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Andrew Reid

Slashcam test reveals Sony A7S 1080/60p softer than 24p mode

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a7s-metabones

Slashcam have chart tested the A7S internal recording modes and the results for the regular frame rates 24-30p are incredibly positive.

However it seems that in 60p the camera cannot utilise the full pixel readout of the sensor, which results in a worse image with moire and aliasing.

You can read my take on this below or head over to Slashcam to read the original piece (Google translated)

Read the full article here

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EOSHD Pro Color for Sony cameras EOSHD Pro LOG for Sony CamerasEOSHD C-LOG and Film Profiles for All Canon DSLRs

The more cameras I try out, the more I believe aliasing/moire/sharpness is a function of physical sensor characteristics, and not firmware (software).  The more time goes on, the more I believe the manufacturers are up against limits of how hot they can run their sensors/ships without shortening the life of the battery or generating noticeable sensor noise.

 

The new sensor for the A7S is the first consumer-grade full-frame sensor made for video. How cool is that!!!

 

Software development is something I know about.  Hiring a few extra programmers to work on software/CODEC is a fraction of what it costs to manufacture a new type of chip.  When you couple that with the physics of shallow DOF on full-frame sensors the A7S has significant benefits over current Canon and Nikon full-frames.  In short, Andrew, this is the camera you have warned Canon and Nikon about.  And the Blackmagics for RAW color depth.  

 

Nikon and Canon currently have no offerings with  full-frame maximized pixel count for video (fewer/larger pixels are better for video), heat-sink technology (Blackmagic), EVF (Sony), or razor sharp MFT 4K (Panasonic).

 

I've been following EOSHD for about a year now.  Amazing what has happened in that time!  These guys have done everything you've asked Andrew, but you're like the Dad where it's never good enough.  "You can still do better, Son!" :)

 

(As for 60P being softer, unless it is double the bit-rate it is obviously an expected still-frame/motion trade-off)

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Sounds like Sony is so close with this camera.  Exciting times indeed.  I know it's a sony article, but your last sentence is what I'm looking for most.   If Panasonic would make a 12megapixel sensor it's low light capability could be improved, along with the fast sensor readouts, internal 4k, and heat shielding work Panasonic has done.    This would be an ideal camera for me.  

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If the Sony could record for 90 minutes straight, it would be my first choice for archiving lectures and concerts.  For now, the GH4 will do fine.

Exactly. I said the same thing and some idiots were ripping me and saying "plenty of docs" are still shot on a 7D.  It's easy to tell which posters shoot for a living and which ones just test cameras for fun. 

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Exactly. I said the same thing and some idiots were ripping me and saying "plenty of docs" are still shot on a 7D.  It's easy to tell which posters shoot for a living and which ones just test cameras for fun. 

I think alot of people still shoot with 7D's because they don't know any better.

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If you'll need a camera when rolling shutter might be a problem, I think you better off with the GH4 then. If you need APS-C crop with Speed Booster to reduce it, unless you really, really need FF, a GH4 with Speed Booster will be more practical. Even more if you account that the 4K in APS-C can't be 4K and that if you'll need an external recorder anyway, GH4 can do 10-bit 422 instead of 8-bit.

 

I'm interested to see if the upcoming LX8 will have a 12MP 1" sensor, sure, this is not even Micro4/3, but it will be a great video camera. It's rumored to have 4K and most of GH4's stuff - just like the FZ1000 -, plus, it will have ND filter and as rumors say it won't feat the same 20MP from the FZ1000, a 12MP 1:1 pixel  in 4K, full readout in a lower count MP - and smaller - sensor should do wonders for video quality. The 24-90mm f/2-2.8 and EVF are not bad either.

 

I can see Panasonic going less MP in a proper camera with Micro4/3 mount like a AF100 successor - if that will ever exist -, but I just don't see Panasonic going 12MP in a GH camera, the GH4 is sold as a hybrid camera and it's one great still camera, the video gets most of the attention, but it got praised a lot by its still capabilities as well, even more for the quick AF even in low light situations. So I don't think they would lower their MP from 16MP to 12MP.

