Can't adjust the F-stop on Canon T1

[krslnguyen]

Hi guys,

I'm a newbie at taking pictures. I took my daughters out today at the park and I set my Canon T1 on AV mode , and use 18-55mm lemse, the lowest setting the camera allow me to set for F-Stop is 4.0 . I'm not sure why I can't adjust lower setting for F-Stop and the pictures didn't turn out
well. Could any body please explain ?

Thank You,

Rose

 

[Vtec44]

Possibly that's the max aperture opening for the focal lenth?

 

[MLeeK]

Would that be the T1 or the T1i? The T1 is a film camera... The T1i is digital.

You were using the zoom on the lens. If you zoom in the lowest possible aperture changes from f/3.5 at the widest to f/5.6 when fully zoomed.

 

[krslnguyen]

sorry it was the T1i the digital SLR .

I forgot to say, when I set on AV mode, F-stop F4 , the meter is at 0 in which my photography teacher said you should always try to set the meter at 0 exposure, but the pictures didn't turn out nice.

 

[MLeeK]

sorry it was the T1i the digital SLR .

I forgot to say, when I set on AV mode, F-stop F4 , the meter is at 0 in which my photography teacher said you should always try to set the meter at 0 exposure, but the pictures didn't turn out nice.

Theoretically you want your meter to be at 0. However you have to know what your meter is doing and what it is trying to make 0 out of before you can get a good exposure.
You also have to understand the metering modes and what your meter is looking at to determine exposure.

Your meter is trying to make 18% or middle gray. It doesn't see your scene or child or anything. It sees the light and dark only. Imagine your scene in grayscale.
Your camera is trying to make that grayscale scene average out to middle gray or roughly this brightness:

The different metering modes determine what the camera is trying to make that shade of light to dark.
Spot metering only measures what is in the center spot on your camera. It can work well if you can imagine the scene in light to dark and are able to know what you'd like to be about that brightness.
Center weighted average takes into account all of the scene or all of the pixels. It averages them all out, but then makes the ones in the center more important or like a weighted test that counts more than maybe homework does.
Evaluative metering evaluates the whole scene and tries to average it out to middle of the road.

If you are taking a photo of a person-skin is not middle of the road. It's lighter. If you are outside grass is often a good middle of the road.
A gray card can be handy for setting exposure because it's 18% gray-middle of the road. You simply place it where you are shooting, meter, set up your camera and it should be accurate.

There is more to metering, but that comes with time shooting and getting to know more about your style and what you need. That will give you a good idea of where to start and how to get things a little closer to good!

 

[scorpion_tyr]

Exactly what MLeeK said! I'll add this. Your lens is 18-55mm (focal length range) and 1:3.5-5.6 (aperture range). Replace that "1:" with "f/" and it might make a little more sense. At 18mm of focal length you can open the aperture all the way up to 3.5, but as you zoom in your maximum aperture will decrease until somewhere slightly before 55mm it hits f/5.6 as the largest aperture you can reach. There are lenses out there that will maintain a constant maximum aperture such and they will look like this "28-75mm 1:2.8" which means it will open up to f/2.8 at 28mm or 75mm. They are usually more expensive... but so worth it!