Sony a7iv FULL FRAME (not crop) 50/60p UHD (4K) recording... Interesting??

Thanks for all of this Chris. I have both cameras and a Ninja, so I will do some testing when I get the time. Makes me wonder what is in store for the future of the camera. Are they going to kills this or have a refresh feature update with internal recording a year from now. I don't see any other benefit from Sony's point of view as the 4k crop was really the ONLY gripe about this camera.
 
Bassman2003 said:
Thanks for all of this Chris. I have both cameras and a Ninja, so I will do some testing when I get the time. Makes me wonder what is in store for the future of the camera. Are they going to kills this or have a refresh feature update with internal recording a year from now. I don't see any other benefit from Sony's point of view as the 4k crop was really the ONLY gripe about this camera.
Click to expand...

Yes please do some testing. Would love to hear about others experiences with this 'anomaly'. Not that I need confirmation as I have satisfied myself that yes in FF HD 50/60p it can output UHD 50/60p when the HDMI output is set to 2160p. Even though it's external this UHD 50/60p with FF lens width capability and functionality with the ability to jump into crop mode is a well worthwhile "feature" in my book. Still find it a bit hard to believe because I would have thought Sony would have seen this 'capability' as a selling point. On the basis of this discovery, I would imagine that with the a7siii firmware upgrade to allow external Prores Raw recording the same could apply with the a7iv if Sony so desired. Yes, I wonder what firmware upgrades will bring to the a7iv. Who knows!

Chris Young
 
With Sony's track record, I doubt this is a "known feature". Could be they try to disable it in a future FW update. But, boy, wouldn't that be great publicity for them.
It's sort of like the shooting 4K in s35 mode on the A7sIII.... pretty much assume it could be done but has been crippled to try & differentiate products.
 
markfpv said:
With Sony's track record, I doubt this is a "known feature". Could be they try to disable it in a future FW update. But, boy, wouldn't that be great publicity for them.
It's sort of like the shooting 4K in s35 mode on the A7sIII.... pretty much assume it could be done but has been crippled to try & differentiate products.
Click to expand...
They might allow it because even though you get around a cripple you can't record internally 4k60/50 and you'll need an external setup. If a few people want to jump through hoops and it doesn't effect sales they'll be like knock yourself out. You have to know the loop hole, have the equipment to do it, then deal with those large ProRes files... If that's part of your work flow then fine.
 
Last edited:
Unsurprising...that 'oversight' was too much.

I was going to mention earlier for someone to ask GU or another YouTuber to take a look but apparently hundreds of others were way ahead of me, ha.

The flow of information is insane right now; everything is at lightning speeds at all times.

Does that mean I'm getting old? :engel017:
 
Yes, all very interesting. As I said good folks suck it yourself and see.

I have nothing to go on other than my observations. I haven't done any chart type tests as for me my final judgement on any image is how does it look? Can I reasonably use it? For any use, I may put this 4K anomaly to I'm quite happy to use it as the picture quality for anything I do is more than adequate. A number of others I know who are quite discerning who have had a look at the output and have tried it themselves have said they would be happy to use it. The other observation we came across is if you shoot 25p FF 4K, which we know the camera can do and compare its 2160 25p output and compare it with the UHD 2160 50p output from the HD 50p we are just observationally not really able to see any difference in picture IQ. Other than the difference in 25/50p motion of course. Gerald is a true technical purist detective and I'm quite happy to go with his observations. It doesn't alter the fact that for me it is a "feature" I can use. Modern hardware upscaling is of such a high order these days that if you have to really drill down so hard to discern any real differences between the two modes well, do your own tests and come up with your own conclusions. I remember a discussion where a number of Alexa users were incredibly happy with the quality of the upgrade that offered them 4K. If shooting 16 x 9 on the Alexa this is an upscale from 2880 × 1620. Judge for yourselves is all I can suggest. It's been a fun discussion :)

Chris Young

https://epfilms.tv/arri-alexa-classic-ev/
 
Thanks for sharing your discovery, and I think at the very least it's worth showcasing all of the thoughts & reactions associated with this to show the companies how their customers feel when they make certain decisions.
 
cyvideo said:
suck it yourself and see.
]
Click to expand...

Is this an australianism?

I haven't looked through the various posted tests, but it seems to me that the operative question is if you get more detail than the FF HD 50/60 capture. If you do and it looks good, then who cares how or why. Why not use it if you have the inclination and the recorder
 
I've been away a couple of days on horse racing OBs so a bit hard to keep up with this thread. When I get back to base I'll try to do some more objective tests. So far to date this FF 4K 50/60p quality thing has all been subjective on my part, purely observational. Asides from anything else I'm curious myself to see just how much of a difference I can discern with a more technical pixel peep. Regardless of the results I'm pretty sure I will use this "feature" sometimes as visually I don't have a lot to complain about on any of the images I've seen so far.

