Sony a7S Review as it Compares to the Panasonic GH4

The a7s and GH4 battle it out to see which one will be my new camera.

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Prices for Equipment Used in this Review:

The a7s is another very important camera, this review will be just as long as my GH4 review. As with my last review you can jump to the conclusion if you don’t want to watch all the side by side comparisons.

Table of Contents for Video

2:49 Detail
5:02 Brittle Hair
6:35 Rolling Shutter
9:28 Aliasing
10:17 DOF
10:57 Purple Fringing?
11:37 Low Light
13:13 Banding
14:15 S-Log2
16:35 Cine2 Cine4
16:58 Exposing S-log
18:50 Color
21:27 Dynamic Range
22:55 Lenses
24:17 Focus
26:47 Stills
30:40 Don’t like
33:01 a7S vs GH4
39:21 Which Camera?
41:48 Audio
44:29 Conclusion

Like I said before in my GH4 Review I am leaving Canon. The question is which one will be come my new camera, the Sony Alpha a7s or the GH4?

The GH4 and a7s is not an apples to apples comparison because one is m43 and the other full frame. I’ll say it right at the start if you need super creamy backgrounds easily get the a7s, if you easily get super detailed images easily get the GH4. In this review you will see me struggle which way I am going to go.

Blue Lakes Colorado - Near Quandary Peak

Both have really clean images. They both have ‘clean’ meaning they have no aliasing. The GH4 is clean because all the wonderful detail. a7S is clean because it has no noise to fight.

Detail (Sharpness)

  • As I showed in my GH4 review, the GH4 at 4k blew the doors off the 5D Mark . The Gh4 also blew the doors off the 5D at 1080.
  • I had a feeling that the a7S even at 108o would also blow the doors off the 5D Mark III and sure enough, it did! Here are both with the sharpness turned all the way down and I added just a little to both equally.
  • Here is no sharpness in post but both using their in-camera default sharpness settings. As you can see the 5D looks pretty nasty.
  • And as you might expect the GH4 at 4k does beat the a7s at 1080, I am going to wait until the Atomos Shogun comes out to retest this.

Maggie Pond Breckenridge

Dynamic Range

By now you have seen the amazing things this camera can do in low light, but I am more interested in the dynamic range. Like I said in my Gh4 review if the dynamic range of the a7S blew me away then I would pick the a7S as my new camera, so I thought that would be a great place to start.

I don’t have the facilities or the knowledge to accurately test dynamic range, but I think my tests will help you see which one is better in real life situations.

S-Log2 Picture Profile

Before we can talk about dynamic range I need to talk about S-log2 which is a professional picture profile [PP7] that Sony has stuck in this consumer camera which can really make the most use of the sensor’s ability to capture the whitest highlights and the darkest shadows.

Ok, I gotta say I’m not even close to being an expert on this gamma curve, but have been learning a lot from testing it over and over and talking to many talented colorists who know this log curve much better than I do.

Apples to Oranges Comparison?

Basically S-log2 is a logarithmic curve that flattens out your image both in terms of contrast and saturation. The purpose of using it is simple, it gives you more latitude which can give you greater control in post. It’s important to know S-log2 will not always give you a superior image over other profiles in camera, but it will give you more options, what you do with all those options might make it worse than a more linear profile (I am guilty of doing this). Don’t confuse s-log with shooting raw which might look similar, raw gives you the greatest amount of control in post (you can’t actually see raw, in order to look at it, you have to make the raw into something, and generally that’s a log image). S-log2 is designed to be graded later in post by adding contrast and saturation back in.

While I am glad they have slog in the camera, and it will be fun to learn how to master it, right now I gotta say I am mostly frustrated with S-log2 when exposing for it and when grading it.

Exposing for S-log2 is tricky since you are looking at a milky image (low contrast). I have tried many ways of exposing, I have tried exposing middle gray two stops under like Sony recommends in their white papers, and while this method might give the greatest dynamic range, it also gives you the most noise. Because when you add a lot contrast you add noise. I found that exposing to the right of the histogram shows the least amount of noise, however it defeats the reason of using S-log for dynamic range.

Sony’s advice for exposing for s-log2:

  • Expose at 38% for middle gray.
  • Expose with light meter, 2 stops lower middle grey becomes 38% ,
  • protect zebras,
  • faces at 45-50% for s-log instead of 65-70%.

Unfortunately the a7S can only record 8bit and in post, when you start adding contrast back, you might run into banding issues.

Juan Salvo who is a professional colorist said,

“8bit (consumer) + slog2 (pro) = not the best combination if you are going to give your footage to a professional colorist. When you stretch the log image out (add contrast) you will see on your waveform it breaking apart which is what causes banding. If that happens with skin tones than it is a world of hurt.”

