blafarm

When the A7s operates at 120fps, it only uses the APS-C crop portion of the sensor (not the full frame area) and it only resolves at 720p.  That means your image will be cropped at 1.5x compared to the Full Frame image and you will likely see some amount of moire and aliasing. 

When operating in that mode, the actual video file that is created on the internal SD storage card is 720p. 

Interestingly, when operating in that mode, the camera does output a 1080p signal that can be displayed on a consumer monitor (that does not support 120fps) -- meaning, the signal is successfully displayed at either 1080p/30 or 60i.  I don't know for sure, but I suspect the consumer monitor is handshaking with the camera over HDMI and telling it what frame rates it supports -- and the camera is subsequently giving the monitor what it needs.  But purely from a raster point-of-view, the signal is obviously being up-converted from 720p to 1080p in-camera.

I have not yet conducted comparative tests to determine if the in-camera resolution conversion is any better or worse than doing it as a post process.  I also don't know if a device like the Shogun, that supports 1080p/120 (and probably conveys that support over HDMI), can coax 120fps of realtime video out of the camera's HDMI port.  Maybe someone else knows that.

But to answer your question, even if it can, you would still be recording a 720p signal that had been up-converted in-camera to 1080p.  

In spite of that, the advantages of that approach would seem to include;  baking the up-conversion to 1080p into your video files, recording said video files at 4:2:2 instead of the internal 4:2:0, having your choice of a preferred codec/bitrate combination and, finally, having your media on a storage device that is intrinsically higher performing (SSD) and conceivably directly usable by your NLE for editing, without the requirement of importing or transcoding.  In aggregate, assuming there is no qualitative image penalty to the in-camera conversion, those represent some compelling advantages.

It's a bit inconclusive at this moment in time, at least for me.  Others might know more and I welcome their input.  I suspect we'll know definitively at the beginning of October (Shogun's expected release date).  In the meantime, I hope that helps a little bit.

Cinema 4k as in 4096x2160?

 

Yes.  Precisely.

They had not articulated that fact at NAB -- at least not to me.

So I was surprised when the tech said that in a phone call.

Good news.

FWIW:  

I just learned from Atomos that the Shogun will support Cinema 4k with a firmware release that is anticipated sometime after the product ships.

I know this thread is a bit dated, but is there a known lack of compatibility between the A7s and SDXC cards that are larger in size than 64GB?

For example, I've been thinking about these two >64GB cards:


SanDisk Extreme Plus 128GB SDXC UHS-1 Flash Memory Card Speed Up To 80MB/s
http://www.amazon.com/gp/product/B00...=ATVPDKIKX0DER

PNY 256GB Elite Performance SDXC 90MB/s Flash Card
http://www.amazon.com/gp/product/B00...A2ZMWBP05360R6


Thanks for your feedback.

... has Sony created A7S LUTs/matrices for conversion to linear/709?

This thread is a bit old, but I though I'd chime in with a piece of information that may already be widely known.

Sony is working very closely with Atomos on the Shogun, which will be capable of displaying an input signal with a 3D LUT on it's Spyder-calibrated 1080p Rec.709 screen.

Atomos has told me that Shogun will have a Sony-supplied SLog2 3D LUT either at introduction -- or shortly thereafter.

And, as users will be able to import their own LUTs into the Shogun, one might assume that the Sony LUT might be exportable.

Well, that's an important distinction that I was not aware of.

And, a deal-killer to boot.

Thank you.

Me too.

For a person having no existing glass (and not being especially excited about the current native glass options), does anyone have an opinion regarding the choice between Nikon Glass and Metabones F adapter -- versus -- Canon Glass and the Metabones EF Adapter?

Trying to figure out which side of the fence to fall on.  The use case is virtually 100% video -- so autofocus is not much of an issue.

I'm not going to spend 10 minutes color correcting every single clip for my own work - I want something that works and looks acceptable with minimal fuss.

I don't shoot for masterbatory purposes ...

