how to change focus

[ryanjennings]

i have a canon rebel t2i and when im recording videos I want to fix my DOF where I can focus in on different objects in the same frame... when i try it does the entire video I just want to do certain objects in the video

anything I have to change in the settings? sorry for the bad explanation im new to this

 

[RobNZ]

I saw a youtube video on how to do this, I have the t1i and you cant alter the aperture when shooting video either. Lets hope they release firmware to allow this to happen (yeah right!!).

So the method is this ( I have done this myself, but I have no idea if you could possibly cause a fault or damage the body or lens). Set your camera to Av mode, adjust your aperture to get the desired dof and hold the DOF preview button down and disengage the lens slighlty, the aperture should remain as set.

Now go to video mode (you will have to focus manually) and shoot.

This works because the lens has lost sensor contact with the body and the camera can no longer control the lens.

As I said before you may risk damaging something, somebody with more experience may be able answer that one perhaps?

 

[RobNZ]

Or if I misread your post (DoF comment) may have thrown me off there.

You have a couple ways of adjusting your focus, I usually use manual focus combined with live view at 10x to make sure what I actually want in focus is. Or use the centre point on the area desired with auto focus ( I use quick mode) and then recompose and shoot/film.

 

[Dao]

Are you trying to shoot a video so that only the main subject is in focus while other objects in the background are out of focus?

 

[ryanjennings]

yes Dao

 

[Dao]

Then you need to understand more about Depth of Field (DoF) and what affects the DoF.

i.e. Depth of field - Wikipedia, the free encyclopedia

 

[ryanjennings]

do different lenses get better DoF? I'm trying to get a a better DoF with a few feet from the subject.... seems like with the stock lense I have with my canon t2i I have to be right against the subject.. or is this usually the same with every lense?

thank you