Nikon D800, yay!
Heck, lets shoot Slog, and rate the camera at 2000ISO. We'll get an extra 2stops of DR in the highlights, and a much more filmic tone curve (tons of highlights, less shadows), yeah baby!
Noisy footage? Of course! But Neat video can do magic and now that it can be integrated inside Davinci resolve, it's a super simple process.
So if the F35 already had a very pleasing highlights rolloff, imagine how good it's going to be now with an extra 2 stops (or 3 if you're crazy) in the highlights.
I shot these tests on 10bit 422, I see no banding issues of course, but I'm sure 12bit 444 would be the best for this workflow, as most information gets concentrated in the lower part of the histogram.
A few tests on the Super enhancer plugin.
Pics by Matt Borek
Samsung just released a firmware update that boosts bit rate up to 80Mbits on 1080p modes among other improvements. Time to test.
UHD downsampled to 1080p shows a clear improvement in image quality vs just recording at 1080p. So yep, it's the way to go unless you need slow motion.
Testing Gamma modes
Does the DR gamma mode get extra dynamic range? Yep, but only on the shadows. Highlights remain the same.
Some real life footage captured with the Samsung NX1 - UHD internal recording. No grading.
- small "turist" camera that delivers pretty good images
- rolling shutter is decent
- AF is impresive
Samsung NX1 vs Sony A7s
by Bruce Allen and Macgregor
Alright, lets compare the NX1 to the king of the 4K mirrorless, the Sony A7s. But please remember, that the A7s requires an external recorder if you want 4K, that makes the combo about x4 times the price of the NX1 (currently $1199). So not a very fair comparison. We used the Odyssey 7Q+ on this test.
1. NX1 UHD internal recording. Camera matches lightmeter reading.
2. NX1 UHD external recording to Odyssey on prores HQ. Camera matches lightmeter reading. Shift in colors/levels vs internal recording.
3. A7s UHD cine4 gamma. External recording to Odyssey/prores HQ. Camera matches lightmeter reading.
4. A7s UHD Slog gamma. External recording to Odyssey/prores HQ. Camera metering.
5. A7s UHD Slog gamma. External recording to Odyssey/prores HQ. Lightmeter metering (which produces under-exposed results).
No apparent change in detail between internal and external recording with the NX1. However there is a shift in levels and colors.
The NX1 seems to produce slightly sharper images at 4K. But it introduces very visible sharpening artifacts. The A7s doesn’t seem to resolve the same amount of detail. Of course this difference is totally invisible when watching the footage at 1080p and even in 4K the differences are subtle.
The levels shift appears to be in the conversion from h.265 to ProRes: most h.265 converters convert the NX1’s files to a 0-235 ProRes file (well, the 10 bit equivalent thereof). The Odyssey saves out a 0-255 ProRes file, so it appears brighter.
The color shift also appears to be in conversion from h.265 to ProRes: if you decode the h.265 file assuming it has Rec.709 color primaries, they don’t match the Odyssey. However, if you decode the h.265 file assuming it has Rec.601 color primaries (old school standard def NTSC colors), the colors do match the Odyssey. Also, if you load the ProRes file and perform a Rec.601 to Rec.709 conversion, they match the h.265 colors. Since the h.265 colors seem better, it seems likely that there is an error in the HDMI output.
Luma and chroma sharpening and blurring issues:
It is important to separately examine luma and chroma on the NX1 as they each have their own issues.
The luma is over-sharpened, yet the chroma has a blurry, heavy-handed noise-reduction algorithm applied, even at ISOs such as 100 and 200. There seems to be no way to turn this off.
This can clearly be seen in the Macbeth chart: the colors of each chip spread for several pixels both horizontally and vertically into the gray dividers. The A7s does not suffer from this to the same degree at all.
This is disappointing as the NX1’s 4K image is supposedly derived from the full-res sensor. The downsampling of that Bayer data from approx 6K to 4K should give it the best color detail on the market, possibly approaching true 4:2:2 color detail. Instead the color detail seems worse than 4:2:0. It’s definitely worse than the A7s.
Unfortunately, the smudging of the color takes place quite early in the pipeline because it is evident in the Odyssey recordings as well. The h.265 compression has little effect on color detail - it just adds some extra blocky compression artefacts.
Hopefully a future firmware update can give us an option to turn off these algorithms that do more harm than good, and perhaps devote those CPU cycles to other more beneficial tasks.
Samsung NX1 vs Sony A7s
4K image quality test - studio version 2
After noticing how the NX1 still applies huge amounts of sharpening I lowered this setting to the minimum level (-10) and I raised the A7s detail to 0 to see if I could get a sharper images out of the A7s in 4K.
At detail 0, the A7s shows sharpening artifacts.
he NX1 still shows sharpening artifacts but it seems to resolve more detail.
Samsung NX1 - dynamic range
I can see about 10 stops of dynamic range.
With the same testing procedure, the Sony A7s delivers 12 stops.
