart


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roygoh

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Hi,

Came across this website with a lot of technical information on DOF an some intersting and useful programs.

The DOF Master program for Windows allows you to create your own DOF chart. The chart consist of 2 concentric disks with the aperture scale on the inner disk and the distance scale on the outer disk. You can customize and create different charts for different focal lengths and film/sensor formats.

Try it for yourself!

http://dfleming.ameranet.com/

- Roy
 

isxzz

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just checked out the web site......!!

it's a very good recommendation. just the thing i need right now. thousand thanks:thumbsup:

but look abit cheem, leh....!!! :embrass:
 

roygoh

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isxzz said:
just checked out the web site......!!

it's a very good recommendation. just the thing i need right now. thousand thanks:thumbsup:

but look abit cheem, leh....!!! :embrass:
Don't have to fully understand the mathematical calculations. Just understand the definition of DOF and Hyperfocal distance should be good enough. Try the DOF charting program. It is great.
 

jasonpgc

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roygoh said:
Hi,

Came across this website with a lot of technical information on DOF an some intersting and useful programs.

The DOF Master program for Windows allows you to create your own DOF chart. The chart consist of 2 concentric disks with the aperture scale on the inner disk and the distance scale on the outer disk. You can customize and create different charts for different focal lengths and film/sensor formats.

Try it for yourself!

http://dfleming.ameranet.com/

- Roy
roy,

I have some questions about this chart,

Take for example,
I set the focal length to 28mm - 200mm, min distance to 1m and max distance to 50m. Circle of confusion for 0.030mm. max aperture=f1.8 min aperture=f32. The Distance unit is in Meters.

Note: I am looking at the diagonal line of f2.8 intersecting Focal length 28mm.

1) I notice that no matter how I change the min or max distance, the f2.8 line always intersect the 28mm line at 9.3m. Meaning, the intersection point is a constant.

As far as I know, if the Min distance refers to the nearest subject in DOF and the max distance refers to the furthest subject in DOF.

And if the intersection point of the Focal Length and Aperture is where you should focus to have the DOF covering the Min and Max distance, It should never be a constant value.

2) If the above understanding is wrong, then where I should Focus to achieve the DOF required for the min and max distance?

3) If the min and max distance is not indicating the range of the DOF intended, then where should I refer to for the min subject distance in DOF?

:dunno:
 

jasonpgc

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Ok I figured it out liao :D

This Chart is only valid if you set your focus to infinitiy. As such, the Intersection point is your min Distance covered by the DOF.

The Min and Max distance variable indicated by the program is only for display only, it is not a part of its calculation.

Strictly speaking, this is a DOF chart at Focus=Infinity for various focal length. It cannot be consider a hyperfocal chart because it did not vary the focus distance to maximise the use DOF of the len of a specific aperture :dunno:
 

roygoh

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jasonpgc said:
Ok I figured it out liao :D

This Chart is only valid if you set your focus to infinitiy. As such, the Intersection point is your min Distance covered by the DOF.

The Min and Max distance variable indicated by the program is only for display only, it is not a part of its calculation.

Strictly speaking, this is a DOF chart at Focus=Infinity for various focal length. It cannot be consider a hyperfocal chart because it did not vary the focus distance to maximise the use DOF of the len of a specific aperture :dunno:
:bigeyes: Yes I am confused by your statement. Sorry I don't think you have figured it out yet! :D

The chart you referred to is the Hyperfocal chart, not the DOF chart.

The Hyperfocal chart tells you the hyperfocal distance for a lens of particular focal length and aperture.

For a 28mm lens set to aperture f/2.8, the hyperfocal distance is 9.3m, meaning that if you set the focal distance to 9.3m, everything from 4.65m (9.3/2) to infinity will be in focus.

The Hyperfocal chart, according to my understanding, is a DOF chart with the max in-focus distance set to infinity. It is mainly used for landscape photography when most of the time you are concered about getting objects from a certain distance until infinity to be in focus.

Your last staement is probably referring to the DOF chart itself. In that case you should use the DOF Master progra, where it tells you the in-focus max and min distance base on lens focal length, aperture and focal distance setting.

http://dfleming.ameranet.com/custom.html
 

jasonpgc

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roygoh said:
For a 28mm lens set to aperture f/2.8, the hyperfocal distance is 9.3m, meaning that if you set the focal distance to 9.3m, everything from 4.65m (9.3/2) to infinity will be in focus.
roy,

I've tested the DOF master Program (The Double Disk one), its working pretty fine. http://dfleming.ameranet.com/custom.html

I've tried the "hyperfocal chart" as well. It does not work according to your interpretation above. http://dfleming.ameranet.com/charts.html

Here's how I think it should be interpretated,
For a 28mm lens set to aperture f/2.8, the hyperfocal MINIMUM distance in DOF is 9.3m, meaning that if you set the focal distance to INFINITY, everything from 9.3M to infinity will be in focus.

