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Sony A7s DIY 4K Recorder


Finn Schäuble

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Hey guys, I build a 4K Recorder out of some ghetto parts, right now that still includes a Laptop and is really not that useful, its not even battery powered yet.  

However I did a small test and some of you might appreciate it, its by far the cheapest solution to get 4K out of the A7s but requieres a lot of knowledge of electronics and soldering (+- 200€) I am going to try to make it battery powered and smaller and add a Monitor, I think the price for the Shogun is too high.   

First priority is going to ditch the laptop in favour of dedicated electronics.  

It is also still dropping some frames (or rather holding them, weird maybe one of the chips is having a timing problem).  The A7s HDMI signal is actually a very normal signal, nothing special going on (contrary to the FS700 for example, which is some kind of weird Sony bullshit) 

 

 

I uploaded a test to youtube, I just used a cheap Igus slider with the A7s just pressed to the slider, I lost the stupid screw for the Tripod Head...  if anyone wants the source .tif files or the Rendered H264, let me know and I might upload them. 

 

 

 

 

 

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Wow, I have no idea how to do that kind of stuff. so maybe it means nothing that I'm impressed, but yeah, I'm always looking for the cheapest option. good luck working on it more. a diy external 4k recorder that's battery powered, has a monitor, and doesn't drop frames if you can fix that, for a fraction of the price of the shogun? sounds good to me! and though I've got a slow, low resolution computer, what i was able to buffer looks really good. Well done!

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I guess it was just a problem with my external harddrive, it plays fine for me on youtube as well. 

I bassically used the same chips used in the kineraw camera which is running on linux so it was not too hard to find drivers for it, right now its still on a deveolpment board, so its not really "small" its about as big as my ikea coffee table..  there are still lots of problems with it and I dont know if I can make it really that usefull, after thinking about it I get the price for the shogun as they have to get back their development costs, but really the hardware is not worth that much, This whole project has taken me all Winter pretty much (I am a engineering student so I had the winter off). 

It was really ment as a proof of concept for a cheap 4K "Recorder".  And I think some chinese Company will probably release a recorder like that on the cheap (wink at Blackmagic)

Now, stuff like ProRes Encoding is a totally different thing and I find it crazy what Blackmagic has pulled of with the pocket, thats just awesome engineering. 

 

This thing will never be a replacement for the shogun .. sadly :) 

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Nice.

I'm also looking forward to buy this unique camera so sensitive to low light in video, to the condition that i can record 4k with it at a reasonable price...

I just posted the question yesterday on dpreview: http://***URL removed***/forums/thread/3818206

Also: Could this converter record 4K from the A7S ? -> http://www.bhphotovideo.com/c/product/1073122-REG/inogeni_4k2usb3_4k_hdmi_to_usb.html

(but anyway it's usb3.0 , while my MBP i7 is only usb2, damn, i would probably have to buy another computer)

And also i saw this card, wondering also if it would work with the A7S but hmm, still expensive, and i don't have a desktop computer: http://www.bhphotovideo.com/c/product/1044784-REG/blackmagic_design_bdlkstudio4k_decklink_studio_4k.html

thanks

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According to the last reviewer on the BHphotoVideo page Inogeni 4K to USB3 converter works with A7S.
But  USB3 output for 4K is only 4:2:0 8Bit while Sony A7S HDMI 4K feed is 4:2:2 8Bit, so there is some loss of color information.
Specs on BHphotovideo page are not full, you can find the details here. 
http://www.dexteralabs.com/inogeni/

Hadrware requirements are Core i5 with 4Gb RAM. Pair it with MS Surface 1 or 2 and you get cheaper (under 1K) recorder than shogun but slightly bigger, heavier and of course without the nice screen and many recording options. Not sure if it is worth it. 

Blackmagic has much cheaper (200$) PCI card for 4K capture if you are willing to use desktop computer. For me it's not viable option but here it is:
https://www.blackmagicdesign.com/products/intensitypro4k

 

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Also... would thoses solutions record kind of 'raw' or 'compressed' on a HD? I'm quite unsure about all thoses video formats... I mean if it's 1Tb for each hour of video it's not gonna be practical to use 4K...

Other question: Is it likely that Sony will come-up soon with a new version of this camera that can this time record the 4K video internally ?

I'm wondering if it's better to buy this camera and wait to a cheap 4K recorder to come-up on the market, or if i should rather wait for a similar extremely sensitive camera that record 4K in candle light... but how long would we have to wait?