Andy Shipsides at Abelcine on YouTube video at 4:20 says:

“… to really maximize and take advantage of slog I need to be in 10-bit. That is not the best option because 8 bit is truncating off a lot of data and it is really not a good recoding option for s-log”

Sony’s ICE ‘Independent Certified Expert’  Alister Chapman: @45:05 in the video:

You really, really, really want to use 10bit recording, I can’t not emphasis this enough, it makes a huge difference when you grade, you can use 8bit, it is not impossible, it can be graded, it doesn’t look terrible but you will find 10bit preferable.”  12:00 “… because with 8bit you only 235 gray gradient of brightness, when you go to 12-13 stops of dynamic range when you grade it those steps will get pulled apart and you will see banding in the image, you want 1023 steps in 10bit”.

Andrew Reid:

I question the wisdom of shooting too flat with an 8bit codec. It requires a more forceful grade and that will introduce banding.”

Another issue with S-log2 is the lowest ISO you can shoot in is ISO 3200, so you are going to need a lot of ND. I am not sure a variable ND is the best because that is going to add a slight green color cast and the colors are already so desaturated that it might cause you even more headaches in post while correcting the colors.

Sony a7S Color profiles

S-log2 is not all bad, I have had success with it in mostly low key situations. I never saw banding. Bring the contrast back into the image for s-log has not been my problem for me, getting the colors to be accurate is where I struggle. Slog2 gives the sky a flat steel greyish purple. You can get the skies to match but I screw up the foreground, you will be spending a lot of time pulling secondaries way too much. Again s-log gives you more options in post, but perhaps not every time with the best image quality.

Halley O'Brien - Which is Full Frame and Which is M43?

I’ve come to the conclusion that I’m glad s-log2 is on this camera and I have a lot to learn, I am sure I will only use it for extreme contrast situation, but for everything else I will use more linear profiles like Cine4. I spoke with 3 Sony users that have s-log with 10bit recording, two of them only use slog in high dynamic range situations while the 3rd person leaves slog on all the time.

Check out David Carstens video on S-log2 color that I demo’ed in the video.

Dynamic Range a7S w/Cine4 vs GH4

Since I will only be using S-log2 occasionally, I needed another profile and after a lot of tests I end up liking Cine4 the most.

S-log 2 over exposed two stops question

Concept with Cine4 and all my tweaking is to get as close of look in camera that I like and I can handle in post. Once I have that profile I then back off the contrast just a little so I have a bit of room in post to play.

Sony a7S Slog2 With and without Color Grading

Both of these cameras are a huge improvement over my Canon DSLR cameras because the always crushed the blacks way to much and left no shadow detail compared to the GH4 and a7S. So big win over Canon however the way I shoot, the a7S has a little bit more dynamic range than the GH4.

DOF

Some say it is easier to get shallow DOF with a full frame compared to a M43, I am not sure if easy is the right word, perhaps it is less expensive, because you can buy really fast glass for the GH4 but it will be expensive compared to $120 50mm from Canon.

Focus, Exposure & WB: Getting the shot fast

  • Focus: win to GH4. While they both have peaking, it’s faster to get focus with AF and then manually adjust from there sometimes. Sony FE lenses are not linear which is slowing me down and I can’t repeat a marked off focus pull.
  • Exposure: tie, they both have zebras and histogram. On the a7S you lose the histogram for ISO, Aperture and shutter. The GH4 lose zebras and histogram when you adjust ISO.
  • White balance: win to GH4 because a7S you have to leave movie mode. A7S sky is not the right color in slog.

Rolling Shutter

Paul Thomas Anderson whip pan – check out this video if you like to do whip pans, with the a7s you will need to correct for whip pans in AE.

You can get less rolling shutter if you use aps-c mode, check out Philip Bloom’s video on this.

Jason Wingrove says, “Rolling shutter looks worst in rolling shutter tests“. I think this is an important quote to remember when buying a camera.

Aliasing at Higher Frame Rates

Both of these cameras are clean from aliasing and moire. That is a wonderful thing!

Both however will get aliasing when you shoot at higher frame rates like 60fps.

