Originally posted by ffking Let me preface this by saying that I'm coming from a position of ignorance re EVF - but I'm struck by a big 'yes and no' as far as this is concerned: I understand that everything will be turnable on and off in this ideal world, but I'm all for keeping viewfinder information to the minimum useful because it interferes with your seeing of the scene. Even now, when taking landscapes, or non-rapidly changing scenes - I tend to compose through the OVF then turn on Live View to check exposure, level horizon etc - because focus peaking, exposure blinkies, histograms etc etc stop me seeing the imperfections in the scene, and can give a false impression of relative brightnesses etc. In fast moving scenes you have to use the viewfinder anyway, so EVF extra information, if switched on, would similarly get in the way of seeing the whole scene - not to mention the fact that the brain (well my brain, at least) couldn't process the information quickly enough to be useful - and if you turn it off - again, it would take a lot of fast mental processing to keep turning it on and off while following the action -you're back to an OVF. So I can't actually see circumstances in which I'd find extra useful - it would either obscure my view in action shots or be unnecessary due to Live View in landscapes.
All very reasonable and practical considerations
The key for me, though - as you've mentioned - is that all of the information in an EVF (and, therefore, in our theoretical hybrid viewfinder) can be switched on and off.
A lot of the time, I have no information in my A7II's EVF other than basic settings (aperture, shutter speed, ISO). If I'm manually focusing a fast lens at close range, I might magnify the view briefly so I can get absolute accuracy, or so I can see the shape and size of out-of-focus highlights and choose the best aperture accordingly. But then I'm back to an uncluttered view with the same information than I'd see in my K-3's OVF. In lower-light scenarios, I find the EVF ideal because I still have a nice, bright image in the viewfinder to work with. Yes, it can be unrealistically-bright (although your brain becomes accustomed to this, like any feature or quirk), but it shows a very good (if not *exact*) representation of what the sensor will record. If it's too bright in the viewfinder, I'm probably over-exposing
I wouldn't have the histogram running in the viewfinder all the time, nor would I depend on it for clipping alerts as it is based on JPEG output, but it's extremely useful when attempting to keep the exposure pushed to the right, where shadow detail recovery will be required. Again, it can be easily enabled and disabled as required, and that's what I do - I cycle through the viewfinder information I want at any given time, but only when I need to see something different.
All of which might suggest I prefer an EVF to an OVF, but that's not the case. There are lots of situations where I prefer a good OVF, but some where I'd choose an EVF in a heartbeat. That's why, for me personally, a well-designed hybrid - where I have the choice of optical, electronic or combined, with no information, a little information, or every-bell-and-whistle information at my finger-tips - would be a dream come true. Then, it's no longer about which viewfinder is better... we'd be able to choose as the situations arise, whilst accounting for personal preferences; which, after all, is a huge factor. There is no better or worse, only personal preference - so if we could tailor that as required, we'd be well sorted... and the OVF / EVF wars might finally die out