The Sony a7S series of cameras is strange. They're described as stills cameras; however, most customers seem to use them for their video features. At best, they're an odd compromise that doesn't fit anywhere properly. For this reason, I'd like to discuss why Sony should get rid of this line completely or at the least, revamp the series.
Low-Resolution Sensors Offer No Advantage in Low Light
The Sony a7S III is the latest in the a7S series of cameras. One of the assumed benefits of this camera and its predecessors is that it offers better low-light performance. This is quite easy to disprove. If you have a lower-resolution sensor, then each pixel is going to be relatively larger. Larger pixels have the potential to be more efficient when it comes to gathering light. And this is thought to help improve high-ISO performance. In practice, this is only somewhat true at best.
For example, if you take a picture with the 12-megapixel full-frame Sony a7S III camera at ISO 12,800, you'll notice some noise in the image. Compare that to an image taken on the new 33-megapixel full-frame Sony a7 IV camera, and the latter will demonstrate slightly more noise in the image. However, if you take the same image from the a7 IV and scale it down to 12 megapixels you'll end up with near-identical noise performance between both cameras.
What's more is that the Sony a7 IV image will appear sharper and have more detail than the image taken with the Sony a7S III. If you're interested in testing this theory, you can hop over to the Studio Shot comparison from DPReview, download high-ISO raw files from the two Sony cameras, scale down the resolution to match, and check for yourself.
Otherwise, here is a quick demonstration of this fact with two different cameras.
The cameras I have used are the Canon 5DS R and the Canon 5D Mark IV. Above, you'll see the difference in noise performance when both files are compared at their respective resolutions. However, as soon as you scale down the resolution from the 5DS R image to match the Mark IV, the difference in noise performance becomes negligible.
As soon as you match the resolution in both cameras, the difference in high ISO performance becomes practically identical. This is more pronounced when you compare images between the Sony a7S III and the Sony a7 IV. Once again, you can find sample raw files to perform this comparison yourself using the DPReview link above.
What this proves is that lower-resolution sensors offer virtually no advantage when it comes to high-ISO or low-light performance. All you have with the Sony a7S III is a low-resolution camera without any real upside. With a higher-resolution camera such as the Sony a7 IV, you have the best of both worlds. The resolution is there when you need, and if you want comparable low-light performance, you can always scale down the resolution for cleaner files.
12 Megapixels Is Not Enough
I always find it a little cringeworthy when someone tries to discuss why 12 megapixels is enough. Common arguments include statements about how large you can print with 12 megapixels or how little resolution is required for printing in a magazine, or even points about how much resolution is required for a 4K display.
By that logic, two megapixels should be enough because you can print as large as a billboard with that amount of resolution. This is hyperbole; however, the point is that using a camera with the lowest feasible amount of resolution is a bad idea. No professional worth their salt would work with the bare minimum that's required in any other scenario. Therefore, this must apply when it comes to resolution too.
An apt comparison would be the two card slot issue I assume there are very few professionals that are comfortable shooting an entire paid shoot with just a single storage card. Realistically, you only need one card, so what is the problem, right?
The answer is redundancy and security. If you're a professional and you're using the bare minimum required for a job, you're leaving yourself open to a whole heap of potential problems.
This translates over to resolution too and more resolution (over 12-megapixels) is better because it offers a greater deal of flexibility. For many photographers, somewhere between 20 and 30 megapixels is the sweet spot of what's required. You have enough resolution for most applications and then some should anything occur.
Of course, I understand that to many, the Sony a7S series of cameras are not precisely geared towards photographers. Instead, it's widely understood that these cameras are designed primarily for their video features, hence the low resolution. Well, let's explore that point in detail below.
A Weird Compromise
As discussed above, the low resolution of the Sony a7S III makes it a poor choice for photographers. Despite this, the camera body is designed primarily for photographers and not videographers.
Cine cameras are built differently, and the Sony FX3 is a perfect example of this. The Sony FX3 is essentially a cine version of the Sony a7S III. It has virtually identical specifications, and the only real difference is that it has a different body and different button layout. With this in mind, what is the point of the Sony a7S III?
