Why 6k Resolution Is Not Overrated... And Might Be Too Little

[KnightsFan]

12 hours ago, kye said:

There are absolutely lenses that will resolve 100MP somewhere in the frame under perfect conditions.  But what about the corners?  and what about CA?  and what about halation?  If a lens resolves as much as a 100MP sensor in the middle, but edges with contrast have CA still visible when you downscale the image to 1080p (2MP) then is it really still a 100MP lens?  and wouldn't adding more resolution in the middle simply make it more obvious that the flaws are so much less?

I think you are missing the point about what digital resolution is. Increasing digital resolution isn't to resolve the world, it's to resolve the lens projection. Whether the lens is projecting sharp lines on a test chart, CA, flares, or bokeh, it is an infinite resolution analog image. The more samples, the more accurately we reproduce the lens' image.

The softer the lens, the more samples it takes to accurately describe its image. If a lens produces a sharp line between black and white, it only takes 2 samples to describe that difference. A soft gradation, on the other hand, takes more samples to describe. That gradation is meaningless if your sampling frequency is not high enough to show it.

12 hours ago, kye said:

Most things in life are hard to see from a huge distance away, and look nice from a sensible distance, but when you get right up close the flaws become visible and the magic kind of fades.  I'm beginning to think that with lenses you want to capture the image well enough to see it clearly but not so well it just points out all the flaws.

Would you rather see chromatic aberration, or pixelation? 6k won't make you see more CA unless you were already close enough to see pixelation in 4k.

1 hour ago, kye said:

It's kind of like taking a super-high-resolution scan of a low quality fax.

It's more like making a a high quality recording of a distorted electric guitar.

 

 

Disclaimer... there's obviously a cost to higher resolution sensors, both financial and other image compromises. I'm not saying 6k is worth it over 4k. I'm just saying that a higher sampling frequency describes a lens' image better than lower sampling frequency

[Eric Calabros]

My problem with 8k is that this industry is a like a jungle that everybody do his things and couldn't care less about what others do. LG is planning to produce 10 million large OLED panel in 2021, but nobody talks about bandwidth, or next gen blueray, or compression and codecs (I just downloaded a movie the other day and it was like 13 or 14GB! And yet the shadows are trash). Even sensors are not ready.. other than heat issues, 8k readout is linked with massive  jello effect. Companies are working hard on global shutter but even at R&D level DR is still in 70db territory, its 11 stop of "engineering" dynamic range. Consider it 9. Even GPU cards are far from ready.. 90 percent of cards in the market are struggling with games at 4k/60, while consume a lot of electricity.

Speaking of numbers.. look at THIS numbers. In Saudi Arabia, yes, that country, 7 in every 10 citizens watch contents on TV, BUT 8 in every 10 watch TV series online on smartphone/tablets! (For average of one hour per day!) So consumers using 5-6 inch displays to see TV has already exceeded those using the actual TV. And tell me what's 8k or even 4k relevance on 6 inch display? 

[Danyyyel]

On 8/11/2019 at 9:10 PM, Video Hummus said:

Buy that tv now and wait 5+ years for 8K content maybe even 10 years if you are in the USA; since our govt persists in allowing companies to drag ass on building out fiber networks (or outright not allowing local municipalities to do it themselves) which are essential if you want general 8K programming to the mass population.

I would prefer to watch 2.8k alexa footage than any 6k footage from most other camera. I just understand people, if you think anything beyond 4k ( I would even say true 2k) is going to bring anything more in terms of image quality, you are completely wrong.

[Danyyyel]

I meant, I just don't understand people... above.

[newfoundmass]

8K is just a way to sell TVs. As stated previously, the screen size needed to get the benefits of 8K is far larger than most people will ever have. The average TV size in the US is under 50 inches. You'll need a TV at least twice the size to begin to see the benefits of 8K. 

We haven't really even achieved the benefits of 4K yet! I don't even know how much of the country can even stream 4K yet. 

From a production standpoint, 8K has some uses. For most of the users on this forum, they don't really NEED 8K even if they WANT it. 

[User]

8k is for men with small penises. In that regard, I still watch, and more precisely, shoot standard def.

