Larger sensors generally also have larger pixels (although this is not always the case), which give them the potential to produce lower image noise and have a higher dynamic range. In fact, more pixels could even harm image quality by increasing noise and reducing dynamic range (next section). This factor may be critical when deciding on a new camera for your intended use, because more pixels may not necessarily provide more resolution (for your depth of field requirements). Furthermore, the diffraction-limited depth of field is constant for all sensor sizes. This pixel size refers to when the airy disk size becomes the limiting factor in total resolution - not the pixel density. Diffraction Limited Aperture EstimatorĪiry Disk Limits Resolution (Deep DOF Requirement)Īn important implication of the above results is that the diffraction-limited pixel size increases for larger sensors (if the depth of field requirements remain the same). To calculate this as well, please visit: diffraction limits and photography. Note that this only shows when diffraction will be visible when viewed onscreen at 100% - whether this will be apparent in the final print also depends on viewing distance and print size. Use the following calculator to estimate when diffraction begins to reduce sharpness. As an example: one could theoretically use a digital sensor as large as 8x10 inches, and so its image would not need to be enlarged at all for a 8x10 inch print, whereas a 35 mm sensor would require significant enlargement. This is primarily because larger sensors do not have to be enlarged as much in order to achieve the same print size. Larger sensor sizes can use smaller apertures before the diffraction airy disk becomes larger than the circle of confusion (determined by print size and sharpness criteria). This option, however, also changes perspective. If you instead use the same lens, then the aperture requirements remain the same (but you will have to get closer to your subject). Note that the above calculator assumes that you have a lens on the new sensor (#2) which can reproduce the same angle of view as on the original sensor (#1). This is why compact cameras struggle to produce significant background blur in portraits, while large format cameras struggle to produce adequate depth of field in landscapes. This means that a 50 mm lens used on a sensor with a 1.6X crop factor would produce the same field of view as a 1.6 x 50 = 80 mm lens on a 35 mm full frame sensor.Ī shallower depth of field may be desirable for portraits because it improves background blur, whereas a larger depth of field is desirable for landscape photography. Similarly, the focal length multiplier relates the focal length of a lens used on a smaller format to a 35 mm lens producing an equivalent angle of view, and is equal to the crop factor. See the tutorial on camera lens quality for more on this. Smaller sensors also enlarge the center region of the lens more, so its resolution limit is likely to be more apparent for lower quality lenses. Since a cropped sensor is forced to use a wider angle lens to produce the same angle of view as a larger sensor, this can degrade quality. Ideally, one would use nearly all image light transmitted from the lens, and this lens would be of high enough quality that its change in sharpness would be negligible towards its edges.Īdditionally, the optical performance of wide angle lenses is rarely as good as longer focal lengths. On the other hand, this also means that one is carrying a much larger lens than is necessary - a factor particularly relevant to those carrying their camera for extended periods of time (see section below). It is called this because when using a 35 mm lens, such a sensor effectively crops out this much of the image at its exterior (due to its limited size). The crop factor is the sensor's diagonal size compared to a full-frame 35 mm sensor. These will thus not be addressed here specifically, but the same principles still apply. Medium format and larger sensors exist, however these are far less common and currently prohibitively expensive. Olympus, Fuji and Kodak all teamed up to create a standard 4/3 system, which has a 2X crop factor compared to 35 mm film. The above chart excludes the 1.3X crop factor, which is used in Canon's 1D series cameras.Ĭamera phones and other compact cameras use sensor sizes in the range of ~1/4" to 2/3". Canon cameras such as the Rebel/60D/7D all have a 1.6X crop factor, whereas mainstream Nikon SLR cameras have a 1.5X crop factor. The relative size for many of these is shown below:Ĭanon's 1Ds/5D and Nikon D3 series are the most common full frame sensors. Sensor sizes currently have many possibilities, depending on their use, price point and desired portability. Background reading on this topic can be found in the tutorial on digital camera sensors.
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