If you're interested in the video features, then the FX3 is the better option. On the other hand, if you're a photographer, then the Sony a7S III is a poor choice considering the many other higher-resolution options available from Sony. The fact is, the Sony a7S III doesn't quite know what it is. It compromises its stills features to try to offer better video features, even though a better cine camera exists with the FX3.
The Biggest Problem
The biggest problem with the Sony a7S III is its impact on the other Alpha series cameras from Sony. The Sony a7 IV was recently released, and this camera could have been the perfect all-rounder system, but it just misses the mark.
For photographers, it's a brilliant option. Unfortunately, it has a disappointing limitation for videographers.
When you're shooting 4K at 60p, the sensor is cropped to what is effectively an APS-C sensor. This feels like an intentional limitation to prevent customers from losing interest in the a7S series of cameras. If the Sony a7 IV did not crop the sensor when shooting 4K at 60p, it's unlikely anyone would pick the a7S III.
This is quite telling about what customers want, and Sony understands this, hence the limitation. Many customers seem to want a camera with a resolution between 20 and 30 megapixels and great video features without crop-factor limitations. This isn't unreasonable by any means because Sony can do it, and manufacturers such as Canon have already done it with the EOS R6.
The fact that Sony has the FX3 available along with the a7 series of cameras means that the a7S series of cameras no longer needs to exist. All it's doing is ruining the potential for the Sony a7 series of cameras and muddying the lineup.
Ultimately, the Sony a7S III just doesn't make any sense and feels confused. It's trying to be a cine camera without being a cine camera while simultaneously trying to act as though it's a stills camera. Worst of all, it's preventing the Sony a7 IV from being the proper all-around camera system that it could be.
Totally agree with the sentiment that lower resolution only reduces image quality, but I think the a7S low resolution exists to overcome processing limitations. It would take much more computing power to down-scale 4k/120 video from a 20 or 24 megapixel sensor, and that would mean more cooling, bigger batteries, larger form factor, and higher cost.
We use the 20 megapixel Canon R6 at 4k/60 and, while the difference is slight, it is cleaner and more detailed than the a7S III. But battery life is awful and it overheats.
Anyway I share your frustration with the misunderstanding that low res produces better results in low-light… I think that idea was seeded by marketing material to make people feel better about it. The idea is not supported by any of our testing.
Or maybe there are a bunch of photographers who do not understand quantum mechanics vis-á-vis noise as it pertains to surface area of photodiodes.
Regardless, modern signal processing renders the conversation moot for any practical purpose.
I can't help but think that if the commentators had any integrity, they'd interview an engineer or physicist, who is involved in the design process; but you'd lose your audience.
If we've reached the point where photographers need to understand quantum theory to learn how to make a good image, then I think it's time for a real revolution in the photo community.
That is not at all what I said. Not even close; not implied, nor explicit.
I honestly have no idea how you've interpreted my post that way.
The irony here is that the sensor in the A7SIII appears to be the same sensor that is in the A1, or at the very least the same density. This is in contrast to the A7S and A7SII which have actual large pixels.
The camera is binning 48MP down to 12MP, like so many smartphones. This was confirmed a month or two ago by some folks who put a damaged sensor under a microscope. Anyone can read the article themselves by doing a quick google, so don’t ask me to do that for you.
Pretty weird cost cutting measure! I’m not going to unintelligibly wank all over about quantum physics though, so that’s all from me. Have a nice day.
Wait, you thought that was unintelligable?
Billy, while I’m sure you’re a really very smart boy, just smooshing together the fanciest words you can come up with doesn’t make for an intelligible point. Nor does it do much in the service of proving your throbbing intelligence.
Allow me to demonstrate how to succinctly deliver a coherent idea, in the writing style of Galileo, because I must also flex to prove how turgid my brainsmarts are:
Upon briefly speaking with you, perhaps at some public function, Richard Feynman would loudly laugh at you, right in your face, before starting to hit on - and subsequently sneaking home with - your wife.
Queue Eeey Deeee my guy
(It’s a good read by the way. I hope everyone gets the joke.)
Oh, sweetheart, this is me speaking at a fairly normal standard. If it's too complex for you, I'm not going to break out the crayons.
Now, during our last interaction, you implied I was an idiot for persisting with someone whose sole purpose is trolling.
