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p.1 #11 · Leica D Summilux 25 mm f/1.4 review | |
theSuede wrote:
"Exposure" as in light effect per unit area is really quite useless as a comparing metric. If you want to use that definition I suggest you try your average cameraphone or compact camera at ISO6400. If that definition is right and just for comparisons, then that should be the same as the D700 on ISO6400. Take a guess.... It isn't. Total amount of light is what matters.
Actually, that is once again a false comparison. What matters for sensor performance is pixel pitch (given otherwise equivalent sensors, ie fill factor, microlens coverage, etc). A phonecamera with the same pixel pitch as a D700's sensor can deliver the same noise performance as the D700 can, albeit at a very low resolution. A D700 with the same pixel pitch as a cameraphone would have the same awful noise performance, albeit at a fairly ridiculous resolution. The advantage to larger sensors is in pixel pitch increases at a given MP count, not the increase in total illumination. The secondary controlling factor is heat (big sensors take more juice and thus run hotter, one reason why MFDB's have worse noise at ISO's other than base, they run hotter than FX sensors)
Of course a good F/1.4 lens is always impressive, and I've seen few other large aperture lenses be as sharp all the way from wide open. As for "haven't used it..." bla bla bla - have YOU ever tried comparing pictures from FX 50/2.8 and 4/3 25F/1.4 taken from the same viewpoint? The results ARE virtually identical, if you disregard the "personalities" of the individual pieces of equipment...
That depends seriously on the subject, since the FX 50/2.8 exposure would either be at 2 stops higher ISO or 2 stops lower shutter speed or some mix of the two. A 4/3rds 12MP shot at f1.4, 1/125 and ISO 800 on say an E-30 would be less noisy than that FX 50/2.8 at f2.8, 1/125 and ISO3200 on say a D700 (Cameras picked to normalize MP count, ISO's picked specifically to invalidate your comparison as ISO 3200 is where visible noise starts to occur on the D700 while ISO 800 is the highest ISO without visible noise on an E-30). Also if you're shooting at the same ISO you run into issues like motion blur on the 50/2.8 shot.
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