Before you switch from DSLR to mirrorless, know how they compare

Compare 7 key areas of DSLRs versus DMIL cameras

With the new Nikon Z series full-frame, digital mirrorless interchangeable lens cameras (DMIL) and Canon's new full-frame EOS R DMIL camera, Sony now has significant prosumer DMIL competition. Now that these manufacturers are fighting it out for supremacy in the quality DMIL market, I think we can expect that improvements in DMIL feature sets and image quality will accelerate significantly in upcoming years.

Major improvements are needed for electronic viewfinders, autofocus on fast-moving targets, battery life and low-light image quality, especially for future pro-level DMIL cameras.

If you're considering a move from DSLR to DMIL cameras, here are seven key areas you need to consider before making the change.

Size and Ergonomics:
DMIL camera bodies are physically smaller and lighter than DSLR bodies. For some photographers this is a big deal, but for others, not so much. When it comes to the size and shape of cameras, there are four major issues: stamina, balance, size and ergonomics.

I often hear photographers, particularly older photographers, complain about the weight of pro-level DSLRs. Let's face it, pro DSLRs, especially ones with built-in vertical battery grips are heavy. For a photographer, carrying that weight around all day plus that of a heavy lens, can be tiring. Lighter weight DMILs decrease the load. The Nikon Z7, for example, at just 1.5 pounds including the battery, weighs less than half of a Nikon D5.

Of course, lighter weight camera bodies change the balance of the camera/lens combination, as some lenses can be significantly heavier than any camera body. That can make hand-holding the camera/lens difficult with the lens pulling a light weight body down. If you have heavy lenses that you plan to use with your DMIL, using good technique, test their balance together to see if it's a hand-holding problem for you.

Many current DMILs are sized with too little surface to comfortably hand-hold them steady. I don't have big hands, but the area of DMIL bodies where I can put my fingers to grip the camera has been uncomfortable and unsatisfactory. In addition, portrait orientation shooting is awkward, making holding the camera steady while pressing the shutter release more difficult than it should be. The Nikon Z series size appears to be a significant improvement, but it's unknown if a vertical grip accessory can be outfitted to the series to improve its portrait ergonomics.

Electronic Viewfinder (EVF):The viewfinder on DMIL cameras is a mini TV screen. Its view of the scene your shooting is different than what you see through a DSLR optical viewfinder. Current EVFs views are not as subtle and may often have distortion. It's a mixed bag for photographers.

Certainly the EVF “what you see is what you get” can be wonderfully helpful, but sometimes you want the best view of the scene possible. EVF doesn't compare well to DSLRs for shooting in low light conditions. Photographing concerts with high contrast scenes from heavy LED lighting can be especially hard, as the contrast washes out the EVF, making it hard to compose images.

The lack of dynamic range in an EVF compared to an optical viewfinder can be a problem in exposure choices. Shooting moving images is more difficult with an EVF due to lag and delay of the EVF image. The “slide show” effect I see in EVFs when panning with moving subjects makes it more difficult than it should be for that kind of photography.

Autofocus:
Autofocus has generally evened out between DMILs and DSLRs even in low light, but DSLRs remain superior for autofocusing on fast-moving targets, which can be critical in sports and wildlife photography. The new DMIL cameras from Nikon have a hybrid of contrast and phase-detection autofocus systems which should substantially improve DMIL autofocus overall.

Battery Life:
You better invest in several spare batteries and keep them fully charged if you switch to DMIL cameras. The EVF coupled with the smaller batteries found in DMILs mean significantly shorter battery life. Of course, DSLRs initially had battery life problems and photographers found the cameras were still worth using. While annoying, this is not the problem some make it out to be. It's a problem of management more than anything. With a DMIL you will find you'll need to regularly switch batteries to ensure you'll be ready for the next shots before your battery dies.

Lenses:
Having the widest possible choice of quality lenses is critical. That has been a problem for some DMIL lines in the past. With the new Canon and Nikon offerings, that should disappear as it appears that their lens adapters to make it possible to couple their existing high quality lenses to their DMIL bodies will enable the DMILs to use the older lenses with no loss of optical quality or lens functionality, which wasn't true in the past.

That said, like many DSLR users, I have a significant investment in my current lenses. If the lens adapters coming out now don't live up to their promise, then until DMIL native lens offerings become much better than they are today, it will be a long time before I could move toward DMIL cameras.

Image Quality:Both DSLRs and DMILs are capable of fantastic image quality. They use the latest and greatest sensors on the market. Sensor size is a major determiner of image quality, particularly in low light conditions. When looking at image quality you must compare sensor size and the number of pixels on them to compare them fairly. While smaller sensor sizes are getting better in low light, full-size sensors still offer the best low light images because they normally have far less noise, even as ISO settings that are significantly increased to capture the image.

One problem that seems to be generally ignored, particularly for those shooting in low light conditions, is heat build-up at the sensor which can cause noise in images. That can come from running a mirrorless system continuously. It's a problem that needs addressing by DMIL manufacturers, though it can be mitigated to a degree by photographers, but at this time, not as much as I'd like.

Video:
While the top DSLRs were the among the first to offer professional quality HD and full HD video coupled with their huge stable of lenses for all kinds of situations, there's little doubt that DMIL cameras have an edge shooting video with equal quality and superior video feature sets not found in the top DSLRs.

Conclusion:
Despite the differences between DSLR and DMIL cameras, the quality of images and video that they can produce with a good photographer behind their viewfinders will be excellent. Whether or not a DMIL is a good choice for you depends on your needs and the genres of photography you shoot, including whether or not you find yourself shooting in low light conditions often.