What about just shooting internally on 1080p?
Samsung seems to win in terms of resolved detail. However I think I prefer the beter DR of the Sony. However, remember that the sony costs twice as much as the Samsung, and the UHD downsampled to 1080p on the Samsung blows the Sony away and gets you 444 color sampling. So it's a hard call.
Slow motion on the NX1:
Testing if the quality drops when shooting 120fps vs 24p. Nop, detail and noise seem to be the same.
No visible loss in quality when switching between 24, 60 or 120 fps.
- Great image quality
- Easy to use
- internal 4K recording
- great price
- s35mm equivalent sensor size
- excellent EVF
- Great 120fps slow motion mode (given the price of the camera)
- EXCELLENT Autofocus performance in video mode
The NX1 seems to have a great sensor but it is hurt by its own processing. Right now, Samsung could seriously improve the quality of the NX1’s video just by:
- creating a true Dynamic Range or Log mode that doesn’t clip the shadows and highlights
- blurring the chroma less (or allowing us to control it or turn it off entirely)
- giving us an easy way to turn sharpening off (0 is clearly heavily sharpened)
- increasing the bit rate in the h.265 encoder or finding some way to get it to stop the heavy blocking artifacts
- disable the noise reduction for real?
These could be accomplished by firmware updates. Given how much the camera has improved in the firmware updates so far, we’re hopeful.
Additionally, there are several functional firmware updates that could really help:
- allow us to hit a button to zoom in to check focus even if using Samsung’s own autofocus lenses.
- allow us to zoom in to check focus while we are recording
- get rid of the Video recording standby mode, it's annoying and confusing
- let us assign video recording to the shutter button, as the video recording button is hard to reach and press.
Oh, did we mention the camera has touchscreen? It's pretty awesome!
I got interviewed after Similo won Best Photography award at Madrid-PNR film festival, yay!
You can read the full interview in spanish here:
Amira - 50mm Sony 4K PL cinealta lens - 2K prores4444 - Davinci resolve - Alexa to 709 LUT - exported as 1080p
A7s in Slog/cinema - nikon 70-200 f4 - shot at UHD on the Shogun - proresHQ - Davinci resolve - data levels - Slog F35 macgregor LUT - exported as 1080p
Note: Have in mind that the A7s was on a magic arm attached to the Amira (which acts as a spring), that explains the jerky bumps (rolling shutter artifacts apart).
Dynamic range comparison
Pansonic GH4 CineD UHD 200ISO
Sony A7s S-Log2 UHD 3200ISO
Sony F35 S-Log 1080p 450ISO
Lets see now how the A7s in S-Log2 mode at 1080p compares with the 5 year old state of the art Sony F35, which uses a +5K CCD sensor to render a 1080p signal:
Hey, the A7s holds up pretty well. A bit less DR. It's softer and maybe colors are a bit more digital. But for a $2500 mirrorless camera, it's not too bad. Also I didn't encounter any issues from the fact that the A7s shoots only in 8bit. (yes you just read that, so stop the nonsense about 8bit cameras being crap. Sure I'll take 10bit over 8bit, but 8bit is still good 99% of the times. HDcam and DVCproHD were both 8bit goddammit!).
Then of course the A7s struggles with massive rolling shutter issues and those ugly highlight edge artifacts...
By Macgregor and Enrique Pacheco - Originally published in spanish on dslrmagazine.com
Those with years of photographic experience, are aware that we a currently living in the crest of a technology wave. Never before has the latest news and advances in photography been so quick and continuous, affecting both the way we shoot or record our images. Even the transition from analog and digital seems slow and progressive when compared with the dramatic emergence of new sensors and software in recent years.
It seems that every 2 or 3 years, the Japanese manufacturers get on the market (sometimes with great effort) and others almost by pure luck, a product that create a vortex in the audiovisual sector.
It happened with the firsts DSLRs that were able to record video -almost five years ago. And it seems to be happening again with the new mirrorless UHD from Sony: the Sony A7s and its ability to record 4K, encode Slog2 and reach ISO levels never before seen.
Sony A7s: Dynamic Range
The reader seeking a clear, concise and clear answer regarding the number of “stops” dynamic range of Sony A7s, may be disappointed after reading this article. the dynamic range of a camera is sometimes a lot more subjective than it seems.
This value is strongly related with the noise, which is key to judging whether or not the usability of the last stops towards the shadows.
Sony A7s vs Panasonic GH4 in CINE4 mode pro ISO 200 the difference of detail in highlights in the sky speaks for itself.
What about the S-log? Certainly the ability to record in S-Log with the Sony A7s is one of the big reasons why the A7s is causing such a stir. Recording in log means having a more equal distribution of the information allocated to each stops, which in theory preserves the highlights better, as well as creates a more adequate image for grading.
