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 p.7 #3 · EOS 1D-X! March 2012! | |
EB-1 wrote:
The ISOs seriously need to be reset to the original progression, i.e., multiples of 16, 25, 32, 40, 50, 64, 80, and 125. There should be 1600, 2000, 2500, 3200, 6400, 125,000, 160,000, 200,000, 250,000, and so on. The crazy fractionalization is meaningless compared to the accuracy of the photo sensitivy. After all, the exact mathematically progressive increments (cube root of 2) are not used for the lower speeds.
EBH
The thing is, for the purposes of reciprocity, the mathematically correct full stop increments of shutter speed and sensitivity are the exact integer powers of 2. Thus, the ISO progression is accurate--it's the shutter speeds that are wrong. So your suggestion to change ISO to match the shutter speed would be compounding one error with another.
The correct shutter speeds in full stop increments should be 1, 1/2, 1/4, 1/8, 1/16, 1/32, 1/64, 1/128, 1/256, 1/512, 1/1024, 1/2048, 1/4096, and 1/8192 s.
Yes, the half- and third-stop increments aren't exact in either case, but that still doesn't justify making things less accurate for an illusory notion of convenience. It's not that hard to memorize the powers of 2. In fact, I often find it easier to remember these values than the shutter speed values.
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. My point is, it is just a designation that can be changed as the need arises. For example, Canon 7D came out of nowhere without any heredity lineage.
The other option is going with small format, e.g., the DX format (D400 or whatever) for teles and medium format for quality. It is a hassle, but so familiar from the film era. 