Post Your Depth of Field Settings
 

Since the last topic was cluttered I thought I would go ahead and post my settings here for the person who asked how.

Set: My office
Camera: XL1S
Lens: 16x stock
Lighting: A couple of overhead Florescents and two floods from overhead and off to the side.
Near Subject/Distance: Coffee Cup/ 4ft.
Far Subject/Distance: Reading glasses/ 7ft.
Percentage of subject to background 25-50% (how much filled the frame)

Camera Settings:
Manual Mode
ND Filter (off)
Gain 0% (not auto)
F stop 1.8
Auto Focus (off)
Shutter Speed 1/60

Using these settings I easily can zoom front to back or visa versa and focus in on the subject I want leaving the rest blurred creating a very nice Depth of Field Effect.

If you have had success with different subjects (distances) and camera settings feel free to copy and paste my settings above then insert your values as a reply.

Great Forum!
I think I'll call it home for now :-)

I've had good depth of field results when shooting through a patterns such as a field of long stalks (grass, flowers) or through a fence.

BobKloss:
Do you have a picture that you can post so we can have a visual reference?

Bob I had similair results with your settings. A short DoF works
best when i zoomed in the furthest possible.

You can also find some helpful information on how you can create a shallower depth of field using Neutral Density (either the built-in ND on the IS and M/S lenses or via filtration).

http://www.dvinfo.net/articles/production/berube1.php

Look for the image samples at
http://www.dvinfo.net/articles/production/berube2.php

Some tips:
1) use a wide open iris setting
- Use ND to cut down on light entering the lens if needed.
2) Place the subject further away from the background
3) Position the camera further away from the subject and zoom in

Keep in touch,

- don

Nice work, Don!

Technically, The Widest aperture (ie lowest number) will always give the least depth of field.

The shutter speed, amount of gain etc. should be down to personal taste

you may find turning down the sharpness will also help make background objects less disinguishable.


This is from my experience as web & multimedia student at university. If anyone has any information/experience contrary to the above, I'd be interested to hear it.

just found the 6 page thread also on this topic!

Don:

I agree with all the parameters except the last: placing the subject further from the camera and using a long focal length. This is a very tricky bit of business, something I have often wrestled with on set. Yes, longer focal lengths tend to have shallower depth of field, but a deeper (more distant) focus setting on that lens will have greater depth than a closer focus setting. And to maintain the same image size, one has to move the subject further away from the camera (deeper focus).

I just spent some time with my PCam software on the Palm, and was a little baffled to find that from a wide lens to a telephoto lens, given the same image size and f-stop, the depth of field stays virtually constant. Here are some figures:

Format: 35mm f/stop: 2.8 Image size: medium close-up.

25mm, distance to subject 2'6". Near focus: 2'4". Far focus: 2'9".
50mm, distance to subject 5'. Near focus: 4'10". Far focus: 5'3".
100mm, distance to subject 10'. Near focus: 9'10". Far focus: 10'3".
250mm, distance to subject 25'. Near focus: 24'10". Far focus: 25'3".

You can see that in each case, the depth of field is 5".

The program gave me the distance to subject measurements based on a fixed image size, it actually never occurred to me that it was as mathematically linear as that! Let alone the consistent depth of field measurement...

This is all sort of a revelation to me, having always just gone by feel. Someone else check my math, let me know if I am missing something!

I don't mean to sound like a smart *ss, but you've just proved the Reciprocity Law. The photographic effect that is independent of either time or intensity as long as the product of the two remain constant. As one increases, the other decreases. If you cut your image size in half, the depth of field should double, if the other factors stay the same.

Jeff

My head hurts! But I think it understand. So... the distance in
which something is focused more or less stays the same, but
the place were it starts and ends changes?

Let's use Charles' example and data.

100mm, distance to subject 10'. Near focus: 9'10". Far focus: 10'3".

100mm, distance to subject 20'. Near focus: 9'8" . Far focus: 10'6".

By making the subject half the size (by doubling the distance from 10 to 20 feet) the depth of field will double.

The same results could be obtained by changing the lens rather than moving the camera.

100mm, distance to subject 10'. Near focus: 9'10". Far focus: 10'3".