So I'll just leave you with this:
"Anyone can read the article themselves by doing a quick google, so don’t ask me to do that for you."
Ah yes, the venerable “attempt to undermine and emasculate your opponent by calling them some combination of feminine pet names” maneuver.
How you have wounded me.
And now for my counter, the “call the blowhard’s bluff on his self-assured expertise by moving the goal post unreasonably far beyond his reach” play:
Care to post a photo of your physics degree with proof that you’re a tenured professor doing research in quantum mechanics at a respected institution? Or should I just search google citations for to get an idea of acclaimed physicist William Murray’s impact factor?
I don’t pretend to understand quantum mechanics, and I’d definitely never run my mouth off about it, because I’m far more familiar with the work of Dunning, Kruger, and this quote (attributed to acclaimed quantum physicist Richard Feynman, and the punchline of my last comment’s joke):
“I think I can safely say that nobody understands quantum mechanics.”
Now normally I’d leave that to hang in the air, and then you’d subsequently ignore it in your arrogant quest to show how smart you are and continue this rally. But I’m going to break from form to say that I’ve had fun, it’s been a few months since I stretched my troll muscles, and it was a helpful catharsis after the holidays. And now I’m going to tuck tail and run, sign out of my account to remove the temptation of that notification icon, and should I log in at some point in the future I’ll continue ignoring any future comments from you.
The next time you hear from me will be after I’ve forgotten who you are 😂
That's the spirit.
Since you tried to call me out, it took two years of university to understand the math; I never "understood" quantum mechanics, despite it being the first 6 weeks of second year physics.
Your assertion I'm trying to prove how smart I am appears to be projection.
I promise you, being "smart" is not much fun.
Jog on, Mr Faceless Trollman.
Out of interest, are you the JD Davis troll who was recently banned, on a new account?
Does anything else in the A7 line have -6 EV autofocus sensitivity?
A7S led by 4 EV, A7S II led by 2 EV, A7S III led by 3 EV (2 EV now).
The A7SIII is a hybrid camera, that’s all the explanation that is really needed.
It performs extremely well with video tasks, but has a layout that is familiar for photographers.
Comparing it to the A7IV, you have to keep in mind that the rolling shutter performance between these cameras is massive. The crop mode helps to fight that jelly effect.
Using expensive hardware to overcome sensor readout speed is the killer feature of the Sony A1. And that’s at least partially why it’s so expensive.
Adding that performance to the A7IV would price it completely out of its niche.
I'm still shooting with 12MP, and printing at 20x30"
Edit: they'll need the chips for other lines.
Edit 2: if the area of photodiodes doesn't matter, then you can go and use a high megapixel mobile phone.
Diffraction unfortunately comes into play then. It’s not much of an issue when discussing other full frame cameras.
Yes, I'm aware, and it gets to stage where the photodiodes are smaller than the wavelength of light (the new ones are there, right?)
However, I was broadly making the point that it does matter.
And all that aside, I *am* making high quality 20x30" prints from 12MP. I suspect there have been 2 occasions in the last year where I've wanted more resolution (not enough to justify the expenditure).
It’s reasonable to disagree :). Thank you for sharing your thoughts.
Any time, Usman.
As an aside, I've shifted from craving the new shiny gear to focusing on alternative processes. It was like flipping a switch about a week ago - life is strange.
The 12MP sensor is not there primarily for detail or low ISO nowadays - it's for rolling shutter (and more 4K options) first and foremost. The rest is valid more or less, but not a reason to not have the camera when missing the most important reason.
I think with the FX3 they are going to kill off the line, but until the FX3 came out you wouldn't be writing this article.
Does the FX3 have built in NDs? Otherwise, it’s not really a “cinema” camera either, just an A7S3 with a fan and 1/4” 20 holes.
Built in ND filters would be so useful though right.
I think the next FX3 will have ND filters. Also, with the FX3 body, Sony could offer up attachable EVF's, battery grips, etc for customization.
Other cinema cameras that don't have built-in ND filters: Arri Alexa/LF/Mini, Red Gemini/Komodo/Raptor...
...you're actually more likely to NOT have built-in ND on true cinema cameras.
I stand corrected, thank you. Been a while since I've been in contact with Alexa.
