There were comments in another thread about EVFs vs OVF and other stuff, which I felt warranted some discussion, but not in that thread, as it was going off-topic, so I thought I start a separate one for open discussion. Now EVFs vs OVFs have been a point of contention for some time, with probably an equal number in both camps nowadays. So too has been the debate about AF speeds of DSLRs vs mirrorless, as well as image quality, ISO speeds etc. I won’t go into the last two points as they have been discussed recently to a fair degree, but I would like to debate the first two points. Firstly, EVFs vs OVFs. In that other thread as well as many other forums, people keep suggesting that OVFs are far brighter and larger than EVFs. My experiences, using just the older gear that I still own, seems to suggest otherwise. When I look through my Minolta SRT303, Pentax MX or E-3 in a poorly lit room, the view is anything but bright and cheerful, certainly not easy to compose the picture. I would suggest that this is the case for any OVF. However, when I look at the same scene through the viewfinder of my E-M1, it’s like someone turned on a set of studio lights. Why is that? It’s because the E-M1 allows me to change the brightness of the EVF to provide a better image. The same can be done with most EVFs. I’ve been using OVFs of all shapes and sizes for many years, from 35mm to 645/6x6/6x7 and 4”x5”, so it baffles me when people say that OVFs are much brighter and better than EVFs. In fact, DPReview provided a very good graphic of the effective size difference of the E-M1 EVF vs others (not too shabby): They went on to say (and note that the quote is referring to size, not brightness, which is adjustable on the E-M1 as I said): Many times I’ve been in the field or indoor events where composing with an OVF has been a major chore; how I would have loved the quality of today’s EVFs back only a few years ago. So when someone says that OVFs are so much better than EVFs, I have a feeling that they really haven’t compared the two in challenging conditions. I haven’t even mentioned the information that can be overlaid on an EVF, which provides all sorts of advantages when shooting under challenging and rapidly changing situations. Secondly, AF speed. Now I won’t go into focus tracking, as I’ll readily admit that the Olympus cameras have never been great at this and the E-M1, as the latest example, doesn’t do much, if anything to improve on this. However, that isn’t the case for every camera and technology is moving ahead in leaps and bounds. Here’s an example of where tracking focus appears to be heading and is another factor that will soon only be a mirrorless camera urban legend until it’s finally dead and buried: http://petapixel.com/2014/03/08/works-sonys-super-fast-hybrid-af-explained/. However, that said, the S-AF on the E-M1 is excellent, even with my 4/3 lenses, which I thought would be woeful considering the dual AF system employed by Olympus and this being relatively new technology. There are hardly any issues whatsoever with the AF and the only time that any issues arise, is when the subject has very low contrast or little differentiation in tonal range/texture, but then I had the same problems with the E-3/E-5 in those circumstances and, I suspect, most DSLRs will have issues under those conditions. As demonstrated by Sony, the AF technology will only improve and I would go so far as to suggest that mirrorless technology will be the equal of DSLRs in the not too distant future. The current advantages of the DSLR in fast and accurate tracking focus will eventually disappear. It’s about the last bastion where DSLRs rule. I guess we'll just have to wait a little longer to find out.