Mirrorless cameras, the e-mount and its lenses

This is a response to the article found at PetaPixel, published by the author Sator, regarding claims that the e-mount is flawed. The “Angry Photographer” (aka Theoria Apophasis in the comment sectionand others have publicly sided with the article; acid tone or otherwise, it’s incorrect. I generally avoid targeting specific articles found on photography websites for obvious reasons. I’m not a great photographer, but I know a little about materials, physics, making things, etc. and it’s frustrating/upsetting to see people mislead. Those who attempt to refute people like Sator, The Angry Photographer, etc. often do it in an insulting fashion and this derails discussion.

I believe the more you go out of your way to argue a point, the further it makes certain people act defensively. Perhaps this article will do nothing for those people. Where I stand is simple, if I buy something expensive and it doesn’t do what I want, I tend to hold it to a higher standard than a cheaper item. With that in mind, I’m a reasonable person. Please be reasonable back, if you respond in the comment section.

Article Published on: 7 Apr 2016 at 16:25. Update for 10 Dec 2019. An "I told you so."

I don't want to re-write/edit all of this. Since writing this article a few things have happened:

•	People like Sator, The Angry Photographer, etc. did not come forwards and admit they were wrong (despite buying numerous mirrorless cameras).
•	Fujifilm released a "medium format" mirrorless camera which is (relatively) small.
•	Canon & Nikon released relatively small full-frame mirrorless cameras.
•	Canon released the RF 70-200 f/2.8 IS L lens which is considerably smaller than the Canon EF 70-200 f/2.8 IS III L lens.
•	Sony released numerous small/light lenses including a long telephoto which is considerably lighter than the DSLR equivalent.
•	Sigma designed lenses for the e-mount but kept many of their DSLR designs proving mirrorless cameras give you options as opposed to creating impossible difficulties. 
•       Tamron designed lenses for the e-mount and made them considerably smaller than their DSLR equivalents.
•       Godox released the best, most colour stable speed light - the Godox V1.
•	Several hundred new lenses have been created for the E-mount.
•	Nikon has suffered considerably more financial difficulty in comparison to Sony.
•	Sony created new, wireless flashes.
•	Sony created a new bluetooth remote allowing you to set macros to the custom buttons.
•	The Sony a9II and Sony a7r IV cameras were introduced; both address battery life, sealing, menus (somewhat), dual card slots, etc.
•	Profoto created a Sony transmitter.
•       Fujifilm, despite being touted as a camera company as opposed to Sony the "consumer electronics company", made a complete mess with its camera line-up. It doesn't compete in full-frame, the most popular format for professionals and the lenses all have different filter sizes.
•       Canon & Nikon still don't have dual card slots for their cameras.

What inspired me to write this

The article at Petapixel was full of disinformation; disinformation isn’t necessarily threatening but I believe these types of articles have a direct impact on the sales of Sony cameras. It transcends beyond a few fallacious arguments and results in fictitious comments spewed over many websites. It is not my intention to convert devout followers of Canon, Nikon or Fuji but rather help those that’re a little more open minded. Perhaps those that’re concerned and might be asking themselves, “is there any truth to these claims?”, and for the most part, the answer is no.

As I said, I’m not a great photographer. I am one of the first to own the Sony a7rII and I’ve had it since release. I’ve hiked around 20 miles a day with it–repeatedly, not just a one day hike–climbed mountains with it on days it’s been really hot and extremely wet and cold, slept with it in a high humidity environment, fell over with it a few times (partly due to the rain), etc. Below are some photographs that show altitude, mist, heat, etc. They’re not good photographs but they show ranging conditions.

If you wish to criticise the firmware–I’m all aboard. I do not support people that say the e-mount is flawed by design and pointlessly whine about it; not only are their claims fictitious but they are counterproductive. I also don’t have financial ties to any specific companies (unless stated in the privacy policy). I like to buy what works for me. I’m explaining this so you see I’m fairly open, honest and unbiased.

Again if you wish to insult Sony’s customer service on certain parts of the world, I’m in agreement with you. This also applies to other large corporations i.e. I’ve received an equal customer service from Canon as I have Sony.

Response to the article

Sator’s article is somewhat old now but the five main points still get brought up numerous times:

  • Size
  • Weight
  • IBIS (In body image stabilisation)
  • Adapting lenses
  • Live exposure preview


Sony’s a company that likes to experiment; sometimes those experiments fail and sometimes they succeed. It’s quite common for electronic companies to take big losses and make big gains. Sator compares Sony’s mirrorless camera customers to “lemmings following each other over a cliff”. His justification is that since he bought the camera, it’s okay for him to insult people–this should never have been published.

Things go south (as if they weren’t already) when he tries to speak objectively about camera size. His size comparisons are misleading at best: there’s cameras with different features and lenses with completely different optical qualities put on the table; there’s even a lens with an incomparable focal length thrown into the mix. If the reader doesn’t have much knowledge regarding specific Canon lenses, he or she might conclude the comparisons are fair, after all, that’s just a “55mm f/1.8” we’re looking at and the other one is close enough if it’s a “50mm f/1.8”, right? By this logic, there’s zero difference between a Canon 50mm f/1.4 compared to the Zeiss Otus 50mm f/1.4. If you really want to be precise in your arguments, you should measure the weights and volume of each lens element. For example, Sony or Zeiss Lens elements might weigh 30% more than Nikon lens elements, even when they’re identical in volume. My advice here to anyone making comparisons is be careful about making them in the first place.

