we're already taking oxfe to 0, which takes us more than halfway there. that step is "free", as in zero downside. no loss of dynamic range, only loss of noise
reducing the preamp gain is the step where we can go too far. the goal is to reduce is only as much as is required to fill the histogram (so to speak) and no further. if we go further, we start to lose highlights (but with cleaner and cleaner shadows as a result). my original work with this was going too far, because i didn't really know what i was doing yet, and only following the basic procedure in the first post of the iso research thread. eventually i started to realize how to make it better, and came up with the "calibration" method, which is now made super easy and more enjoyable/usable by enabling the raw_diags window in the liveview so we can see the instant results of changing settings expressed as dynamic range in EV!
i show how to do it in the recent tutorial video:
https://www.magiclantern.fm/forum/index.php?topic=24720.msg223628;topicseen#msg223628try it out!
I know that a1ex said the realtime calculations aren't as accurate as doing graphs, but as you can see from the graphs i included in the thread, it's even better! the important aspect of the realtime readout is that it is consistent. all we need to see is how we are doing in relative terms. when we see the readout reach its maximum value before falling off, we're ready to go!
it would be AWESOME to automate this
-- your expertise would be MOST appreciated!
