Medium-format cameras can offer wider dynamic range than their smaller format counterparts. If/when RAW results become available, we’ll update and amend these rankings.Īnother thing to bear in mind is that Image Engineering has only tested one medium-format camera to date (Fujifilm’s GFX-50R). There are several reasons why Image Engineering restricts their measurements to JPEG files, including the (lack of) availability of camera profiles in RAW processing software when the camera arrives in their lab. Image Engineering test results only measure JPEG performance, not RAW files (which will have wider dynamic range). No list is perfect. In this case, there are a few things to note about these rankings. A dynamic range of 10 f-stops equals a contrast of 1000:1. Every f-stop equals a doubling of the contrast. Image Engineering report the dynamic range normally in the common unit “f-stops” or “EV” (Exposure value). The dynamic range is a ratio which can be expressed in different units. While the ISO standard defines the threshold based on the signal theory with SNR=1, Image Engineering uses a slightly more difficult threshold of SNR=3, based on their two decades of experience in digital photography. So as soon as the signal-to-noise (SNR) gets too low, the information is lost and an even darker object cannot be differentiated. The lowest luminance is limited by noise. Thus, if a bright object is rendered to the maximum digital value (for example, 255 for an 8-bit image), an even brighter object will not get a higher digital value, and the information is lost. The highest luminance that can be reproduced is limited by clipping. The dynamic range of a camera is defined by the contrast between the highest luminance that can be reproduced and the lowest luminance that can be reproduced. (The complete IE test methodology can be found here.) The measurements they perform are defined in the ISO14524 and ISO15739 standards. The analysis consists of checking how the camera renders the gray patches. The chart consists of gray patches that show a well-defined and regularly re-measured luminance (in unit cd/m2). Image Engineering (IE) uses a special transparent test target to measure dynamic range. How Image Engineering Tests for Dynamic Range We’ve broken the list into two categories: the dynamic range achieved at a camera’s base ISO as well as the widest dynamic range they can achieve irrespective of ISO. In this list, we’ve gathered up the test results from our lab partner, Image Engineering, to rank cameras by how many stops of dynamic range they provide when shooting still images. While camera makers frequently tout the dynamic range they can achieve in video, they’re typically mum about the dynamic range of their models when shooting stills. There are plenty of variables that go into still image quality but dynamic range is arguably one of the most important. This article, first published in December 2018, was updated on May 8, 2019.
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