50mm, distance to subject 10'. Near focus: 9'8" . Far focus: 10'6".

By making the subject half the size (by changing the lens from 100mm to 50mm) the depth of field will double.

Jeff

more thoughts
 

I just returned from seeing "city by the sea". It had a lot of nice shots (dof) but wasn't that good of movie, unfortunatly. Anyway,
I wanted to try to replicate some of the scenes (indoors) I noticed right away that my previously posted settings were just fine for a coffe cup but...

When using the same settings I cant get an actor into the scene without using the whole frame. So, to that extent I guess there is a problem with the xl1s and the standard lens (16x) and DOF.

I wish I had canons indoor lens (3x) to try out. Maybe some one who has it will read this and try it with my settings or come up with some of their own and report back to us.


Rob Lohman and Don Benrube, I personally don't see any difficulty with shooting the types of frames as shown in Don's examples. (beutifull work by the way, Don) The subjects are at long distances from the background.
I would think of that as a large DOF. I think for the most part that the issue here is coming up with short DOF as in a short background or distance from the subject to the background and being able to blur the background without distorting the subject.

Lets say we have a mob of demostrators as an example in the foreground as the subject and another group opposing the demonstrators
(in idealogy) directly behind them. Can we then blurr out from one to the other when we focus? A short DOF. Maybe not with the XL1s and the 16x lens.

We can easily have good DOF when focusing in on a face (extremly zoomed in) from one group to the next but probably not when zoomed out.

I dont think that this has to do with the zoom. In fact, when you think about it it simply has to do with the difference in distances the camera is from the subject and background (or foreground) Without looking at any math books common sence dictates that

distance from background-distance from subject=DOF

Lets try it-

background is fixed at 100yrds. So we will keep it at "A"=100, OK?

Distance from subject is 50yrs. So say "B"=50, OK?

So we get 100-50=50 DOF (just for an example)

Now, using those settings the subject is taking up half the frame (chest and head)

So, if we change the distance from subject, say to 100yrds then we must zoom in to keep the subjects chest and head using half the frame.

So what this amounts to is, a distance of 100yrds to the subject with full zoom is the same as the distance of 50yrds to the subject with no or less zoom.

So the zoom probably amounts to nothing more than changing values of the distance to subject. Actually, it is changing the values of the distance to background but, at a lower rate. Let me explain.

No zoom= distance to subject 50yrds, distance to back ground 100yrds.

Full zoom=distance to subject 1 yrds, distance to back ground 51 yards.

Zoom has changed distance to subject by a factor of 50 but has only changed the distance to background by a small factor of about .5.

So, this ruins our DOF. Why? Because when we,,,

OH Shit! this is just beoming more of the math dribble I was trying to avoid. Or is it? Is this helping anyone? I dont know so Im going to stop unless asks to talk about it more or wants to show me that Im all wrong so far or wants to come up with an easy way to explain their findings.

Depth of Field is a subject that I have to struggle with all the time. It is one of the hardest concepts for my students to grasp (I teach photography). But DoF is a mathematical formula. Formulas are nice for figuring out the charts and all. But the trick is to put it into words that everyone can understand. The thread *What effects Depth of Field * http://www.dvinfo.net/conf/showthread.php?s=&threadid=2452&perpage=15&pagenumber=1 has the formulas for DoF on page 5 and my post on page 4 has the factors that affect DoF. DoF is governed by Laws of Physics. It's not something that we have made up or just agreed to as a group. Charles' Palm just does the math. He inputs the parameters and it states the DoF. Things like filters, gain, exposure mode, distance to the background are a means to an end. They help the photographer control DoF (make it less apparent), but they are not one of the variables in the DoF formula. The diaphragm opening (effective aperture, not F-number) is part of the DoF formula. But how do you get a large opening (small numerical F-number)? The diaphragm will open to let more light in. An open diaphragm will reduce DoF. The use of a neutral density (ND) filter will reduce the amount of light, thereby forcing the diaphragm to open and reducing the Dof.

Jeff

Small F-number
 

Jeff,

Thank you for taking the time to correct me on that. I was thinking about it backwards. Smaller number less light.