I stand by my statement that built-in ND does not define a cinema camera.
I agree! I always say high res sensors produce high res noise.
Your example of upsized and downsize is not proof of anything! I think you are hooked and trying to sell high MP cameras for no reason. I started with the A7s in 2014 captured the October Lunar Eclipse with a Canon FD telephoto lens with an adapter and started Astro Milky Ways in June of 2015. It is like color night vision. I bought it because it would do 5 images @ +/- 3ev it was the HDR days, if you were around back then. You talk about using high ISO's but with f/4 lenses (16-35 or 12-24) I rarely got above 6400 and with the newer f/2.8 lenses most always below 3200 and with the new f/1.8 14mm and 20mm or f/1.4 24mm I am around 600 with SS 6 to 8sec. For those not familiar with dark sky capture the wider the f/ lens the faster the shutter speed needed not to have elongated stars, check PhotoPills Spot Stars for the NPF SS for any make Camera and lens combination.The A7sm2 brought IBIS and continued to have on camera apps like the filter app that allowed MW's over a lit runway without using filters on the lens or blending in PS or other program. I was waiting to buy the Sm2 but when the Sm3 came out the Sm2 disappeared so I bought the A7Sm3 and was very happy with clarity, detail and less noise with panos with more detail I never got before.
I will admit the A7m3 is as good or better than the original A7s but it also has bright monitoring and ISO invariance also on the A7sm3. The 3rd image was printed the size of a long wall in my eye doctor's office with even more detail than you see on a computer screen.
I have printed most all my A7s and A7sm3 astro and daytime images poster size and change in the many frames in my house every month ALL with great detail.
4th A7s using FE 1018 f/4 in full frame @ 12mm this was before all the new lenses today.
The A7SIII has a 48MP sensor that 2x2 bins down to 12MP files. Which not only proves exactly what the author was stating, but also makes your comment funny because the measured noise coming out of the sensor is actually inferior to sensors with large pixels. You will want to google “landingfield” and some combination of A7SIII and 2x2 pixel binning.
Yep, you do seem to be correct about the 48mp point. Here’s the odd thing though, when you scale down images from the a74, it still appears sharper than the 12mp images from the a7s3.
Not sure why that is, any ideas?
While quad-bayer is great for reducing noise, it does nothing for detail. Using a photo editing program to somewhat intelligently scale an image will produce much better results than a quad bayer which always dumbly averages light.
Much appreciated, thank you for the information.
I think you might have left those photos in the oven a bit too long there.
Good old early 2000s…
The next thing Sony could do is to make some minor improvement in the a7c vf and give it the a7iv guts
Then they'd. Have the perfect serious travel camera
As long as one doesn't need to answer to an event client at the end of a session, continuous backup to the shooter's cellphone makes card slot 2 unneeded
There are lots of benefits of low resolution sensors, but almost entirely for video. These lower resolution sensors can be read out much faster, lowering rolling shutter and increasing the framerate options at the full sensor resolution (IE without cropping, pixel binning or line skipping). Low resolution (4k) video is also useful in that it has much more reasonable file sizes and requires a less beefy computer to edit than 6k or 8k video. If you want to shoot RAW video, a larger resolution will result in enormous file sizes or substantial compromises on image quality. It's also worth noting that for video, you really can get away with 3k-4k of sensor resolution and your viewers won't complain--when watching a video, they can't pixel peep because they have to sit far enough from the screen to comfortably view the whole image, whereas anyone can walk up super close to a large print of a photo on your wall.
For a single photo, yes, you can get excellent rolling shutter performance by simply using a mechanical shutter, and typically bursts aren't done at 60 or 120 fps, so most of these advantages disappear.
The A7s is a great camera, perhaps the greatest documentary camera ever made for video. Stop thinking about precious pixels and think about the subtlety of the form factor. Most regular people are self conscious around video cameras but have been around still cameras their entire lives. If you use the amazing viewfinder, it looks like you are just snapping a photo. Add the xlr-k3m and you have great sound. The ability to get stunning video in nearly any light in a subtle package makes this camera crucial to own for documentary filmmakers….and it can snap decent enough stills. While small, the fx3 has a foreign appearance and lacks a view finder.
