Petapixel is a photography site I used to follow and I felt there were a few articles worth reading. Unfortunately, I have noticed too many controversial articles that lack objective information. For example, the author Sator wrote an article about how the e-mount is doomed; he’s not the “Angry Photographer” but he comes across with a similar acid tone to his speech. I don’t really want internet drama, hatred or negativity to be a part of my website, so I generally avoid targeting specific articles found on photography websites. I don’t want fame through infamy either; one day, I would like to acquire a skill worth following rather than hits driven through controversy.
I believe a few people have buyer’s Stockholm syndrome and the more you go out of your way to argue a point, the further it makes them act defensively. In doing so, they’ll usually lash out at you to avoid cognitive dissonance. Why write this then? You may ask. The article at Petapixel was full of disinformation; disinformation isn’t necessarily threatening but I believe these types of photographers are causing a negative impact on the community and the sales of Sony cameras. Moreover, it transcends passed the drivel, usually in a wave of ignorance (I mean this in the literal sense–lacking knowledge) spewed over comment sections of various YouTube videos. 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 this article?”, and in my opinion the answer is no, there isn’t.
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.
Response to the article
I’ll start to address the main points brought up by Sator. I’d originally written this page in a way that targeted each paragraph and quoted them directly but it’s obnoxious to write and it’s tiresome to read. His article is somewhat old now but the five main points still get brought up numerous times:
- 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; we only need to look at Samsung’s recent fiery phones to see proof of this. Sator compares the demographic of people that buy Sony cameras 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–just perfect.
Things go south when he tries to speak objectively about camera size. He’s compared a Sony body with IBIS to a Canon body without IBIS–he did not pick the first generation Sony cameras that lacked IBIS and were somewhat smaller–how convenient. His size comparisons are extremely illogical, erroneous and most of all misleading.
The comparisons are obviously unfair: 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. A reasonable thinking knowledgeable person would instantly disregard the article but the problem manifests itself in the truly ignorant (from the Latin verb ignorare: “not knowing.” I do not mean the informal insult). What if the reader doesn’t have much knowledge regarding specific Canon lenses? What if the reader hasn’t even picked up a Sony lens? The reader might then draw the conclusion that 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. In reality, this is far from the truth.
The laws of physics
The “the laws of physics” rhetoric is used to try prove his point but unfortunately he does not mention what these “laws” or principles are. He doesn’t give us any objective information, optical formulas or solid math to use–he simply refers to quotes taken out of context by employees of known companies. A A while after I wrote this page, Kazuto Yamaki (president of Sigma) confirmed that Sigma plan to make Sigma lenses for Sony Full Frame E-Mount.
The “laws of physics” rhetoric sounds powerful and catchy, but it doesn’t make it fact–argumentum ad verecundiam. His 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 include a retrofocus lens element group (whether that’s in a positive or negative configuration) for certain designs, 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) with retrofocus elements; in layman’s terms, you can make your lens shorter than its focal length. Conversely, you’re able to use a similar retrofocus design but in a reversed (some people say “inverted”) 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 comes 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. With a DSLR, you only have one option; you don’t 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. 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? Why do they gimp the design of their own camera? It is quite simple; it allows camera manufacturers to use the same lens mount for many cameras and this helps synergism between different camera formats–it helps keep costs of manufacture 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.
We may wonder why it is that some 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 70-200 f/2.8 GM 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). 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 companies like Sigma are trying hard to milk their products; they want their lenses to be compatible across many formats rather than risk losing money by only developing a lens for one format. This to me is a great shame; 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.
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.
If we put logic aside and we agree with Sator that if you “take something from the camera body”, you have to “give it back to the lens”, then we can do simple math to prove he’s still wrong about the total system size. Calculating the volume of an object is not a difficult calculation, but many people are insistent with 2D side by side camera comparisons; the real world is not 2D, lol.
Lens design is far more complicated than just 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. My apologies if this comes across as condescending. We can conclude that even if removing the mirror and completely changing the sensor’s position relative to the mount makes no difference to lens design, then the system can still be smaller.
In many cases, a Sony full frame mirrorless system works out considerably smaller than a comparable (in terms of sensor size) 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.
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 have announced/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.
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.
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 in itself pure conjecture and there’s no proof to suggest this is true. It is a false dichotomy because 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.
Edit–They’ve just released a new a-mount DSLT. It disproves his argument in two ways:
- They have not abandoned a-mount
- 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. At best, his argument is a perfect solution fallacy.
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.
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.
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. The 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.
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.
From the comment section of the Zeiss Loxia 21mm f/2.8 lens:
Carl Zeiss Lenses
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.
ZEISS Camera Lenses Team
If you have any questions, I will try my best to answer them.