top of page

The DSLR - Life & Death


Before the DSLR and even before film SLRs were retrofitted with digital components - Digital sensors started out in "compact" & "mirrorless" form. These cameras were initially consumer toys; playful with deign, but crippled by emerging technology. Tiny, low-resolution sensors. Low capacity, sluggish memory. Slow and simple processing. Poor autofocus and screens. Basic and poorly laid out menus systems. All this made for a rather unpleasant user experience. Certainly nothing that would inspire professionals.


First purpose build DSLR - Nikon D1

A Star Was Born

Adding a shutter, mirror and prism of an SLR to the rapidly improving digital technology was a stroke of genius that made for a much nicer shooting experience (even if manufacturers rather stumbled into it). Using familiar controls and the same lenses were important aspects for professionals, but the real success was the way the mechanism masked the technologies rough edges. It added a sense of elegance that digital would not possess on its own for quite some time.

Burning Bright

This trend started very naturally by initially bolting digital components to existing film SLRs. Beginning with Kodak's DCS 100 in 1991, which used a Nikon F3 (without permission from Nikon). Purpose built DSLRs started with the Nikon D1 in late 1999. For the next decade and change the DSLR improved massively. Its popularity soared as we saw huge jumps in image quality and even lens design refined itself to cope with digital imagery. Full frame sensors emerged early with the Canon 1Ds in 2002, but ramped up in popularity with the 5D in 2005 and again with Nikon's D3 in 2007. Full frame got much cheaper with cameras like the D600 in 2012 and it seemed ou


Technology moved really fast, mirrorless cameras emerged in 2008 with Panasonic's DMC-G1. The first professional mirrorless camera (Sony A9) came out in 2017 and in 2021 Nikon's Z1 removed the physical shutter mechanism entirely. The last mechanical relic from SLRs has started to disappear. The writing is on the wall for DSLR development now, but why is this not happening, why can't DSLRs continue to exist, side-by-side with mirrorless? After all; APS-C and full frame sensor sizes had different lens systems, so why is this now a bigger problem?


Unfortunately for DSLRs, they are being attacked from all sides. Firstly; Mirrorless cameras can have more features and speed, in a smaller, cheaper package. Secondly; Smartphones are rapidly improving. They will never get as good as a dedicated camera, but everyone has one and so the camera market is continuously shrinking. Ideally manufacturers need to focus on a single system to stand a chance of survival. Last but not least DSLRs have several limitations....

Mirror Limitations

The optical viewfinder, mirror and shutter mechanism of the DSLR are a fascinating piece of engineering history, but it's also true that they somewhat held them back. As technology has evolved its once greatest strength has become its biggest weakness. It restricts lens design, limits their focus systems and makes previewing depth of field difficult or even impossible. It limits their usefulness in dark conditions, or with ND filters. It simply doesn't work in UV or IR wavelengths (usually after conversion). Information overlaid on an optical viewfinders is extremely limited and using them to look towards the sun can be dangerous. None of this would be an issue for electronic viewfinders.


The exponential improvement of digital components over the last few decades has enabled mirrorless cameras to leapfrog over the venerable DSLR's functionality. Although mirrorless was initially marketed on simply being smaller & lighter, ultimately they're becoming more capable (reliable, versatile, faster and silent). To illustrate this let's compare features from Nikon's latest flagship DSLR (D6 - 2020) to Sony's first flagship mirrorless camera (A92017):


Feature        | Nikon D6 Sony A9 

  • Price (USD)

  • Weight (g)

  • Resolution (mp)

  • Burst (max fps)

  • Buffer (# of RAW)

  • Shutter Lag* (ms)

  • Shutter Speed (max)

  • Startup Time (sec)

  • ViewFinder Blackout

  • AF Points

  • AF Coverage (%)

  • Eye AF

  • Battery Life

  • Silent Penalty**

  • DxO score: DR

  • DxO score: ISO

  • Lens Calibration***

  • IBIS (Stops)

  • Vertical Grip

  • LCD Screen


















No (0)




















Yes (5)



NOTES: BetterWorse / Similar

* Shutter Lag: A prefocus shutter lag time to state how responsive the camera is in its natural mode.

** Silent Penalty: Whether the camera slows down or loses functionality during silent shooting.

*** Lens Calibration: Whether lenses suffer from front/back focus issues, requiring calibration.


Mirrorless technology and electronic viewfinders (EVFs) have allowed cameras to keep all the functionality from DSLRs while being smaller, but they also bring a host of additional features. Many of these things don't show up on a specification sheet, but can make a tangible benefit to your photography:

