Aperture + Camera+ Lens

[Alex60]

Hi, I own a Canon 50D, and the exposure rating goes from F3.5 up to F22, I use a Tamron 28 to 300 XR Di lens with a range of F3.5 to 6.3. My question is does the lens govern the camera range, or does the camera disregard the lens aperture and you can set the aperture at any F stop from 3.5 to F22. Hope this makes sense...

Alex60.

[MattUK]

The lens

The aperture readings on a lens state the maximum it is capable of at either end of the focal length. So at 28mm, the max ap is 3.5. At 300, it's 6.3. Lenses will also have a min ap at either end, usually around f22

[Cathus]

I think you may be getting a little confused, where are you getting the camera's exposure rating from?

Cameras don't have apertures, the aperture is the size of the hole that lets the light through the lens, so it's the lens that has an aperture rating.

Generally, more expensive zoom lenses have a single aperture rating at say f2.8 or f4, this means this is the widest aperture you can use at any focal length of the lens.

The cheaper zoom lenses show like your lens f3-5 to f6.3 which, as Matt says, just shows the widest aperture at 28mm (f3.5) and the widest at 300mm (f6.3)

You can demonstrate this by setting your camera on Aperture priority, zoom out to 28mm & set it to f3.5, then just zoom in slowly on your subject & you'll see the aperture gradually change until it hits f6.3 when you get towards 300mm.

[OldBoy]

Originally Posted by Cathus

Cameras don't have apertures, the aperture is the size of the hole that lets the light through the lens, so it's the lens that has an aperture rating.

I thought the Aperture was where you attached the lens to the camera!

[Cathus]

nah, that's the lens mount

[Alex60]

Hi thankyou for the replies you get to my age confusion is an everyday occurrence.