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Other question: Is it likely that Sony will come-up soon with a new version of this camera that can this time record the 4K video internally

Doubtful, power requirements too high / too much heat generated.  Panasonic can do 4K because they use smaller chips and a different sensor technology optimized for video, not photography.  

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Doubtful, power requirements too high / too much heat generated.  Panasonic can do 4K because they use smaller chips and a different sensor technology optimized for video, not photography.  

​Besides Samsung can do it (NX1) because they have expertise in cell phone technology.... They are using technology optimized for cell phones, not photography... And as we all know, cell phone technology is leaps and bounds more advanced.  Cell phone technology is not available for sony or canon.  After all, sony has never had a really successful cell phone product.... and actually, they are getting out of the cell phone market.

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Doubtful, power requirements too high / too much heat generated.  Panasonic can do 4K because they use smaller chips and a different sensor technology optimized for video, not photography.  

​Thanks for the explaination... that sounds so mysterious to me why a 'different sensor technology' would make such a change in heat and power needed when compressing/recording pixel information. :-O and while several samrtphones already record 4K.  ?
About the power i wouldn't care to have a heavier battery, or several ones to change often, if i can record 4K. (my purpose is to make photos from video-frames in high-shutter speed, because of the subject moving fast and sereval reasons ( http://www.avsforum.com/forum/161-camcorders/1949529-any-cheap-4k-external-recorder-coming-sony-a7s.html ) 

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According to the last reviewer on the BHphotoVideo page Inogeni 4K to USB3 converter works with A7S.
But  USB3 output for 4K is only 4:2:0 8Bit while Sony A7S HDMI 4K feed is 4:2:2 8Bit, so there is some loss of color information.
Specs on BHphotovideo page are not full, you can find the details here. 
http://www.dexteralabs.com/inogeni/

Hadrware requirements are Core i5 with 4Gb RAM. Pair it with MS Surface 1 or 2 and you get cheaper (under 1K) recorder than shogun but slightly bigger, heavier and of course without the nice screen and many recording options. Not sure if it is worth it. 

Blackmagic has much cheaper (200$) PCI card for 4K capture if you are willing to use desktop computer. For me it's not viable option but here it is:
https://www.blackmagicdesign.com/products/intensitypro4k

 

​For any of two solutions, the Inogeni converter, or the Blackmagic PCI card, wouldn't be any cheap PC solution? (battery powered or not) "Raspberry-Pi-like" or so?

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​Thanks for the explaination... that sounds so mysterious to me why a 'different sensor technology' would make such a change in heat and power needed when compressing/recording pixel information. :-O and while several samrtphones already record 4K.  ?About the power i wouldn't care to have a heavier battery, or several ones to change often, if i can record 4K. (my purpose is to make photos from video-frames in high-shutter speed, because of the subject moving fast and sereval reasons ( http://www.avsforum.com/forum/161-camcorders/1949529-any-cheap-4k-external-recorder-coming-sony-a7s.html ) 

​Why do Nikon sensors have close to 12 stops of dynamic range and MFT's about 9?  http://home.comcast.net/~NikonD70/Charts/PDR.htm

Why does Kirk Tuck LOVE and champion MFT cameras, but still own and use a D800? http://visualsciencelab.blogspot.com/2015/03/past-due-reviews-second-in-series-nikon.html

Yes, some cell phones can shoot 4K, but it isn't very good 4K next to a GH4 say.  And a GH4 is a nice, but not next to a Sony FS7.

If you're a professional videographer you MUST have XLR inputs and a camera that won't shut down in the heat, etc.  You're probably on a tripod all the time, so size is not a big concern.  If you're an enthusiast you don't care about the XLR, you want small size, but you also want the camera to do as much as possible.  If you ever shoot with a Nikon Full-Frame you would want it ALL the time for photography.   I see two types of enthusiasts.  One that shoot best photo camera/sub-par video (Canon/Nikon) and those who shoot best video (Panny) and sub-par photos.  Or people like me with 5 cameras and a need for professional help ;)

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  • 9 months later...
  • 4 years later...

Can you share the details - even as if a virtual machine and a parts / component list / diagram - of course make it all copyleft so you keep credit / rights to control and keep credit for.

I would be very curious if some of the SOC kits with built in video touch screen interface, driver, screen, etc and quad core would be fast enough to do any 10 bit captures of 4K. More likely it would require something like Nvidia Tegra which migth still be cheaper if it could have HDMI 2 video input added.

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