Quick review of A7S vs GH4

To me , this highlights why folks with discerning eyes should not be looking at DSLRs for their work. There is no free lunch (although it is getting cheaper). These cameras will always have shortcomings. Why is it in today's world that we expect ourselves to produce an A-list product using C or D level tools comparatively? This mix of wanting big screen images from ~$2,000 still cameras is kind of out of control. Part of me thinks Panasonic has yet to release an AF-200 because it will never be seen as "good enough" to be a financial success. It would have to shoot 4k RAW and have 4:4:4 1080p60 for anybody in numbers to pay $5,000 for it :) I joke, but it is not far from reality.
 
Both cameras are useful tools. If one had to pick just one, especially for shooting stills as well as video, the GH4 is a more well-rounded camera (and shoots 4K video internally- very useful when there's enough light). For low light and easier shallow DOF (especially if one has FF lenses already), the A7S is excellent. They differ in actual dynamic range by only about .4 stops (12.8 for the GH4 and 13.2 for the A7S, per DXOMark). The A7S does well in low light via extreme digital noise reduction processing- the camera gets hot (vs. the GH4 which does not and runs all day on one battery).
 
jcs said:
Both cameras are useful tools. If one had to pick just one, especially for shooting stills as well as video, the GH4 is a more well-rounded camera (and shoots 4K video internally- very useful when there's enough light). For low light and easier shallow DOF (especially if one has FF lenses already), the A7S is excellent. They differ in actual dynamic range by only about .4 stops (12.8 for the GH4 and 13.2 for the A7S, per DXOMark). The A7S does well in low light via extreme digital noise reduction processing- the camera gets hot (vs. the GH4 which does not and runs all day on one battery).
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12.8 vs 13.2 is only at base ISO, start to bump up the ISO and the gap widens considerably. The DXO numbers are basically even with the GH4 at 400 and the A7s at 1600 - already a 2 stop difference at very low ISO's. When the GH4 is at 3200, its DR is even with the A7s at 25,600 - a 3 stop difference. With the exception of 100/200, the difference is pretty significant. Panasonic ISO's are off by quite a bit more than the A7s as well, according to DXO's measurements. They are both incredible for what they offer at this price point and everyone is going to have preferences.
 
chris- that's true.

Shooting with the A7S + Canon 50mm F1.4 @ F2 and the GH4 + Voigtlander 25mm @ F.95 (similar FOV and DOF), the cameras both look very good in normal to even medium low light (indoors). The GH4's monochromatic noise turns to colored noise as the light decreases and looks like the A7S noise, only much less controlled. The A7S of course continues to pull away in relative quality as the light level drops. In well lit conditions, the GH4's 4K image looks super clean and detailed. The A7S isn't as detailed but has a nice film-like look to it (with proper settings- not Slog2 (Movie or one of the cinegammas). Walking around with both cameras, the GH4's significantly better displays help with focus, as does the GH4's (IMO) better focus peaking. The GH4 also just feels better as a tool: button+dial placement is much better (can start/stop video with main photo button. Sony DISABLES the photo button when in video mode! That should be one of the first things they fix in the next firmware upgrade. The GH4 appears to have had design assistance by folks with human factors / cognitive science training (my background), whereas the A7S was designed by engineers and product folks without a such a background). The GH4 gets an A- for cognitive engineering and the A7S gets a C- (being generous). The most challenging issue with the A7S is rolling shutter- really important to keep camera movement smooth (no whip pans :)). Someday we'll have one camera that can do what both of the cameras can do and more (and a global shutter :)).
 
I agree with lots of what you're saying, but some of it definitely comes down to personal preference. I find Sony's peaking superior to the GH4's, but I found it to be very effective on other Sony's I've owned including the Nex5n and FS100. I also prefer the two control dials used to adjust aperture and shutter speed on the A7, there's more tactile feel with the resistance and defined clicks at each stop. I've always used the record button and the AEL button for a quick AF while shooting video instead of the shutter, but again that's subjective. There's more real estate on the GH4, so more room for buttons. I did like having a dedicated WB and ISO button on top of the GH4, but having used the A7 I was already comfortable with the layout. I'm not a studio shooter, and I routinely used 3200 and 6400 on the 5d3. Given the GH4's DXO number, I was hoping I could do the same with the GH4, but that just wasn't the case. For me it pretty much topped out at 1600. That's not an issue with the A7s as I'm comfortable pushing it to 25600. They both perform at a high level and are pretty much the best thing going at this price point, good times for sure.
 
I'm not sure the Panasonic curves preserve in video mode all the DR that the sensor offers for RAW stills. I haven't seen any GH4 samples that gave me the impression of great DR. I expect to see an a7s+slog2 advantage of around 3 or 4 stops when somebody shoots a test like this one.
 