Actually, I think SONY will drop the A7s series and that is why the FX3 was released. I see the FX3 eventually being the main competitor to the Blackmagic DSLR style cameras with a few features added. Plus, unlike Blackmagic, the FX3 can take excellent photos if needed and has a world class auto focus system.
I see a camera like the FX3 that eventually eliminates the stills side being the way forwards as it will also eliminate any compromises when combining the two and can go all out on the video features like Blackmagic have done. Plenty of people buy mirrorless cameras just for the video. If people really want a hybrid, cameras like the A7IV will still exist.
As a BM person, I highly doubt the Sony camera(s) will have the majority of them out to replace their cameras with Sony.
There is really only one reason this would happen IMO, and that is the autofocus function of Sony. This is also the reason I am looking to get the FX3, to mount a compact video camera on a gimbal that shoots 4k60.
BM shooters that shoot in probably almost all other situations have no problem with manual focus and what that entails, at least for now.
But on a gimbal, to me, a great auto-focus system is a feature that is worth buying into the Sony system.
I'll be happy to take one off your hands!
Would be odd if I went out and bought one after writing this article lol.
For photos alone, I think this is more or less accurate. But, where say the A7 base line are seen as hybrid cameras, but more focused on photos than video, the A7S line can be seen as hybrid cameras that are more focused on video than photos. You can still take very good photos with the A7SIII, and it has good ergonomics as a photo camera, even though it wouldn't be a first choice primarily for photos. The same can't really be said for the FX3, which critically doesn't have a viewfinder and isn't weather-sealed due to the fan.
Overall, the A7SIII has the distinction of being the best sealed full-frame 4K video camera available for event videography because it is the most resistant to overheating, and being sealed it can be used outdoors in dusty environments or light rain/drizzle with less concern for external substances getting into the camera and damaging it. Other cameras arguably may produce incrementally better video quality at a pixel-peeping level, but that's a minor factor compared to having a camera that will reliably keep working in a wide range of environmental conditions to capture critical moments that there will only be one shot at.
Lastly, Sony has a new 2-layer sensor tech that will be able to gather twice the amount of light by moving the electronics to a separate layer and allowing the entire surface area of the sensor to be used for light gathering instead of only about half of it. It's still in the lab phase at the moment, however - and unfortunately I can't remember where I saw this - I read about product plans to make several sensors based on this tech, including a full-frame sized variant. But the initial sensor product won't have a very high resolution - I believe it was 20MP or less.
So it could make a lot of sense if say, 2-4 years down the line, the next A7S camera was the first to feature this new sensor technology, which would keep it a 4K-only camera, but would truly offer superior low-light performance.
The problem here is mirrorless and DSLR’s before them are hybrid cameras trying to attempt the impossible of producing cameras with top quality stills and high end cine-like video. The fundamental differences that separate the two have always ended with compromises, yet many people’s expectations seem too high as to what these cameras can realistically achieve, which is why there is constant disappointment. This high quality is also pointless if people aren’t going to invest in a decent rig and lighting setup or take the time to learn storytelling, scripting, editing and other essential skills. Simply pointing a camera at a subject with a shallow depth of field and using IBIS doesn’t really require a camera that struggles with heat and other issues due to an unnecessary high resolution and overly sharp lenses (without sharpness reduction in the edit) being used. We’ve never had it so good when it comes to video quality but, if social media is anything to go by, people never seem satisfied enough, always wanting more.
OK I had to create an account just to post this. I can't believe anyone with camera experience would post something so inaccurate about the relationship to megapixels and light gathering.
The low megapixel sensor offers an insane level of light gathering - which translates to less noise - because it shoots at lower ISO. Their entire writeup is not based on facts. Saying iso 12800 is the same noise as iso 12800 on a high MP sensor, that's pretty much true. What you are not accurately conveying thoughiso 1600 on the siii would take iso 6400 on a 33mp sensor. So the siii gathers a ton more light and in the end translates to less noise in the image.
Yes but the point is that high resolution sensors offer both options. A low resolution sensor doesn’t.
None of what you just said is remotely accurate.
ISO is ISO. If you shoot that a7S3 at ISO 1600 when the a74 is using ISO6400, either the one is two stops underexposed or the other is two stops overexposed.