The laws of physics

It would help me to know what “laws of physics” he is referring to in the article; moreover, it would help me to refute. It’s difficult to refute something when you don’t prove that something exists. He doesn’t give us any objective information and quotes taken out of context by employees of known companies doesn’t do much for me. It is imperative you understand Sony published a lot of information about the e-mount and they stated it was designed for full-frame from day one. They made this claim before e-mount APC-S was on the shelvesAs an additional note, a while after I wrote this page, Kazuto Yamaki (president of Sigma) confirmed Sigma’s plans to make lenses for the Sony Full Frame E-Mount.

Sator’s main argument regarding physics is that the mount is too small in diameter to support IBIS, and “if you take something from the camera body, you have to give it back to the lens, and by the same amount“, note “have to” i.e. an absolute. This isn’t a “general rule” (as per the Angry Photographer’s claims in the comment section below) type statement–it is binary logic…

Having the sensor closer to the lens mount gives designers choice. A spacer can be added to a DSLR lens design and this equates to a smaller total system volume (it would potentially allow room for drop in filters too) or they can design a different lens type altogether specifically for that mount to sensor distance and sensor design (my preferred method); they’re not forced to rely on retrofocus lens group designs (whether that’s in a positive or negative configuration), as is the case with DSLR lenses. To elaborate, you can reduce the size of a lens by reducing the back focal length (the distance from the vertex of the last optical surface of the system to the rear focal point i.e. distance from the sensor to the rear element); in layman’s terms, you can make your lens shorter than its focal length. Conversely, you’re able to reverse (some people say “invert”) the configuration (relative to a DSLR) to increase the back focal length and circumvent the issue of having the mirror hit the rear lens element–you can make the lens longer than its focal length but it might come at the cost of extra elements.

If your rear lens element jams against the mirror of the camera, the camera isn’t going to work too well; in other words, you have less options with a DSLR. You might not have the choice of putting a spacer between the rear element of the lens and the lens mount because the sensor is already way too far back, so you’re forced to design lenses around an inherent flaw (compromise: it’s arguably not a flaw). It’s not that the laws of physics change, it’s purely that you changed the variables. You don’t walk slower in water because the laws of physics changed (no one claimed that); you walk slower because a variable has changed: water is more dense than air.

If this still isn’t clear, imagine a wide angle lens and the light rays are coming off of the rear lens element (the end that faces the camera) at a steep angle. Now imagine you’ve put a toilet roll on the end of the lens and you’ve attached that to the camera. The light rays can no longer hit the sensor; at that same angle you imagined, they would hit the walls of the toilet roll; to get around this, you can add extra elements to redirect the light rays towards the sensor.

Crop DSLR vs Full Frame DSLR back focal length

Obviously a crop DSLR has a smaller mirror because its sensor is also smaller. Therefore, should the distance between the sensor and the lens mount be the exact same as on a full frame camera? It certainly doesn’t have to be, so why do they do it? This allows camera manufacturers to use the same lens mount for many cameras and this helps synergism between different camera formats–it helps keep the costs of manufacturing down too. With the e-mount, things are different; there’s no mirror in the way, so all of the cameras can benefit from the short sensor to mount distance. DSLR 0, Mirrorless 1.

Lens size

We may wonder why it is that a few Sony lenses are large, but that might be because a) they’ve chosen to use designs primarily based around older DSLR lenses to increase the speed at which they can create a full line up of lenses, with the intention of expanding their lens line up at a later date i.e. they’re rushing slightly so as to expand their system rapidly b) they’ve gone for optical perfection and have increased the size of their lenses in a similar way to Zeiss with the Otus series of lenses c) they felt that because their cameras are so small, they had room to make bigger lenses and it wouldn’t matter d) reasons not thought of or known.

Lens design in general is difficult, it is one of the reasons that most manufacturers are using the same or similar optical designs from the 1950s. It is difficult, but not impossible to design a smaller lens; Sator implied it was impossible to have a smaller total system volume due to some hidden law of physics that no one else knows about except him or people of his kind–such people cannot explain themselves or prove their claims to be true, they can only insult (please refer to the comment section below.)

