Let's talk sensor...

[Dustin Cross]

Since we live in a 16x9 world it doesn't seem smart to make future Red sensor 4x3. If you want to use anamorphic, only use the middle of the sensor. If there is truly enough demand, someone will start making 1.33x cine anamorphics to use with a 16x9 sensor.


Mahalo,
Dusty

 

[Peter Majtan]

Amrrahmy - what You are referring to as a crop-factor only applies when You are using 35mm STILL PHOTOGRAPHIC lenses with a smaller sensors (APS in still - or S35 in cine). Red One is digital CINE camera and when used with CINE lenses (RED's, ARRI's, ZEISS's, etc...) - will yield NO CROP FACTOR what so ever as its sensor if full-frame S35 cine size...

 

[amrrahmy]

okay,
did u see other posts saying that the 4K image would make prestine 3K files.
did u see other posts saying(i think some of them by jim) that the 5k epic would make pristine 4K files.

why is that??????????????????????????
?????????????????????????????????????
?????????????????????????????????????

 

[J. Bernard Vallon]

the whole notion of a crop factor in dslr land is just mental shorthand for how lenses will look on today's cameras compared to how the same lens would have looked on YESTERDAYS cameras. Since a 50mm looks the same on a red as it would on yesterday's film cameras, there is no crop factor. Look at the evolution of digital medium format cameras as another example. A camera is only called "full frame" if it is 48x48 or more, until thm it has a crop factor.

 

[J. Bernard Vallon]

4k bayer sensors produce 4k images with the apparent sharpness of a 3.2k RGB image due to the imperfect spacial sampling of bayer color matrix. The file size is 4k, the only thing that is less is sharpness. Since red is sharper than many film stocks anyway, no one really cares.

 

[amrrahmy]

4k images with the apparent sharpness of a 3.2k RGB image

the only thing that is less is sharpness

Since red is sharper than many film stocks anyway

dont go cheap on the stocks.

no one really cares

i do(but i'm not of any importance, u can just exclude me).
that my last post on this thread.

 

[J. Bernard Vallon]

there are plenty of reasons not to use a red. Sharpness isn't one of them. Unless your choices are Imax or Red, red is sharp enough for any finish today.

 

[Brook Willard]

Man this thread got off topic fast. This is why I hate crop factors.

 

[Bruce Allen]

Brook, what a great post. And thanks for pointing out that we're only seeing 78% of the normal frame. That explains so many things that have been confusing me. You rock.

I fear RED is already too far into production on the Epic sensor to do what you suggest, though.

However, I will cross fingers they size up the sensor as you say to allow for look-around with a correct-size recording area. I think that the 4/3 aspect ratio thing may only come with Monstro. But hey, maybe I got it backwards and Epic will be 4/3 size, and Monstro a bit larger to allow for full-size recording area

Bruce Allen
www.boacinema.com

 

[J. Bernard Vallon]

With the lens market what it is, i'll bet if someone designed a set of 1.33 stretch anamorphic primes that were of excellent quality and aperture, people would be happy using them as an anamorphic solution to a 16:9 red.

2:1 anamorphics were designed because all cameras at the time used 4:3 frame sizes, not nessisarily because it was the perfect choice. Today nearly all cameras are 16:9, why not make a new set of anamorphic as appropriate.

 

[David Mullen ASC]

okay,
did u see other posts saying that the 4K image would make prestine 3K files.
did u see other posts saying(i think some of them by jim) that the 5k epic would make pristine 4K files.

why is that??????????????????????????
?????????????????????????????????????
?????????????????????????????????????

You're confusing effective measurable resolution with file sizes, and uprezzing with debayering algorithms. I think you are also confusing the RED with HD cameras that reduce pixel resolution before recording. You are also mixing up DSLR issues with cine camera issues.

4K RAW Bayer can create an effective 3K resolution even though the file size is 4K RGB. So 5K RAW Bayer can create a 4K RGB file that has a true 4K resolution.

But recording 4K RAW and converting it to 4K RGB does not involve cropping & uprezzing to or from 3K. It involves converting a 4K RAW Bayer pattern into 4K RGB, in which the measurable resolution of the image in those 4K files is 3.2K, according to RED. But the loss of resolution isn't due to overall cropping, it's due to the fact that a Bayer pattern has 50% of its photosites filtered green, and 25% filtered red and blue respectively. So the overall RGB resolution is around 75% of what a monochrome version of the Bayer image would be. Plus there is an optical low pass filter that reduces high frequency detail to prevent aliasing. Something that allowed nearly 100% resolution retained from 4K RAW to 4K RGB would have aliasing artifacts.

So if you want measurable 4K RGB resolution, you have to start out with a sensor and a RAW recording with even more resolution than 4K. But it's not a question of cropping, it's an issue of oversampling to improve picture quality.

 

[Finner]

Just put an ignore on that amrrahmy guy. He really has no clue what he is talking about. I figured this out quite a while ago.

 

[amrrahmy]

okay, since u insist.

oversampling to improve picture quality

that's cropping
so the image recorded is not the image played back and u need to remove the oversampling.

4K RAW Bayer can create an effective 3K resolution even though the file size is 4K RGB

so it can't create a workable 4K file from a 4K recorded image.only 3K

so ur saying there is ||||no|||| factor (and the image recorded is 1:1)at the same time that ur saying(that the image is not 1:1 and is oversampled by 25%) and u can only use the image by reducing the size to 75%.

applying anything to the image will reduce it's quality compared to an uncompressed image.