Id like to know how these cams stack against the FS100 (and C100) for HD delivery. The FS has little jello, no moiree even at high FPS and a S35 sensor.

S
 
Samuel, haven't had time to do a test, but DR wise the GH4 at cine d with no other highlight/shadow tweaks seems very similar to the C100 using WDR.
 
Cosimo Bullo said:
Samuel, haven't had time to do a test, but DR wise the GH4 at cine d with no other highlight/shadow tweaks seems very similar to the C100 using WDR.
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That's pretty close to what I found too. My test was more "real world" than scientific (just point them at the same blown out window, bring the exposure down until it's just touching maximum exposure, and then look into the shadows to see how far it goes.) The GH4 has quite a bit more noise in shadow areas than the C100 (cineD with no tweaking vs wide DR) at the same ISO, and the harsher highlight rolloff makes it looks like it has less DR... But I think there's probably no more than a half stop difference between the two. The C100 image responds to grading a heck of a lot better (even with the GH4 recorded externally at 10bit... Albeit 1080p not 4k)

The GH4 at 4k has nasty levels of jello compared to the FS100 and c100. And I think the A7s looks worse... But none of them are too bad for reasonably controlled handheld work.

Personally I found the GH4 performed as you would expect at the price point, and isn't a serious replacement for either of those cameras... But I'm sure there are plenty of people who would disagree with me.
 
I have just sold my GH4 and brought the Sony a7s ( which I have had for 2 days a very short time) . I also own the canon c100.
There are 3 things I dislike about the sony a7s

1 Rolling shutter
2. Very poor battery life
3. The lcd screen is not that great at least compared with gh4.

But even with these issues I love this camera

The images coming out of this camera are just stunning (in the c100 ballpark maybe even better more time needed for testing )
The low light performance is just amazing
It has a very organic look to it
I feel that this camera needs a bit of tweaking to get a nice image and with time you guys will see more better videos footage from this camera
People have mentioned that this camera tends to render yellow blotches in the skin. I think this could be due to the S - Gamut color mode . I would advice people to try different color modes and gammas to see what works for them
 
So, from the comments by Cosimo Bullo and AlexLeith, say the GH4 has about half a stop less DR than the C100+wideDR internal. Which should have somewhat less DR than C300+clog internal (very small somewhat this one, basically just whatever the AVCHD codec destroys in the shadows that the 422 C300 keeps alive, since wide-dr and clog seem to have the same range). Which has around 2 stops less than F3+slog internal (here, from 10:00 onwards; around half a stop in the highlights, a stop and a half in the shadows). Which has somewhat less DR than the a7s+slog2 (here; similar in the shadows, but a clear advantage to the a7s in the highlights; no idea how big it is in terms of stops).

That's 2.5 stops plus two somewhats, so, probably in my 3-4 stops range. I have some GH-fan friends, I may be able to run the scientific comparison once I get my a7s.

I am totally aware that this is stretching the 8-bit color space very thinly. Yet the clips I've graded so far seem to survive some decent pushing and pulling before they break down, so this will only be a problem if you plan to go for a very strong grade, in which case you should just shoot with something other than slog2.
 
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Gh4 has the worse highlight roll-off I've ever seen, especially in cine d or wide dr mode. So people count the extra dr in the highlights as "measured dr" but it doesn't count because if you smooth out the roll-off all of a sudden we some stops down on overall dr :( without getting technical at the end of the day by the time I set the roll-off smooth it ends up looking like a low dr camera so sorry to say.
 
Samuel H said:
Which has around 2 stops less than F3+slog internal (here, from 10:00 onwards; around half a stop in the highlights, a stop and a half in the shadows).
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They look about equal in the shadows to me. The difference is canon log compresses shadows more. Within reasonable limits of "correct" exposure this is a non-issue and in fact helps for fatter 8-bit signal where it matters. You might get more margin for error with underexposure with the F3 s-log but I wouldn't say that's more DR.
 
I see the shadows falling apart in the C300 a stop and a half sooner than they do in the F3. Yes, you are underexposing by a lot by then, but staying within reasonable limits of "correct" exposure on a scene that doesn't have a lot of contrast in real life is not going to tell you a lot about DR (unless the camera totally sucks). This test tells me that if there was a super-bright window in the background and I wanted to keep it alive, I could do it much better with an F3 than with a C300.
 
The gen 1 SpeedBooster works on the A7S! (lol). It goes into APS-C mode (when in AUTO APS-C). The quality is pretty good in crop mode- perhaps a tiny bit of aliasing (and apparent increase in sharpness from said aliasing). Tested with the 24-104 F4L at 'F2.8'- worked pretty well. After shooting everything so far with the 50mm F1.4, the IS works great handheld. With APS-C mode turned OFF, one can use the 'Crazy Wide Super Vignette' mode ;). Gotta try this with the 16-35 F2.8. With A7S+SB that extra stop of light is like double the ISO, right, so ISO 410K is now 820K? ;)
 
That's pretty funny. Thanks for trying that - yet another option to play with on the camera.
 
jcs said:
chris- that's true.

