DSLR or mirrorless… what should I buy?

A question I have been asked a lot recently by customers who are either significantly upgrading their system, or getting into a new interchangeable lens camera system, is whether or not I would recommend a digital single-lens-reflex (DSLR), or a mirrorless camera. Each system has pros and cons, and I am going to try and explain those here, mostly in point form, but some points I will elaborate on a little more. For ease of writing, I’ve decided to use the abbreviation ILC (interchangeable lens camera) to refer to mirrorless interchangeable lens cameras in general. Note that every major manufacturer we deal with at Beau Photo, be it Canon, Fujifilm, Hasselblad, Nikon, or Sony, are all now offer very compelling ILC bodies that are generally up to the task of fulfilling the demanding needs of professionals for most types of photography. Mirrorless cameras are no longer mainly of interest to amateurs!

The primary difference between a DSLR and an ILC is the system you use to view and compose an image. A traditional DSLR allows you a direct optical view, through the lens itself, by using a 45º diagonal mirror in front of the shutter and sensor, and a system of prisms or mirrors in the DSLR’s viewfinder “hump” to relay that image directly to your eye. When you are framing a shot through the viewfinder (VF) of a DSLR, the shutter is closed and the mirror is flipped down.

With an ILC, there is no mirror in front of the shutter and sensor, and in fact while framing through the electronic viewfinder (EVF) or rear LCD display, the camera’s shutter remains open. This is because the camera’s sensor is relaying the live image of what you are photographing through the lens itself (like a DSLR), to your eye by using a miniature high-res display, either an LCD or an OLED display. Modern DSLRs also offer “Live-View” options, and they work by temporarily flipping up the mirror and opening the shutter to relay the live image to the back LCD screen, however you cannot use the camera at eye-level since the VF will be dark, unless you opt for a bulky external LCD display magnifier, like those available from Zacuto and others, and then use the rear LCD as a sort of EVF. There are a large variety of sensor sizes for ILCs as well, ranging from Micro-4/3 (a 2x crop factor) to medium-format, with a 0.79x crop factor when compared to full-frame 35mm cameras.

This one major design difference dictates a number of advantages each system has over the other, although in some cases the clear advantages that a DSLR once had are being steadily whittled away. Note that I used DSLRs for about 9 years, and film SLRS for 20 years prior to that, before switching to a mirrorless digital system. Personally, for my type of photography (landscapes, cityscapes, macro, night and astro, as well as some portrait work), I would never want to switch back to a DSLR again. I am very happy with my mirrorless system and feel the pros far outweigh any cons. So, on to the comparison…


  •  Effectively zero-lag viewing of your subject since you are not relying on an electronic system to transfer the image from the sensor to your eye via an EVF.
  • A very bright scene will give you a very bright VF image, whereas the EVFs used on ILCs generally have a cap on absolute brightness. This can make it easier to compose a shot with a DSLR in, for example, bright sunlight if the sun is coming from the top or the side, which can really interfere with your EVF view when using an ILC.
  • For studio photography with strobes, where the light levels are low and the live preview of an EVF has no real advantage, since it cannot preview the flash exposure live anyway, a DSLR feels like a more natural choice to use for some people, since it does not require changing any settings.
  • Good battery life since the camera is not having to read off the sensor continuously, process the image and display it using the EVF. There is almost no battery consumption while framing a DSLR through its VF.
  • A DSLR’s generally larger size and weight, as well as its often larger handgrip, can balance better with larger lenses and offer a more secure grip with heavier tele zooms or large primes in some cases.
  • Many manufacturers have spent decades perfecting SLR cameras, and now DSLRs, so the general performance, reliability and AF accuracy of the best pro-level DSLRs has only recently been challenged by some ILCs.
  • DSLR systems, specifically those from Canon and Nikon, offer a truly vast array of lenses, including exotic tilt-shift optics, fisheye zooms, as well as a large number of incredibly high performance super telephoto lenses and telephoto zooms. It is no surprise that Canon or Nikon DSLRs are generally the systems of choice for professional sports and wildlife photographers.

