it is said that full frame aperture equivalent of 2.8 to aps-c is 4.2. does it mean that shutter speed of aps-c is one stop slower that full frame on the same aperture? given the same focal length equivalent e.g. aps-c 23mm and ff 35mm.
it is said that full frame aperture equivalent of 2.8 to aps-c is 4.2. does it mean that shutter speed of aps-c is one stop slower that full frame on the same aperture? given the same focal length equivalent e.g. aps-c 23mm and ff 35mm.
Larger aperture diameter (with the same field of view, as in this case) will collect more light over the same amount of time (and also the depth of field, DOF, will be more shallow). Thus with equal exposure time the larger format will have better image quality (due to more light being collected).
The density of light will be the same though as the light is spread over different areas (FF is 2.3 times larger than APS-C). This is relevant for the exposure calcualtion of the cameras exposure meter. Thus if you use an automatic exposure program, then same f-number on different formats gives you the same exposure time. That’s kind of the point of the whole f-number system.