Shooting with the A7S + Canon 50mm F1.4 @ F2 and the GH4 + Voigtlander 25mm @ F.95 (similar FOV and DOF), the cameras both look very good in normal to even medium low light (indoors). The GH4's monochromatic noise turns to colored noise as the light decreases and looks like the A7S noise, only much less controlled. The A7S of course continues to pull away in relative quality as the light level drops. In well lit conditions, the GH4's 4K image looks super clean and detailed. The A7S isn't as detailed but has a nice film-like look to it (with proper settings- not Slog2 (Movie or one of the cinegammas). Walking around with both cameras, the GH4's significantly better displays help with focus, as does the GH4's (IMO) better focus peaking. The GH4 also just feels better as a tool: button+dial placement is much better (can start/stop video with main photo button. Sony DISABLES the photo button when in video mode! That should be one of the first things they fix in the next firmware upgrade. The GH4 appears to have had design assistance by folks with human factors / cognitive science training (my background), whereas the A7S was designed by engineers and product folks without a such a background). The GH4 gets an A- for cognitive engineering and the A7S gets a C- (being generous). The most challenging issue with the A7S is rolling shutter- really important to keep camera movement smooth (no whip pans :)). Someday we'll have one camera that can do what both of the cameras can do and more (and a global shutter :)).
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I own both cameras right now and I have to agree with all of this. I am shooting in Cinelike D and Slog however and the A7s definitely has a wider DR, especially in the brightest and darkest parts of the spectrum. Using faster glass on GH4 to compensate, I have been able to shoot in pretty damn low light alongside the A7s just fine, and both look similar after grading - which is to say quite nice.

Other than that - yes all that you said.
 
Nicholas Christopher said:
Gh4 has the worse highlight roll-off I've ever seen, especially in cine d or wide dr mode. So people count the extra dr in the highlights as "measured dr" but it doesn't count because if you smooth out the roll-off all of a sudden we some stops down on overall dr :( without getting technical at the end of the day by the time I set the roll-off smooth it ends up looking like a low dr camera so sorry to say.
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No way. The FS100 (which I also owned once) had horrid highlight rolloff. The GH4 is nicer looking than that camera - so the issue isn't in the highlights. It's no C100/300 (or A7s- both roll similarly) but it's certainly not like the FS cameras. Those were horrible, comparatively speaking.
 
Samuel H said:
I see the shadows falling apart in the C300 a stop and a half sooner than they do in the F3. Yes, you are underexposing by a lot by then, but staying within reasonable limits of "correct" exposure on a scene that doesn't have a lot of contrast in real life is not going to tell you a lot about DR (unless the camera totally sucks). This test tells me that if there was a super-bright window in the background and I wanted to keep it alive, I could do it much better with an F3 than with a C300.
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The F3 has more DR in Slog than the C300. The A7s seems similar to the F3. It's not a huge difference either way however, talking about shooting a scene like you mention. They all do a decent job. The Gh4 - not so much - but it's not horrible by any means. It just doesn't have a pure Log mode to grade.
 
I'm astounded that it took 3 pages for someone to type the word 'organic'.

The A7s definitely has some advantages in certain applications, but I don't know how anyone that has used both cameras (I finally got my hands on one) could possibly find the A7s better as a working tool. The depth of features with the GH4 are so great that users are barely coming to grips with the possibilities at this point and we still can't look at the outboard 4K for either camera. At the moment the in cam 4K of the GH4 is some fertile soil to plow, and while I actually enjoyed the A7 for shooting stills I really felt like the system was far from mature in terms of peripherals and lens selection (and much of that applies to the A7s). A couple things that haven't been mentioned are that the GH4 is a superior 'time machine', whether time lapse or overcrank (I use the 1080 60p), and the wifi remote has evolved from 'smartphone toy app' to a serious useable tool. In terms of color science I'm certain that in the right hands and with the right tools the Panasonic output can be made to look just as satisfying as the Sony output.

At the moment, for the type of work I do, if there were no GH4 I would choose a 5d over an A7s unless I was really doing a bunch of night shooting. . .and even then. Also, while I realize this is a discussion about just two current camera models there is a tendency in the 'forums' to ignore the broader view, the Panasonic GH line has from the beginning been INNOVATIVE and it can be argued that there has been a responsive evolution of the line that is pretty much unmatched, the A7 series is Sony's first mirrorless foray. Don't get me wrong, I was mister Sony for like 20 years and they could always lure me back, but I wouldn't hold my breath for firmware updates to fix things in A7 series. I look forward to testing the A8s 18 months from now.
 
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