I believe Sony’s tried to go for optical perfection with their Sony 70-200 f/2.8 G Master lens since it’s aimed at a certain demographic that won’t care too much about size, and they’ve perhaps rushed a little with other lenses such as the 24-70 f/4 (it’s still smaller and lighter than any equivalent though). The Sony 70-200mm f/2.8 G Master lens also fits an extender. I believe that when the system has matured a bit more, we’ll see different companies try to make smaller lenses (after writing this article, this was proven to be so as numerous companies came out with numerous lenses, many of which are smaller than a DSLR equivalent.) If I were to make comparisons about the distance between the sensor and the front element of a lens, I would at least line up the sensors so they’re in the same position–he didn’t do that–cameras have markings on the top to help with this. Another belief I have is that certain compared try hard to milk their products and they want their lenses to be compatible across many formats. I adore Zeiss’s method as they have an approach that appeals to the purist. They probably could have made their Milvus lenses compatible with the Sony e-mount system but instead they made an entirely separate system altogether; The Zeiss Loxia 21mm, Zeiss Loxia 35mm, Zeiss Loxia 50mm and the Zeiss Loxia 85mm are all beautiful lenses in my opinion. When you compare them to the equivalent DSLR lenses, they’re smaller; this, however, doesn’t fit the agenda of someone like Sator or the Angry photographer so you’ll rarely hear them mention these lenses.

The Sony Zeiss 24-70 f/4 is not a great lens optically, but it has a metal shell and it’s surprisingly lighter than the competition. There are many examples where this is the case for Sony mirrorless full frame lenses. In some cases, a direct equivalent doesn’t exist. There is no 55mm f/1.8 made by Canon that’s optically comparable to the Sony Zeiss 55mm f/1.8. This is why “comparisons are odorous” ~ Shakespeare’s deliberate misquote.

Lens design is far more complicated than the back focal length, but if in the worst case scenario the same design of lens was used on a mirrorless camera as the DSLR camera, and a spacer was added to make the lens a further distance from the camera, then the overall volume would still be greater on the DSLR.

In many cases, a Sony full frame mirrorless system works out considerably smaller than a comparable DSLR. For street and landscape photography, there are plenty of smaller lenses compared to DSLR equivalents. If Zeiss could have designed DSLR lenses as small as their rangefinder lenses, I believe they would have. This is something else you should consider. Small lenses aren’t exactly new to the world. We’ve seen small rangefinder lenses before.

Originally developed for SLR cameras in which, due to the mirror box, a long back focal distance is required for short focal lengths (the distance between the back lens element and the film plane must be considerably longer than the focal length), the Distagon lenses (retrofocus design) are also ideal for mirrorless system cameras thanks to their optimized ray path. This also enables excellent image performance with large image angles for digital camera systems without mirrors.

In SLR systems, when extremely large image angles are needed, the distance between the rear element and the image plane must be considerably longer than the focal length – the original field of application of Distagon lenses. This advanced retrofocus design can also be put to outstanding use in modern, highly corrected lenses with longer focal lengths.

It’s in street and landscape photography where a smaller size is most beneficial, I believe.

There’s an entire range of Voigtlander, Leica and Zeiss m-mount lenses that work on the Sony cameras. I understand they’re not the same mount (at the time of writing; however, Voigtlander released quite a few smaller lenses after this article was published, proving my point all the more), but it at least proves physical and optical possibilities. Some may argue that “street photography” or “landscape photography” or the lenses I have mentioned make for an exception fallacy. If you read the comment section below, you’ll see the Angry Photographer aka Theoria Apophasis aka Ken Wheeler aka Photographer100, has stated my argument is “THE FALLACY OF EXCEPTION.”

If you make the claim that it’s optically impossible to create something because it defies the laws of physics (scroll up to see the original quote, and observe where I quoted “have to“), then someone only needs to find one exception to prove that it’s a fictitious claim. It’s not like saying “the Earth’s surface is mostly water”; it’s more like saying “the Earth’s surface is only water” and then someone pointing to Russia, China and America; exception fallacies do not exist when contesting absolutes.

We also have to define “bigger” and agree on a premise. What is “bigger”? Volume? Mass? Area? Width? Depth? Height? I’m sure there’s someone that would argue it’s bigger for all of these, but it’s not the case. The GM lenses are undoubtedly quite large, but if we take the 85mm f/1.4 GM lens for example, it was designed to be optically superior to any 85mm f/1.4 lens Sony had made previously. When Zeiss decided to do the same thing with their Otus lenses, no one said “full frame DSLR is larger than medium format”. A large lens doesn’t change the properties of a smaller lens.

Sator makes matters worse by bringing up the Leica SL, and implying that someone, somewhere, said it is small. The Leica SL was not, at any point, advertised as a small camera. The Leica M series is:


The world’s most compact professional camera

Constructed with a depth of less than 42 mm and an extremely quiet shutter, the M-Cameras are ideal partners for travel photographers and photojournalists.

This is a direct quote.

To maintain the illusion of size advantage, Sony and Zeiss seem to be peddling the grand revelation of the obvious that slow lenses make for more compactness as though this were some spectacular technological innovation. It seems that f/1.8 is the default maximum diameter for nearly all FE mount primes, with only a couple of exceptions.

An 85mm lens is typical for portraiture, and the 85mm f/1.4 GM lens has a larger aperture than the Zeiss Batis 85mm f/1.8. Sony haven’t gone beyond an 85mm prime lens yet (excluding the Sony 90mm f/2.8 macro; its focal length is very slightly longer), so we cannot make conclusions from the available lenses alone. They have made a larger aperture 35mm lens, and the 28mm lens is so cheap that I’m surprised it has such a wide aperture. GM lenses may diminish the size advantage of the system somewhat, but it’s only true if they’re the only lenses you own. These lenses are aimed at professional photographers with specific needs in mind; I doubt those needs are for all types of photographers.

