MovieChat Forums > Photography > The dawn of digital mirrorless cameras

The dawn of digital mirrorless cameras

posted 10 years ago by poem
9 replies | jump to latest

I think its pretty exciting times right now for photography.

Digital mirrorless has three big challenges over digital single lens reflex:

- The EVF (electronic view finder) needs to have no noticeable delay, sufficient resolution, and sufficient quality. The best available EVFs (Olympus OM-D, Fuji X, various Sony) seem to have solved this problem suffiently, though future improvements are still possible.

- With mirrorless, we have a much shorter distance between optics and sensor. Current digital sensors cannot handle light falling in at an angle very well. The only camera that can handle this relatively well right now is the Leica M, but even that one is far from perfect. All other companies have to instead create optics that basically work like those made for DSLRs,

- With mirrorless, there is no space left for a specialized separate AF sensor. This leads to inferior autofocus performance. There are a couple of solutions around for this:

A) Contrast Autofocus, which needs no calibration, but also doesnt have a clue about the direction the focus has to be moved, leading to "pumping" (moving backward and forward). Olympus had optimized this with autofocus frequencies (recomputation of the focus) of up to 240 Hz.

B) Phase Autofocus on the Sensor. Like a DSLR Autofocus Sensor, the image sensor of the Mirrorless can have phase detect autofocus, which measures the angles light are falling in and thus detects in what direction to move the optics and by how much to move it. This however is done by masking light falling from certain angles on the sensor. That means only a couple of pixels do the phase detection, and the phase detection is much weaker than for DSLRs, i.e. doesnt work in low light.

C) Combined Contrast and Phase Autofocus. This tries to combine the advantages of contrast (needs no caliration) and phase (knows the direction to move) autofocus. Surprisingly few companies have tried this (AFAICS only Nikon with their Nikon 1 system, and Sony in some of their cameras)

D) Dualpixel. This is currently only available for some Canon DSLRs (the 70D was the first one). This is used when the mirror is locked up (socalled lifeview mode) and the DSLR acts like a Mirrorless (with the backside monitor as EVF). Necessary for example for video.

E) Bokeh Evaluation. Panasonic recently came out with the idea of evaluating the quality of out of focus areas to compute the focus. Kind of improving the ordinary contrast focus with a knowledge about how far to move the focus, just like with phase detect autofocus. I dont know if it is also possible to know into which direction the focus has to be moved. This only works with one camera right now and only with certain Panasonic lenses. However, first reports state it works really well.

I think sooner or later these challenges will be solved and DSLRs will be replaced, even for people who shoot action in low light.

What are the advantages of digital mirrorless cameras over DSLRs ?

- Smaller size, lower weight.

- Reduced cost. The optical system for the OVF of DSLRs is actually an extremely complex thing and needs precise alignment.

- Cheaper and higher quality optics for wide angles. Unless you are forced to avoid too steep angles, at which point to have to make wide angles work just like for DSLRs (i.e. socalled "retrofocus" constructions)

- Better viewfinder. Not only can the viewfinder be intelligent, displaying all kinds of information such as magnification of the focus point or realtime histograms, it can also be large and bright, even if the sensor itself is small. For OVFs this is only possible in dependence of the sensor size.

Though will they ? Mirrorless also have two huge problems:

- Increased requirement for power. Either you have to accept larger batteries, or you have to accept less photographs per battery charge.

- Increased heat at the sensor. Because the sensor has to run nonstop for the EVF, over time it might heat up a lot, which results in increased noise. There are already video cameras out there that use active cooling of the sensor, however this doesnt really lower the requirements for power either.

I wonder how the world will look like in 5 or 10 years. Will DSLRs indeed vanish completely ?

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A gentleman will not insult me, and no man not a gentleman can insult me.

[–] rowan_morrison 10 years ago

I am not at all excited about mirrorless cameras.

Smaller size and weight is not a factor for me at all. The size is right in my hands now with a D-SLR. A reduction in size would give me no benefit and might even be a problem. A tripod doesn't care how much the camera weighs.

Reduced cost isn't a factor for me either. Lenses are still the most expensive aspect of photography and that isn't going to change. e.g. My 200mm f4 lens would still be just as expensive and the same size and weight whichever camera you put it on.

I don't recognise the wide angle problem you mention and, to be honest, I am not sure what you mean. Could you expand on that please?

I am perfectly happy with the standard viewfinder. All it has to do is allow me to view the scene and compose my image. It's less effective than using a "view" camera, but perfectly good enough for composition and that is all it has to do.

So, no. The D-SLR will not be going away any time soon. If you want flexibility, high quality and ease of use then the D-SLR still stands out as the professional choice and I don't see that changing.

b l u e
r e d

[–] poem 10 years ago

DSLRs obviously have no advantage in sheer image quality. Not even right now.

The Leica M can already produce as good, in many cases higher image quality than any small format (36x24mm sensor size) DSLR, because the optics tend to be superior - no wonder, they are much more pricey. Theres of course extremely good optics for DSLRs, too, like the new and expensive Zeiss Otus 55mm f1.4. But especially when it comes to wide angle, Leica M profits from the shorter distance between optics and sensor, though some old Leica M optics still have to steep angles in the incoming light and will no longer work with digital Leica M.

