DSLR vs Mirrorless cameras -how I see it

Created: 2019.10.29

The last couple years, mirrorless cameras have been getting a lot of mind space. I expect my next camera will be a Mirrorless. Here are my thoughts on why and why not.

I am not planning on buying a new camera immediately, but I see a business need coming up in the next year or so, so I've started thinking about whether my next will be another DSLR, and it might not be an SLR, it may be mirrorless.

First my biases so you can think about my comments about Mirrorless vrs DSLR

I've shot SLR and DSLR as my primary cameras since about 1968. I've had a few others, a 4x5 View camera, a Polaroid, a few 'single use film' cameras, some point and shoot, and since before the iPhone was invented ... what essentially is a cell phone camera. I look longingly at my Canon AE-1 with 18mm and my 4x5 view camera- but never use them anymore.

Today (2019) I almost exclusively shoot with a Samsung S9+ cell phone, a Canon 20D, and a couple Nikon DSLR's. And I have a couple Fuji S2 Pro's that I plan on using to train my young children (aged 4 to 7 as of 2019)

But for my next 'high quality' camera, I'm pretty sure it will be a mirrorless. I really like (on paper at least) the high end Sony 61Megapixel one. But it is rather expensive, and who knows what Canon and Nikon will have by the time I'm ready to do the upgrade. (Yes, I do see it as an upgrade - very VERY few exceptions - and ones that for me I think will be close enough to irrelevant that it will become my main 'real' camera - I'll use my cell phone for all the simple stuff that doesn't need the highest quality ... in other words I'll use the cell phone for 75% of my photographic needs.)

DSLR

Mirrorless

Comments

Mirror & Prism

true

false

Mirrorless is smaller and lower weight

Auto-focus phase and contrast detection sensors

true

Many/Most Newer (2019) have this, but cheaper ones don't

Make sure the mirrorless camera has both, or don't buy it - wait until there is a model you like with this feature. Note this is currently a 'cost' issue - more expensive recent models all have it.

Preview

2 great choices, viewfinder and preview option

In poor light, it will be jerky and slow, in good light, just as good as DSLR

At least one mirrorless has this. Try and decide whether you can live with this. The 'optical' view of a DSLR changes 'at the speed of light'. The view on a mirrorless will vary in quality and speed depending on the model and amount of light available. The problem in part is that currently (2019) human eyesight still far exceeds cameras in many important ways. We can look and 'see' stars - stars that might take a mirrorless camera several seconds or even a minute or more to 'see'. And if it can't see it, it can't show you a preview - even though a DSLR can.

Eyepiece

Yes, your eye is better in low light than any modern camera

Some, but it will be an electronic, so same problem as the big preview screen

If you shoot a lot of low light, you may need to stick with a DSLR for a few more years. Note, if you think 'low light' is what the Pixel 4 or 3 cell phones call low light - you are OK, ANY DSLR or mirrorless will work fine with all of THAT light. (The cell phone sensors are extremely tiny and need a LOT more light than modern 'real' cameras' need with a good lens. So when Google brags that the Pixel 4 can see in low/no light - it is comparing itself to other phones like my Samsung S9+ not comparing to 'real' cameras with low f numbered lenses and large sensors that can 'see' in less light. Test the cameras you are thinking of buying in the lowest light you expect to shoot, and see whether this is your 'killer' feature that means you need a DSLR, or whether you can live with 'point and shoot and check whether you got it' photography the few times you are in low light. If you like the eye piece of a DSLR, make sure the mirrorless has one, note that it likely will be showing the same (or close) to what the 'main' LCD shows - but in bright light this can make it easier to view.

Image Stabilization

Lens only

 Lens and electronic. For video  5-axis IS is good.

If you want to do good video, get a mirrorless with 5-axis IS.

