What lens for my mount?

[bribears]

I may be making this more difficult than it needs to be but I can't figure out how I know if a third party (Sigma, Tamron, etc.) lens will fit on my Canon T1i, Is there an easy way to know?

[bribears]

I see that the Sigma website actually has a lens finder that can narrow down to "Canon cameras", but do all Canon DSLR cameras use the same mount? And that still leaves me to wonder about the Tamron site where it isn't easy to narrow down if the lens can go on "my camera".

[zona5101]

maybe a good approach would be to research the lenses on the manufacturer's site then go to Adorama or B&H and use the filters to narrow down the versions to the canon mount.

[OsmosisStudios]

Sigma, Tamron, Tokina, et al. make the exact same lens for different cameras by simply changing the mount - nothing else. So just make sure you're looking at the Canon mounted version of a lens.

[bribears]

Originally Posted by OsmosisStudios

Sigma, Tamron, Tokina, et al. make the exact same lens for different cameras by simply changing the mount - nothing else. So just make sure you're looking at the Canon mounted version of a lens.

AH! I didn't get that impression from their sites. Though I guess that would explain why they do not call out what camera each lens can got with.

[inkista]

Actually, with all three websites, if you go to the listing for a specific lens, the specs will also mention which mounts it comes in. Typically, you don't have to worry too much with Canon or Nikon about 3rd party lenses--they're almost always made for at least those two mounts. You just have to make sure you purchase the Canon version.

One other thing that you will want to be aware of, though, is that some of these lenses are designed for crop sensors. And unlike Canon lenses, where there's a clear delineation between full-frame and crop-body lenses (EF vs. EF-S), with the 3rd parties, they may have made the physical mount EF-compatible, but the image circle will only cover a crop sensor. So while these lenses can be mounted on a 5D, they will vignette (leave dark edges/corners). If you plan on upgrading to full frame in the future, you want to take the time to note Sigma's DG/DC, Tokina's DX, and Tamron's Di/Di II nomenclature.

[bribears]

okay, so now a new problem. What is crop sensors or full frame? I have no idea what you are talking about.

[Stryker]

Full frame

Crop factor

It is a measure of the size of the sensor in the camera.

[inkista]

Originally Posted by bribears

okay, so now a new problem. What is crop sensors or full frame? I have no idea what you are talking about.

Full-frame means a camera with a sensor that's the same size as frame of 35mm film. The only models out there of dSLRs that are full frame are the Canon 1Ds & 5D (all versions), Nikon's D3 and D700, and Sony's A850 and A900. Every other dSLR has a sensor that's smaller than that. They're called "crop sensors", because the effect of using the smaller sensor is a lot like cropping the edges off the frame:



Lenses that are designed for a crop sensor project an image circle that's only big enough to cover the smaller sized APS-C (or four-thirds if you're talking Olympus/Panasonic) sensor. So, when you put a "designed for digital" lens on a full-frame body, the circle won't cover the whole sensor, and you'll see the edges of the circle (black corners, edges).

With Canon's EF/EF-S lenses, you cannot physically mount an EF-S lens onto anything but a 1.6x crop body (digital rebels, xxD bodies, 7D, etc.) There's a bumper on the lens that keeps it from being mounted. With Nikon, DX lenses can be mounted onto FX bodies, but the camera will crop the image it gets so the full frame is filled--and you're not using your full sensor. Using Tamron/Tokina/Sigma crop lenses on a 5D is sort of halfway inbetween: you can physically mount the lens, but you'll see the vignetting.

[DeltaRay]

If you look on enough website reviews for the lens you will generally find one that tells you whether the lens is full frame or cropped or both.