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If you'll need a camera when rolling shutter might be a problem, I think you better off with the GH4 then. If you need APS-C crop with Speed Booster to reduce it, unless you really, really need FF, a GH4 with Speed Booster will be more practical. Even more if you account that the 4K in APS-C can't be 4K and that if you'll need an external recorder anyway, GH4 can do 10-bit 422 instead of 8-bit.

 

I don't think most people will be buying the A7S BECAUSE it is full frame but more so because of its low light capability.

 

If you JUST want full frame there are other choices. (especially if buying for stills and video as most would).    FF video market is pretty small compared to other video and stills markets but this camera is a low light king because it is full frame but also a decent camera for video for specs requirements.

 

The A7 (ordinary) has all the right specs other than codec and a great low light sensor for stills but video is not the best (I do love it as an amateur though and the video is good enough for me).

 

 

 

I'm interested to see if the upcoming LX8 will have a 12MP 1" sensor, sure, this is not even Micro4/3, but it will be a great video camera. It's rumored to have 4K and most of GH4's stuff - just like the FZ1000 -, plus, it will have ND filter and as rumors say it won't feat the same 20MP from the FZ1000, a 12MP 1:1 pixel  in 4K, full readout in a lower count MP - and smaller - sensor should do wonders for video quality. The 24-90mm f/2-2.8 and EVF are not bad either.

 

LX8 if it lives up to rumours will possibly replace my GX7 and a pocket point and shoot (unless the GX# below comes along).

 

I can see Panasonic going less MP in a proper camera with Micro4/3 mount like a AF100 successor - if that will ever exist -, but I just don't see Panasonic going 12MP in a GH camera, the GH4 is sold as a hybrid camera and it's one great still camera, the video gets most of the attention, but it got praised a lot by its still capabilities as well, even more for the quick AF even in low light situations. So I don't think they would lower their MP from 16MP to 12MP.

 

How about a Panasonic 12mp GX7 with stabilization for video and a mic and headphones input?     If they do that I would seriously consider that.

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Hello.

 

 

according the A7s catalogue.( In sony Korea official website)

 

http://store.sony.co.kr/handler/ViewProduct-Start?productId=32827460&intcmp=Main_ì¸ê¸°ì œí’ˆ02_140625_ILCE-7S

'>

 

 

All mode of the A7s has the Full-Pixel readout. (without Pixel-binning).

 

but, FF60p(60i) mode is full-pixel readout with pixel-binning. 

 

 

I think, 

A7s's pixel-binning is cause of moire, softer image. 

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I see the low pixel count sensors as a temporary phenomenon.  I believe pixel count will rise again in hybrid DSLRs as CMOS read speeds increase, and processing power increases, as they naturally do over time.

 

What is concerning regarding the a7S is the color science.  I have been using comparison tools at various websites  The a7S colors are just off.  It's particularly noticeable on flesh tones.  The a7S has a strong greenish-yellowish cast, that makes people look like they have Jaundice.  The Canon 5DMkIII seems pretty much on target, and the Nikon D610 and D800 are close with a slight magenta cast.  The Panasonic GH4 also tends towards a yellowish cast, but it is subtle.  These results seem to align well with what I have seen in videos.

 

Michael

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I see the low pixel count sensors as a temporary phenomenon.  I believe pixel count will rise again in hybrid DSLRs as CMOS read speeds increase, and processing power increases, as they naturally do over time.

 

What is concerning regarding the a7S is the color science.  I have been using comparison tools at various websites  The a7S colors are just off.  It's particularly noticeable on flesh tones.  The a7S has a strong greenish-yellowish cast, that makes people look like they have Jaundice.  The Canon 5DMkIII seems pretty much on target, and the Nikon D610 and D800 are close with a slight magenta cast.  The Panasonic GH4 also tends towards a yellowish cast, but it is subtle.  These results seem to align well with what I have seen in videos.

 

Hi Michael.  The pixels are made larger on the a7S to be more sensitive/accurate to light (especially low light).  This has little to do with processing speed.  If the camera has a problem it's that it can't save internal 4K.  The drawback of larger pixels is less resolution for still photos.  There is no drawback for 4K full-frame video--only positives (AFAIK).  You should also know that there is space on a sensor between each pixel, space that can't be used to read light and space which creates aliasing issues.  