Sensor

Full frame, APS-C

Full frame, APS-C, tiny

The smaller are mostly older mirrorless and only good for consumer grade. There was a time when mirrorless had lower resolution (Megapixels) cf DSLR and if you wanted high res, you had to get DSLR, but now (2019) you can get more pixels (61 Megapixels) than the current best Canon and Nikon (50 and 47 respectively.) Expect that new models will bounce back and forth as to which has the max, and what the cost is at each level, so this is not a mirrorless vrs DSLR conversation anymore, it is simply a model x vrs model y. Full frame and APS-C have benefits and weaknesses, discussed in several other articles I've written - but since both types of cameras come with both - it isn't a factor between DSLR and Mirrorless, it is simply the decades now old 'Full frame vs APS-C' discussion.

Video focus

Poor

Better live changing of focus

If the video work you do always allows you to have fixed focus, this is not an issue, but if you want to be able to accurately and 'best quality' you want mirrorless. Note: Older and poorer quality modern articles/blogs on the web tell you DSLR is better because of lenses - ignore them, they are now wrong, and see my comments on lenses below.

Mechanical Shutter

true

The better ones have a shutter!

Sensor chips receiving too much light need a shutter to close, then open, then close to get excellent exposure. Think about your eyes when you are subjected to bright light and then try to see - you get ghosting, sensors have the same problem. Modern sensors 'recover' in a fraction of a second - much faster than your eyes, and the shutter gives them the time they need to recover.

Lenses

All DSLR

Need special lenses, very few available in 2019

This is the BIG one where DSLR's have historically won. The Mirrorless theoretically allow better quality lenses at a lower price - fewer glass elements. Canon and Nikon may create smart adapters to let all older DSLR lenses work just as well on Mirrorless as they do on DSLR (but none of the advantages of fewer lens elements of newer mirrorless lenses.) There are 3rd party Canon/Nikon adapters, like Canon to Sony, some are high quality and high price (Metabones), and others are cheaper but they don't pass through all the electronic features. Where it was impossible to create an adapter that would allow Canon lenses on Nikon or vice versa without adding complex glass elements because of physics - there just wasn't room, because the mirrorless NEED space to use DSLR, in theory a Canon DSLR lens could be used on a Nikon Mirrorless body if someone creates the correct converter! And vice-versa. Now a Canon or Nikon lens made FOR a Canon or Nikon mirrorless camera respectively will not be able to be converted to run on the other brand - because, once again, there is no room.*

Battery life

Better

Not as good

Carry spares either way. If this really is a problem for you - you aren't really all that serious about photography and so you never read down this far! But you DID read down this far, so just get used to carrying an extra battery if you need no matter what camera you use and don't let this be a deciding factor, or learn how often you need to charge, and make sure you charge before you run out of power. (I keep a car charger and a couple charges at home and in my office.) Some people point out that 'because the camera is physically smaller the battery has to be smaller'. Well, OK, no, that doesn't follow - you can make the camera body big enough to fit whatever size battery you want to have, and for years DSLR's have had 'battery grips' and other ways of getting bigger batteries. However, while their logic of the reason is flawed, if the mirrorless camera you are looking at only allows for a small battery - it doesn't really matter to you what the reason is! But again, my response is simple, carry enough spare batteries for what you want to do, and charge the batteries when convenient and when you need to. When I do a professional shoot - I carry a minimum of twice as much battery capacity as I need. (And I carry 5x's minimum for storage space too.) Here's an interesting side note: If manufacturers made the camera bigger for a bigger battery, they could also get around the 'not enough space for controls' issue (see below.) So this issue of 'not enough space' is just a excuse for the design choices the manufacturer made, not a valid reason. If the manufacturer thinks they will sell more with a bigger body - they'll make the body bigger just like DSLR's with battery grips. Same with battery size and controls. But obviously, any manufacturers that CHOOSE a smaller body have made a choice of what they think consumers will pay for. Note that DSLR's cannot be made as small as mirrorless, so the opposite doesn't hold true, because they need the room at a minimum for the prism and the mirror. So with mirrorless, making the body smaller is a marketing choice, not a necessity - but most are choosing that so the effect to me the consumer is the same - for now at least. Interesting side note - since DSLR's need the space for the prism and mirror - you can actually have a BIGGER battery in an mirrorless if the bodies are the same size.

