Depth of Field Preview

[Deep5]

Hi all,

I wanna ask a mebbe quite stupid question

What is Depth-of-Field Preview button used for? I read in my camera's manual that it is to confirm the depth of field through the viewfinder

But when i see through my viewfinder, i see no difference from the view i saw before i press the button.

Thanx for any reply,

Deep5

[darkness]

DOF preview steps down the aperture to the size you selected to let you see the DOF.

If you choose the maximum aperture, the DOF preview does nothing becoz the aperture is opened at full wide all the time when you are composing.

As a test, try using aperture priority mode and set a small apeture (f/11, for e.g.) and press the DOF preview button. You should see the viewfinder go darker.

[Deep5]

Ok, I see

When the view gets darker it is because the aperture size becomes the same as the setting. Then there is less light coming through the viewfinder becoz the hole size is smaller.

But then what use is this function for?
Everything i saw after i press is as blur or clear as before i press the button?

Is my equipment not up to standard or is there something I should focus on when I see through the viewfinder?

Btw, Thanx alot for ur reply

[YSLee]

Depth of field preview previews the depth of field. Sorry, couldn't resist.

*hides somewhere*

[Deep5]

LOLz..
Sorry lor... newbie question...

[darkness]

Maybe you can try this:

- focus on an object close to you (but not too close until cannot focus lah!), but make sure you can see another object in the background, but out of focus due to shallow DOF
- now press the DOF preview, see if the background comes out more focused (but darker overall)

[Deep5]

finally understand
thx a lot