Mirrorless Camera Limitations

We’ve gone over the many advantages of mirrorless cameras over DSLRs. Now let’s talk about some of their current limitations:

1. EVF Lag: some of the current EVF implementations are not very responsive, resulting in considerable lag. While this is certainly a nuisance compared to OVF at the moment, it is a matter of time before that lag is eliminated. The latest EVFs are already much better than what they used to be before. But as EVF technologies evolve, the lag issue will be resolved completely.
2. Continuous Autofocus / Subject Tracking: while contrast detect has already reached very impressive levels on mirrorless cameras, they are still very weak at continuous autofocus performance and subject tracking. This makes them pretty much unusable for wildlife and sports photography at the moment. However, with the rise of hybrid autofocus systems and their continuous development, we will soon start seeing mirrorless cameras with much better continuous autofocus capabilities. One of the reasons why mirrorless cameras have been slow in this department, is because most mirrorless systems are small and not well-suited to handle large telephoto lenses. So manufacturers have not been putting much of their R&D efforts into this specific area. Again, it is a matter of time until this is implemented on mirrorless cameras.
3. Battery Life: another big disadvantage of mirrorless cameras at the moment. Providing power to LCD and EVF continuously takes a toll on the battery life, which is why most mirrorless cameras are rated at about 300 shots per battery charge. DSLRs are much more power efficient in comparison, typically in 800+ shot range per charge. While it is not a huge problem for typical camera use, it could be an issue for someone that travels and has very little access to power. Still, I believe that the battery issue is also something that will significantly improve in the future. Batteries will be more powerful and power-hungry LCD screens will be replaced with OLED and other much more efficient technologies.
4. Red Dot Patterns: due to the very short flange distance, most mirrorless cameras suffer from a “red dot pattern” issue, which becomes clearly visible when shot with the sun in the frame at small apertures. Basically, light rays bounce back and forth between the sensor and the rear lens element, creating grid patterns of red (and sometimes other colors) in images. Unfortunately, there is no way around this limitation on all mirrorless cameras with a short flange distance.
5. Strong EVF Contrast: most EVFs designed today have very strong, “boosted” contrast, similar to what we see on our TVs. As a result, you see a lot of blacks and whites, but very little gray shades (which help to understand how much dynamic range can be captured). While one could look at the histogram overlay in EVF, it is still a nuisance. Manufacturers will have to find ways to make EVFs display images more naturally.

As you can see, the list is rather short and I expect it to get even shorter within the next few years. I believe that all of the above issues are addressable and they will get better with each iteration of mirrorless cameras.

In summary, I would like to say that DSLRs simply have no way to compete with mirrorless in the future. I am not saying that everyone will be switching to smaller and lighter mirrorless cameras soon – no, we are still far from that point. However, it simply does not make sense for manufacturers like Nikon and Canon to continue investing into making DSLRs better, when the technology advantage is clearly with mirrorless. Below is what I believe what Nikon and Canon should do in the near future.