Calculating DOF

[Moriarty]

How do you guys calculate DOF in the field? I'm talking about times when you need a pretty tight DOF window and want to be accurate. I know some of you have applications on a PDA that allow you to calculate this, but I don't have that luxury. I tried to create charts for each of my lenses, but I can't think of a good format for these charts, seeing as how I'm measuring 3 dimensions (aperture, focal length, distance to subject) on a 2D piece of paper, and each point has two values (near and far points of focus). It looks like I'll need to create a set of charts for individual focal lengths (zoom lenses) that plot aperture and distance axes, but that's still messy. What do you guys do?

[robertwgross]

First, I'll have a vague idea in my head of what the depth of field ought to be.

Next, if I am concerned, I'll hit the depth of field preview button.

When I try to teach a beginner, I tell them to think of it as a depth of focus button, even though the proper term is depth of field.

---Bob Gross---

[Bruford]

Here is a link that may help ;)

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

[Tom W]

And one of my favorites:

http://www.liquidsculpture.com/DOF/DOF.htm

Requires Java to run the graphic. Might be a bit heavy for 56K, but I don't know for certain.

[tim]

http://www.dofmaster.com/dofjs.html

Simple, no Java.

[PacAce]

First, I'll have a vague idea in my head of what the depth of field ought to be.

Next, if I am concerned, I'll hit the depth of field preview button.

When I try to teach a beginner, I tell them to think of it as a depth of focus button, even though the proper term is depth of field.

---Bob Gross---

I have to agree with Bob. If you need to know for sure, nothing beats actually seeing it with your own eyes by using the DOF button. Of course, you'd need to have moderately good lighting, especially at the smaller apertures, but a 420ex or 550ex flash with the modelling light would help in low light conditions.

[Scottes]

As for charts, I went here: http://www.johnhendry.com/gadget/dof.php

For a zoom lens I'd pick a set of lengths and print a page for each length. So my 17-40 got something like 17mm, 20mm, 24mm, 30mm, 35mm, and 40mm. I then printed a chart for each length at the full stop apertures,so 4.0, 5.6, 8.0, and so on. For my primes I simply did one page with each full-stop aperture.

The charts ended up being kinda small, which was good, but still easy to read. I then simply cut each out and stapled them together and put the little book into a ziplock so it wouldn't get wet in the field. That fit nicely into one of the flat pockets in my bag.


I never, ever took my little booklet out of my bag. Not once. Not one single time.


I either didn't have time to look up the info, or I had all the time in the world. If I needed maximum DoF but didn't have the time to check the chart I simply set the aperture until I saw the shutter speed reach my max hand-holding ability. If I had all the time in the world then I set up my tripod, took time to compose, set the aperture to f/16 or f/22 and focused on something a little ways into the scene.

Either way it was the best picture I was going to get. So I took it.

[Moriarty]

As for charts, I went here: http://www.johnhendry.com/gadget/dof.php

For a zoom lens I'd pick a set of lengths and print a page for each length. So my 17-40 got something like 17mm, 20mm, 24mm, 30mm, 35mm, and 40mm. I then printed a chart for each length at the full stop apertures,so 4.0, 5.6, 8.0, and so on. For my primes I simply did one page with each full-stop aperture.

The charts ended up being kinda small, which was good, but still easy to read. I then simply cut each out and stapled them together and put the little book into a ziplock so it wouldn't get wet in the field. That fit nicely into one of the flat pockets in my bag.


I never, ever took my little booklet out of my bag. Not once. Not one single time.


I either didn't have time to look up the info, or I had all the time in the world. If I needed maximum DoF but didn't have the time to check the chart I simply set the aperture until I saw the shutter speed reach my max hand-holding ability. If I had all the time in the world then I set up my tripod, took time to compose, set the aperture to f/16 or f/22 and focused on something a little ways into the scene.

Either way it was the best picture I was going to get. So I took it.
Thanks for all of the info guys. This is exactly what I was looking for. I have a feeling that my situation will be the same has yours, wrt the never taking it out of the bag, but I think think it worth going through making them all.

[ron chappel]

http://www.dofmaster.com/dofjs.html

Simple, no Java.
I second this one!:D

[HKFEVER]

Anyone have the DOF formula or calculator in PDA format?:oops:

[aam1234]

Or in an Excel sheet (so I can use it in Nokia Communicator).

[steven]

Anyone have the DOF formula or calculator in PDA format?:oops:

For the palm OS http://www.dofmaster.com/custom3.html

very nice :)

[HKFEVER]

Thank you for your help, how about WIN CE version. But I have a HP PDA.

