Depth of field function

Cuervo79 · Apr 28, 2004

Hi, I have a Canon EOS 500N (rebel in the US) I use mostly the manual function or the P (when I´m not interested in control) but I've never used the depth of field option, and I´ve lost the manual. could anybody explain it to me? I have 2 zooms a 35-80 4.0-5.6 and a 75-300 4.0-5.6.

ltrz

markc · Apr 28, 2004

Do you mean setting the aperture (which affects DOF)? You can set it in manual mode, but I usually shoot in aperture-priority (Av) mode and let the camera pick the shutter speed. The smaller the number, the bigger the aperture and the less in focus.

With a max aperture of only f4.0 (smaller number = bigger aperture), you won't be able to blur the background out much (like you could with f1.8 ). What you see in the viewfinder is it. You can use the DOF preview function to see what it would look like with smaller apertures (more in focus).

cypilk · Apr 28, 2004

wait..changing the aperature changes the depth or something?

cypilk · Apr 28, 2004

and change the focus?..i mean blur and everything? how!!!

Cuervo79 · Apr 28, 2004

Well its not exactly what I´m asking, I know how to control the depth of field manualy, thepth of field Cpylk is when you see a photo of a portrait outdoors and the subject is focused but the background isn´t, I know a 4.0 aprerture isn´t all that, but it still kinda workx, what I meant is that in the functions bejind the M and before the Roll rewind ther is a D-field option wich when I read the Elan7 features says that it automatically works it out for you, that is what I mean.... (I´m not sure if it says D-field or not, don´t have my camera here)

markc · Apr 28, 2004

Ah. There's one where you can press the shutter a couple of times so that the camera picks the correct aperture so that both points you focused on are in focus. On the EOS cameras I've had, it's labeled DEP and is on the function dial.

There is also a DOF preview option that will stop down the aperture so that you can see what you are getting. That seperate and I think enabled with a custom function. I don't have my manual handy at the moment.

drlynn · Apr 28, 2004

Mark's right. On my Rebel it's labeled A-Dep, and basically you tell it which two points you want to be in focus, and it automatically sets the aperture needed.

I've never used it, so if you try it out, let us know how well it works.

ksmattfish · Apr 28, 2004

cypilk said:
and change the focus?..i mean blur and everything? how!!!

depth of field: The distance between the nearest and farthest points in an image that appear in acceptably sharp focus. DOF is controlled by aperture, focal length, and focusing distance. Larger apertures (low f/#) have less DOF than small apertures (higher f/#). A wide angle lens will have more DOF at any given aperture than a longer focal length lens at that same aperture. DOF decreases as camera to subject distance decreases.

copied from the handy FAQ for newbies at the top of this forum. If you've never heard of DOF then there is all sorts of good stuff for you here:

http://www.thephotoforum.com/forum/viewtopic.php?t=3362

Cuervo79 · Apr 29, 2004

So its just as simple as selecting the A dep function focus both points and shoot? sadly my 500N doesn´t have DOF preview option... anywayz I will be experimenting with it... ltrz