Camera resolution vs codec resolution vs lens resolution

[kye]

Is it just me, or is the resolution of coming out of cameras about a billion miles ahead of the resolution of our lenses?

and, to be clear, what I mean by that is:

• the limits of a sensor are typically around one quarter of the number of RAW pixels being read off the sensor (eg, 4K is really only 1080p 4:4:4)
• the limitations of a codec are the size of fine detail that is obscured by the compression, either in high-contrast areas (like stray hair against a dark background) or in low-contrast areas (like the texture of hair or skin in shadow areas)
• the limits of a lens are the size of the halation, the size of the CA, the size of the corner sharpness, etc
• and that when comparing cameras with lenses we have to compare within certain budgetary limitations, for example we can't fairly compare a $2,000-4,000 camera body with lenses that cost $10,000 each

I find myself looking at sample footage of the A7III, the Z6, the GH5S, the S1, the S1H, the P6K, etc and just thinking "why would I be glad that I can see the lens problems in oversampled 4K when I could see less of them in straight 4K or even 1080p" and "if I was making a promotional film for this camera why the f*#k wouldn't you hire a nice cinema lens for a day?".

The wedding video of the P6K was a tour-de-force of technology over common-sense - it was CA city, visible from the comfort of my chair and through the evisceration of YT compression - thank goodness we now have 6K RAW now - what a revolution!  

Don't get me wrong, I like 4K and I shoot 5K on my GH5, but the $2K I spent on it absolutely crushes the lenses that I can afford to put on it.

I guess you can buy the super-fast lenses and then only shoot them at F5.6 to give yourself a fighting chance, but when I look at the S1H and think about how I could go from 5K to 6K, I just think about my $1000 Voigtlander 17.5mm f0.95 lens and think that wide open it's probably only 1080p at best (maybe not even that good) and that many other lenses are similar.  Thank goodness we've got the technology now - all that extra memory card storage, editing SSD space, backup HDDs, CPU and GPU, it was totally worth it!

Take the excellent Rokinon 50mm T1.5 lens for example.  Here's a frame of it wide open, saved as a 4K 5MB PNG file vs a 1080p 700K Jpeg file, and there's barely any perceptible difference in resolution (there is a shift in colour though as photoshop seems to have changed the colours for some reason):

Also, note the small amount of CA on the models right upper-shoulder where you can see some green fringing on the edge.  Note that it's still visible on the 1080 version, and it's also still slightly visible on the 720p frame I didn't bother to upload.

I did the same comparison on the spectacularly expensive Master Prime and there is a decent difference between 4K and 1080p with that lens, however there is still a minor amount of CA visible in the same location.  This is a weakness on a $40K lens that would be visible on any budget 4K sensor, and as it is visible over a band 4 pixels wide on the 1080p downscale of that image, will also be visible on a 1080p camera too.  

I know I'm nit-picking, but so is anyone who is talking about the difference between 6K and 4K, and apparently these differences seem to matter enough to make people want to spend thousands of dollars on upgrading equipment.

The more I think about this stuff, and the more that I do my own image quality tests with my own equipment the more I realise that I can't afford (and am not strong enough to even hand-hold!) any lens that is remotely in the same class of resolution as the camera I own.  Or the camera that any of you guys likely own for that matter.

Maybe we should be buying the best lenses we can afford and only buying enough camera to capture the image of those lenses, and not spending thousands more that will only do a better job of exploring the faults and limitations they have.

Look at how bad even really expensive lenses really are:

Am I missing some kind of really obvious lens-fault fetish that everyone has?  Do people go weak at the knees because of CA?  Can I just make my camera "cinematic" by applying halation and fringing in post?

[thebrothersthre3]

I only usually notice a difference when cropping in on an image a lot. I imagine I'd also notice on an absurdly big monitor close up. 

Beautiful model btw