DSLR 21mm f/2.8 vs mirrorless 21mm f/2.8. DSLR weight 851g vs mirrorless weight 394g.
Elements/group, DSLR 16/13 vs mirrorless 11/9 (less is better).
DSLR 35mm f/2.0 vs mirrorless 35mm f/2.0. DSLR weight 702g vs mirrorless weight 340g.
Elements/group, DSLR 9/7 vs mirrorless 9/6 (less is better).

These are just a few examples; please do your own research for direct comparisons. It is wise not to be mislead too much by “crop versus full frame” comparisons; an 85mm lens stays an 85mm lens regardless of what body it is put on. Even if you think calculating the focal length and aperture gives you an equivalent photograph, there will be differences. Whether those differences matter to you, is subjective. It’s also wise not to be mislead about ISO, aperture and other comparisons. Fujifilm’s ISO 200 is different to the competition’s ISO 200, furthermore, larger sensors are generally superior for low light shooting because the pixel densities are generally less per square inch–there’s many advantages to shooting full frame.

To get meaningful compactness, you still have to drop down to a smaller format. Mirrorless APS-C really is more compact than DSLR APS-C

From this, we’re to infer that the rules of physics don’t apply to APS-C. For some reason, you can take from an APS-C body and not have to make the lens huge, but for full frame cameras, they follow a different set of physics? That’s interesting, but not true. What about larger formats? I mean, the new Fujifilm medium format camera is pretty small, or is there some God that dislikes full frame but loves everything else?

It’s challenging to develop lenses for any mount; especially since many optical formulas are from the 1950s; however, lens design for a DSLR is compromised. On one hand you have the advantage that there’s a billion lenses already made and you can use those designs, but on the other you’ve potentially got a mirror in the way of your rear lens element. If you look at the Zeiss lenses they’ve made for e-mount and you do direct comparisons to the Leica m-mount equivalents, you’ll see the only optical hurdle they really had was to circumvent the issue of the glass covering the sensor plus the different microlens structure–Leica angle their microlenses inwards slightly.

Challenging? Yes, definitely. Was it anything like what he’s implying? No, of course not. Zeiss probably speak to a million wonderful people like him and don’t know how to respond other than say “it’s challenging”. Let’s not forget that for a lot of companies, English isn’t their native language.

The size advantage

Sony might have decided to design bigger lenses because their cameras are so small. If the only lenses available were the Zeiss Otus series of lenses, would this prove that it’s physically impossible to design a smaller lens for a DSLR, just because it didn’t exist yet? Of course not. It would be silly to think we know exactly what is physically impossible when history has taught us time and time again that a greater understanding of physics has meant we’re able to develop new things.

As an update to this page, I have noticed the Canon RF 70-200 f/2.8 L lens is considerably smaller than the competition. I wonder if this is a lens which extends like the Sony 24-70 f/2.8 G master lens or if they’re using extra elements to decrease the absolute length of the lens relative to its focal length. In either case, I think that a Canon 70-200 f/2.8 L IS II would be as small as the Canon RF 70-200 f/2.8 L lens if it could be and this lens is likely born from the advantage of mirrorless cameras. I like that Canon’s trying to push the size advantage with mirrorless and I’d love to see a Sony 70-200 f/2.8 II G master lens as small as the Canon RF 70-200 f/2.8 L lens even if that meant a slight trade off with image quality. I am not a fan of lenses which extend though, as they often introduce dust.

The weight advantage

If you look at my Pacific Crest Trail Gear List, you’ll see that I was able to create a kit that lets me charge my camera and take great landscape photographs (excluding my skill from the equation–no comment there) with a minimal amount of weight.

  • The Zeiss Milvus 21mm f/2.8, the equivalent lens to the Zeiss Loxia 21mm f/2.8, weighs a lot more
  • The Canon 50mm f/1.2 isn’t a complete equivalent to the Sony Zeiss 55mm f/1.8 because it has a wider aperture, but it is a lot heavier
  • The Canon 50mm f/1.8 simply isn’t as good and should be dismissed
  • The Canon body would weigh a lot more and the total would require a heavier, larger filter, and a much much heavier and larger tripod
  • Sony full frame mirrorless cameras are lighter than full frame DSLRs
  • Lenses at certain focal lengths can be designed with less elements if designers want to–this lowers weight
    • I’m not saying all the available lenses are low on elements–they might have been designed with extra elements to account for other abnormalities.
    • Sony could make their lenses even lighter if they used a higher plastic content, as per the competition. I’m glad they don’t–metal lenses are nice. I do wish the 24-70 f/4 Sony lens was superior optically because it’s significantly lighter than the competition, and when you add that to an already lighter body, it makes for a vastly different shooting experience. It’s still a good lens, I just wish it were sharper
  • DSLRs also have a much higher current draw in liveview, and for certain types of landscape photography, liveview is essential

There are too many different lenses, cameras, tripods, and lights to give meaningful comparisons.

