The Ultimate Sony a7S II vs. a7S Test – What’s the Difference?
The Sony a7S II is finally shipping and en route to filmmakers. It offers a few nice upgrades over its predecessor the Sony a7S. We shot a review with the new 4K mirrorless camera for some hands-on experience. But how do the cameras ACTUALLY compare in the lab? Here is the ULTIMATE Sony a7S II vs. a7S Test.
The two cameras have a very similar design, very similar functionality and a very similar if not identical sensor. Still there are a few enhancements Sony built into the new Sony a7S II, the biggest improvement is 4K internal recording. Let’s see how the two cameras compare in the lab, we will look at the specs in theory and then in real life.

Sony a7S II dynamic range tested with a XYLA-21 transmissive chart.
Dynamic Range
Dynamic range is important for us filmmakers, it gives us the ability to capture high contrast scenes without over or underexposure, highlights and shadows are saved resulting in an organic, filmic look and possibilities in post production.
In theory:
Apparently the Sony a7S and a7S II share the same sensor and thus should have a very similar dynamic range.
In reality:
At 4K resolution in Slog2 (a7S via Atomos Shogun, a7S II internal) both cameras have the exact identical dynamic range slightly below 12 stops in our scientific lab tests.
Interestingly in Slog3 Gamma the a7S II gave us about half a stop more dynamic range.
We use a a DSC labs XYLA-21 transmissive chart and IMATEST evaluation software with a crisp Zeiss 50mm CP2 T/2.1 makro lens.
Conclusion:
Set your Sony a7S II to Slog3Cine (PP8 under Picture Profile Settings) in order to get the most dynamic range.
Rolling Shutter
The so called “rolling shutter” is a phenomenon that skews a camera image when fast moving objects are recorded or during fast pans and handheld camera movement.
In theory:
Due to the same sensor the rolling shutter could be similar, but the internal processing could speed up sensor readout and improve rolling shutter on the new a7S II.
In reality:
In 4K the Sony a7S II had the same rolling shutter performance in our tests as the a7S. Both in 4k as well as HD the a7S took about 20 milliseconds to readout the picture from top to bottom.
Same goes for the HD crop mode. Both cameras have the same rolling shutter performance in HD crop mode.
Conclusion:
No difference in rolling shutter performance.
Resolution / Quality in 4K
Obviously the Sony a7S II has the internal 4K advantage, but how does it compare to the Sony a7S recording 4K via hdmi to the Atomos Shogun?
In theory:
The quality of the images should be virtually identical with the only difference that the a7S II records to the XAVC-S codec in 8-bit and the Shogun will record the a7S data in a better codec like Apple ProRes HQ also in 8-bit color.
In reality:
Here’s a comparison crop image between the Sony a7S II vs. a7S in 4K. The only difference I see is that the 4K hdmi output does its typical Gamma change and slightly raises contrast and saturation. When matched the internal footage from the Sony a7S II looks virtually identical. I can definitely see more noise on the a7S though at its base ISO compared to the new a7S II. It’s nice to see also how well the XAVC-S 100 mbit codec preserves the image.
Concsluion:
In 4K the images look almost identical. The a7S II has a more accurate representation of Slog2 and less noise at the base ISOs (ISO 1600 & 3200). The image looks very similar to that of the GH4 as well.
Resolution / Quality in HD
Here’s where it gets complicated. The new a7S II has a lot of new format options. The original a7S had a full frame mode and a crop mode. The crop mode had slightly worse quality but was still acceptable.
In theory:
The new a7S II has the following options to record HD:
- Full Frame HD
- 1.6 crop HD
- 2.2 crop HD
- 2.2 crop HD slow motion 120fps
How do they compare to the original a7S HD modes?
In reality:
- Full Frame HD looks virtually identical (best in HD)
- 1.6 crop HD also looks virtually identical (see image above) (slightly worse)
- 2.2 crop HD / Slow Motion looks worst of all 3 modes, yet still provides an acceptable image. We can see some aliasing / moire happening in this mode and the sharpness is slightly lower. Also there is more noise. Clearly a smaller portion of the sensor is used and blown up to HD.
As you can see on the danes-picta sector stars above (crop from full HD image, zoomed in), the images look really really similar between the a7S II and old a7S in Slog2.
The Slow Motion Mode degrades the image a little further introducing some aliasing / moire (see tie image above).