Whatever gets the job done and makes both the client and me happy.  

Nicely articulated.

 

did you find out if the new Atomos Shogun will take in true 4K, and not just UHD?

 

I'm pretty sure the only specs I've ever seen talk about 3840 x 2160 UHD (Atomos' website and reliable resellers).

I admit it's an odd choice to not support true 4k.  I guess it's possible final production units might deviate from the published specs.

However, maybe the choice was due to the panel being natively 1920 x 1080 -- and not wanting to include the additional expense or power consumption of a real time scaler.

Hello Oferlevy,

 

The Sony A7S doesn't shoot raw with the shogun, it shoots prores 8 bit 4:2:2.

The statement regarding the lack of raw output is absolutely correct.

However, it is not really a comprehensive answer.

In actuality, the Sony A7s outputs uncompressed 8 bit, 4:2:2 via its HDMI port to the Shogun, which in turn can be used to record ProRes, DNxHD or  Cinema DNG.  And, for the record, the reason the DNxHD codec is not included in the Ultra HD 4K category is because Avid has not yet released their Ultra codecs.

Codec / Format Support

Ultra HD 4K:
Apple ProRes HQ, 422, and LT (10-bit, 4:2:2)
Cinema DNG Raw

HD:
Apple ProRes HQ, 422, and LT (10-bit, 4:2:2)
Avid DNxHD (10-bit, 4:2:2)

have u thought about the tamron 24-70mm stabilized lens? Tamron has gotten some good reviews for that lens

Roger's Lens Rentals review has some useful information on that lens.

Get the 70-200 2.8 IS and then you have both (for that range). 

 

Also, Sony has a native wide (16-35) that will have OSS announced next month.

Yes, the 70-200 2.8 IS makes complete sense.  I'm a bit more concerned with the wide end.

I believe the Sony 16-35 is f/4 -- and the native lenses might not be appropriate for my application. 

Hence my question about the actual need for anything faster f/4 in the 16-35 IS or 24-70 IS lenses.  

Is a long piece of string longer than a short piece of string?

 

 

Thank you.

Maybe an alternate characterization is in order:

Is the speed difference between those two lens-types largely rendered immaterial, in the majority of practical lower-light environments, given the A7s' sensitivity?

I'm using Canon IS lenses with a Gorilla pod ...

First of all, thanks for your post and your generous sharing of LUTs.

Quick question if you don't mind:

Regarding the Canon IS lenses, do you think their slower f/4 speeds represent an impediment to capturing lower light level environments -- as opposed to their non-IS f/2.8 cousins?

I am considering buying new Canon glass for this camera and am torn between the non-IS f/2.8 lenses -- versus the IS f/4.

Thanks.

Does any camera support Rec. 2020 yet?  That's a much wider color gamut.

 

Michael

Resolve.

The gamma issue between Mac and PC has been a problem in the film industry for decades -- especially in terms of the QuickTime 7 system framework, which has been deprecated.

Unfortunately, media applications on these two disparate computing platforms *do not* read the file-based gamma data and compensate accordingly.

And aside from file-based gamma differences, you also have issues surrounding the calibration (or not) of the user's display.

Color grading is very definitely a subjective art, but I can tell you that I would never let the image at the top of this thread out my door -- unless of course, it was an intentional stylistic decision.

On a somewhat related topic, it is interesting to note the number of comments on the Internet questioning the color science of the A7s.  Interestingly, when that color science has been called into question, I have found myself in general agreement after watching the clips on my calibrated monitor.

However, it's hard to know if these issues are related to computing platform gamma differences -- or users posting S-Log2 footage on Vimeo (or an alternate picture profile) -- without having pulled it back down to Rec. 709 or Rec. 2020. 

Indeed! I am wondering how wildly different people's display calibrations are.

I would wager that some of you are on PC and others are on Mac.

I will share that on a calibrated PC monitor, the OP's image appears washed-out (elevated gamma).

I have quietly thought this since the inception of this thread -- but it is now worth pointing it out.