Weight comparisons boil down to what you shoot and what you want to shoot with; I’ve seen people that like to bring a 24-70 f/2.8, an 85mm f/1.4, a 70-200 f/2.8, 16-35 f/4 and 2 camera bodies to a wedding. To save you the math, that’s about 700g lighter on the Sony compared to a Nikon D810. To me it seems fairly meaningless because I’m interested in certain focal lengths and I’m only interested in the total size and total weight of the system under any given scenario compared to the same optical performance of another system. One scenario might be going to the restaurant with a 35mm f/2.8 lens–Sony’s smaller and lighter. Hiking the Pacific Crest Trail, a Sony a7rII & three prime lenses is drastically lighter than a DSLR. Bird photography? In my opinion, I wouldn’t even include Sony mirrorless in this battle as I don’t think it’s a suitable system for bird photography. However, if you already own a Sony system and a bunch of lenses, you might want to think about trying the Sony a6500.

I challenge anyone to find me a comparable full frame DSLR with a 21mm f/2.8 manual focus Zeiss lens and a tripod, all weighing less than 1.1 kg.

Sony 16-35mm f/2.8 G Master lens = 680g.
Nikon 17-35mm f/2.8 = 745g.
Tamron Sony 28-75mm f/2.8 = 550g.
Tamron Nikon 24-70mm f/2.8 = 825g.
Sony 24-70mm f/2.8 G master = 860g.
Nikon 24-70mm f/2.8 = 1070g.
Sony 16-35mm f/4.0 = 518g.
Nikon 16-35mm f/4.0 = 680g.
Nikon D850 = 1005g.
Sony a7rIII  = 657g.
Nikon D5 = 1415g.
Sony a9 = 673g.

In body image stabilisation

Sator’s article suggests that IBIS would be better suited for a DSLR or DSLT camera. First off, the notion that Sony have abandoned a-mount is conjecture but moving behind that, it is a false dichotomy (they’re able to include IBIS in both systems.)

It’s easier to design IBIS for a mirrorless camera than it is a DSLR because you’d risk putting the viewfinder out of alignment with a DSLR. With a mirrorless camera, you’re seeing what the sensor sees. Moreover, the main contenders for full frame right now are Canon, Nikon and Sony. Canon and Nikon do not make a full frame DSLR with IBIS. You could implement stabilisation in a DSLT camera; there’s no proof to suggest they won’t.

Not too long after his argument was published, a new a-mount camera was released:

  • They had not abandoned a-mount when his article was published
  • It includes stabilisation

Lens mount diameter

But Houston, we have a problem. There is also a major flaw with the implementation of Sony E mount IBIS. The Sigma CEO has been quoted as expressing grave concern for the narrowness of the FE mount diameter

  • Sigma have recently announced some e-mount cine lenses that work on both e-mount cameras and canon mount cameras
    • Of course they’ll face difficulties if they want to be cheap and make the lenses compatible with many cameras
    • If they designed their lenses from the ground up for e-mount, they would be more respectable in my opinion
  • Nearly all lenses from Canon work with an adaptor on the Sony mirrorless system, thereby proving the mount doesn’t provide a choke point big enough to cause significant problems
  • The Leica m-mount cameras also have a small mount diameter

If you want IBIS, you have to design the mount in advance with a wider diameter

Not true; if it works, it works; it works. We must not forget that not all DSLR variables apply to mirrorless cameras; the sensor is closer to the mount which means that the diameter of the lens mount can be slightly smaller. His comparisons regarding lens mounts are also misleading. I believe he has not thought about the angle at which light has to travel when the sensor is further back, nor has he thought about just how little the sensor moves; it does not move by ten millimetres. Moreover, even if there is somehow one lens out of the 500+ that have been found to work flawlessly with IBIS, Sony could just disable IBIS for that one lens. If it works with 99.999% of lenses, it’s still good.

You’ll notice some issues when mounting certain Leica lenses but this is because they were designed for a different sensor (the microlenses are completely different.) It has nothing to do with IBIS.

Lens Adaptors


Micro-misalignment between lens-adapter-body also causes degradation of IQ in the corners particularly at shorter focal lengths

The issue he’s likely thinking of has nothing to do with misalignment–no examples or proof was provided so it’s slightly difficult to debate.

Lens adaptors are great and most lenses, old or new, work without too many problems. It is worth noting that it not a perfect solution. They do not have any optical elements and they make the distance from the sensor to the rear lens element the same as if the lens was mounted natively; however, much more goes into lens design than just the back focal length. A good example of this is to look at Leica cameras; their sensors have microlenses that’re angled inwards slightly and this effects their ability to gather light. Different glass covering the sensor (Sony use Schott 39, to my knowledge) and a different thickness of glass could also make a difference.