Here is part of the DOF chart of a 28mm F2.8 lens provided by canon

Aperture=f2.8, Focus Distance=inf, ND=8.25m, FD=Inf
Aperture=f4, Focus Distance=inf, ND=5.89m, FD=Inf
Aperture=f5.6, Focus Distance=inf, ND=4.18m, FD=Inf
Aperture=f8, Focus Distance=inf, ND=2.97m, FD=Inf
Aperture=f11, Focus Distance=inf, ND=2.12m, FD=Inf
Aperture=f16, Focus Distance=inf, ND=1.51m, FD=Inf

In the "hyperfocal Chart" the intersection distance of various "aperture vs focal 28mm" is somewhat close to the Canon's ND(Near Distance) value. This make me believe that the Focusing distance for the chart was fixed at Inf.

A proper hyperfocal chart should be giving you a variable focusing distance instead of a fixed one. Meaning, to get the MIN hyperfocal distance to Infinity for 28mm set to f16. The Chart should be asking me to focus at 2m, so that anything from 0.9m to inf will be in DOF. Sad to say. The "hyperfocal chart" is not able to do that at all. By asking me to focus at inf, 0.6m of usable DOF is wasted at f/16.
 

roygoh

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#9
jasonpgc said:
roy,

I've tested the DOF master Program (The Double Disk one), its working pretty fine. http://dfleming.ameranet.com/custom.html

I've tried the "hyperfocal chart" as well. It does not work according to your interpretation above. http://dfleming.ameranet.com/charts.html

Here's how I think it should be interpretated,
For a 28mm lens set to aperture f/2.8, the hyperfocal MINIMUM distance in DOF is 9.3m, meaning that if you set the focal distance to INFINITY, everything from 9.3M to infinity will be in focus.

Here is part of the DOF chart of a 28mm F2.8 lens provided by canon

Aperture=f2.8, Focus Distance=inf, ND=8.25m, FD=Inf
Aperture=f4, Focus Distance=inf, ND=5.89m, FD=Inf
Aperture=f5.6, Focus Distance=inf, ND=4.18m, FD=Inf
Aperture=f8, Focus Distance=inf, ND=2.97m, FD=Inf
Aperture=f11, Focus Distance=inf, ND=2.12m, FD=Inf
Aperture=f16, Focus Distance=inf, ND=1.51m, FD=Inf

In the "hyperfocal Chart" the intersection distance of various "aperture vs focal 28mm" is somewhat close to the Canon's ND(Near Distance) value. This make me believe that the Focusing distance for the chart was fixed at Inf.

A proper hyperfocal chart should be giving you a variable focusing distance instead of a fixed one. Meaning, to get the MIN hyperfocal distance to Infinity for 28mm set to f16. The Chart should be asking me to focus at 2m, so that anything from 0.9m to inf will be in DOF. Sad to say. The "hyperfocal chart" is not able to do that at all. By asking me to focus at inf, 0.6m of usable DOF is wasted at f/16.
Still disagree...

My interpretation of hyperfocal distance is from here:

http://dfleming.ameranet.com/hyperfocal.html

Hyperfocal distance is fixed for any focal length and aperture. When the focal distance is set to the hyperfocal distance, the DOF extends from 1/2 the hyperfocal distacne until infinity.

Lets compare the Canon DOF chart with the hyperfocal chart provided the website.

From the Canon table, for a 28mm lens at f/2.8, if you focus the lens to infinity, then the DOF extends from 8.25m to infinity.

From the hyperfocal chart, for a 28mm lens at f/2.8, if you focus the lens to 9.3m (the hyperfocal distance), the DOF extends from 4.65m to infinity.

I don't see any disagreement between the 2 sets of data. You get more DOF by focusing the lens at the hyperfocal distance than focusing the lens at infinity.

Setting the focus to infinity does not maximize the DOF, but setting the focus to the hyperfocal distance does.

I don't see why a proper hyperfocal chart should give a variable focus distance. That is not the defnition of hyperfocal distance.

I think you have misunderstood the definition of hyperfocal distance, and mixed up the concept of DOF chart versus hyperfocal chart. ;)
 

jasonpgc

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#10
Roy,

You're right. Since Hyperfocal Range always stretch to inf, it should always be a fixed focus hyperfocal distance for a particular focal length and aperture. Thanks for clarifying. I really got mixed up between a DOF and a hyperfocal chart :bsmilie:
 

roygoh

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#11
jasonpgc said:
Roy,

You're right. Since Hyperfocal Range always stretch to inf, it should always be a fixed focus hyperfocal distance for a particular focal length and aperture. Thanks for clarifying. I really got mixed up between a DOF and a hyperfocal chart :bsmilie:
:thumbsup: :cool:
 

myloplex

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#12
really good stuff here.. but the big question is anyone put it to the test on your xxmm lense ?
:)
 

willyfoo

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I used to have one that is done in excel... thus can use on my pocketpc when I'm on the move... anybody knows where to get this?
 

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