Aperture : Just Got My Camera!

[campbmic]

Hey guys! I am completely new to this site and new to photography and filmmaking in general. I purchased a Canon t2i and am having a blast learning about it. From what I've heard filmmaking has a lot of its foundation in photography concepts. So Ive decided to start learning as much as I can.

Today I tackled the concept of aperture and wanted to know if I got it right. From my understanding aperture (fstop) has a drastic impact on the field of view.

The lower the aperture the smaller the field of view, objects at various distances from the subject in focus will stay blurred.

The higher the aperture the longer the field of view, and more objects at various distances from the subject in focus will be clear and in focus as well.


Example-
We have three tomato cans at various distances down a table.

Aperture- 1.4f
ISO-100
Shutter Speed- 25



[URL=http://img97.imageshack.us/i/4211083.jpg/]

[URL=http://img828.imageshack.us/i/4211084.jpg/]



Aperture- 10f
ISO- 400
Shutter Speed- 4

[URL=http://img31.imageshack.us/i/4211085.jpg/]


I did notice that when you increase the aperture the picture gets darker, so I had to increase the ISO or slow down the shutter speed in order to compensate for this. Is this normal?

Im planning on taking a look at ISO and shutter speed next. Any tips? Or advice on what I should be looking at afterward?

 

[Theodebernacius]

Now I'm confused again. Does that mean that you can actually obtain a shallower DOF with the 5D than with 35mm film?

 

[chilipie]

Now I'm confused again. Does that mean that you can actually obtain a shallower DOF with the 5D than with 35mm film?

Effectively, yes (if you mean a 35mm MP camera, not stills).

Edit: A visual explanation might help.

A stills camera uses eight perforations per frame - a motion picture camera uses four (or sometimes only three). The arrows show how the film moves through a camera.

 

[knightly]

http://toothwalker.org/optics/dof.html

 

[Cracker Funk]

Just to confuse matters further, it's worth pointing out that while the 5D has a full-frame sensor, a 35mm stills frame is much larger than a 35mm motion picture frame - crop sensor cameras like the 7D and 550D have sensors a closer size to 35mm motion picture film than the 5D.

Interesting. I didn't know that.

BTW -- I meant to mention this earlier -- I googled a little bit for the "circle of confusion" that you mentioned, and I only ended up confused. What is it?

 

[wheatgrinder]

lame ASCII art might help..

       im confused
   +                       +
next                      go to next step for answer
    +                       +
              next

see, its a circle and its confusing..

 

[campbmic]

chickens make me happy

 

[harmonica44]

I don't get it. On my T2i the aperture, does not go any lower than 4.5. And my shutter does not go any lower than 30. How is yours able to?