As the lens element gets closer to the sensor, the angle of light increases but the angle of the light alone is not why you get colour smearing or sharpness issues with some rangefinder lenses. It’s a combination of the angle of light and the glass and the sensor design. Lenses are designed for a system; they are not simply designed to have a specific back focal length. As such, it’s utterly ridiculous to criticise Sony for not being able to mount non native lenses perfectly–it’s impossible to do so without cloning the competitors design. It’s a great option that suits many photographers, and it’s an option unavailable to most DSLRs; therefore, it’s unreasonable to criticise it.

To be safe, my advice is to research the exact camera and lens combination you are interested in using and Google to see the results of that combination. People find different levels of colour accuracy and sharpness acceptable.

The native Zeiss lenses work absolutely fine without corner issues. You could not design a DSLR lens to have light hit at an incredibly steep angle as the sensor is too far back. Zeiss were able to overcome any optical issues with their native e-mount lenses so clearly great wide angle lenses can exist.


Mirrorless advantages

Here’s a breakdown…

The advantages of mirrorless cameras

  • A liveview histogram can be shown
  • Your exposure can be seen as you’re composing the photograph
  • They can be sealed and built in a superior way to a DSLR, as they have less moving parts (that’s not to say they are built in a superior way; this article is about the theoretical as well as the applied)
  • They have less screws than a DSLR (by a considerable amount; it is enough to effect maintenance; it’s about 29 screws vs 120 in 11 different sizes)
  • White balance can be set using the viewfinder as an aid
  • Manual focus aids can be introduced into the viewfinder without affecting exposure
  • They’re much lighter than a DSLR
  • The shorter sensor to mount distance actually opens up opportunities for certain lens designers; most critics only offer one side of the coin
  • Reverse retrofocus lens groups are no longer required for certain lenses; the mirror box and the distance between the sensor and the mount change a lot for lens designs. This means that the lenses can have greater transmission and other optical characteristics generally sacrificed by additional elements
  • You can use a retrofocus lens group to make the lens even shorter; a DSLR can use a reverse retrofocus lens group to circumvent a problem, but a mirrorless camera can use a retrofocus lens group as an advantage
  • Lens mounts can be smaller in diameter
  • Front heavy systems mean that your left hand (which mostly does nothing other than add support) takes the weight, leaving your dominant (from a control standpoint) hand free to operate the camera. It’s entirely subjective as to whether you like this; some may consider this a con
  • IBIS stabiliizes what you see in the viewfinder, as you see what the sensor sees; however, IBIS in a DSLR would put the viewfinder and sensor out of alignment
  • Autofocus does not need to be fine tuned as the autofocus system is part of the same sensor, whereas DSLRs have a secondary sensor specifically for focusing that can have parallax issues
  • The autofocus can be more accurate. When the aperture changes, the point of focus changes slightly too, this would mean that for perfect focus at all apertures, with a DSLR, you would have to set the focus for each aperture. Mirrorless cameras focus differently and so they aren’t necessarily effected by this problem (unless they’re set to open the aperture when they focus)
  • Lower current draw than a DSLR in liveview; this is useful for landscape photography
  • Better for videography

The advantages of fullframe mirrorless compared to crop mirrorless

  • Calculating aperture, and focal length equivalents does not give you the same photograph
  • Larger lenses and sensor sizes mean that glass does not have to resolve as much with the same quantity of pixels
  • More megapixels for printing
  • Better high ISO performance
  • The sensor gathers more light
  • The read noise is less
  • More shallow depth of field at the same aperture
  • Easier to take sharper photographs (assuming the pixel density is less, which it almost always is) because when you down sample the effects of shake are reduced at a 1:1 ratio
  • Better I.Q
  • Better video performance


Complaints about battery life

I have my own complaints about the battery life, but once again it’s a double sided coin. Canon 5DSRThe Canon battery weighs twice as much as the Sony, it’s almost twice the capacity and its live view performance is actually less than the Sony. If you’re a landscape photographer that uses live view a lot, mirrorless will give you a better battery life. I wouldn’t suggest using the viewfinder for landscape photography on a DSLR because the focus is inaccurate, plus it can be annoying to operate when the camera is mounted to a tripod.

I’ve found that I can take more photographs than what is depicted here but these are straight from the user manual.Sony Power Consumption

As you can see, its power consumption is considerably less than a DSLR. The DSLR has a longer battery life in general because it’s not constantly displaying
information to a monitor; however, when it uses electricity, it uses a lot (it has an extra autofocus sensor and most DSLRs have extra processors too). This means that if you were able to attach a solar panel directly to the camera, like you can with a Sony, it would not benefit you because the current draw would be too high.


Most of this article is compromised of my own knowledge but I suggest reading a couple of articles by Mr. Kasson, as he tests the current draw more objectively than the information provided in the instruction manual — 1 & 2.

Zeiss’s comment

From the comment section of the Zeiss Loxia 21mm f/2.8 lens:

Carl Zeiss Lenses
Dear Mike!
We have an answer for you now: because of the shorter flange focal distance of mirrorless camera systems compared to SLR systems (e.g. E-mount: 18mm, F-mount: 46.5mm), some lenses could be designed differently. This could result either in a slightly smaller (shorter) barrel, or in a more complex, higher performing lens compared to a comparable SLR lens of the same focal length and speed. Of course, it is not possible to overcome the laws of physics. The diameter of the entrance pupil is always fixed by the focal length and speed.
Completely new optical designs like our Loxia Distagon T* 2,8/21 benefit from the short flange focal distance of the E-mount, leading to a more compact lens compared to the SLR lens with the same data.
Best regards
ZEISS Camera Lenses Team

If you have any questions, I will try my best to answer them.