The new Fuji X cameras, while pricey, also offer excellent image quality, and are rumored to take the step to full frame (36x24mm sensor size), with the upcoming X-Pro2. Assuming their full frame optics will have the same quality as the optics for their APS-C camera (24x16mm sensor size), they will surpass standard Canon or Nikon optics as well, just like Leica.

Technically the Sony A7* cameras also offer good image quality, but of course as long as the available optics are sparse and the adaptation of Leica M and other glas at normal to wide focal lengths is rather disappointing, because the Sony sensors are fantastic, but cant handle light coming at an angle very well, this is really not much of an option right now.

Ease of use is also no factor. If at all, the useage of DSLRs is more complex because you have to know about special things like mirror lockup. The massively increased complexity thanks to the SLR technology isnt easier to use.

Flexibility, well thats the AF quality. So that price still goes to DSLRs. Thats exactly one of the problems that Mirrorless have to solve. However, they are already faster than DSLRs with AF-S, with Phase AF on the sensor and predicative AF like the new Fuji X-T1 or the Nikon 1 cameras they can already do sports in good enough light, and they offer a wider field for the AF system.

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A gentleman will not insult me, and no man not a gentleman can insult me.

[–] rowan_morrison 10 years ago

The D-SLR wins on quality, usability and flexibility and nothing on the horizon at the moment is a serious challenge to it. My lenses are worth several times more than my camera and that is the key: lenses.

You can learn how to use all the functions on a D-SLR simply by reading the manual.

b l u e
r e d

[–] poem 10 years ago

Uh-hu.

So you dont like the idea to react to arguments and rather post your beliefs instead. Fine by me, but then I have nothing left to say.

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A gentleman will not insult me, and no man not a gentleman can insult me.

[–] poem 10 years ago

What drives me nuts recently is the constant claim that "mirrorless takes market shares".

Nope they dont.

1. Demand for mirrorless is CONSTANT. In fact slightly falling. The only reason why mirrorless wins by percent is because the demand for DSLRs is falling even faster.

Why ? Because the initial rush is over, technology has matured, and the predecessor models of cameras offer less and less additional features that are actually relevant. So people are less likely to upgrade.

For example, the Nikon D90 progressed into the D7000, the probably last really noteworthy step, an APS-C camera that offers 14 stops of dynamic range right out of the bat. Then the D7100 came and had no relevant improvement to offer. It doesnt even have WiFi yet, the next really big step for photography.

Mirrorless demand will also fall. Thats because at one point the technology will also mature, and after that, the demand will go down.

2. Mirrorless companies are "more innovative" is another stupid claim. Yes of course they are more innovative - thats because they are BEHIND. They arent even leading in image quality, a crown they had in the past with the Leica M. But the best image quality from any small format 36x24mm camera available ? Thats the Nikon D810 with Zeiss Otus optics.

It gets worse when we discuss autofocus performance of course. Still much to do for the mirrorless companies. Their AF-S is already good, in fact can beat DSLRs in the lab - but when it comes to AF-C, even worse in low light, they are still without any chance against DSLRs.

3. Mirrorless doesnt even try. Ignoring the special case Leica M, ironically there is only one system that offers digital small format in a mirrorless system camera - Sony FE. A system not without problems, most noticeably not many choices in the area of native optics for the system.

Everyone else is offering APS-C or lower.

Of course that we are in a global recession and people dont have money also contributes.

So what does this mean ? It means that yes, mirrorless have more demand than DSLRs right now. Only when it comes to bodies, though, lenses are still in high demand. And "on the street" I still only see DSLRs, DSLRs, DSLRs everywhere.

Mirrorless will have its breakthrough, but right now DSLRs are still in the lead.

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A gentleman will not insult me, and no man not a gentleman can insult me.

[–] poem 10 years ago

Ooops sorry, linked german source. Deleted.

Found a nice replacement, even if its Sony-specific, but it comments on the state of the market, not as it is in the imaginations of some people, but in reality: http://www.dslrbodies.com/newsviews/more-doom-and-gloom.html

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A gentleman will not insult me, and no man not a gentleman can insult me.

[–] Alexej 9 years ago

Demand for mirrorless is CONSTANT. In fact slightly falling. The only reason why mirrorless wins by percent is because the demand for DSLRs is falling even faster. Demand by whom? I suspect that demand is based on what sells, but probably makes no distinction between the general public and serious photographers, whether professionals or hobbyists.

The general public demands different types of cameras and lenses than serious photographers. And since only a small portion of camera buyers are serious photographers, if the demand makes no distinction, it is not a valid measure of what serious photographers prefer. So, assuming that most participants of this forum are into serious photography, the general demand is fairly meaningless to us.

My name is Colin Creevey
and I’m a photoholic.

[–] poem 9 years ago

The information you answered to is from the end of 2014 and out of date.

So, assuming that most participants of this forum are into serious photography, the general demand is fairly meaningless to us. A look at the content of this forum disproves you. The vast majority of posters here couldnt explain what the exposure triangle is.

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You shall have no other Kates before Kate Winslet.