DoF question

Captain IK · Jan 31, 2009

Is there a way to determine the "depth" of the depth of field in a given shot?
For example:
If I set my focus point at say 10' at f2.8...is there a way to know in advance what range will be in focus...from 8' to 12' or 9' to 11' etc.

puyjapin · Jan 31, 2009

Hi, not that im aware of but it would be useful to know anyway ! I mean if the viewfinder showed what the result would be it would be handy!!

Captain IK · Jan 31, 2009

I do have depth of field preview so technically you can see it there, but it is pretty hard to view accurately through the viewfinder.
I thought perhaps someone knew of a formula or had a mathematical table of sorts.

Katier · Jan 31, 2009

Yeah, buy a Yashicamat .. job done

Not kidding either, the focus dial includes a depth of field gauge that is very nifty.

puyjapin · Jan 31, 2009

wots one of them then? does it work with any DSLR?

Phranquey · Jan 31, 2009

Online Depth of Field Calculator

Captain IK · Jan 31, 2009

Just found a depth of field table...Online Depth of Field Calculator

sultan · Jan 31, 2009

All manual focus lenses have depth of field markings on the lens. Get one

P.S. Determining the DOF is actually very subjective, because you have to decide if you consider something in or out of focus. Its not like it's perfectly sharp inside the markings and totally blurry outside; it's actually a gradual transition. Its like looking at a black to white gradient and deciding where it switches from black to white. There is no fixed point, really it just goes through various shades of grey.

Katier · Jan 31, 2009

puyjapin said:
wots one of them then? does it work with any DSLR?

*chuckles* Yashicamat is a 50 year old Twin Lens Reflex camera.

Captain IK · Jan 31, 2009

sultan said:
All manual focus lenses have depth of field markings on the lens. Get one

P.S. Determining the DOF is actually very subjective, because you have to decide if you consider something in or out of focus. Its not like it's perfectly sharp inside the markings and totally blurry outside; it's actually a gradual transition. Its like looking at a black to white gradient and deciding where it switches from black to white. There is no fixed point, really it just goes through various shades of grey.

If all manual focus lenses have DoF scales, but Dof is subjective...what do the lens manufacturers use as a bench mark?.

BTW..I have several manual focus lenses and none of them have DoF markings...they have distance markings, but that is not the same thing.

Captain IK · Jan 31, 2009

I stand corrected, my manual lenses do have a DoF scale.

dxqcanada · Jan 31, 2009

I am not sure why but most Photographic equipment Manufacturers have removed the DoF markings on their lenses.

Almost all manual focus lenses had DoF markings on them ... but they did not do the same for auto focus lenses.

I know Canon started doing this after they built in a camera function to calculate this for you by using the AF sensor (focus on foreground then focus on background ... camera calculates the aperture).

I am not sure which camera's currently have this type of function (my Sony does not ... but it does have Stop Down, which I use frequently when shooting Macro shots).

I liked the DoF markings ... I use this to set manual focus at the Hyperfocal distance and just shoot.