Hybrid Viewfinder

Some people see a Hybrid Viewfinder EVF DSLR type camera as the answer. DSLR’s reflect light into mirrors; while you’re viewing something through the lens, that light is not going to the sensor. If it’s not going to the sensor, then the EVF doesn’t get a live feed. The way around this is to make the mirror go up, but if the mirror goes up then the secondary autofocus sensor doesn’t get any light to it… That’s why liveview on a DSLR often isn’t as fast as the viewfinder’s autofocus. It’s also why DSLRs need calibrating. Secondary processors help too. It’s all a bit of a mess in my opinion. You can include lots of auto focusing systems but it’s poor.

Sony tried to get around this with the translucent mirror idea but it was a mess from a purist perspective, others might disagree.

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20 thoughts on “Mirrorless cameras, the e-mount and its lenses

  • 02/05/2016 at 21:58

    Hi there Chirp. Thanks for pointing me to this article via “The Angry Photographers” YouTube channel regarding this –https://www.youtube.com/watch?… . It was a really interesting read. I found it interesting that Ken (aka – The Angry Photographer) removed your comment (To lead to this article) to the conversation thread I started. I really enjoyed his videos in the past and even put a few $$ his way to help him out – but when I made the comment he even went as far to say I suffer from BFS (Butthurt Fanboy Syndrome). I was a bit surprised by this to say the least.

    • 02/05/2016 at 22:12

      It is really funny that this self proclaimed seeker of truth and hardcore platonist bans and censors people that just bring up arguments.

    • 03/05/2016 at 20:23

      Sorry to hear you wasted your money. Perhaps it was worth it just to realise not to do it again (we all make mistakes). I haven’t seen all of his videos, but I’ve been linked a few and from what I can gather, he’s controversial to gain more views (money) and doesn’t care about accurate information.

  • 29/04/2016 at 19:23

    I’m starting to wonder now if the issue is full frame or IBIS. I can’t see how having the sensor further back in the camera can be advantageous and what’s the argument against full frame when Nikon’s mount is not even bigger. What I gathered from the article is that theoretically Sony/Zeiss can make smaller lenses but are currently making lenses based on DSLR designs since it’s what they know and is convenient. Personally I like the system because it is adaptable and it does the job for me. For the most part I often grab it before my DSLR. It’s got a few tricks and features that I like. How people can get so emotional about what other people choose to use is beyond me. I find it funny though when people resort to insults in what should be a civil debate about facts and science. Kind of reminds me of a particular political candidate. Even funnier is how he says he’s owned every Nikon camera yet pronounces the name wrong and claims he’s not a fanboy. I’m sorry but you’d have to be a fanboy to get so emotional or threatened about such things. I really don’t know anyone who bought A7 just for the size. If the article was about costs then I might agree but you can have an a7 and use full frame lenses from across the board that’s not a claim that can be made by many companies. I think they’ve done relatively well for a relatively new system.

    • 01/05/2016 at 01:06

      Politics, religion and camera gear seem to follow similar trends. A select few put people into a group based on what system they buy into, and the members of the group assume that identity–their real identity is stripped. The haters feel that we do not have our own thoughts, but rather, we’re all the same. Once they hate one Sony user, they hate us all.

      I bought into the system because of its size. It remains to be smaller for the focal lengths I shoot, and if and when I do buy a 16-35mm f/2.8 GMaster (which is considerably lighter than the Canon and Nikon equivalents) lens, it won’t prevent my 35mm f/2.8 from working.

      • 01/05/2016 at 10:40

        I completely agree with you. I think the market needs competition and it benefits everyone. I went to a lens show yesterday and saw the new Pentax K-1 with its interesting twisting screen. I look at the new Nikon D5 and D500 and I find it difficult to believe that if Sony weren’t doing what they do, half the features offered on many of these recent cameras wouldn’t exist and if they did they probably would be poorly integrated and priced extremely high in comparison.

        There’s no such thing as a perfect camera but there’s a camera for every person and every need. Technology will improve on all of them if innovation is allowed. Sony has come out with 2 series of mirrorless full frame and I’m sure they will learn and improve. Saying something can’t be done simply because it’s never been done before without explaining the actual “physics and science” why is narrow minded to me and doesn’t convince me that they are as informed as they claim to be. We’re very privileged as digital photographers these days because there were many limitations before and people were still able to take brilliant pictures which is what it’s all about.

        (On the religious note, I myself am “religious”. I can accept that others aren’t and really don’t get hung up about it because to me “God is God” whether anyone likes it or not and what anyone thinks about it won’t change that, but who I or anyone serve/worship shouldn’t and doesn’t make them or me better. Intolerance is a form of insecurity and is often associated with ignorance.)