[Jon]

Jonathan Sachs (http://home.comcast.net/~jonsachs/) has a DOF calculator for WinCE. I used it on my Jornadas and now on my Toshiba e800. It expects you to enter resolution in lines/mm, but we're more used to circle of confusion, which he identifies in the help file as 1/resolution. I believe he's defaulting to a resolution suitable for "normal" 35 mm use, which you can also use for the 1DS Mk II. A theoretical max. resolution for it, using his calculations, is about 70 lines/mm.

[tim]

For the palm OS http://www.dofmaster.com/custom3.html

very nice :)

I just tried it, and it seems to be a real b*stard to use. Even after reading the instructions i'm not sure how to use it.

[Chazs]

My old Olympus lenses had DOF markers on the barrel. I wonder if Canon could incorporate this. The ambitous out there could make up their own possibly.

http://members.isp01.net/snevetsc/photos/dof.jpg
Zuiko 50mm

CHAZS

[Jon]

My old Olympus lenses had DOF markers on the barrel. I wonder if Canon could incorporate this. The ambitous out there could make up their own possibly.
CHAZS
Not all Canon lenses even have a focussing scale, and DoF markings on zoom lenses are very tricky to set up except on a one-touch zoom, since the DoF changes as you change focal lengths.

[steven]

I just tried it, and it seems to be a real b*stard to use. Even after reading the instructions i'm not sure how to use it.
Possibly I don't remember what I had to do to set it up but for using it now you just point at the fstop, the focal length then you have the choice of either entering in a focus length and the display will show the Near and Far in focus lengths (also has a useless graphic scale) or you can hit the Hd button and the dispaly will show what minimum distance you should focus to get infinity for the far in focus length.

But then I am a self described geek and gadget lover so many things appear obvious to me and don't to normal people:o

[tim]

I think I worked it out now - it's a terrible interface. btw i'm a software engineer, I run 4 websites, and I have about all the gadgets I can think of that are worth buying ;)

[kiwimichael]

Bob Wheeler also has quite some info on DOF programs on his site http://www.bobwheeler.com/photo He also has his own program available.

Cheers
Michael

[tim]

That's even harder to use!

[Tom W]

My old Olympus lenses had DOF markers on the barrel. I wonder if Canon could incorporate this. The ambitous out there could make up their own possibly.

http://members.isp01.net/snevetsc/photos/dof.jpg
Zuiko 50mm

CHAZS

My primes (some of them) have DOF markers on the barrel. My older primes do as well (FL/FD mount). Its some of the newer lenses with no distance scale, as well as the zooms that don't incorporate this feature.

Here's the 24mm prime:

http://www.pbase.com/photosbytom/image/38286517.jpg

[dfleming]

I think I worked it out now - it's a terrible interface.

Three taps is all it takes to use the calculator. Tap a button on the left to set f-number, tap a button on the right to set focal length, and tap the scale to set the focus distance. The indicator on the scale shows the near, far, and focus distance.

Tap the HD (hyperfocal distance) button to set the focus on the scale to the hyperfocal distance.

To configure the focal length buttons for your system, use the setup functions on the menu.

[dfleming]

How do you guys calculate DOF in the field?

I use a DOF calculator printed by DOFMaster ( http://www.dofmaster.com/custom.html ). The calculator for a 28-75mm zoom (on a digital SLR) is shown in the link below. Note that the calculator has DOF scales for the 28mm, 35mm, 50mm, 60mm, and 75mm focal lengths.

The scales work in the same manner as the DOF scales on lenses. When the focus index is set to the focus distance, you can easily read the near and far distances for each of the f-numbers. In the picture linked below, the focus distance for the 50mm scale is set to about 10 feet, and the DOF for f/22 is from about 6.5 feet to 21 feet.

Don

[O/confusion]

I use a DOF calculator printed by DOFMaster ( http://www.dofmaster.com/custom.html ). The calculator for a 28-75mm zoom (on a digital SLR) is shown in the link below. Note that the calculator has DOF scales for the 28mm, 35mm, 50mm, 60mm, and 75mm focal lengths.

The scales work in the same manner as the DOF scales on lenses. When the focus index is set to the focus distance, you can easily read the near and far distances for each of the f-numbers. In the picture linked below, the focus distance for the 50mm scale is set to about 10 feet, and the DOF for f/22 is from about 6.5 feet to 21 feet.

Don

Just joined this Forum, and never posted to one before, so please let me know if I'm barging in and not using the right etiquette here.

This looks pretty useful to me, as I mainly use zoom lenses, but does anyone know if there's a similar printable calculator (rotatable wheel-style) available for Mac OSX users like myself?