Chris Young
 
jmone said:
https://www.youtube.com/watch?v=HvCCbll7swo&ab_channel=GeraldUndone

Looks like it is upscaled 1080p
Click to expand...

Yes. I've confirmed that for myself now.

Trying to be a little more objective in looking at this undocumented FF UHD 50/60p output on the Sony a7iv.
These are the steps I have taken to further investigate what's coming out of the a7iv when it is in FF HD50/60p mode and when the HDMI output menu is set to 2160p. My conclusions are at the bottom. If you just want to see the full-res TIFF file results just head down the page to where you see,

DOWNLOADS =====================================

All the images were exported from Resolve from S-LOG3 Prores 422 files that were captured on a Ninja V. I used a short optical HDMI cable to minimise any cable degradation.

A number of years back I was talking to a visiting Sony engineer who was here for one of our broadcast shows. Back then I often used to demonstrate editing with Sony equipment at these shows. We were discussing the developments in Sony's proprietory ALAC v2.0 firmware which corrects lens aberrations and chromatic aberrations with both Fujinon and Canon B4 broadcast lenses. ALAC v2.0 had not long been out. The discussion then drifted on to the topic of still camera photo lenses being used more and more since the introduction of Sony's S35 cameras. These lens usage developments he said had led Sony to address the photo lens compatibility of their still lenses when being used with their S35 video/cine cameras.
In summing up this engineer said to me that if I really wanted to check just how good any Sony camera's performance and output can be is to use one of Sony's lens file compatible lenses and shoot in S-LOG. Select your camera from the drop-down list for full lens compatibility.

https://support.d-imaging.sony.co.jp/www/cscs/lens_body/index.php?mdl=PXW-FS7&area=eu&lang=en

As in S-LOG there is no detail, aperture of frequency parameters applied to the output. The observed output is purely a product of the lens and the sensor without any additional detail, frequency selection or detail applied. He went on to say that in modern camera design to keep lenses smaller lighter more efficient and better compatible across a wider range of sensors, resolutions and crop sizes it is almost impossible to do so without lens files circuits that work in conjunction with the lens file correction circuits in the various camera bodies.

This is the prime reason why I have specifically used the SELP28-135G (FE PZ 28-135mm F4 G OSS) zoom lens as it is designed to work with a7 full-frame cameras in both full-frame AND crop mode with its two sets of lens correction files. One for shooting in full-frame and one for shooting in crop mode or on S35 sensor cameras like the FS7 and FS5. This Sony engineer went on to outline some of the parameters that were contained in these two lens files which he said were quite different between the full-frame and crop files. It all depended on whether the camera was in full-frame mode or crop mode as to what particular lens file corrections were applied. I asked him to jot down down some of the lens file parameters that were modified between the two and were being applied. All of these file parameters are different between full-frame and crop mode. This is the list he gave me.

Axial color targets at infinity and MOD
Lateral color targets, various field positions, infinity and MOD
MTF targets at various field positions and distances
Maximum distortion
Minimum corner illumination (different for FF and Crop)
Maximum ray angle at sensor corner
Focus shift when stopping down
Color contribution index of the lens

All of the above parameters have to be corrected in real-time with video acquisition whether in full-frame or crop mode. With stills, the lens information is baked into the file and can be read and corrected when editing the RAW files, as long as the lens information is in the database.

Anyhow, to sum it all up I set up a test and shot some footage in three different modes. They were FF UHD 25p, FF HD 50p and APSC UHD 50p. The images below are just a guide. To really see the full size, full rez TIFs out of Resolve go to:

DOWNLOADS https://www.sendspace.com/pro/dl/6y1ijd

Where you can download a ZIP file with the results.

CONCLUSIONS
I'm 100% in agreement with Gerald Undone's findings. The internal HD 50p output to HDMI 2160p UHD is upscaled to UHD. One can clearly see the differences in the full-res TIFF files. Also interestingly this "pseudo" UHD 2160 FF 50p output clearly showed far better rolling shutter response. The same response as the a7iv displays in APSC UHD 50p crop mode. Interesting. That's me done. I have my answers. I think you can even get an idea of the results from the following lo-res 1280 JPGs.

Chris Young

a7iv Internal FF UHD 25p HDMI out 2160p_1.1.1.jpg
a7iv Internal FF HD 50p HDMI out 2160p_1.2.1.jpg

The following one is reframed of course as the camera was now in APSC Crop mode.

a7iv Internal APSC UHD 50p HDMI out 2160p_1.3.1.jpg
 
You must log in or register to reply here.
Back
Top