To Be or not to be - Printable Version +- Opticallimits (https://forum.opticallimits.com) +-- Forum: Forums (https://forum.opticallimits.com/forumdisplay.php?fid=4) +--- Forum: Just Talk (https://forum.opticallimits.com/forumdisplay.php?fid=17) +--- Thread: To Be or not to be (/showthread.php?tid=3754) |
To Be or not to be - canoman - 08-07-2010 Surely a lens maker does not differ between crop and full frame. As I mentioned earlier regarding the Tamron 28-75mm lens. The specs are identical and the description only mentions DI. I am confused about this. To Be or not to be - Guest - 08-07-2010 The Tamron 28-75 is a fullframe lens. As such it can be used on Aps-C, too, without any problems apart from the changed field of view because the image circle of the lens, is far bigger than the aps-c sensor. Third party manufacturer do in fact differntiate between Aps-c and full frame lenses. They usally use differnt letter codings in the lens names to identify for which sensor size a lens was made. APs-C lenses have a smaller image circle which results in black corners when mounted on fullframe.This is why it does not make sense to use Aps-c lenses on full frame. (In case of Canon aps-c lenses (called EF-S) it isnt even possible to physically mount an aps-c lens on a fullframe body, because of the mount. Canon full frame lenses can be mounted on aps-c cameras however.) Unlike Canon themselves, third party lensesmaker do not use the EF-S mount for APS-C lenses. This is why their Aps-C lenses can be physically mounted on full frame cameras, without damaging the mirror. If done so, Aps-C lenses do deliver black corners, however, because their image circle is not sufficient for full frame. To Be or not to be - Brightcolours - 08-07-2010 [quote name='geriatric' timestamp='1281163284' post='1563'] Surely a lens maker does not differ between crop and full frame. As I mentioned earlier regarding the Tamron 28-75mm lens. The specs are identical and the description only mentions DI. I am confused about this. [/quote] APS-C lenses just have to have a less wide image circle, making them potentially lighter, and cheaper to make. Full frame lenses can be used on both ASP-C and full frame lenses. Canon calls their APS-C lenses EF-S, full frame lenses are called EF (electro-focus). The S stands for Short, the distance between sensor and lens can be a bit shorter for their APS-C lenses. Lens brands and their APS-C naming conventions: Brand : full frame / APS-C Canon : EF / EF-S Tamron : Di / Di II Sigma : DG / DC Tokina : - / DX Nikon : - / DX Sony : - / DT Pentax : A big mess. To Be or not to be - netrex - 08-07-2010 [quote name='Brightcolours' timestamp='1281185211' post='1566'] APS-C lenses just have to have a less wide image circle, making them potentially lighter, and cheaper to make. Full frame lenses can be used on both ASP-C and full frame lenses. Canon calls their APS-C lenses EF-S, full frame lenses are called EF (electro-focus). The S stands for Short, the distance between sensor and lens can be a bit shorter for their APS-C lenses. Lens brands and their APS-C naming conventions: Brand : full frame / APS-C Canon : EF / EF-S Tamron : Di / Di II Sigma : DG / DC Tokina : - / DX Nikon : - / DX Sony : - / DT Pentax : A big mess. [/quote] Pentax a big mess? DA is for digital, FA for 135 film (which of course would cover a 36x24mm sensor), and they do have a couple of D FA lenses. I don't see the mess. Some DA lenses do cover the 36x24mm area as well, but the lenses are still intended for APS-C sized sensors. |