Might be a stupid question but I'm a beginner.

[rmcheek]

I have the rebel t1i with the kit lens which has a filter size of 58mm. I was curious if another lens, Canon EF 28-135mm f/3.5-5.6 IS USM for instance, that has a larger filter size of 72mm would work on this camera body.

[ravncat]

it will, you`ll however need to get a step-up ring to take you from 58mm threads to the larger 72mm threads

[Sterling]

The filter size is just the diameter of the threads on the front of the lens. This just determines what size of filters will screw onto the lens. Filter size has nothing to do with the ability of the lens to mount to a particular camera.

[rmcheek]

Oh ok... so whats the big deal with lenses with larger diameters?

[RichardTaylor]

The large diameter lenses let more light through them (just like a water pipe) enabling shoots in in low light without the addition of extra lighting or a tripod to hold the camera steady.

It also gives you more control over Depth if Field (zone of acceptable sharpness).

See this thread. (Part of a series on exposure)
Exposure (3): Aperture

[ravncat]

ACk - sorry, I misunderstood the first time....

The mount is what is important, Filtersize and Mount are two different things -

I don`t use canon, so i`m not sure what the canon mount is called, but the nikon mount is the Nikon F mount - any lens with the Nikon F mount will mount on the camera body. - likewise, if it has a canon mount, it should mount on a canon camera... The mount is on the rear side of the lens and connects to the camera.

The filter size, is as above - the diameter of the front end of the lens. I thought you were asking about using a filter, with a larger diameter on a lens with a smaller diameter - which can be done with a step-up ring.

The diameter of the lens - is only important for filters, lenshoods, caps and other things. The mount is what determines if you can use it for your camera - hopefully that clears things up?

[rmcheek]

Ok thanks guys.

[OsmosisStudios]

Originally Posted by ravncat

it will, you`ll however need to get a step-up ring to take you from 58mm threads to the larger 72mm threads

Not quite either: Step up rings allow the 58mm lens threads to use a 72mm diameter filter.