Scarlet & Epic 5K resolution only 1667 pix?

[Pietro Impagliazzo]

RED looks better.

That's the ultimate math isn't it... haha

 

[Stuart English]

Resolving power

Resolving power

Or am I missing something here?

Yes, the fact that resolving power (i.e the system level resolution) is usually measured in one direction at a time, normally horizontally...

 

[Jeff Kilgroe]

Nikon D2x. I was referring to 12.4 mp recorded image. DSLR spec sheets tend to call that "effective pixels" or "effective resolution" so I thought he was telling me that the R1 recorded a 7.36 mp image.

Ah, I have the D2Xs and I almost made a lengthier post using it as an example. The D2X actually only has 12.2M effective pixels with a max record resolution of 4288x2848. You need to shoot a resolution chart with it, but it's CMOS sensor suffers the same fate as any other sensor that must be de-bayere'd and demosaiced. And even with a a good quality lens like the Nikon 85mm f1.4 (at it's sweet spot of f5.6), the camera at it's best will only show 3500~3600 horizontal lines of nominal resolution. Which is actually quite good, I really like the D2Xs. The D3 has been alluring more due to it's full frame "FX" sensor than the increased sensitivity and range, but I've held off, thinking I'd wait for the next generation after... Now there's the DSMC angle to consider for my future "DSLR" purchase.

The part about it recording a 9.44 mp / 4K image that's actually 7.36 mp / 3.3K resolution just 'wooshed' so far over my head I couldn't even see it.

Got a link to a Wikipedia article or something?

No link off the top of my head, but there's lots of info out there. Graeme's posts on these forums are always very informative. The Panavision anti-RED propaganda does offer some insight... It's somewhat accurate in terms of analyzing the shortcomings of a Bayer filter array, but it's also heavily biased marketing FUD in that it doesn't delve into the advantages of a Bayer pattern sensor, nor does it discuss the shortcomings of the sensor tech they have chosen or how the two truly compare. You can Wikipedia or google Bayer Pattern, Bayer filter CMOS, etc.. Anyway, no matter what sort of digital system we are looking at, there will always be a trade-off in actual resolving power or measured resolution in favor of reducing aliasing and other pixellation artifacts, also conditional on the optical path.

 

[JanneJansson]

hehe, cool to see that this topic never goes away

 

[Lee Saxon]

Thanks for the explanations Jeff!

 

[Dan Hudgins]

Digital resolution in general

Digital resolution in general

Resolution for digital images is not limited to just the sensor pixel count, it relates to any digital image since the pixels are in fixed locations.

If you take the diaganal line over the digital image you get about x*0.707 and y*0.707 for high MTF limits.

In analog video you can get 1.5 pixels wide, or 1.25 pixels wide spots, but in digital you get 1 or 2 pixels wide and the brightness varies for those two pixels, so video is a little different than digital if the amps had enough bandwidth. And in film the image spots can be anywhere on fine grain film, or at lease average out to being where they should be over a few frames.

So a 2K projector only "resolves" about 1.4K, and 2K on a monitor may "resolve" less then 1280x720 in full RGB true detail at high MTF. You can check the monitor with a black and white checkerboard test pattern for single pixels or blocks of four pixels, you will probably not be able to see the single pixel black and white checkerboard well on your monitor at 1:1 100% size.

Since you are going to lose resolution in projection you get compond losses, so it should be better to shoot 4K and project 2K to stay above 1280x720 rather than shoot 2K and project 2K which would blur the blur more and maybe put you under the 1280x720 value.

Some 2K film recorders only use about 1806x976 so if you do 1806x0.707 you get 1276x690 which is about what people see on prints now, because the film recorders are only "resolving" that much anyway, and you can add losses to that from the film recorder lens, the film printing, and the projector being out of focus.

See these tabels,

http://www.celco.com/FormatResolutionTable4K.asp

It does not matter much so long as you "resolve" more than true 1280x720 which is about what an out of focus 35mm movie projector gives the viewer in the back half of the theatre off a film print.

Other factors such as contrast, highlight and shadow detail, art direction, color purity, etc. will pass through the generations of compression in the release formats more than "resolution". Pixel counts about 8K for movie use to filmout on 35mm would add little in the reduction of aliasing and bayer artifacts, and sensors less than about 2K can show some, so RED ONE having 4K was a good idea and has worked well, as you can see if you go see CHE #1 and #2 in the roadshow prints.