        • 01/05/2016 at 19:49

          That tilt screen looks bizarre! I like the tilt screens on Canon cameras but they’re not included on many models.

          I wouldn’t be surprised if Canon surprise us with something at some point. They were pretty innovative with their 600ex-rt flash at the time, and the 5d mk II was the first DSLR to be used consistently with video.

          Sony might be better suited to making mirrorless cameras because of their experience with consumer electronics. I believe that Nikon or Canon could be in great danger at some point, perhaps when the auto focus speed gets even better.

          I think the term for me is an agnostic atheist; I don’t believe in a God but I accept I have no knowledge either way.

  • 14/04/2016 at 00:46

    in your “great wisdom” you ALSO forget that SIGMA, ZEISS, and FUJI head reps also said the SAME GODDAMN shit i did about a FF sensor in that shallow mount.

    I was repairing cameras and lenses 20+ years before (most people, including you probably) likely picked one up.

    Im not paid or sponsored by anyone, if someone wants to buy a camera from a FUCKED company (a consumer electronics company, NOT a camera company)…. that DOESNT even repair its own goddamn cameras (they outsource it)……….then let them

    i dont make a dime either way

    on your site you quote:

    In many cases, Sony FF mirrorless works out as being bigger than a comparable DSLR

    and thats the case, AND you cannot point to a FEW EXCEPTIONS to “disprove the rule”

    that is called THE FALLACY OF EXCEPTION

    its like a fool pointing to petrified crap as “PROOF” that its not necessarily true that “shit stinks”

    i own a Sony Point and Shit camera, they make great Point-and-Shit (haa) cameras.

    you’ve got one thing dead wrong, for FAST FF lenses, there is NO FING DENYING that a “tiny A7Rii” with a 85mm fast, or 70 200 fast , or 24 70 fast lens mounted is a HUGE FING beast compared to a HUUUUGE Fing Canon or NIkon (D810 etc) with the EXACT SAME SPEED AND FOCAL

    you can’t stick a goddamn fucking FF sensor in that Fing A mount with IBIS and not incur the WRATH of Optic, Physics and Math

    Sony CANNOT get around Optic, Physics and Math

    love and hugs

    • 24/04/2016 at 13:00


      Think you may need to try some new medication, or learn some social skills.

    • 24/04/2016 at 13:07

      You are unable to grasp the simplest of comparisons. The length of a Mirrorless body + lens of a certain focal length (adapted or not) is always equal or smaller than that of a slr body + lens of the same focal length. If we are speaking about volume you can omit the “equal or” in the former statement.

      I know that the following will seem like blasphemy to you but it just works like a charm 🙂

    • 25/04/2016 at 00:46

      A post on the Zeiss website gained my curiosity; their argument is the same as mine. Fuji don’t make full frame mirrorless cameras; I’m not sure what incentive they would have to talk about its positives. I wouldn’t give too much thought to their sales pitch, especially if it’s taken out of context.

      I didn’t state you’re sponsored, I’m guessing you want to be? I think most people would like to be sponsored if given the choice. Send your donations and money from advertisements my way if you like, they may not be worth a “dime” to you but I can put them to good use, haha :).

      Nikon, Canon and Sony outsource repairs depending on where you’re from–it is no problem.

      The fallacy of exception cannot exist for a white swan and black swan argument where absolutes are concerned. Lastly, the mount isn’t that shallow. Sony explained this in 2010. It was originally designed for full frame

      • 28/04/2016 at 19:04

        you’re mentally ill and delusional son

        the entire quote from zeiss doesn’t support a goddamn one of your delusions.

        the IBIS and FF sensor and that shallow mount are INESCAPABLE, but keep reinforcing your own little delusions

        the goddamn fact that the lenses on body ARE LARGER than even a goddamn D810 with 24-70 2.8 is proof enough son.

        that mount was NEVER designed for FF sensors son, period.

        i admit this was some humorous bullshit, only PROVING how mentally ill the Fanboy crowd is

    • 07/05/2016 at 11:47

      Difference is with Mirrorless you can have a lens and camera combo that’s:
      – small and great
      – big, fast and excellent

      With DSLR you can’t be as small as A7RII+35f2.8 or with a pancake lens.

      With mirrorless you CAN be both with just 1 body! Sony’s system is still very new so they haven’t produced the full spectrum of lenses the system is capable of.

      We will see smaller lenses sooner than later and then it’ll be clear for everyone to see how much smaller mirrorless FF can be compared to DSLRs.

      By the way I’m not talking about length but volume!
      Why is everybody obsessed with comparing length instead of volume?

  • 08/04/2016 at 19:52

    Thanks for the article!

    One thing – Is it just me, or was Sator arguing that Sony’s mount diameter is too small at 46.1mm when it is LARGER than many other mounts using data he himself provided? (Nikon and Pentax both at 44mm, both have FF bodies, the latter has an FF body with IBIS now.)

    • 09/04/2016 at 00:13

      No problem :). I wonder if he actually means the internal diameter, but he did give the dimensions of the external diameter. There’s nothing to worry about in either case.

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