4,5k is enough for IMAX

I read somewhere that IMAX is equivalent to near 10,000 horizontal pixels. But still, other movies have been shot on 35mm and still go to IMAX. I think there were even High Definition movies that made it to IMAX.

2540p(seemingly now called 4.5K), isn't that much higher resolution than 4K. If you want the full IMAX resolution, I don't think that even Ultra High Definition would be able to do it. Maybe 8K though.
 
Problem with Imax is that it's 4:3 rather than widescreen, and our chip is widescreen. Guess you could letterbox though :-)

Good news is that 4k looks really good on a 60ft screen, or however big that screen was at IBC, and Jim and I got up real close to look for pixels, and it looked really smooth close up, so I guess look-wise, 4k would be fine on Imax.

However, the thing for me about Imax, is not the resolution, nor size of screen, but the POV - in that they're generally shot really wide, and they fill your field of view. It's a fantastic, but also tiring experience.

Graeme
 
A while back I worked out that you would need a Beyer sensor of about 21k if you were using a 16x9 format letterboxed to give you 4x3 at the maximum possible Imax resolution. However In reality film suffers all sorts of losses in the processes from camera to projection. Check out this thread: http://www.cinematography.net/Pages%...mTechSpecs.htm the last 3 posts are particularly telling. They imply that Red footage would probably just about hold up in an imax presentation, though I think it would be pushing it a touch.

Martin
 
I gave this some thought as well. But actually, I assume that 35mm would still blow up better than 4.5K if you were transferring to IMAX.
 
I suppose the question is what resolution 35mm film is scanned at when it is run through the IMAX DMR process for upconversion to IMAX. I can't find the answer to that one, but if it's 4.5k or less, presumably Red footage would look as good as 35mm when converted to IMAX.
 
Sorry but 4.5k is not imax, you might be able to project it with an Imax projector, but it doesn't make it imax. Imax is 70mm horizontal, that would be at least 6k.
 
In the film world the difference between S35 and Imax is the size of negativ, so for me, if you want a digital Imax , you should have a camera with a 70mm (or whatever is the Imax size) digital sensor...

I agree with Graeme, when saying that "the thing for me about Imax, is not the resolution, nor size of screen, but the POV", which comes form the HUGE size of the negativ it is printed on.
 
I was talking to someone about this and their opinion was that you would be talking about 8K or more to "match" IMAX. Also, if you were transferring (blowing up) from 35mm to 70mm, wouldn't you do it optically (analog) rather than digital? 4K is clearly lower res than 35mm, so you'd be losing a lot of resolution by using a DI.
 
People, calm down.
IMAX format has shorter DOF at the same given frame. That is cool. You can watch wonderfull portraits on IMAX, as those done with a medium formar 6x6 film photo camera. But that is not what gives the IMAX quality.

IMAX is about a screen so big that you must turn your head in order to see the image. Together with pristine image quality makes the true experience.

Now, as Graem mentioned, the problem is the aspect ratio. If RED is closer to 16/9 then there is the problem.
But i am almost sure that a square sensor capable of true 4,5k pixels would certainly be enough for IMAX. WHY?
Well, 70mm means quite a lot of information. True. But after labs processing, and multiples copies, i wonder what is the real resolution of the copy in the theater.

We all have seen 35mm films displayed on IMAX, and to me, they looked really well. Now i believe digital 4,5k is at least in resolution better than 35mm film. I have in front of me 2k cineon files from S35 that would not get much more details if they were scanned at 4k.

So answering myself, 4,5k by 4,5k would be enough for IMAX. And taking advantage of no loss of detail in the postprocessing would make things even more interesting...
 
macgregor said:
People, calm down.
I have in front of me 2k cineon files from S35 that would not get much more details if they were scanned at 4k.
..
Click to expand...

Hi Mac,

I have just scanned the same negative at 3k down sized to 2K & 6k down sized to 4k. After the spot has aired I can give you a link to some DPX's.

Best wishes,

Stephen
 
Nick_Shaw said:
I suppose the question is what resolution 35mm film is scanned at when it is run through the IMAX DMR process for upconversion to IMAX. I can't find the answer to that one, but if it's 4.5k or less, presumably Red footage would look as good as 35mm when converted to IMAX.
Click to expand...

the "usable" resolution from a 355mm scan even with low grain stock is around 3.5k. So Red footage would do a better blow up on paper... and since Red is very low on noise levels, there would be an added advantage.

Now Digitally, Imax digital deliverable requirement is 5616x4096, not a world away from Red's native 4900x2580... in fact if you put a mesmerizer lens onfront of the red camera and rotated it vertical, you would do a vertical anamorphic that would get you to more or less the right aspect ratio, and only need to interpolate a few hundred lines.

It makes a valid point though.. perhaps Red should test out 65mm instead of 35 :)
 
I don't know if it was mentioned already but superman3d was projected in imax. (really bad move in my opinion becasue it clearly wasn't shot for image or 3d.) When someones nose takes up half of an imax theatre it can get kinda nosiating to have to turn your head to see the other end of the nose. Imax should be wide POV as greame had mentioned. 35mm is scanned in at 4k and a high def digital projection can at times look better than a 35mm projection just because the origin was digital and cleaner. I don't see why 4.5k digital projection wouldn't look cleaner than an imax film projection. Even if the theory of the resolution needed is 10k or something around there I think digital just blows up better in the end.
 
Superman Returns looked tight on Charleston's IMAX screen. That was pure digital workflow for the 3D version from Genesis masters. RED should have plenty of room to burn for IMAX releases.

e
 
Man, Stephen, you are everywhere!

The thing about film is that double the resolution does not mean double the detail, while in digital SLRs, usually it is.
 
Jarred Land said:
the "usable" resolution from a 35mm scan even with low grain stock is around 3.5k. So Red footage would do a better blow up on paper... and since Red is very low on noise levels, there would be an added advantage.
Click to expand...

Wait. I thought Hollywood films were beginning to be scanned at 6K? No?
 
macgregor said:
IMAX is about a screen so big that you must turn your head in order to see the image. Together with pristine image quality makes the true experience.

We all have seen 35mm films displayed on IMAX, and to me, they looked really well.
Click to expand...

I think there is a fundamental difference between how conventional features play on an Imax screen and how you shoot specifically for an Imax presentation.

The idea behind Imax is that the screen should fill your peripheral vision so the point of interest should be framed to fill a small central part of the screen towards the bottom. Ideally you won't be turning your head too much because the rest of the image is just there to immerse you. This is the main failing of 35mm presentations, they tend to take up too much of the screen. I wonder how well a 35mm presentation would hold up if it was shot specifically for Imax and all the action was only using a quarter of the frame area.

Having said that I still suspect Red would hold up and would do a better job than 35mm because of the absence of noise/grain.

Martin
 
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