Durability

Some models

Some models

If you need dust, water protection, make sure you get a model with it, and yes it will cost more with both types.

Dust on sensor

Much worse than Film, but they have a mirror to protect somewhat.

Much worse than Film Slightly worse than DSLR No mirror for 'protection'

You really should be careful changing lenses, if you are, this should be a minor downside. And really, if you get dust inside the body, with the mirror flipping up and down, dust is eventually going to get onto the sensor in a DSLR, so this is a minor advantage to DSLR. Well, maybe not: The mirrorless is easier to clean, first because it doesn't have a mirror you have to get out of the way, and second because the sensor is not as deep in the body so it is easier to reach and clean it. But then that also makes it easier to scratch the sensor. I think I'm going to call this one an unimportant draw.

Controls

Relies on lots of dials and buttons.

Relies mostly on touch screen.

In part because the bodies of mirrorless are smaller, you will have most of your controls on a touchscreen (like your cell phone) rather than lots of buttons. Current (2019) models end up like this: The mirrorless are, especially for beginners, easier to use because of the convenience of the touch screen. The DSLR are, especially for experts, faster to use because you have 'everything there' and available to change instantly - you don't have to wade through a 'pretty' UI several steps to do a common adjustment you like to make between photos. There is no REAL reason this has to be. A DSLR could easily have everything both on buttons and in a nice touch screen UI - so that you can do YOUR common changes with buttons, and the things you don't do often enough to remember which of the 20 buttons to use - you can use the user friendly touchscreen to do the things it isn't worth memorizing how to do. In addition, there is no reason a mirrorless can't have a body big enough to allow all the buttons. In other words this is more a decision of the camera designer than it really has to be a DSLR vs mirrorless. Part of the problem from a design perspective is that different photographers have different needs for what to change. For example, I'm always playing with the ISO and compensation setting - but I very seldom use the 'mirror lockup' function and focus preview and have to figure it out every time I need them, but another photographer might need those and not care as frequently about the features I use.

* I want to discuss the issue of interchangeable lenses from different systems a bit more technically

.

Lenses are very complicated devices. I'm just going to talk about the practical differences between DSLR and Mirrorless.

Here is the important difference: The distance from the flange (where it is mounted) to the sensor is about 44-47mm (Canon 44mm, Nikon 46.5) on DSLR cameras, but on Mirrorless, it is much smaller: 16mm Nikon Z, 18mm Sony-E,

Plus, there is no mirror flipping up and down, so the back element of the lens can protrude into the body!

On lenses less than about 46mm (whatever the flange to sensor distance is), you need to put some extra glass in the lens to make it work on a DSLR. On lenses less than about 18mm for mirrorless in theory you need to put extra glass in unless you have the lens protrude into the space where the mirror would be on a DSLR, so in practice, given that there aren't many lenses much shorter that 18mm - I don't expect ANY mirrorless lenses to have this extra set of glass - I expect the lenses that go less that 18mm on mirrorless to just protrude into the body.

\ This means that in every zoom lens that can zoom less than 46mm, you have to have extra glass for it to work. Now, every piece of glass you add will degrade the quality of the image - slightly on a good quality lens, but slightly is more than 'zero'.

In the following, to avoid giving a host of different numbers that are really insignificant, I'm going to use the Canon 44mm to Samsung 18mm Mirrorless cameras (26mm difference, very close to 1" for my American Friends.)

If you take a Canon DSLR lens, run in Manual mode, and want to attach it to a Sony Mirrorless camera, all you have to do is extend it out from the body by 26mm (44mm minus 18mm is 26mm) and voila, you are running a DSLR lens on the Sony body. Now, hand holding this with a black tube would be impossible, but there are low cost adapters that let you run DSLR lenses on Mirrorless bodies (Nikon DSLR on Sony, Nikon or Canon, Canon DSLR on Sony, Nikon or Canon.) Now if you are happy with full manual mode, you are done.