Concsluion:
2.2x Crop Mode is new and offers Slow Motion. The rest of the HD modes on the a7S II are virtually identical to the ones on the a7S. Keep in mind though, that a 4K recording, downscaled to HD in post production will definitely look nicer, but require more processing power and storage in your workflow.
Lowlight!!!
Yes, I kept the best for last. Is the a7S II EVEN better in lowlight than its predecessor which made big headlines as being the best lowlight camera available today. The short answer is: Yes.
Let’s go straight into reality on this one:
I compared all ISO speeds of both cameras. I used Slog3 on the new Sony a7S II and Slog2 on the a7S. Surprisingly the a7S II is better in lowlight and I would say it’s roughly a full stop if not more across the whole range as the footage is much cleaner. Very good news indeed. Below is a shot of medium to very low light levels compared at ISO 25,600. I felt the difference was most striking at this ISO:

Lowlight difference between Sony a7S (top) and Sony a7S II (bottom) at ISO 25,600. Shot brightness was matched.
Conclusion:
In lowlight the Sony a7S II is even better than the old a7S. Especially in terms of noise the annoying shadow noise of the a7S is gone and the images are cleaner and provide more dynamic range all the way.
Note that the camera has lowest noise levels at ISO 1600, ISO 2500 and ISO 3200. At ISO 2000 there is slightly more color noise in the shadows.
Overall Conclusion
There’s a small dynamic range increase for the a7S II with the new Slog3 Gamma Mode, but noise and lowlight is about 1 stop better overall. Rolling shutter is virtually identical as well as quality in HD and 4K, though the old a7S cannot record 4K internally.
Problems on the Sony a7S II
- We can see a raised amount of shadow noise in Slow Motion Mode in comparison to normal motion.
- There are some issues in HD Crop Mode when Slog3 is enabled (see image below)
Should you get the Sony a7S II?
This is the big question. Does it makes sense to go for a Sony a7S II? Here are some arguments:
The Sony a7S II is definitely the better camera. Noise performance is improved making also the lowlight behaviour even better. Many people complained about noise on the a7S even at its base ISO 3200. For really professional jobs the step up in quality to the a7S II makes sense.
On the other hand the a7S II quality is more like the honey on the bread. The cameras are really very similar overall and the old a7S gets you very far already, with the option of external 4K that looks almost identical. So for the camera enthusiast who is on a budget the $800 price difference might not be worth it eventually.
That said if not only the added convenience of internal 4K, but also the option of
- “ok-quality” 120fps Slow Motion mode
- a 50% quicker autofocus in video mode
- the sensor-side image stabilization (for unstabilised lenses)
- and some small ergonomic improvements
are useful to you, then you should definitely consider the Sony a7S II. It’s a powerful little camera and at the end of the day $2,998 for a tool that delivers such good quality and so many options is just the best you can get at this price-point at the moment.
Recommended read: Sony a7S II vs. a7R II Test – Which One Is Right for You?
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Interesting information here but kind of bizarr to me that you wouldn’t also compare apples to apples and draw a comparison of images recorded externally from the A7sii father than just the internal. If you need to use an external monitor for its waveform/better focus for example you might already own the shogun anyways. The codec into the atomos is far better than the internal a7sii and so this would hVe been interesting to see
Hi Ashley,
When you get to work with these files you realize that between ProRes HQ externally and XAVC-S the compression is the least of your worries. In other words: The difference in quality is not big enough to affect these tests that I made. On top of that, what I as a user really want to know IS the difference between the a7S external and a7S II internal…
So you could take away from this test: the difference is minimal and you can work with internal just fine. If you’re going for maximum quality though and want an instant edit file format, you want to choose external of course.
Totally, and its a super useful test to see. The trade off of not needing to carry a shogun is massive but out and out quality is what im looking at at the moment. To me the value of having an external monitor for its waveform is fantastic, especially when exposing sLog3 for maximum latitude sits 3 stops over or so and using 3D luts to compensate vs the display gamut from sony which is useless if your exposing the camera for minimal noise (3 stops over). I own the A7sii and have been doing several tests but ive not got access to a shogun yet to straight up see the difference. Would still love to see this.
Thanks
Got it. The Shogun’s scopes are very good. But I doubt you will be able to tell the difference if I show you a non Shogun vs Shogun image… The camera’s 4K is not perfect. So the codec will not make it more perfect, first the camera needs to be better, the codec is not the bottleneck on this one. it is not an Arri ALEXA and not a RED camera. This is a Sony.
