10D "Depth of Field Preview"

[jerome_yesavage]

I have been workingo n getting maximum depth of field in some tricky

landscapes, e.g. a fence moving from forground to background, and I

do not have an inituitive idea of what the 10D "Depth of Field

Preview" button gives me. Says in the manuel "Press the Depth of

Field Preview button to stop down the aperture and see the range of

acceptable focus in the viewfinded". This is a bit of Greek to me.

Can anyone translat to English?

[gary_ferguson1]

The 10D. like most modern cameras, lets you look through the viewfinder and compose the shot with the aperure wide open. The aperure is the iris-like mechanism in the lens that controls how much light is allowed through. When it's wide open the viewfinder is nice and bright, but the depth of field is very narrow.

 

The Depth Of Field Preview Button closes down the aperure to the actual setting that will be used for the shot. The viewfinder image becomes darker, but the depth of field increases, and it keeps increasing the smaller the aperture gets. The theory is that you can see the actual depth of field that you'll get in the final print by looking at the image in the viewfinder.

 

The problem is that this way of working originated with large format cameras, the big wooden cameras where the photographer works underneath a darkcloth. With a large format camera the photographer is looking at a huge image, maybe 4"x5" or larger, projected onto a ground glass screen. So it's possible to gauge the degree of sharpness directly from the ground glass image. With the tiny 10D viewfinder image it's almost impossible to decide if something's acceptably sharp or not.

 

In truth the stop down button is a fairly impractical feature that's of use to only a very small percentage of photographers. If you're determined to use it then you could try the Canon angle finder with your 10D tripod mounted, this would give you a touch more viewfinder magnification.

[RobertChura]

I find it quite useful. I use an F3,Hassleblad and a 4x5 as well as a 10d and was a key point in getting the 10d over the 300d. It takes practice but it is handy.

[alfred_maragh]

Robert, the 300D does have depth of field preview just like the 10D.

[samusiskin]

I find it useful in certain situations. You can peer through the gloom of a DSLR viewfinder to see a degree of sharpness increase.

 

Robert, I hope that wasn't the only reason you splashed out on the 10D, cos my 300D seems to have a DOF preview button!

 

Cheers.

 

Sam.

[jerome_yesavage]

Very helpful. I actually imagine I can see the difference in the preview, now that I know what I am looking for. I think this will be very helpful in the field.

 

Now, what is the Canon angle finder? One question leads to another...

[melissa_eiselein]

The DOF preview is kind of hard to work with until you get used to it. When you stop down, the viewfinder gets dark. But if you look through the darkness, you should be able to see how much of the scene is in focus. The farther you stop down, the darker the viewfinder and the more depth of field.

 

<p>This depth of field calculator might help you find the right setting to achieve maximum depth of field with your lens and your camera.

 

<br><a href="http://www.dofmaster.com/dofjs.html"> http://www.dofmaster.com/dofjs.html</a>

[wakeforce]

You could also use hyperfocal distance if you have distance markings on your lens...

 

- Focus on the nearest subject, then note the distance of it.

 

- Focus on the farthest subject you have if it isn't infinity then note it too

 

- Find the gap on the distance markings that show how much DOF you want and choose appropriate f-stop to use.

 

For example, say you wanted that everything from a bit more than 3 meters all the way through infinity be in focus, you would focus exactly the way the focus ring is on the attached image and close down to f/11. (Actually, I didn't pay close attention and shifted the infinity mark the wrong way, the middle of the infinity mark should be *inside* the f/11 mark, sorry!) Some people prefer to close down an f-stop more so that their background is more than only "acceptably sharp", but explaining that would need to go a lot farther than this simple post.

 

Hope it helped you! (It also proves me that *I* understand well now!)

[RobertChura]

Sorry all, that wasn't the only reason I chose the 10d.

[mormegil]

Another handy function of the DoF preview button is to startle your subject when you have a Flash with modelling function built in!

 

The flash starts quickly strobing (15-30 hertz?) making a buzzing sound.

[steve_pearce]

<a href="http://www.steve-pearce-photography.com">

www.steve-pearce-photography.com</a></p>

 

<p>Don't forget the A-Dep mode on the 10D with which you focus on the nearest

and farthest points (can't remember in which order) in the composition that you

want to have in sharp focus and the camera then adjusts the point of focus

automatically, also taking into account hyperfocal distance.  This method

has the additional advantage that the aperture actually needed is selected, so

the shutter speed remains as high as is possible to give the depth of field that

you want.</p>