But most of us want the automatic features. So now we need an adapter that is smart - it can convert (where necessary) and pass through the 'messages' from the Camera to the lens and the other way. Turns out, with 26mm (1") of distance, there is lots of room to "easily" add the electronics, of course Metabones might disagree with my comment "easily", but the point is - they exist and they work.

So now, you can use your Canon and Nikon DSLR lenses on Canon, Nikon and Sony mirrorless bodies, and if you have a good quality adapter, it will give you exactly the same quality and benefits as using the lens on a DSLR camera.

Noting, that if the lens is or goes to a focal length less than about 45mm, essentially all your wide angle lenses, will 'only' be as good as when you use them on a DSLR camera. But because of the lower flange to sensor distance, you can (at least in theory) get better quality lenses than DSLR will ever be able to down to about 16-18mm (whatever that camera has as it's flange to sensor distance) and with the ability to protrude into the body, even that 16-18mm limit is not a real limit.

Can you see why you can't get an adapter to put Canon DSLR lenses on Nikon DSLR cameras or the other way around? If you want to put a Nikon DSLR lens on a Canon DSLR you have 2 choices:

  1. Make it 2.5mm thick (think the thickness of about 27 pieces of paper.) not a lot of space
  2. Put an extra set of glass in a thicker adapter(lowering the quality of the image.)
  3. Use whatever space you need, but now the lens cannot focus on 'infinity'.

This is why there are no adapters (that I know of) to allow a Nikon DSLR lens to work on a Canon DSLR

If you want to put a Canon DSLR lens on Nikon DSLR camera.

  1. Put an extra set of glass in a thicker adapter(lowering the quality of the image.)
  2. Use whatever space you need, but now the lens cannot focus on 'infinity'.

If you want to put a Mirrorless lens (any manufacturer) on a DSLR lens, you need to chop about 26mm off the lens (obviously you can't do this) or add a bunch of glass in-between.

So in summary:

  • Using a DSLR lens on a Mirrorless camera, any brand to and brand, is relatively easy and if you get a good adapter, it will almost always* be exactly as good as it is on the DSLR camera it was designed for.
  • You can not put a mirrorless lens on a DSLR
  • You can not put a lens of one DSLR on a different brand (unless it has a special replaceable mount like a T-mount)
  • You can not put a lens of one Mirrorless on a different brand (unless it has a special replaceable mount like a T-mount)
  • In theory, lenses, especially wide angle or zooms with wide angle, should be BETTER at any given price when built for mirrorless than when built for DSLR because they need less glass down to about 16 (Nikon)-18mm (Sony) focal length lenses, and because the back element can extend INTO the body, even that 16-18mm limit is not a real limit. If you want to have an 16mm on a Sony (18mm), you need only to have the back element protrude 2mm (22 sheets of paper thick), if you want a 9mm, you need only have it protrude 7 to 9mm (about a 1/4") into the body.

*when I say "almost always" - that is weasel words. I'm assuming there is probably some condition I have missed and therefor some lenses in some conditions may not work as well. I can't think of any, even fancy tilt/shift lenses. But I'm hedging by bets so that if someone tells me I'm wrong in condition x with lens y, I'll be covered and be able to say I was right! Update based on a verbal comment from a friend: No, I would not make a good politician.

There is ONE little detail that the camera manufacturers have to worry about to achieve these benefits. You mostly ignore this other than if you are interested, as long as the camera manufacturer says a specific lens will work with their mirrorless camera. The sensor has to be able to accept light coming on it at a sharp angle, possibly an extremely sharp angle in the case of my imaginary 9mm lens. But this doesn't affect you - other than if there is a limit to which lenses work. This should have NO problem with ANY DSLR lenses, since a mirrorless camera HAS to be designed for light coming from angles based on the 16-20mm flange to sensor distance (compared to the 40+mm distance of most DSLR flange to sensor) distances. So right off the bat, a good quality sensor on a mirrorless camera must work with sharper angles than DSLR must work with.