The image is as good as it gets from this camera. Youre kidding with that. Have you even seen, much less learned anything from “the Great Zacuto Shootout”?
I’m guessing he’s not really talking about the sensor specifically but the fact there is no 10 bit or raw output from the a7s therefore the 4k is somewhat crippled in comparison to a real cinema camera.
Good read…
Thank you, I bet that was a great deal of work to produce! I’d be interested to see a similar test between the A7Sll & A7Rll. As a stills guy (coming from an A7S & A7R background) I opted for the A7Rll as a generalists hybrid camera. I’d appreciate (even pay for) a good article /tutorial on setting up an A7Rll for hybrid “multi-media” photography, stills and motion.
Something that explains the inner workings of picture profiles would be extremely helpful too. As stills guys LOG profiles are very difficult to work with as they tend to peg minimum ISO for both motion and stills at there base ISO, 800 ISO on the A7Rll.
Thanks for your remarks and feedback Chris. This definitely helps to better understand what our readers are interested in. We’ve seen a lot working with all these cameras and technical stuff, so it is really a question of understanding what our readers want.
Yes, these tests are a lot of work. So if more people can comment on what they find helpful we know where we can direct our energy. We try to listen. Take care
Hi Sebastian,
I’ve been looking for that “Swiss Army Knife” approach to motion imaging. Whenever I see one of Johnnie Behiri’s camera reviews pop-up on cimena5d I’m loving every second of them! That’s my idea of “Swiss Army Knife” motion imaging, they’re PERFECT! Give me a whole series of tutorials like those, please!
Like the military, there are those who need a flushing toilet, commissary, and step-by-step instructions of what to do all day (and a whole mess of money & support to do it). Then there are those special operators, who only take what they can carry, and get there under their own steam and get the job done every time, that’s what I’d like to learn, and the best thing I’ve seen to date is one of Johnnies “Photo Ninja” camera reviews.
This is perfect https://vimeo.com/80148687 and there isn’t a (transitioning) still photographer alive who wouldn’t kill to learn how to; think-up, shoot and edit a piece like that each day! I’ve seen thousands of short films since watching this one, but this sticks in my mind, especially the ending, fantastic work!
Thanks again,
Chris
Chris.
Thanks for your kind warm wards. Highly appreciated!!.
All the best for now.
Johnnie
Hi Sebastian,
as a follow up to Chris’ post I’d like to chime in on his suggestion. A comparison of the sony a7s II and a7r II would be a really great piece of advice for me – And I guess a lot of others, too. All these different A7x mk I or II models out there right now makes it really difficult to see through clearly.
In addition, I’m having a hard time to find anything about the differences on the web, as well.
Ok Olaf, Thanks for letting me know. I’m working on this and it should be finished by today and then we’ll see on what publish time it fits. It should come some time between today and Monday at the very latest.
Looking into the differences in great detail I now understand the need for a comparison. Indeed it’s hard to compare those two, but the lab tests help a great deal to see the differences clearly. I hope I can present them in a way so it is helpful and makes sense.
Hi Chris and Olaf,
Here’s the a7R II vs. a7S II comparison:
https://www.cinema5d.com/sony-a7s-ii-vs-a7r-ii-test-which-one/
Chris, I can recommend this. Have a read
http://videoproduction.training/sonya7riiguide.html
Thanks Ashley, I’m going to have a good look over it. ~Chris
Andrew Reid discusses both cameras on EOSHD.com. His consensus seems to be that there is no advantage to the A7SII over the A7RII. I purchased the A7RII for both stills and video as well. As for the S-log, many overexpose it by two stops, so you can rate it for ISO 200.
Hi Tim,
There is actually a big difference between a7S II and a7R II. Maybe your source was not the best choice.
Concerning Slog, you can definitely not rate it at ISO 200. I don’t know how you came to that conclusion.
You haven’t quantified your argument. What advantage does the A7SII offer over the A7RII? And you most certainly can rate S-Log for ISO 200, I generally do unless there’s extreme contrast in the scene.
I should clarify I was referring to rating the A7RII at ISO 200 (two stops over native). You’d have to rate the A7SII at ISO 400 to achieve the equivalent exposure.
How do you “rate” your ISO speed differently in practice?
We’ve got a a7S II vs a7R II comparison coming up.
You set your incident meter to ISO 200.
I want to make a guess how many people who buy the a7S II or a7R II use an incident meter on their shoots. But you go first.