 

As for color science.  White balance is so difficult to get perfect without expensive equipment that it's really impossible to factor out user error.  Even on my own somewhat calibrated monitors each video looks different.   For properly exposed video, I believe all the manufacturers end up with the same values.  Even if a camera has a certain "color cast" you should be able to adjust for it.   I'm no expert in color grading, but haven't heard it a problem for anyone.  Dynamic range or bit-depth is another thing.

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Hi Michael.  The pixels are made larger on the a7S to be more sensitive/accurate to light (especially low light).  This has little to do with processing speed.  If the camera has a problem it's that it can't save internal 4K.  The drawback of larger pixels is less resolution for still photos.  There is no drawback for 4K full-frame video--only positives (AFAIK).  You should also know that there is space on a sensor between each pixel, space that can't be used to read light and space which creates aliasing issues.  

 

As for color science.  White balance is so difficult to get perfect without expensive equipment that it's really impossible to factor out user error.  Even on my own somewhat calibrated monitors each video looks different.   For properly exposed video, I believe all the manufacturers end up with the same values.  Even if a camera has a certain "color cast" you should be able to adjust for it.   I'm no expert in color grading, but haven't heard it a problem for anyone.  Dynamic range or bit-depth is another thing.

Hi Maxonics,

The reason I say that the direction will be to more pixels again, is because as time has gone on, low light performance has improved, even as pixels have shrunk in size.  Right now the 1:1 pixel mapping used for 4K, is really just mapping pixels which are sensitive to one color to a pixel on the screen represented by a red, a green, and a blue pixel (excluding color subsampling).  The ideal case is a set of RGB pixels per pixel of resolution for maximum color fidelity, similar to what is done on 3-chip cameras.  In addition, I think DSLR cameras (vs. dedicated video cameras), will always be under pressure to perform well as a still camera, and that means high pixel counts.  Sony is really pushing the limits of creating a video camera in a DSLR type body.

 

Also there is the issue of hot and dead pixels.  It is easier to cover those up with more pixels to work with.  I saw one test where the a7S had a lot of (big) hot pixels if the noise reduction was off, way more than they saw on the a7R.

 

I am no expert, but I would be surprised if you could fix the bad color science I am seeing by just tweaking white balance.  White balance adjustment would shift all colors, but from what I see not all colors need shifting.

 

Michael

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In this comparison the Nikon D810 video appears to blow away the Sony A7S. It looks like it was done by "Nikon" so I'll wait for further corroboration from independent sources.

 

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Is this a joke? Am I missing something? All those images are 240p in size and I can't figure out how to view them fullsize to check them. People are actually talking about these little images?

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Guest Ebrahim Saadawi
 

I see the low pixel count sensors as a temporary phenomenon.  I believe pixel count will rise again in hybrid DSLRs as CMOS read speeds increase, and processing power increases, as they naturally do over time.

 

 

I kind of agree. While it sounds cool, I really don't believe that the low megapixel count approach really helps in the light sensitivity of a camera that much, only theoretically and just slightly when all the other factors being equal.

We've always had many s35 sensors with 2 megapixels (all 1080p video cameras) and we don't see these native, extremely low megapixel count-video cameras being much more sensitive than photographic sensor, in fact it's almost quite always the opposite

Other technology incorporated in the sensor, how each pixel collects light, and noise reduction algorithms are what really make a difference. 

In the photography world it seems to be also true, that increasing the megapixel count does not have that  huge impact on low-light performance, the nikon/sony 24mp aps-c sensors show that

and the 36mp D800 files are incredibly clean in low-light, that In fact, when downsamped to 16mp, they nearly match the D4 in terms of noise. They should be horrible! 

The A7s seems to be indeed the best camera ever made for low-light, but I wouldn't say it's all because of the 12mp count, it's because Sony really seem to be making such amazing work in their sensor technology and noise reduction techniques. 

and I think they chose that low number for proximity to 8 megapixels to get all the benefits one gets from a 1:1 readout for 4K video, like eliminating aliasing and moire, avoiding crop factor, 

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Actually with Sony's curved sensor technology the megapixel counts are low on that too. So for some cameras we will be seeing much more of the A7S low light prowess in future.

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