ILC Pros

  • Viewing an image live through an EVF means that generally speaking, you can get an accurate preview of how your camera is metering the scene. This is incredibly helpful for challenging available light photography to help ensure that your exposure is right where you want it. Many ILCs offer live, blinking highlight overexposure warnings too, and actual image lag is extremely minimal.
  • Since there is no 45º angle mirror to flip up out of the way, ILCs can be smaller, thinner and lighter than most DSLRs. With some compact systems, like those from Fujifilm for example, lenses that are optimally designed for use only with APS-C bodies are also much smaller and lighter than their DSLR and/or full-frame competition, so the total system weight and size can be significantly less than a DSLR system.
  • In addition, without a bulky mirror in the way, the flange distance can be much shorter than a DSLR, that is, the distance between the lens mount and the sensor. This has major benefits for the optical design of some types of lenses, allowing them to have a more compact size without compromising on their optical performance.
  • The shorter flange distance also allows for the creation of lens adapters, ways to mount many different brands of DSLR, SLR or even interesting vintage lenses onto modern ILC bodies.
  • With no bulky mirror to rapidly flip up out of the way, there is less vibration and noise when shooting with an ILC. In fact, most modern ILC cameras allow you to shoot in almost complete silence by using a fully electronic shutter mode, leaving the mechanical shutter open and using purely electronic means to start and stop each exposure. While there can be some significant drawbacks to electronic shutters when it comes to image quality (banding under flickering light sources, distortion of fast moving objects, reduced dynamic range or other minor image artifacts), the faster readout speeds of modern sensors and faster onboard processors mean that going forward, these problems are becoming less noticeable. For some ILCs, the issues are very nearly nonexistent. If you use any ILCs fully mechanical shutter, then those issues go away completely of course.
  • The very latest ILCs also have very short or, in some cases, zero EVF blackout during rapid shooting. This makes it easier to track moving subjects since you never lose sight of them while shooting continuously. With no mirror flapping up and down, they can often also shoot stills at extremely high frame rates.
  • Shooting video is much easier in bright conditions since the EVF allows you to block out extraneous light without the need for adding a bulky LCD magnifier.
  • Photographing night scenes can be easier since the EVF “gains up” and can make things look a lot brighter than the naked eye sees. This can make it easier to fine tune a composition.
  • Most ILCs allow you to magnify the image in the EVF when focusing manually, making it a whole lot more accurate when focus precision is needed.
  • With a good ILC, a slow f/5.6 zoom gives just as bright an EVF image as a fast, f/1.2 prime, even in relatively low light levels. On the other hand, a slow lens will give a very dim VF image in a DSLR compared to a bright prime.
  • Since the image sensor itself is also being used as the focus sensor, there are no calibration issues with AF. In other words, the majority of ILCs will never require any front-focus or back-focus fine-tuning. Usually, static subject AF is bang-on perfect, presuming of course than one can minimize the size of the focus area sufficiently, which can be done for most ILCs.

So there you have it: a brief rundown of the main pros of DSLRs over ILCs, and the pros of ILCs over DSLRs. Generally speaking, if you are a professional architectural or food photographer who may need access to tilt-shift lenses, are a professional wildlife or sports photographer who needs the very best, fast telephoto primes, you will need to choose your system carefully. In most cases, a Canon ILC can be easily adapted to take Canon DSLR lenses, and a Nikon ILC can take Nikkor DSLR lenses, so those two systems offer the greatest native lens versatility perhaps. That said, Canon lenses can also be adapted to Fujifilm and Sony bodies via third-party lens adapters with very close to full functionality, although often times their AF performance is not as good as when those lenses are mounted on a native Canon body.

However, most other types of professional photography can be done very successfully with ILCs and indeed, I often hear from photographers that feel as I do. Once they try an ILC, they are hooked and don’t want to go back to shooting a DSLR system!

I’m sure there are other points I have missed, but if you are still unsure of what route you should go, DSLR or mirrorless, please do feel free to contact me!

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Beau Photo Supplies Inc.
Beau Photo Supplies Inc.