Lack of Native Lenses

  • Sony has 20 lenses. 5 for full frame the rest for APS-C. It might take them 2 years to get the glass I need, by then the camera landscape could change again (perhaps Canon will get their sh*t together).
  • Lack of fast a7S native 2.8 zooms is bumming me out. Mark from Sony, “We decided to make the lens size appropriate to the camera size, as a result we are making the 24-70 constant aperture f4 instead of f2.8. It is easy to make an f2.8 it is easy to do but it is going to be a significantly larger lens appropriateness size and balance alpha 7 camera probably wouldn’t be a great match.”
  • I’ll have rethink primes again for fast AF, which I know constant switching primes out will slow me down. Have to rethink my 16-28, 24-70, 70-200mm zooms.
  • Canon lenses on the a7S do work for aperture, AF and IS, but if you are thinking you can use them for sports photography, think again, worse case it takes 4 seconds for the a7S to focus a Canon lens! I have not tried Canon’s STM lenses but I bet they work much faster, but they are usually slow kit lenses.
  • You can focus faster with peaking than AF with canon lenses.
  • Balance issue with the Canon 70-200mm and a7S, it is really awkward holding it.

a7S vs GH4

  • GH4 has more detail than a7S but that only holds true until you get to about ISO 800 then the a7S has more detail because all the GH4 noise softens the image.
  • Colors are more accurate on GH4 when using auto WB or custom.  Skin looks better, more accurate. A7S gets the water wrong, too green. Which one do I like best, pretty much every time the GH4, then I match a7S to it.
  • a7S I love that you can zoom in while recording! (see broll)
  • a7S love the info after a custom wb! Great learning tool. (see broll)
  • Gh4 has brittle hair sharpening artifacts. Truly pixel peeping hard to notice unless side by side. Stu also noticed this. Gh4 you have to turn the sharpness all the way down when you have lots of hair in the frame. Add sharpening it back in post. When compared to a7S, the a7s handles hair much better.
  • GH4 has a touch screen! Will it make your images better? No, but if the touch screen prevents you from deep diving in to the menu you will get more shots off.
  • GH4 is great for wide shots, so much detail compared to a7S. A7s might have cleaner shadows at higher ISO but I like the look of the detail over the little bit of dynamic range the a7s might have.
  • GH4 is still crashing. The Sony has not crashed yet unless you use Apps.
  • GH4 screen and Evf has aliasing, however I like that one better because it is nice and bright and sharp.
  • A7S when you punch in you feel more confident you have focus vs the GH4.
  • APS-C crop for video works nice! I really like having it as an option to use when I really need it, perhaps I can’t change lenses fast enough but I can change the mode fast, I know I will get some aliasing however.
  • The GH4 with standard zooms attached is lighter and easy to carry than the a7s.
  • a7S App is not as good unless I am missing one you can download, like the time lapse one, but it is very simplistic compared to the GH4 app. GH4 app connects faster and responds a lot faster than the a7S app.
  • Xavchd vs gh4 computer CPU use. Gh4 4k uses more CPU. 11-14% CPU for a7S and 25% for the GH4.
  • For stills only the Canon 5D is the best if you have the money and don’t mind the weight.  But if you do any video too, then these other two are better.
  • Don’t be fooled the a7s body is smaller but once you attach lenses the gh4 wins in portability. But if are shooting at 1600 or higher the a7s lighter because you don’t carry as many lights.
  • Battery test on the #a7S 1:56 minutes for one battery at the Zoo. Not as good as #GH4 but the GH4 battery is 2x size.
  • I can match both of these cameras, but it takes work.
  • GH4 is less money than a Atomos Shogun – think about that if you need 4k on the a7s.
  • fyi: Panasonic bakes in the lens correction into the raw file no Lightroom presets.

Stills on the a7S

  • Sometimes even when I zoom in I say wow look how clean the image is on their face. Maybe big clean pixels are better.
  • The a7S is really slow for continuous shooting as well by today’s standards.
  • You only get 12MP to print with which I was concerned with, but I did a large 20×30 and it looks really good!

Which Camera is Right for You?

  • A7s with for darker evening shots perhaps a dimly lit wedding reception when light can become very challenging.
  • A7S for real estate because easy to shoot wide on a FF and the dynamic range.
  • A7S for slow motion at ISO3200 or higher because even though the GH4 is more detailed the noise soften the Gh4’s image.
  • A7S for higher ISO and close ups on skin, the a7 wins.
  • A7S pretty much whenever you shoot above ISO 800.
  • Gh4 is great when you absolute need it to be in focus for like event run and gun coverage where you are moving fast. More looks in focus because of all the detail.
  • GH4 if I was doing Glidecam work I would definitely use the GH4 because less rolling shutter and everything is in focus.
  • Gh4 for wide master shots and textures, blows the doors off the a7S at this for now until the Shogun comes out. Not master shots just when someone’s face doesn’t fill the frame.
  • GH4 for sports photos, super fast FPS and quick continuous AF.
  • GH4 for extreme close up where you want everything to be in focus, hard to do with FF.
  • GH4 for vacations when you want to travel light while you walk around all day.
  • Old Canon T2i: If this is your very first camera, get a used t2i for $200 on Craigslist and learn on that for a year, by then another camera will be out that will be better than these two.

GH4 with ColorChecker

Things I Don’t Like About a7S

I have talked to Sony about each one of these items, perhaps others can voice their request:

  • Record button is in a really bad spot! Remap c2 or the shutter button.
  • Can’t set custom WB in movie mode! You have to leave movie mode to set this.
  • Lose histogram when ISO, shutter, aperture is changing.  CORRECTION: you can, even though Sony said I couldn’t! David Sikes says, “In the menu, go the second tap—the gear—and under its second page there is an option called “Exposure Set. Guide”. Switch it off
  • Histogram too small and has an 8-bit stair steppy look to it
  • Doesn’t update TN on playback to where you left off, GH4 doesn’t either
  • You can’t see meta data on video playback.
  • Again the lack of fast native zooms that I can also use for stills with fast AF is probably the weakest thing for the Sony.
  • I notice in Aperture priority you can get x4.2 and x8.3 zoom but in movie mode you can only get x4.0. Can I increase that x4.0 to a higher number?

A7s S-log2 Sky Matches but not grass

Audio

  • Both GH4 and a7S sound pretty clean. However the a7S has a leg up with balanced audio inputs in the hotshoe, new mic is coming out.
  • GH4 only pads down to a -12dB (18 step) which doesn’t make it that flexible for hot mics like the Rode VideoMic Pro or Shure Vp83
  • a7S has a 31 step range
  • a7s doesn’t have built in limiter like the GH4
  • Why is the GH4 always out of sync?

Other

I used both cameras in 97° heat, they both did fine. The a7s is weather resistant.

Conclusion

  • I love the clean image you get from the a7S pretty much no matter what ISO you use.
  • I love all the detail the GH4 provides at low ISO’s.
  • I love full frame look from the a7S when I have a person filling the frame
  • I love how small and unintimidating the GH4 and all it’s lenses are, it is so easy to carry around all day especially the 70-200mm equivalent, and the battery will last you all day too.
  • I love GH4 for it’s internal 4k so I can pan and scan when I edit.
  • I love the 5D Mark III for it stills capabilities especially for sports photos, but my ratio of pictures/video doesn’t justify keeping it, in fact I sold it.

You really need to turn the sharpening all the way down on the GH4 and then add a little bit back in post, if you are doing an interview I would pick the a7S as your close up.

I don’t want to understate the importance of the EVF on both of these cameras. Your exposure and focus will thank you.

The skin tones on the a7S can be challenging.

To generically sum it up if someone is filling my frame I would use the a7s, if I am shooting a wide shot I would use the GH4, if I was shooting above ISO 800 I would shoot with the a7S, if I was shooting outdoor stills for sports the GH4, if I was shooting portraits I would use the a7S.

Would I use the Shogun for 4k recording once it comes out, I’ll try it but I have a feeling I would not use it much and just stick with 1080 for speed and convenience. Also the GH4 does have more detail than the a7S at 1080, but is the GH4 blowing the doors off the a7S like it did with the 5D, no.

Both of these cameras are evenly matched, and to put things in perspective they are better than the Canon DSLR’s. If you do a ton of two camera shoots you might want to buy two if the same camera. I will need more time in post to match them.

I have only been in this for 4 years while others have been in it for 20 years and they have seen shifts in the market. Perhaps I’m witnessing my first market shift. Let’s face it the 5D3 has been king for video for a long time. But reading about 1000 comments on my gh4 review sounds like a big shift going towards a7s and gh4. Canon need to do something, perhaps a 7D Mark II that will have all the features of a 1Dc but $2,000?

Two sets of people. The set like me that want the latest and greatest tools to make you shooting easier. I’ll admit it, if a tool can help with just a few of my deficient skills as a filmmaker than I’ll take it and jump to a new brand. I understand that the new camera will not make me into a Rodger Deakins but I’ll take any help I can get. The other set will not switch brands at all and will have patience to wait until their brand gives them a reason to upgrade.

At the end of the day I don’t want to carry the big heavy Canon 5D Mark III anymore!

As I make courses on these cameras and dive in to them further I’ll have a much better sense when to shoot with each and how to make them match in post.

So what am I going to buy?

Should You Leave Canon?

  • I sold all my Canon bodies and some lenses. If these cameras interest you but it is too painful to switch brands you might wait. I bet if you wait a couple of years Canon will have to respond to the market and come out with something just as good that has an EVF in this price range. I don’t want to wait two years. When you are heavily invested in Canon glass you tend to get frustrated at them since it is hard to leave their system.
  • Canon has given me a way to create stunning images over the past 4 years which I am grateful, I just hope the can perhaps innovate a little more and respond to the market demands and create a mirrorless camera like the Gh4 or a7S in the next few years that doesn’t cost $10K.
  • Jason Wingrove sold his 5D Mark III and 1DC and picked up an a7S, I think that speaks volumes, I really respect Jason’s work as I think many others do.

Thanks

James Drake

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