If you're buying new, the choice is mostly made for you. Canon and Nikon have moved their development to mirrorless, Canon's last new EF lens design came out in 2018, and in September 2026 Ricoh said it would end production of its current Pentax K-mount DSLRs while it works on a new series. Used is different. Some of the best cameras ever made are DSLRs, there are lots of them for sale, and they still take superb pictures. So the real question is which kind suits how you shoot, and which lenses you want to end up with.
How they differ
A DSLR reflects the light from the lens off a mirror and up through a prism, so the viewfinder shows the scene through glass. When you press the shutter, the mirror flips up out of the way. A mirrorless camera has no mirror. The lens shines straight onto the sensor, and you compose on an electronic viewfinder or the rear screen, which shows you the exposure before you take the shot.
Everything else follows from that. The mirror box makes a DSLR bigger and gives it a separate autofocus module under the mirror. Taking it out lets a mirrorless body be smaller, focus with the sensor itself, and sit its lens mount much closer to the sensor.
Viewfinder and battery
An optical finder shows the world with no lag and uses no power. That's the main reason DSLRs run so long on a charge. The Nikon D750 is rated for about 1,230 shots per charge under the CIPA test, while the Sony A7 III, which had one of the longest-lasting mirrorless batteries of its time, is rated for 710. Older mirrorless bodies with smaller batteries manage far fewer, so plan on carrying spares.
An electronic finder earns its keep in other ways. It shows exposure, white balance and focus peaking before you shoot, it can magnify the view for manual focus, and it brightens a dark scene. Plenty of people who learned on optical finders never go back once they've used a good EVF. Others find it tiring. If you can, try both before you buy.
Autofocus
Mirrorless bodies focus using points on the sensor, so focus points cover most of the frame and many cameras recognize and track eyes. A DSLR's viewfinder autofocus uses a separate module, and its points cluster nearer the center. The good ones, like the 51-point system in the D750 or the 61-point one in the Canon 5D Mark III, are fast and dependable. Because the module sits apart from the sensor, a DSLR and lens pair can focus slightly in front of or behind the subject, and many DSLRs have an AF fine-tune setting to correct it. Mirrorless cameras don't have that problem.
Lenses and adapters
This is where used buyers should think hardest. DSLR mounts have deep lens catalogs. Nikon's F mount dates from 1959, and Wikipedia counts over 400 Nikkor lenses compatible with it. Canon's EF mount dates from 1987, and Pentax's K mount from 1975. All of that glass is on the used market.
Buying into DSLR lenses isn't a dead end, though. Canon makes adapters that let EF and EF-S lenses work on its RF mirrorless bodies, and Nikon launched its Z mount in 2018 alongside the FTZ adapter for F-mount lenses. Sony's E mount sits just 18 mm from the sensor, so it adapts lenses from almost every SLR system. If you build an EF or F lens kit now, you can move to a mirrorless body later without starting over.
Stabilization
Most mirrorless bodies in our catalog stabilize the sensor itself, so every lens you fit gets stabilized, even old manual ones. Most of our DSLRs don't, and rely on stabilized lenses instead. The exception is Pentax, whose K-1 and K-3 III stabilize the sensor. If you shoot handheld in low light with fast primes, in-body stabilization is worth a lot. You can filter for it on browse.
Video
If you shoot video, mirrorless is the stronger choice, but read the limits. The Canon R5 records 8K, and Canon's own figures give about 20 minutes of it at room temperature before heat stops the camera. Among the DSLRs, the 5D Mark IV shoots 4K as Motion JPEG with a 1.64x crop, which fills cards quickly, and the 6D Mark II has no 4K at all. If video matters, check each camera page for its limits before you choose.
Wear and what to check
Both kinds have a mechanical shutter with a rated life, and that's the number to check first on any used body. A DSLR adds a mirror that flips with every shot, so a high count means a well-worked mirror mechanism as well. Many mirrorless bodies offer an electronic shutter that doesn't move the curtains, which spares the mechanism but, depending on the brand, may not show in the count. Either way, our shutter count guide covers how to read it.
Dust reaches any sensor when you change lenses. A test shot of a plain sky at f/16 shows what's there, and our arrival checklist covers that test and the rest of a first-day check.
Size and weight
A full-frame DSLR with a fast zoom is a heavy kit, and that matters if you hike, travel or carry a camera every day. Mirrorless bodies are usually smaller and lighter, though full-frame lenses stay large either way. If light weight is the priority, look at the Micro Four Thirds Olympus bodies or Fujifilm's X mount, where the lenses shrink too.
Who should buy which
- Buy a DSLR if you want the longest battery life, like an optical viewfinder, or already own EF, F or K lenses. A used pro DSLR is one of the best-built cameras you can buy for the money.
- Buy mirrorless if you want eye-tracking autofocus, in-body stabilization, a smaller kit or better video, or you want to adapt old manual lenses.
- Either way, choose the lens mount first. Our guide to choosing a system walks through them.
There's no wrong answer on the used market, only better and worse examples of each. Check the shutter count, the sensor and the box, and you'll get a camera that lasts.