 

[Ken Martini]

I am glad to see my remarks have sparked such a lively debate, as I thought it would. Reading some of the comments I gather that there is about a 1/4 loss of resolution in the Bayers chip and subsequent processing, or is that an oversimplification? As some of you hinted, I got my info (propaganda) from Panavision.

 

[Daniel Browning]

As some of you hinted, I got my info (propaganda) from Panavision.

Ah, so this is yet another in a long line of threads started by Panavision misinformation. There should really be a sub-forum for debunking them.

 

[Liam Hall]

I am glad to see my remarks have sparked such a lively debate, as I thought it would. Reading some of the comments I gather that there is about a 1/4 loss of resolution in the Bayers chip and subsequent processing, or is that an oversimplification? As some of you hinted, I got my info (propaganda) from Panavision.

The Panavision info looks correct to me. You may be misunderstanding it.

 

[Jeff Kilgroe]

The Panavision info is a little bit off. But the real problem with it is they don't address the advantages of Bayer sensor implementations, nor do they discuss the shortcomings of the RGB stripe array used by the Genesis.

@ Ken, to assume a 1/4 loss of resolution for a Bayer pattern sensor is indeed an oversimplification. In the case of RED, it's more like an 18~20% loss depending on how it's measured. With most any digital sensor system, it's difficult to put a hard number on effective resolution retained because it varies from one implementation to another. Every step in the image acquisition pipeline plays a role, from the sensor design, to the OLPF, data processing, etc.. One thing that does remain constant however, is that effective resolution is always less that physical resolution within a digital system. Anyone who tells you otherwise is pooping out of their mouth.

 

[Ken Martini]

The Panavision info looks correct to me. You may be misunderstanding it.

I was extrapolating some info from what I read. After reading the posts to my original questions I come away with some varied opinions. It appears that Panavision's views are correct, but nonetheless biased by not presenting true comparisons. I see that some of the resolution is gained by interpolation. I also see that Red's approach is one approach of a few ways of getting there, all with pro's and cons.

I am a practical person and do not have allegiance to any system. What is hot today will eventually become passe. I have bought too many cameras not to see that this is the case. Red's advantage may evaporate with the onset of liquid lens technology, who knows.

 

[Michael Olsen]

Red's advantage may evaporate with the onset of liquid lens technology, who knows.

A few years ago I was quite the PC enthusiast. The rate of technology evolution there is disgusting (and still is) for anyone who wants the newest/greatest at a relatively reasonable price. Even more frustrating was the evolution of formats and connectors: that newest SATA hard drive won't work because the current generation motherboard doesn't support it, the newest CPUs have a different socket, the newest video cards required a different type or speed of slot. Adding a single element which had advanced significantly often required purchasing different versions of supporting hardware that hadn't changed signficantly.

Having this knowledge, the modularity principle that RED is built upon has always seemed its greatest advantage. They could price their products identically to their competitors, but offer the idea of modularity and upgrading brains and they would still have a terrific MO.

Unless I've really misunderstood things (which is certainly possible) new liquid lenses could come out with a new type of mount and different AF requirements. Shortly thereafter someone will inevitably make a mount for the RED cameras, and RED will offer an update to the firmware allowing for the new focusing system and boom - problem solved. It won't happen instantly, but I wouldn't have to buy a new camera to use the new lenses, either.

Let's say a breakthrough is made in CMOS or CCD technology (or even something new). RED can put out a new line of brains, you could buy one for much less than a completely new camera and still keep your lenses, recording media, batteries, I/O, rail setup, etc.

At least, that's what I'm hoping for...

 

[Liam Hall]

I was extrapolating some info from what I read. After reading the posts to my original questions I come away with some varied opinions. It appears that Panavision's views are correct, but nonetheless biased by not presenting true comparisons. I see that some of the resolution is gained by interpolation. I also see that Red's approach is one approach of a few ways of getting there, all with pro's and cons.

I am a practical person and do not have allegiance to any system. What is hot today will eventually become passe. I have bought too many cameras not to see that this is the case. Red's advantage may evaporate with the onset of liquid lens technology, who knows.

Well said