You're confusing effective measurable resolution with file sizes

no i'm not, i said the 4K recorded is 3K usable.(it's a 3k image pretending to be a 4K image.)it doesn't mean that the file size is not 4K, it means the actual file size quality wise is less than 3K, not size wise.quality wise.
and also that an uncompressed full frame 4:3 1:1 3K would have more quality.

 

[David Mullen ASC]

You're still confusing your terminology.

and also that an uncompressed full frame 4:3 1:1 3K would have more quality.

More quality than what? Now you're mixing apples and oranges, saying that a 4x3 sensor would have more quality than a 16x9 sensor. Not if you need a 16x9 image. And again, 1:1 is meaningless when talking about conversions from RAW to RGB. You can't record 3K RAW Bayer and get 3K RGB of equal resolution. There is no 1:1, pixel for pixel, process possible when talking about RAW Bayer conversions to RGB. It's only possible in sensors where there is an equal number of red, green, and blue photosites, which is not what a Bayer sensor is. A 3-CCD HD camera with individual 1920 x 1080 sensors can create an RGB recording where there is 1920 x 1080 pixels for each color, but even then, there is an optical low pass filter involved to reduce aliasing, so there is some loss of measurable resolution.

 

[David Mullen ASC]

okay, since u insist.

that's cropping
so the image recorded is not the image played back and u need to remove the oversampling.

so it can't create a workable 4K file from a 4K recorded image.only 3K

Oversampling is not cropping. Cropping is cropping. Chopping off part of the picture is cropping. Oversampling or resizing or uprezzing or down-rezzing does not have to involve cropping, otherwise the framelines you composed with in the camera would be useless.

You can create a perfectly "workable" 4K RGB file from a 4K RAW recording, it just won't measure out using a line chart at 4000 lines. But it is still "workable" and it's not a 3K file, it's a 4K file.

You can't play back the image exactly as you recorded it -- because a RAW image is not viewable. It has to be converted to color to be viewable. A RAW image is a monochrome image with a Bayer pattern to it.

Measurable sharpness is not the same thing as file size. By putting an old lens on the RED or a diffusion filter or having the focus slightly off, my 4K RGB files might not even measure out to 2K in resolution. But they are still 4K RGB files.

This is just a silly numbers game. What matters is how it looks. The 4K image from the RED looks pretty good, and pretty sharp. A 5K sensor would give you even more sharpness. But there is no particular practical reason for measurable 4K to be some sort of exact target that you need to hit. Lenses, film stocks (in film cameras), contrast of lighting, filters, atmospheric haze, working f-stop, etc. all affect sharpness in ways that can exceed the differences between 3K and 4K. So there are limits to how much you need to think about these numbers.

 

[Jose Alvarez]

Sorry, but you're not helping...

Sorry, but you're not helping...

also i'm out for today, i will take a look at the thread tomorrow. i'll try to help out with any info needed, if i can.

Sorry but nothing of all the things you have said made much sense at all. I'll have to decline that offer.

 

[amrrahmy]

Oversampling is not cropping. Cropping is cropping. Chopping off part of the picture is cropping. Oversampling or resizing or uprezzing or down-rezzing does not have to involve cropping, otherwise the framelines you composed with in the camera would be useless.

resizing the image to a smaller image is cropping, u dont have to crop a par of the image to be cropping, resizing to a smaller image from a biggr image is cropping.

You can create a perfectly "workable" 4K RGB file from a 4K RAW recording

it's a good thing that u quoted the workable part, "workable" is not workable

You can't play back the image exactly as you recorded it -- because a RAW image is not viewable. It has to be converted to color to be viewable. A RAW image is a monochrome image with a Bayer pattern to it.

i'm talking about the quality.(it wont be "workable" if u can play it back full size)

Measurable sharpness is not the same thing as file size. By putting an old lens on the RED or a diffusion filter or having the focus slightly off, my 4K RGB files might not even measure out to 2K in resolution. But they are still 4K RGB files.

relative quality.

 

[amrrahmy]

it's 3am the next day dude, and i only posted because i was quoted.

 

[Jeff Kilgroe]

For EPIC to resolve pristine 4K it would have to have at least 5252 (which is slightly more then 5K - 5120). I am confident it's going to have even more - close to 6K...

Yes, I just said 5K because that's all RED has said about it so far. I believe it will be a bit over actual 5K myself, even a full 6K possibly.

Now this will not work as Scarlet (based on Mysterium-X) is 2/3" with 3K resolution. Maybe EPIC will have the same density as Scarlet, but in full S35 frame...

Do'h! :biggrin: I guess my logic is a little flawed today. Good point.

Doesn't it say "full frame S35"? (Same size as Red One...)

Nevermind... I guess the NAB brochure also says it about the RED One. My brain is not functioning today. I think I'll go do something else like take a nap.

 

[David Mullen ASC]

I think we are running into a language barrier here because my definition of "cropping" and "workable" are different than yours. But here is the Wikipedia definition of cropping:

http://en.wikipedia.org/wiki/Cropping_(image)

And my definition of "workable" is "something that works". And my 4K RGB files seem to be working just fine.