It's impressive, but it's irrelevant to 99% of photography.
I'd personally rather have an optical viewfinder than all of those features, impressive as they are.
It's a very specialized piece of equipment for a very specific user, sure, but Sony has other bodies suited for different jobs. What the A9 shows is that there are advantages unattainable to mirror systems. As technology matures and cost of entry lowers, the more limited and cumbersome mirror systems will be cast away.
Optical viewfinder, albeit nice, won't sustain the whole market for DSLR. The advantage of no having vibration or rolling shutter or silent operation, will eventually drive people to mirrorless systems.
>The advantage of no having vibration or rolling shutter or silent operation, will eventually drive people to mirrorless systems.
Vibration is a red herring. Mirror damping for small format DSLRs has been a solved problem for decades. In any case, all of these advantages can be obtained with a DSLR too when it's in mirror lock-up mode.
Those are mostly advantages of shutterless systems (which DSLRs can be and some have been, though sensor quality issues made them niche and actually mitigated some of the advantages; shutterless cameras historically have still had rolling shutter effects, especially at "shutter speeds" higher than those current DSLR mechanical shutters operate at, which is why those shutter speeds are used), except the vibration one is affected by both mirror and shutter (though DSLRs already have mirror lock-in to address the mirror impact.) Also, mirrorless has battery impacts compared to DSLR.
So what this says to me is that, if the sensor is really qualitatively good enough to allow this without the problems shutterless cameras have faced before, Sony has a sensor technology lead that will give them a better market position. But assuming everyone else catches up on sensors, DSLRs aren't what is in trouble, its mechanical shutters that are doomed.
Why? OVF doesn't show you what your picture is going to look like. You have to move from the viewfinder to look at the LCD to check exposure then go back to the viewfinder, repeatedly.
EVF shows you exactly what your picture going to look like.
Uses less battery and works much better in low light.
>You have to move from the viewfinder to look at the LCD to check exposure then go back to the viewfinder, repeatedly.
If I want to check the histogram then I shoot with the mirror locked up, but modern DSLRs have very reliable autoexposure systems, in my experience at least.
>EVF shows you exactly what your picture going to look like.
It shows you what it will look like on a small screen with low dynamic range. You have to look at the histogram to see if you're losing shadow/highlight information.
Sure...which you only get on an LCD. IMO the only dealbreakers with EVFs are refresh rate, battery consumption and color gamut. If I were a camera maker, I would not be banking on any of those not being solved problems in the next five years.
EVF shows me the histogram (can toggle it on and off without moving my eye).
You'd need to have to reduce the optical image size to make room for an LCD display, have a HUD to overlay a digital image over the OVF optical image, or have another moving mirror and toggle between EVF and OVF to do that on a DSLR.
Which is to stay that an in-viewfinder histogram is possible but not easy for a DSLR.
https://en.wikipedia.org/wiki/See-through_display
"Small scale see-though LCDs have been commercially available for some time."
It's more accurate in many respects, and lower latency, than current EVFs.
> EVF shows you exactly what your picture going to look like.
An idealized EVF with perfect quality and a resolution equal to that of the sensor would do that, sure.
But real EVFs don't.
That mechanical mirror is fairly expensive to build and imposes some restrictions on lens design (the back of the lens can't move too close to the sensor), and both will go up over time (the mirror hardware will get more expensive because fewer and fewer mirrored cameras are sold, and larger sensors require larger mirrors)
As far as I can tell (corrections welcome), the main advantages of a mirror are battery life and behavior in low light conditions (it isn't easy to rapidly update a LCD viewfinder in low light conditions, and that viewfinder may be too bright). Battery life becomes less of an issue with better battery technology. That leaves low light photography. I don't think that, over time, will be sufficient to keep a market for such cameras.
Hmm, is it though? I don't have any data on that, but I wouldn't necessarily assume that a relatively simple mechanism of that sort is expensive to manufacture when cheap labour is available. I suspect that the cost of the mirror mechanism is a tiny fraction of the overall cost of making a high end DSLR.
>imposes some restrictions on lens design
For sure, but the de facto biggest lens systems are for DSLRs. Given the usability of old lenses (on Nikons at least), that's not going to change for a very long time. The restrictions on lens design have not proven to be a problem in practice.
Also, there are reasons to use retrofocus designs other than the presence of the mirror. Ultrawides with non-retrofocus designs have serious vignetting issues. I have a 75mm Schneider Super-Angulon that I use with an old 4x5, for example, and the corners can be around 1.5 stop darker than the center. The problem is bad enough that they make dedicated filters to compensate: https://www.schneideroptics.com/ecommerce/CatalogSubCategory...
Also an interesting quote from https://www.bhphotovideo.com/explora/photography/hands-revie...
>If there’s a downside to non-retrofocus lenses, it would have to be vignetting, which depending on the lens, can be 1 to 2 stops of light falloff toward the corners of the frame. When coupled to digital cameras, these issues can become exaggerated because, ideally, light shouldn’t strike the sensor at angles greater than 90° [sic], which is the case when it comes to non-retrofocus lenses.
So you might find that mirrorless cameras end up with similar wide angle lens designs to DSLRs.