Epic X, Epic FF35 and IMAX...

[Tom Lowe]

I had a conversation with Lee Parker, who shot all the motion-control and timelapse sequences for Disney's "Sacred Planet" IMAX film on 15-perf a couple of years ago. I randomly mentioned to Lee the specs of the forthcoming FF35 Epic -- 6K 3:2 RAW Full Frame. The very first thing he said was, "Wow.... if that's true... you'd have an IMAX camera."

"Exactly!" I said. :hurray:

Anyway, we got to discussing aspect ratios. What Lee said is that because many of the IMAX theaters around the world have tried to cut costs on construction, many of them do not even display the full height of the IMAX aspect ratio, 4:3. The tops and bottoms end up getting cut off, leaving IMAX viewers with roughly a 3:2 aspect ratio (and pissing off the DPs who shot them and framed for 4:3). Anyway, Lee suggested that 3:2 would actually be a better finishing aspect ratio for digital IMAX.

This makes a lot of sense to me. The added benefit of finishing digital IMAX at 3:2 is that the cropping to 16:9 is relatively painless. It can be done.

So then this got to me thinking, "Why not Epic X?" I can't seem to find the Epic X specs online anymore. Can anyone tell me what the exact pixel count is, and what you would be left with by the time you crop to 3:2? 4.2K? Something like that?

The Epic FF35 will obviously be better for IMAX (a slamdunk IMO), but I do think that Epic X has potential. Any thoughts about this? Is Lee correct about the defacto 3:2 aspect ratio?

 

[David Mullen ASC]

There are some specs here:
http://en.wikipedia.org/wiki/IMAX

The 15-perf 65mm negative is 4x3 (1.33 : 1) but projection is often around 1.44-ish, so anything between 4x3 and 3x2 (1.50 : 1) would be fine.

The issue is more one of resolution -- I don't think 4K RAW really cuts it as matching 15-perf 65mm quality, though it may look fine on an IMAX screen with the right sweetening, ala IMAX DMR processing.

Personally, I'd hope that a true digital replacement for an IMAX camera would be between 6K to 9K RAW for starters. I would think the EPIC 645 would be the RED IMAX camera, not the FF35.

 

[Tom Lowe]

Of course you are right, David. I'm just trying to consider the "minimum" needed to even talk seriously about cutting digital cinema images against 15-perf for example (dynamic range issues aside). Obviously people have been cutting F900 underwater footage against 15-perf for IMAX films for a while, but I'm talking about trying to shoot digital cinema that could realistically blend with 15-perf, or at least stand on its own handsomely on a huge IMAX screen with 4K projection.

I really don't know whether 4.4K Bayer or whatever the Epic X's sensor cropped to 3:2 will put out is enough for full-on IMAX. Obviously, with RAW, how well exposed the shot is plays into this. Would it help to have Master Primes on the Epic X? I tend to be very conservative about the true "pristine" spatial resolution of Bayer images. I feel much more comfortable with a 40% downsample than a 20% downsample, but as you say, perhaps IMAX will have some tricks up their sleeve with the DMR. Speaking of which, I guess the DMR can work for digitally acquired material, as well as film? Is the same system used? Or two totally different systems? I assume "Superman Returns" went through some kind of DMR? I did see it on IMAX. I thought it looked decent on the IMAX screen, but not super-duper. :smile5:

It was interesting, from my point of view, that Parker said, unprompted and with zero hesitation, that the 6K FF RAW camera would essentially be a slamdunk for IMAX screens. This is coming from a guy who is an expert on 65mm 5-perf and 15-perf. Lee set up Fricke with his 65mm cameras for Baraka. I've been thinking along the same lines myself regarding the FF35 Epic, just knowing how stunning these 5.6K RAW images I have been working with really are. My prediction is that IMAX projects will be lined up and waiting for Epic FF35 "Tattoo" cameras by the time they start coming out.

 

[Ralph B.]

To your question of sizes at my last point of reference:

Epic-X S35 physical size 30mm x 15mm / Resolution 5,120 x 2,700 / price $10,500 (+) RED1 body
Epic FF35 physical size 36mm x 24mm / Resolution 6,000 x 4,000 / price $33,000
Epic 645 physical size 56mm x 42mm / Resolution 9,334 x 7,000 price / price $43,000
Epic 617 physical size 168mm x 56mm / Resolution 28,000 x 9,334 / price $53,000

In my opinion I don't see how you could pass up the 617 if you are interested in shooting IMAX. I mean there will be fewer of them around than the 645 but certainly more of them than there are IMAX cameras out there. I know the 645 is really really close to and the closest approximation to the actual frame size of IMAX.

All of these are Monstro chips so when they show up is anyones guess. I'm hoping within a year because that would mean my Scarlet FF35 would be here to couple with my fixed scarlet.

 

[Tom Lowe]

Well, it's not a matter of wanting to pass up 645. Everyone can agree that this camera will be better for IMAX. It's a matter of getting started with the cameras that will come out first. Jim has already stated that FF35 will be developed and released before 645.

 

[Iannis Holwech]

This is complicated question that is hard to answer properly before somebody shoot IMAX and various digital sensors side by side, and do a side by side projection.

