9/25/2023 0 Comments Frame lens on crop sensor camera![]() ![]() Manufacturers of crop-sensors like to use the term “ equivalent focal length“. In order to obtain the same AOV on a cropped-sensor camera, a new lens with the appropriate focal length must be chosen. What changes is the AOV of each of the lenses, and consequently the FOV. Therefore a 50mm lens in FF, APS-C or MFT will always have a focal length of 50mm. The focal length of a lens remains the same – regardless of the sensor on the camera. Now it should be made clear that none of this affects the focal length of the lens. ![]() An example of this is shown in Fig.1 for a 35mm lens (showing horizontal AOV).įig.1: AOV for 35mm lenses on FF, APS-C, and MFT For example a 35mm lens on a FF camera has the same focal length as a FF on an MFT or APS-C camera, however the AOV will be different on each. The camera with the APS-C sensor will have a more narrowed AOV. Take a photograph with two cameras: one with a full-frame and another with an APS-C sensor, from the same position using lens with the same focal lengths. The most visible effect of crop-sensors on lenses is the angle-of-view (AOV), which is essentially where the term crop comes from – the smaller sensor’s AOV is a crop of the full frame. But what does focal-length equivalency mean? Focal-Length Equivalency A 300mm FF equivalent in MFT only needs to be 150mm. The benefit is that for lenses like telephoto, a smaller size lens is required. This allows crop-sensor lenses to be more compact, and lighter. Mostly this has to do with size – because the sensor is smaller, the image circle doesn’t need to be as large, and therefore less glass is needed in their construction. Canon APS-C cameras have a crop factor of 1.6x and Olympus who use a ‘four thirds’ system have a crop of 2x.Lenses used on crop-sensor cameras are a little different to those of full-frame cameras. This means a 200mm lens has an effective field of view of a 300mm lens. Nikon DLSR APS-C cameras have a crop factor of 1.5x. To calculate the effective field of view of APS-C cameras, multiply the focal length of the lens by the crop factor.įujifilm X mount cameras have a crop factor of 1.55x, this means my 100-400mm lens has an effective field of view of 155mm to 620mm. However, some manufacturer’s dedicated APS-C lenses will not physically mount. If not you will get a very obvious lens vignette around the edges. You may still be able to use a lens designed for a APS-C camera on a full frame camera if you can set up the sensor to only use the smaller image area. Lenses which are designed for cropped sensors are physically smaller than their 35mm equivalents because they require a more narrow channel for the light to pass through. Note, it isn’t exactly to scale, just an approximate illustration. The green and red represents the differences in the fields of view between a 35mm sensor and APS-C. It is much like looking at something through two different sized windows. An APS-C sensor is physically smaller so the field of view is smaller than that of a camera with a full frame sensor. What changes is the effective field of view seen by the camera sensor. Optically a 300mm lens will always be a 300mm lens regardless of whether it is made for cameras with a cropped sensor or full frame. ![]() Most importantly it doesn’t physically increase the focal length of a lens. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |