Slow-mo shootout – which camera gives the most detail at 120fps?

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I recently decided to find out which of the current 1080/120fps capable cameras does it the best.

In the first half of the video we have a relatively close-up shot at F2 and ISO 200 with soft lighting, which is relatively forgiving of any detail loss or aliasing. Pixel peep the video to see which image you prefer.

In the second half we have more challenging lighting, at ISO 1600 with the lens stopped down to F5.6 and the camera brought back further from the test scene so that fine details in the objects become even smaller and finer, thus more challenging for the cameras to capture. This sequence is also a good test of the high ISO performance of the cameras.

The candidates

  • Panasonic GH5 (120fps to 180fps variable)
  • Leica SL (120fps)
  • Canon 1D X Mark II (120fps)
  • Sony A99 II (120fps)
  • Sony A7S II (120fps)
  • Sony RX100 V and RX10 III (120fps continuous, 240fps cache)
  • Sony A6500 (120fps)
  • Samsung NX1 (120fps)

I also throw in at the end the good old Panasonic GH4 96fps for reference. It is incredible how much better the colour and dynamic range is on the GH5 in comparison to the old camera, not just in 10bit but in the 8bit 120fps slow-mo files as well.

Overview of features

Panasonic GH5

The latest from Panasonic is a monster when it comes to slow-mo and the new VFR mode. This variable frame rate mode converts one frame rate to another in-camera, giving slow-mo files straight off the card with no effort in post required. The VFR feature is full HD 1080p but quality varies depending on how fast you crank the sensor. The lovely 10bit codec is not available in this mode. Although this test focuses on 120fps or more, lovers of a milder slow-mo result from 60p will like the GH5 a lot – it’s the only camera on this list to shoot 4K 60p along with the 1D X Mark II.

Leica SL

Quality is not just about resolution. Sensor size matters as well. The Leica SL is one of just 3 full frame cameras to shoot 1080/120fps without a crop.

Canon 1D X Mark II

The 1D X Mark II also does 1080/120fps from the full frame sensor, with no crop, along with Dual Pixel AF. But does it have the resolution?

Sony A99 II

The A99 II may use a similar sensor to the A7R II but the slow-mo capabilities are far better because of the new front-end LSI. The faster processor is able to take an intelligently sub-sampled 1080p image off the 42MP full frame sensor at 120fps whereas the A7R II only managed a brutally line-skipped 720p. Until the Nikon D850 comes along the A99 II could be considered the absolute cutting edge of current sensor and image processor design.

Sony A7S II

The A7S II does 1080/120fps but with a heavy 2x crop of the sensor. You can however use a Metabones Speed Booster to reduce the 2x crop to something resembling Super 35mm (1.5x).

Sony RX100 V and RX10 III

The smaller sensor with a memory buffer stacked directly on the back of it results in a bit of a slow-mo specialist here. I won’t just stop at testing the continuous 1080/120fps recording, but also the 1080p 240fps cache record as well (250fps in PAL mode). The latter crops the sensor but only by a smidgeon more than 120fps.

Sony A6500

Sony isn’t done yet… the A6300 and A6500 both shoot an identical standard of 1080/120fps and like the other Sony cameras it’s a continuous recording mode. Although the camera can conform the slow-mo result in-camera, it’s better to do it in post as the bitrate of the continuous 120fps recordings is an impressive 100Mbit compared to just 16Mbit in S&Q mode.

Samsung NX1

A long-time favourite of mine, the NX1 has done 1080/120fps continuous recording in HVEC H265 since 2014 without breaking into a sweat.

Recording modes and audio

If you have a 120fps file, you can interpret the footage as 24p on your timeline to induce the 5x slow-mo effect.

If your camera does this onboard then the good news is you don’t have to do it in the edit, but you usually lose the audio track. Although it may appear it, slow-mo isn’t baked into the file, you can return the clip to normal speed by speeding up the frame rate 5-fold, or conform to a slightly less slow frame rate like 30fps or 60fps in post.

Only the Sony cameras and the Samsung NX1 output directly 120fps recordings. These are at very high bitrates to maintain quality across so many frames. 100Mbit on the Sony cameras and continuous, with audio recording. On the NX1, H.265 is used at up to 80Mbit (equivalent to 160Mbit in H.264 quality but half the file size).

Conforms in-camera from 120fps to a slower frame rate like 24fps:

  • GH5
  • Leica SL
  • 1D X Mark II
  • All the featured Sony cameras in HFR or S&Q mode
  • Samsung NX1 in slow-motion mode

Records 1080p 120fps files direct to card:

  • All the featured Sony cameras in 1080/120p continuous recording mode
  • Samsung NX1

So on the cameras that record 1080p 120fps directly to the card like a normal video mode you can have a funky slow-mo audio track to your slow-mo videos too, when they are slowed in post.

The scores

I am the most impressed with the A99 II and GH5. The quality of the 120fps on the A99 II is a huge step up from the A7R II and A7S II. 1080p, with almost the same level of detail as the 1080p at 24p, with no sensor crop. Aliasing is well suppressed, with only a little moire on occasion and excellent resolution. The camera maintains 5 axis image stabilisation at 120fps along with all the other features such as S-LOG. It is incredible that Sony were able to extract such a high quality high speed image from a massive megapixel count and with absolutely no crop of the full frame sensor! Also, if you don’t mind shooting at F3.5 the SLT AF mode works a treat (nearly to Dual Pixel AF standard) even in 120fps.

The Panasonic GH5 is extremely close in 1080/120p VFR mode to the quality of the A99 II but it does have more jaggies as a result of a bit of aliasing. It does however seem to have almost supernatural levels of dynamic range for a Micro Four Thirds camera even in 8bit along with massively improved colour over the GH4 and amazing low light performance. At 1080/180p the image quality does reduce with a more pixilated look and heavy aliasing & moire but depending on the shot you might not notice as much as you’d think. Overall a superb performance.

The Leica SL is a close third. It’s VERY close between this camera and the GH5. Some may give the win to the Leica as it’s full frame. It is a little softer than the A99 II and GH5 in 1080/120p but it has slightly less aliasing than the GH5’s 120fps mode. There’s no sensor crop in 1080p like there is with 4K on this camera. The GH5 needs fast glass or Speed Booster to look as aesthetically pleasing as the Leica SL does! It’s a shame the LOG profile on the Leica is still so poor though with a black level that’s far too high and banding present as a result. There’s also some quite heavy compression noticeable in the 1080/120p slow-mo recordings compared to the other two top-dogs.

When it comes to the 1D X Mark II in 1080p, the Leica SL definitely has the edge. The Canon is a cinematic beast in 4K but the 120fps mode should produce slightly better results given it costs $6000, I think. It isn’t up to the other cameras I’ve mentioned so far in terms of detail. Aliasing is quite a bit heavier than on the Leica SL and it’s certainly softer. But it’s the aliasing which tends to bite you the most. The good news is there’s no crop so it remains one of only 3 cameras to do full frame 1080p/120fps until the Nikon D850 arrives.

The Samsung NX1 is far more affordable than the A99 II, GH5, Leica SL and 1D X Mark II. Also it’s actually more detailed and sharper than the 1D X Mark II… but what hurts it is the extreme level of aliasing. It has detail enough, but with hard sharp edges and quite some pixilation – it could do with some kind of digital low pass filter to smooth those edges out like the A99 II. It’s less soft looking than the 1D X Mark II though. The NX1 remains an absolute pleasure to shoot with ergonomically in 2017 and the 4K image is extraordinary – and did I mention it’s 1/6th the price of the 1D X Mark II?!

The RX100 V, RX100 IV and RX10 III all shoot identical slow-mo results and they are nicely detailed, with very little aliasing or moire. These crank to very high frame rates above 240fps but quality suffers a lot if you do this. The main issue with these cameras is they need a lot of light, especially for 240fps and the lens on the RX10 III is not the fastest at F2.8-F4. I regularly find myself using ISO 1600 or 3200 on these cameras in slow-mo mode, which is pushing the limits of the smaller 1″ sensor.

The Sony A7S II has a similar image to the 1D X Mark II but from a huge 2x crop of the full frame sensor. This is a bit of a mediocre performance but at least you can put a Speed Booster on there to mitigate the crop and get it back to Super 35mm-ish.

The A6500 definitely brings up the rear the worst of both worlds – soft detail, but tons of aliasing as well. It isn’t really 1080p and it just doesn’t hang with the other Sony cameras for 120fps quality.

  1. Sony A99 II
    10/10 – The most detail and the least aliasing – did I mention all this from a full frame 42MP sensor?!
  2. Panasonic GH5
    9/10 – The most flexibility in frame rates and the 120p is close to the A99 II for quality (just a bit more aliasing)
  3. Leica SL
    8/10 – A solid option for full frame 120p, albeit with some aliasing
  4. RX100 V / RX10 III
    8/10 – Great feature-set, good detail with low aliasing, but significantly noisier than the others especially at 240fps
  5. Canon 1D X Mark II
    7/10 – Quite soft with aliasing issues – could be better but nice dynamic range
  6. Samsung NX1
    7/10 – High detail but high aliasing. I do like it though.
  7. Sony A7S II
    6/10 – Soft with a crop, not exactly a stella performance
  8. Sony A6500
    5/10 – The softest yet also the one with the most aliasing, so clearly the worst of the bunch

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