  1. Live Exposure - No more guessing exposure. Makes shooting full manual much easier, faster and better

  2. Silent functionality - the viewfinder & primary autofocus functions equally when shooting silent or video

  3. No Chimping - reviewing images is now unnecessary - correct DoF and Exposure are shown in real-time

  4. Augmented Info - the viewfinder can show: histogram, levels, eye-AF, focus peaking, clipping etc.

  5. True Focus DoF - permanent DoF preview that shows the correct depth & unaffected by brightness

  6. Focus Magnification - makes manual lenses or checking focus, very fast and accurate

  7. No light leaking - viewfinder doesn't need to be covered during long exposures

  8. Focus & Speed Unhindered in Live-View - due to no mirror moving to switch systems

  9. Shooting Into The Sun - is no longer dangerous for your eyes

  10. Image Review In Sunlight - when you struggle to see the rear screen

  11. Crop Lenses - show just like full frame (zoomed in and 100% coverage)

  12. Viewfinder Colour - showing the world with white balance adjusted colours (full spectrum game-changer)

  13. See With Opaque Filters - strong ND, IR or UV pass can still show a normal exposure in the viewfinder

  14. IBIS - DSLR viewfinders would bypass the sensor stabilisation effect, if any DSLRs had the feature

Extreme Speeds

DSLRs fastest burst speeds are seemingly at their limit due to the mirror and shutter mechanisms. Speeds, like 14-16fps (for the latest Nikon and Canon DSLRs respectively) mean the mirror is only in position (for you to see and the AF to function) for a tiny fraction of a second. In many circumstances this is not enough time for focusing system to track subjects reliably, forcing these speeds to drop.

The focal-plane autofocus sensors of mirrorless cameras are more efficient and accurate than an SLR system (never needing focus calibration). They can be more responsive with no mirror to move out of the way and if you remove the shutter as well they can constantly see and track the subjects while being silent, giving them a huge speed and reliability advantage, as well as making them more useful for other types of photography (like: weddings, sports, church, wildlife, street etc.


DSLRs try to incorporate both systems to desperately compete, but having two entirely different focus systems is expensive, increasingly unnecessary and even confusing. Even if you don't mind the extra bulk, complexity and cost of these two systems, DSLRs still lose their viewfinder when using the more advanced features. Their battery life can drop below that of a mirrorless camera despite being much bigger and usually don't have in body stabilization or articulating rear LCD screens. 


Rolling Shutter

Electronic shutters have a host of benefits (higher shutter speeds, reduce mechanical wear, silent shooting), but unfortunately rolling shutter has been an annoying limitation. This is due the time it takes the sensor to read and store all the pixel data (from top to bottom). This can be a confusing issue to understand, but without the physical shutter there is no easy way to stop traditional CMOS sensor photosites from gathering light before they get written to memory. Simply writing the data faster has not been an option due memory speed and heat issues, so they simply scan slowly, like a flatbed scanner.

For static subjects this is not an issues, but panning with moving subjects can distort objects that can ruin an image. Thus, with the electronic shutter, "rolling shutter" (or "scan speed") can be very important. Although it's something that's gradually getting better over time, many cameras are still too slow to shoot fast moving subjects without distortion. Here are some sensor scan speeds from a few popular cameras that I could find around the internet (for stills photography, NOT video). Colour coded to help illustrate severity.


NOTE: Take this data with a pinch of salt as most come from single independent sources (usually not from the manufacturer).

Rolling Shutter | Speed | ms

  • PhaseOne IQ4

  • Hasselblad X1D

  • Fuji GFX 50s

  • Fuji GFX 100

  • Sony A7R IV

  • Sony A7R II

  • Canon EOS R

  • Sony A7 III

  • Nikon Z7

  • Nikon Z6

  • Sony A6400

  • Sony A7S

  • Fuji X-T2

  • Sigma FP

  • Panasonic GH5

  • Sony A6300

  • Canon EOS R6

  • Fuji X-T3

  • Canon EOS R5

  • Fuji X-T4

  • Sony A7S III

  • Sony A9

  • Sony A1

  • Global Shutter

















































- Don't

- Terrible

- Poor

- Ok

- Good

- Great

- Perfect

Several professional cameras (Canon 1Dx III / Nikon D6) boast high "electronic" burst speeds without mentioning rolling shutter performance, despite being built for action photography. If this speed were high enough not to cause issues you can be sure they would shout about it, thus if it's something you think could affect you I would advise avoiding these models for silent shooting.

Some people are more sensitive to this issue than others, but this will mostly depend on the subject you're shooting and what it's doing. Larger birds in flight will often not be an issue, smaller birds - more likely. Panning shots with geometric detail in the background is a common issue, but it will depend how fast you're moving, how long your focal length is and how much the subject fills the frame. High speed spinning things like propellers, fans etc. are the worst case so consider carefully how likely you are to photograph these things in silent or burst mode.

The End

Like film cameras in the early 2000's, DSLRs will still function, be enjoyable to use and available on the second hand market for some time to come. However, it's increasingly clear that their commercial viability will soon be over. Mirrorless cameras simply offer more features in a more reliable package and for less money as time goes on. Sure some people will be disappointed that they can't go out and buy a brand new DSLR for a while, but eventually they will realise that they gained a lot more in the transition than they lost.

What's Next

Lens size is intrinsically linked to image quality due to physics, so phone cameras aren't going to make mirrorless cameras obsolete. The next jump in hardware innovations will probably be from something like global shutters. On the more fantastical side; I'm hoping for curved image sensors, which would remove the need for so many corrective elements in lens design. Although this would shrink lenses a bit, it would also make cameras bigger, more complex and expensive, pushing cameras to a smaller niche of user... 

bottom of page