The Life And Death Of The

Digital SLR

35mm film cameras were popularised by Leica rangefinders in the 1920's. That format shifted to SLRs during the 1960's, giving photographers the ability to see through the lens. With the Nikon D1, purpose built digital SLR cameras initially embraced the format, but their second decade has largely been spent demonstrating just how much better off cameras are with no mirror at all.

DSC07038bs.jpg

The Nikon D1 (1999) - The first purpose built DSLR

 

After 6 years of mirrorless exclusivity I recently went back to using a DSLR. The initial shock of it being large and clumsy was soon overshadowed by the several things that it straight up couldn't do.

The debate over whether a camera should use a mirror or not has been raging for a while and I wasn't quite sure where I sat on this topic until now. Previously: I saw the two technologies as having fairly equal pros and cons, but over the past few years this has changed. It's easy to view optical viewfinders (DSLR) as superior because they have no lag, unrestricted dynamic range and infinite resolution. However, as EVF technology rapidly approaches the limits of human vision, they bring a host of benefits in their wake. 

 

To help illustrate what I mean, let's look at two modern professional cameras...

This is a feature comparison between Nikon's latest flagship DSLR (2020) and Sony's first flagship mirrorless camera (2017):

Feature        | Nikon D6 Sony A9 

  • Price (USD)

  • Weight (g)

  • Resolution (mp)

  • Burst (max fps)

  • Buffer (# of RAW)

  • Shutter Lag* (ms)

  • Shutter Speed (max)

  • ViewFinder Blackout

  • AF Points

  • AF Coverage (%)

  • Eye AF

  • Battery Life

  • Silent Penalty**

  • DxO score: DR

  • DxO score: ISO

  • Lens Calibration***

  • IBIS (Stops)

  • Vertical Grip

6,999

1450

20

14

133

39

1/8,000

Yes

105

26

No

3600

Yes

12.3

2434

Yes

No (0)

Yes

3,499

673

24

20

241

20

1/32,000

No

994

93

Yes

650

No

13.3

3517

No

Yes (5)

Optional

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 the camera's lenses suffer from front/back focus issues, requiring calibration.

Summary

It's pretty clear that this didn't go well for the DSLR. Now, the D6 wasn't the most exciting camera launch ever, but it has a three year advantage over the mirrorless competition and the story doesn't change drastically for other manufacturers. Other than battery life there are no clear objective benefits for DSLRs, but the benefits for mirrorless goes far beyond this list...

EVFs (Electronic ViewFinders) And The Future

Replacing the optical viewfinder with an electronic one brings a host of features. DSLRs have tried to bring some of these features over when using live-view, but it's not always possible. Here are the most obvious features for EVF (over OVF):

  1. Live Exposure - makes shooting full manual much easier, faster and better

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

  3. No Chimping Required - no need to review images - 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

I love DSLRs as a piece of history, but it's impossible to ignore that the optical viewfinder holds back the users creativity. It restricts lens design, limits their focus systems, makes previewing depth of field impossible (for fastest speeds) or just so dark you can barely see when stopped down. It limits their usefulness with ND filters or simply doesn't work at all for UV or IR wavelengths (after being IR or full spectrum converted). The information overlayed on an OVF is extremely limited on a DSLR, while looking in to the sun is actually dangerous. All this while making cameras (and often lenses) bigger, heavier and more expensive.

Silver Lining

The extinction of a format is unpleasant, especially for anyone invested in those systems (new models and support for existing ones will soon dry up), but there is a silver lining to this imminent change. The sooner the industry moves on the sooner manufacturers can focus on features for this more logical step in the evolution of photography. 

Mechanical Obsolescence 

Silent shooting reduces the strain of mechanical fatigue on a camera. The ultimate progression of that to a sensor with global shutter will entirely remove the need for a physical shutter mechanism and any moving parts during shooting. This will drastically reduce key points of failure in future mirrorless cameras.

What's Next

Some might assume that camera phones (and computational photography) will someday replace mirrorless cameras, the way they did with compact cameras. However, this is unlikely to happen given how large lenses have always been intrinsically linked to high image quality, light gathering and depth of field. Shorter flange distances have allowed wider lenses to be a little shorter, but many modern optics have also gotten larger due to an increased demand in optical clarity while reducing aberrations.

 

Lens size is most likely a fundamental issue of physics, however there is hint that curved image sensors will soon be developed commercially. This will remove the need for so many corrective elements in the lens groups. Although this will shrink lenses further it won't bring them down to phone sizes and they will have some really difficult caveats to overcome before they are viable for different focal lengths. The short answer is don't hold your breath for pocket sized wildlife cameras, or shallow depth of field.

Back To DSLRs

Just 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 far more features in a smaller, cheaper and more reliable package. If you haven't switched yet, start thinking about it...

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