Being a long time serious (amateur) photographer, I fully understand f-stops, depth-of-field, hyperfocal distance, focus distance, etc. etc. as it applies to the real world.

I want to use depth-of-field to progressively blur further objects and the background (just like in real-world photography), but what I can't get my head wrapped around is - how can I determine what to set the Focus Distance to.

I Read TFM and it's no help. All it tells you is that the Focus Distance is determined by a 'control object' within the scene and to enter a desired value in the camera's Focus Distance field (the focus_Distance parameter dial for that camera) - What object? What deired value?

My question is - What is the control object, how do I select it and how do I determine what the Focus Distance is?  Any help will be greatly appreciated...

Oh and btw, I'm using P6 and did a quick search but came up blank...

TIA
Walter

Hi Walter, I'm sure thre are more knowledgeable people here, but here's my little help.

1. Go to render setting and check "Depth of Field"  box.

Then select the camera you are using to render, and get the parameter dial displayed.

Set the f stop you like to use, and then move the "Focus_Distance" dial, and pay attention to the screen. When you slide the dial, you will see the cross target mark displayed for a brief moment.

Use that target to select focus point. Default setting for that parameter is rather rough increment, so double click the focus_distance dial and set it to finer increment.

Now, you are ready to render.

If you use wider f stop, it will add considerable amount of time to render, so experiment.

lam2

Thank you lam2. I never noticed that cross target. Displayed for a brief moment is right and it doesn't move as you adjust the focus distance so it's very difficult to set the precise focus point, specially when that point is not directlly under the center or under the cross hairs.

It's better than nothing though...perhaps P7 will have an improvement on this?

Again, thanks for your help.

W.

Display -> Guides -> Focus Distance Guide

Thanks Dizzi - that's much better.

...gotta check those menu items once in while - maybe I'll learn something.

It does sound like you got it all figured out now, but here's a link to a tutorial just in case!

http://trekkiegrrrl.dk/DOFtut1.htm

Thanks a lot everyone - got it all sorted out. Like I said, I'm thoroughly familiar with the real world concept of depth-of-field (and apparent wide angle distortion and telephoto compression, etc., etc.) from my photography days - it's just how to implement it in Poser 6 that had me stumped...

It actually works pretty well.

Again, thanks folks.
Walter

IMHO - A short Camera Z Translation with a large Focus setting is better than Vs Versa, at least for Facial Shots.  Otherwise figures start to look like bottlenose dolphins...

You're absolutely right. A setting of at least 80 to 100 (my pref is 135 to 150) is best suited for portraits. That "bottlenose dolphin" look as you call it is what's known as apparent wide angle distortion where objects close to the camera appear abnormaly large.

Example: - With a wide angle lens (short focal), you have to be pretty close to fill the picture with just the head. The nose might be 4" away and the ears will be  4" further, or 8" away. That's twice as far. So of course the nose will appear abnormaly large. Where as with a large focal setting, you have to back away to fill the frame with just the head. The nose might be 50" away and the ears still only 4" further, or 54" away. That's not much of a difference so the nose and ears will appear the correct size in relation to each other.

I hope this makes sense to you...

you can also use the DOF python script. set units to feet, select camera, select your object, run script. answer is distance to object in feet.

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Where is that DOF script available from?  I just spent an hour looking for it.  I finally found a script, in my P6 > Python > PoserScripts > RenderControl directory, named dof_p5.py.  Is this the script to tell you the distance between you camera and a figure?  I hope not, because when I have the Figure selected; and then set the Document Window and Parameter Palette to Main Camera, it does'nt matter how far I move the camera away, the python always yields a result of 0.0?  I even checked to make sure my Poser Unit of Measure is Feet.

Angelouscuitry,

load an object & make sure it's selected (e.g., its properties/parameters tabs are showing).

usually the preview window is from the Main Camera, but any one will work.

on menu bar, click Window>Python Scripts to open the Python Scripts window.

Click Render IO and then Calc DoF Focal Distance. A window will open that shows the distance to the object in Feet.decimalFeet. You can then use that number for your focus_Distance entry for the camera.

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Thanks, wow, now I can calculate how fast a figure is running at the camera!

BTW - What does DoF stand for?

DoF = Depth of Field, e.g., the zone in front of the lens which will be in acceptable focus for any given focal length, f-stop and focus setting.

The longer the focal length of the lens (300mm) the shallower the zone. The shorter the lens (28mm), the deeper the zone. This is why you should always zoom in to focus and then set your frame by widening the shot, if desired.

The wider open the lens (f/2.8) the shallower the zone. The more stopped down (f/16) the deeper the zone. This is why you should always focus with the lens set to its widest aperture and then stop down to the proper exposure.

The closer the lens is focused (2 feet) the shallower the zone. The farther the focus (40 feet) the deeper the zone.

This is all based upon the Circle of Confusion at the film plane which is an arbitrary definition of sharpness of the image on the film. This is intimately connected to the depth of focus which is related to how all the above combine behind the lens onto the film to provide an image that is "in focus."

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Thanks!