But as you can see both in the video test in the chart, the S-log2 gamma curve only seems to move the dynamic range towards the highlights at the expense of significantly increasing the noise in the shadows. Therefore, although we believe will be very useful in situations where we need those extra steps in highlights its use should not be generalized to all work since, as in most situations, it will be more convenient to record at a lower ISO and achieve a cleaner image. Perhaps at this point we should remember that Slog only works with ISO settings higher than 3200.
As you can see in the table and the video above, CINE4 offers a a dynamic range as wide as the S-log profile but with much less noise. Our recommendation would therefore would be to use Slog only when you plan on color grading the footage in a professional environment; otherwise, you might be OK choosing the CINE4 profile (you may even consider underexposing one stop to better preserve the highlights).
Sony A7s: noise
A lot has been said about the low noise levels of Sony A7s. Again, we must emphasize that noise is rather subjective. That said, we can say that the noise levels of Sony A7s are certainly the lowest we’ve ever seen so far.
Of course, the larger full frame 12Mpx Sony sensor helps for this low level of noise.
We want to emphasize again that the A7s tends to create a fair amount of noise especially in the shadows in S-log2 mode. While this is greatly lessened once grading or applying the corresponding LUT, for users looking to achieve the cleanest image possible we recommend trying other profiles such as CINE4, which also allows us to work at lower ISO levels, down to ISO 100 (ISO 200 in the case of CINE4), Therefore we must choose between a more cinematic dynamic range with more noise, or a less rich range in highlights with a much lower level of noise.
Sony A7s: resolution
One of the great strengths of the Sony A7s is its ability to output UHD video. That is 3840 x 2160px, which is 4 times larger than FullHD, 1920×1080.
Unfortunately, the A7s has no internal 4K recording, needing an external recorder for this. The problem is that the Sony only has a 4K output through HDMI, and currently there are no HDMI 4K portable recorder’s on the market.
Soon several options will be available on the market, one of the most interesting prodcuts will be the Shogun from Atomos (shown above), which will also feature a touch screen and a variety of different recording formats.
The only option available to us at the moment to capture the native resolution of the Sony A7s, is the Blackmagic UltraStudio 4K capture card. This is a desktop rack (shown below) that connects to your Mac computer through a Thunderbolt port.
At 4K resolution, the Sony delivers a crisp, rich detail, with few digital artifacts such as aliasing or moiré.
Compared to the Lumix GH4 we must note that although the A7s images might appear sharper, actually both cameras seem to capture the same level of detail.
Sony A7s: codec XAVC-S
Here’s one of the greatest improvements regarding Sony A7s: the codec..
Previous cameras recorded internally on AVCHD codec, which had a low transfer rate of 25Mbps, which produced highly compressed images, with poor quality and color artifacts.
Finally Sony has listened to the requests of users and has implemented a much more slid codec in the A7s: XAVC-S. Now the A7s can internally record at a maximum resolution of 1920×1080 at 50Mbps with this codec, which offers higher quality than AVCHD although it still samples color at 4: 2: 0 and records at 8 bits of color depth.
XAVC-S (the amateur version of XAVC, which reaches up to 12 bits and 4:4:4), although not perfect, offers a very acceptable quality / size ratio. It seems to be solid enough to let us do color corrections without the fear of “breaking” the image. For these tests we have used Davinci Resolve, getting fantastic results with XAVC-S from the Sony A7s.
Regardless of the internal recording, the A7s has “clean” HDMI outputs, both 1080p HD and UHD 4K. However both options are limited to 8 bits although at a significantly improved 4: 2: 2 color sampling.
An interesting factor for those who only need a 1080p finish is being able to capture in 4K and then downsample to 1080p in post. Thus not only achieve an image of higerh quality with virtually no compression artifacts, but also oversampling from 4: 2: 2 to 4: 4: 4.
Sony A7s: moiré and aliasing
It seems that moiré and aliasing will no longer ruin our productions. Finally, manufacturers have listened to the demands of users and have fixed the annoying and persistent problems that almost all DSLR cameras suffer.
The A7s Sony is the first CSC camera that makes a complete reading of the sensor when recording video in both Full HD and UHD. This is due in large part to the fact that the 12 Megapixel sensor. Such low-density photodiode sensor lets the A7s use every pixel to form the final image, so there is no line skipping. Line skipping is what produces those unwanted digital artifacts, the most common are the moire and aliasing, which are almost always shown in areas of fine detail or closely spaced lines.
In our tests, both the Sony A7s as GH4 Lumix produce great results. However, the Lumix shows a tendency to produce color aliasing in some cases and we've seen moire artifcats on the A7s in occasions as well.
Sony A7s: Conclusions
This is a camera with unique characteristics in terms of video recording, a fantastic response at high ISO levels, and a huge dynamic range. If we want to be able to record in 4K, an external recorder is definitely necessary, making the whole kit more expensive than cameras like the Panasonic GH4 or even the 4K Blackmagic. It is always difficult to make a comparison, since both prices and features differ from model to model.
We want to thank Camaralia, Adrian Cabello and ePlató for their assistance to perform this review.