Depth of field preview: what's the point?

[hugy789]

My camera, the nikon D40, has a depth of field preview button but most call it the shutter button so my question to you is this: what is the point of the depth of field preview button when you can just press the shutter to see the depth of field?

There are also advatages to using the shutter over the depth of field preview button
ie: It is under-exposed and if you, for some strage reason, like to see it under-exposedthen you can just dial that in on the exposure compensation.

Please correct me if i have any spelling mistakes, thanks in advance

[jprime84]

useful info here

[dcclark]

I would say, in a board sense, that the DOF preview button was much more useful on film cameras -- when you couldn't instantly preview the results.

[Murtasma]

Depth of field and exposure are totally unrelated. Pressing the DOF button will tell you nothing about your exposer. What it will show it is what will be in focus when you decide to take a picture.

Sure you could sit back and guess what aperture you should use and perhaps get pretty close. Take the camera down from your eye, check the screen, cover the screen to avoid any harsh glare from the sun, zoom into the image to determine where the depth of field falls off, select a new aperture you may think will give you enough depth of field and try the process over again.

Or you can compose your image, hold down the depth of field preview button, adjust your aperture and watch the view finder to see what will be in focus. Once you find the aperture you wish to use release the button and press the shutter.

This is a much faster process then relying on your LCD screen to show you what will be in focus and what won't be. If you are attempting to photograph a bug on a flower you will have much more luck using your depth of field button instead of juggling your camera around to figure out what aperture will give you enough depth of field.

You can also bring around a depth of field calculator, expo imaging has a really nifty one that will let you know how much depth of field you have given a certain subject distance and focal length you are shooting at.

There are other uses for the depth of field button as well such as discovering distracting elements, hot spots, dark spots, vignetting, graduated filter placement, compositional aid, lens flare ect.

It can be a very powerful tool if you practice using it, learn to read what the view finder is telling you. It's much quicker then relying on your LCD screen in certain situations.

[hugy789]

Thanks, that clears things up and my camera dosn't actually have a depth of field preview button, i was just saying that for the shutter refrence

[Murtasma]

I don't follow Nikon gear but I'm shocked the D40 has no depth of field preview button.

[dcclark]

Originally Posted by Murtasma

I don't follow Nikon gear but I'm shocked the D40 has no depth of field preview button.

The D40 is really aimed at people who probably wouldn't know what to do with it anyhow -- it's intended to be easy and fast, not feature-packed. However, I also don't miss it at all.

[Murtasma]

The Rebel XTi has a depth of field preview button and mirror lockup. This is the entry level for DSLR's on the Canon side. I wonder why they they decided to leave it out, not like something like this is an issue at all to implement into a camera.

[vandergus]

I wonder why they they decided to leave it out

Because they're cheap bastards. And what about bracketing? What is that like three extra lines of code in the software. I don't need a button, just put it in the menus.

Alright, done bashing my camera. I like it... I really do.

[inkista]

Hell, the Canon XS has a DoF preview button. But as to why Nikon left it out of the D40/D60, it's probably for the same reason Canon left the infrared remote sensor off the XS: to make the camera mechanically simpler and therefore cheaper to produce. Entry level cameras are expected to have fewer features. I'm also surprised that Nikon left mirror lock-up out and focus motors and stop-down metering with manual lenses but then Nikonians are surprised we Canonites can't master remote flashes with our pop-up flashes or directly mount old manual focus Canon lenses. It all depends on your POV.