[kye]

On 9/1/2019 at 10:20 AM, KnightsFan said:

I think you are missing the point about what digital resolution is. Increasing digital resolution isn't to resolve the world, it's to resolve the lens projection.

I understand your point, but I suspect we have a philosophical difference here.

My end goal is to make art.  Out of the many ways I could do this, I have chosen video as the medium, and for this purpose I own a camera.  If I could stick a USB stick in the side of my head and render my memories to it then I wouldn't bother with any of the opto-electric-trinkets that we talk about here.

So, when we talk about spending many thousands of dollars on equipment instead of $40 for a 10-year-old point and shoot on ebay, we are doing so because we think that expensive equipment gives us a nicer image.  For me, and I suspect most others, nicer typically means that the end product looks far less crunched when compared to what we pointed the camera at than a cheaper camera would do.

This is why our discussions talk about everything in the image pipeline.  Walking through it, we talk about filters, lenses, the sensor stack, the sensor, the digital processing (colour science), the codec, editing, grading, delivery codecs, distribution, and final projection.  We care about everything. 

I understand that not everyone wants to have perfectly realistic imaging, there is this concept of a 'cinematic' image and we talk about how certain distortions have a pleasing effect.  Swirly bokeh lenses are an example of this - not everyone wants the modern look.  However, when we're talking about what we want vs what we don't want, not everything is desirable.  For example CA isn't something most people want.  It's definitely not something I like the look of.  There are other things we sometimes want to get rid of.  

..and here we get to the crux of the problem - if there is a problem with something in the image pipeline then we have the choice of having everything else in the pipeline have high-quality and therefore ruthlessly reveal the issue, or we can deliberately lower the quality of something in order to effectively hide that issue.  It's a question of how clearly do we want to see the best part of the image, knowing that we will also make it clear to see the worst part of the image too.

For me, it's about spending the money on the worst part of the image pipeline.  If someone said they had an Alexa and PL cine lenses but used a scratched $10 ND filter and were thinking of upgrading to an ARRI LF because they wanted to get better image quality we'd think they were crazy because they should replace the ND filter instead as that's clearly the worst part of their setup.  

For me, I think that lenses might be the worst part.  I watch a lot of Netflix and on almost everything I watch I'm seeing bad image quality caused by lenses, not by filters, not the sensor stack, not the sensor, not the digital processing (colour science), not the codec, not editing, not grading, not delivery codecs, not distribution, not the final projection, the weakness is the lens.

And when I look at moving from 4K to 6K I think about what lenses people are using and I think "4K isn't your bottleneck".  Using a Helios... 4K obviously isn't your bottleneck.  Using a Sigma 18-35, Panasonic 12-35 f2.8 or Canon 16-35... I still think that 4K isn't your bottleneck.  Using a CP.2... Even then I think 4K isn't your bottleneck.  

I know it's a taste thing, but when I see lens issues I'm just thinking everyone is spending big dollars to make high-resolution copies of fuzzy 70's polaroids.

[KnightsFan]

12 minutes ago, kye said:

if there is a problem with something in the image pipeline then we have the choice of having everything else in the pipeline have high-quality and therefore ruthlessly reveal the issue, or we can deliberately lower the quality of something in order to effectively hide that issue.  It's a question of how clearly do we want to see the best part of the image, knowing that we will also make it clear to see the worst part of the image too.

We agree more than you think. This is basically what I was saying. Either pixelation or lens aberrations will be the limiting factor. Personally, I find analog flaws to be more acceptable than digital flaws. I'd rather have CA than be able to see individual pixels. Similarly, I'd rather hear analog noise from a 60's mic than hear MP3 compression.

And ultimately, if you are sitting far enough away from a 65" 4k TV that you can no longer distinguish individual pixels, then you will not be able to see optical problems any better with a 65" 8K TV at the same distance.

20 minutes ago, kye said:

For me, I think that lenses might be the worst part.

I disagree. Stop down on any decent modern lens and you can easily outresolve 6k on most of the frame. And if you are using a lens for character, then higher resolution will more accurately capture that character.

 

However, I fully agree that higher resolution is not financially worth yet for many people, including myself.