Depth of Field for Dummy's

[glorybound]

Okay, I still don't get it!

Let's say I have a room that is 30 feet long and I want the foreground (within 2' from the camera) to be blurry. What do I do? How do I control the intensity of the blur?

I would like to stay inside V-Ray so let's not consider post being an option. Is my target that 2' and I lower my f-stop and compensate with my shutter speed? I would like everything part the 2' to be in focus and everything before the 2' to be blurred. With trial and error I can accomplish this, bu I would like to understand the science so it isn't so time consuming.

[JeffG2]

Use this.

http://think.maxwellrender.com/dof_cue_tool-111.html

[JeffG2]

F 1.4
Shutter speed 4000
Focal distance 5m

To reduce blur, lower shutter speed and raise f-stops to compensate.

[Crayox13]

Hm, since when does the shutter speed have anything to do with DOF? Motion blur, ok, but DOF???

[dlparisi]

Hm, since when does the shutter speed have anything to do with DOF? Motion blur, ok, but DOF???

These should really be reversed... "To reduce blur, raise f-stops and lower shutter speed to compensate". i.e., a higher f-stop will reduce blur but will stop down the image (darker).

[glorybound]

is this all based on a ISO of 200? If my scene is dark can I raise the ISO to compensate?

[JeffG2]

Actually I was thinking in terms of 100.

Yep - you can raise the ISO.

[Crayox13]

Why do you guys use exposure? Isn't it just a nuisance? Unless you are doing a photo match or something. I usually disable exposure, only use f-stops for DOF.

[glorybound]

great script!
http://goo.gl/nrFu (at the bottom of the post)

[glorybound]

if I need a shutter speed of 1/250 I place a 250 in the shutter speed field. What do I put the the shutter speed field if I have something like 1 second?

[dlparisi]

if I need a shutter speed of 1/250 I place a 250 in the shutter speed field. What do I put the the shutter speed field if I have something like 1 second?

1 (1/1 = 1 second)

[stef.thomas]

1 (1/1 = 1 second)

0.5 = 2 seconds, etc....

[glorybound]

what about going into minutes? My FotoSharp chart tells me that if I were to take a photo of an aerial fireworks then I can use:

ISO = 100
f/Stop = 45
Shutter Speed 4 min

[CA Portugal]

This is a nice exposure tool:

http://www.dpreview.com/learn/?/key=exposure

[dlparisi]

what about going into minutes? My FotoSharp chart tells me that if I were to take a photo of an aerial fireworks then I can use:

ISO = 100
f/Stop = 45
Shutter Speed 4 min

enter ".25". 1/.25=4 seconds