question about my aperture..

[Sontizzle]

i have a rebel xti with the stock 18-55mm lens and i can only go down to a F4 aperture. is it because of my lens or the camera only supports F4 and up?

 

[lifeafter2am]

Lens.

 

[John_Olexa]

Yes, it the lens. Any camera will only go down as far as the lens allows. If you get a 2.8 lens then you will be able to go to 2.8

 

[That One Guy]

lens determines aperture amount

example

70-200mm f4

the "f4" is f4.0. that is the largest aperture for that lens.

1 more example

50mm f1.8

f1.8 is the largest aperture value for the lens.

hope that helps :thumbup:

 

[Shibby!]

In other words, your lens restricts the light. Larger the opening, the lower the F-stop. Vise versa for higher f-stops.

The kit lens is great for the price, but if you're into shooting moving objects (sports, etc), or want a more crisp image, an upgrade is required.

I bought a 70-200 F2.8 L lens, and although I hoped for more sharpness, the speed is what surprises me. I shoot a lot of action sports so I need the fast shutter speeds, often in low light.

I'm also buying the 24-70 F2.8 L this week.

Also, I may be blabbling here, but you don't need to buy top of the line lenses to get impressive images. Don't feel you need the "L" lens to get a quality picture. I buy them because I take mine dirt biking, sledding, hiking, mountain biking, and whatever else I end up doing where weather sealed, and durable construction are required.

Ok, I'll shut-up now.

 

[reconstyle]

It should be able to go to 3.5, are you in Av mode or M mode?

 

[bango707]

It should be able to go to 3.5, are you in Av mode or M mode?

3.5-5.6 depending on focal length right?

 

[adolan20]

Yes 3.5 at the lowest range and 5.6 at the highest I believe is how it works.

 

[Cicak]

Because it is a zoom lens, most zoom lenses as the focal range increases, the minimum aperture also increases. As the lens says 3.5-5.6, means at the shortest focal range, the smallest aperture is 3.5, and when it's fully zoomed to the max, the smallest aperture is 5.6.

On more expensive zoom lenses, the smallest aperture does not change as the lens zooms.

 

[bango707]

so Sontizzle, you will only be able to shoot at an f3.5 when your lens is at or around 18mm. at 55mm your aperture will only open up to a f5.6 and at say 36mm you will be at an f4 which is probably near to where you were shooting.