Today's dumb question: Gather Around!

[unpopular]

Do cameras even have a DOF preview anymore? I used this feature extensively when I was shooting film and now that I shoot stopdown.

Certainly the higher end models do, right?

 

[jwbryson1]

My D90 does, but I never use it.

 

[Josh66]

Do cameras even have a DOF preview anymore? I used this feature extensively when I was shooting film and now that I shoot stopdown.

Certainly the higher end models do, right?

Every SLR I have (film and digital) has it. The only cameras I have that don't have it are rangefinders. On those, I mostly just make educated guesses on how far the DoF will extend.

 

[jwbryson1]

I just know intuitively that a larger f/stop (f/2.8) will yield a shallow DOF and a smaller f/stop (f/16) will yield a longer DOF.

Yes. But. How much different and how does the DoF distribution change.

I think it's a very common amateur mistake to consider DoF only in terms of lens aperture, ignoring the several other factors that affect DoF, particularly the focus point distance.

When I shoot, I am always keenly aware of my focus point distance relative to the lens focal length and aperture I am using.

I think this is a very good point, Keith, and kind of goes to my initial comment that I don't really consider the focus point relative to the DOF, and I think this is limiting my shots. Don't get me wrong--I shoot images that are in focus, but I don't consider where the DOF falls in relation to the focus point and I think that makes me less useful of a photographer.

I guess I just always assumed that the DOF fell on both sides (front and back) of the focus point.

So, for example, if I am shooting an image and I have set up my camera for a single focus point through the camera's custom settings, I assume that the DOF starts ahead of that point (between me and the focus point) and ends somewhere beyond the focus point. What am I missing? Do I need to work more on understanding the total DOF and trying to make my focus point fall somewhere near the center of that to maximize sharpness? I think I'm making this too complicated.

 

[Josh66]

It is on both sides. 'Generaly' 1/3 in front, 2/3 behind. This is why on group shots, you want to focus on the nearest person.

 

[Josh66]

If you want to test that, print out one of those focus test charts. When you focus on the 'focus here' line, you will notice that the DoF distribution is roughly 1/3 in front of the line, 2/3 behind.

Longer distances bring it closer to 50/50, from what I have read...

 

[tirediron]

I think I only have two or three lenses left that have DoF scales on them. For most shooting I rely on my experience and mental DoF tables, backed up with a DoF Preview check. For critical work, I have a set of tables on my smartphone and a measuring tape in my bag.

 

[KmH]

More often, the DoF distribution is closer to 50/50 than 33/66.

Put your point of focus on that part of the photo you want sharpest, because at the point of focus (PoF) is the only place (it's actually a plane approx. parallel to the image sensor) in the DoF.

Focus sharpness begins falling off both in front of and behind the PoF, which is what DoF is all about.

Play with numbers using a online or app DoF calculator, like http://dofmaster.com/dofjs.html and pay attention to how the DoF distaribution changes as you alter aperture, focus point distance, focal length, etc.