I thought that Olympus was already overstating the ISO in that camera by a factor of two.No, that is belief is based on misinterpretation of the fact that EM5 raw files have more than the _minimum_ highlight headroom specified by the ISO standard for minimum or base exposure index, so that the _base ISO speed_ is less than the lowest ISO exposure index setting. It is nothing to do with the camera giving more exposure than specified by the ISO exposure index setting. People who study those DXO measurements really need learn the differences between the various different measurements of sensor characteristics defined by ISO standard 12232, and avoid referring to them all as simply "ISO".
Later,
Johnny
It seems Olympus is now learning from other brands such as Fujifilm, offering its customers really useful firmware updates.I am with Thom - Fuji's upgrades are because their cameras were released not fully executed... come on, how many firmware updates for AF speed ;D = http://www.dslrbodies.com/newsviews/how-myths-get-started.html ...
I thought that Olympus was already overstating the ISO in that camera by a factor of two.
I'd guess Olympus is assuming folks who want to use ISO LOW with the E-M5 will understand the need to be more careful with exposure.this setting is for JPG shooters really, raw shooters can use whatever existing gain is the best for the needed exposure (aperture and exposure time) and raw processing in mind.
Finally I wonder why camera makers never like to provide really low ISO settings in digital cameras that would be very useful to a good amount of users. I guess there is some technical reason behind and not just a marketing decision.
take Sony 16mp m43 sensor in GH3 and EM1 - there is a theory that to provide "LOW" ISO Panasonic does allow ADC not to clip well into non linear area near well saturation and Olympus does not (always clip well below well saturation) ... hence DxO sees Panasonic "LOW" ISO as real one and Olympus "LOW" ISO as just firmware trick with exposure/metering... so Panasonic wants to squeeze something extra for itself @ the expense of potential ill effects near saturation (that does not mean that GH3 gets better DR than EM1).
Having shot for year with the GH3, I can confirm ISO 100 acts perfectly normally, at twice the exposure, with possibly slightly more highlight headroom than at IS0 200 (certainly not less), but in RAW only.
I noticed early on with the E-M5 that it had plenty of RAW highlight headroom.
E-M1 has the difference between ISO200 and LOWISO within 1/6 EV or less...
Yes, the point here is not so much that gapwell, 1/3 EV gap for E-M5 is interesting by itself... do they intentionally apply 1/3EV more gain postexposure to improve S/N in deep shadows ?
These images are straight out of lightroom, no matting in, nothing but slider processing.ACR/LR will apply different hidden expocorrections for ISO LOW vs the rest - at least for E-M1... I bet the code is not yet update for E-M5 (unless they were thinking or informed by Olympus in advance)... conversion of ORF to DNG using ACR/LR/Adobe DNG converter and checking the relevan DNG tag shall tell.
One the em-5 image I will pull the exposure down and put more detail into the window because there is a lot more there, with the 1dx file, I will have to use a separate background plate I shot because the doors are devoid of detail.