The whole question becomes two parts; One is the capture technology, the second is how will we be able display the quality we have captured.

It is also a question that will have a different answer if we talk about IMAX full resolution film out, or IMAX "lite" digital.

FF35 is "only" 24megapixel (for the time being), and cropped to IMAX Aspect Ratio we are left with somewhere around 2x4K resolution (18mpx).
That resolution falls very much short of IMAX resolution.

Many people believe IMAX resolution to be 18K.
But during a discussion around this earlier this year I found this blog from 2005 with a supposed answer to the IMAX resolution in a mail from Sr. Vice President of Technology at IMAX;
http://www.tristanpipo.com/2005/03/1...te-was-sunday/

He states that IMAX is "12000 horizontal pixels x 8700 lines of vertical resolution", (mixing pixels and lines in the answer). (more than 100mpx)
Which gives about 12K.
But he also states, due to "MTF loss, It is estimated that audience can discern no less than 4500 lines of vertical resolution from a good IMAX release print."
This gives again about half the resolution of 12K.

To give IMAX some margins, I would say IMAX has about 8K(33mpx) - 9K(65mpx) resolution. (LOL, see how resolution doubles from 8-9K :crazy

Even if it is slightly higher, I wonder if one could see any difference between IMAX 15/70 analog or digital 9K(65megapixel) capture projected back on a 8K (33mpx) projector like the coming JVC 8K or Evans&Sutherland 8K laser projector (if they have light enough that is).

The 645 might be good enough for printing to IMAX film.
For digital projection there really isn't much choices as the 8K projectors are still not powerful (light output) enough for any cinema screen size. Even less so for the huge IMAX screens.
Only solution is stacking multiple 4K projectors with edge blending.

I desire very much a FF35, but that is because I believe that it will look very good down-sampled to 4K, and that the full 24 mpx resolution will hold up (up-converted) in future digital projected formats like 8K.
We might even get a 6K projection format on the way to the maturity of 8K projectors. Texas Instruments just released a 4megapixel DLP chip, 78% more resolution than 2K, just months before the release of 4K DLP.


So for IMAX resolution it's the 645 that is in the game as long as we're not going backwards talking "good enough" :mad5:, again.

 

[Tom Lowe]

FF35 is "only" 24megapixel (for the time being), and cropped to IMAX Aspect Ratio we are left with somewhere around 2x4K resolution (18mpx).
That resolution falls very much short of IMAX resolution.

What cropping do you need to do? The FF35 Epic sensor is 3:2, perfect for IMAX. Why would you crop it? That that's the beauty of FF35... the sensor's native aspect ratio is perfect for IMAX. Epic X, on the other hand, is only 16:9, as far as I know.

 

[Michael Hastings]

Tom:

I think Iannis pretty much nailed it in terms of the technical aspects.

I see the practical aspects as this:

Imax films have been made from High Def cameras - can it work? Of course, but it is a somewhat diminished product from the 65mm film format that originally distinguished IMAX. As you step up from HD to EpicX obviously it gets better (and many people think you need to double resolution to get a real noticeable difference - "JND in psychological terms") and full frame gets you a little closer but it is still far short of the next doubling that happens when you get to 8K, so I just don't see that the line for Imax shooting with EpicFF35 will be that much bigger than for Epic-X.

The increase over say the RED1 to Epic will be the perception that, as a second gen camera - with a little more resolution, better dynamic range and better packaging/integration/relliability - it is ready for prime time.

The big jump will happen with Epic645 because at that point it will be very easy to make the technical case that it is equivalent to "REAL" IMAX.

What cropping do you need to do? The FF35 Epic sensor is 3:2, perfect for IMAX. Why would you crop it?

I would note that that is only true for your proposed least common denominator "digital" Imax format.

 

[Tom Lowe]

....I just don't see that the line for Imax shooting with EpicFF35 will be that much bigger than for Epic-X.

The increase over say the RED1 to Epic will be the perception that, as a second gen camera - with a little more resolution, better dynamic range and better packaging/integration/relliability - it is ready for prime time.

The big jump will happen with Epic645 because at that point it will be very easy to make the technical case that it is equivalent to "REAL" IMAX.

To me, the larger 3:2 native sensor in Epic FF35 is a huge, huge advantage in terms of being able to use it to cut against or replace 15-perf. I think a lot of people are underestimating the FF35's usefullness as an IMAX acquisition tool. Their eyes are fixed on 645, but they might be missing what is right in front of them.. the FF35.

As Parker said to me, once somebody actually goes out and uses one of these Epic cameras for IMAX and screens the prints at 70mm or 4K projection, then it will be a proven route and the floodgates will open. :wink5:

In terms of the Epic X being able to acquire for IMAX, that is a more questionable route, because the sensor is smaller and you have to deal with the crop to 3:2. But I think it's worth at least considering and testing... and I plan to do so!

I would note that that is only true for your proposed least common denominator "digital" Imax format.

Even David said anywhere between 4:3 and 3:2 should be safe. I believe that is correct.

 

[JD Holloway]

Tom you may be on to something.

Iannis, I don't mean to contradict Imax's technical people, but research in 35 mm projection (there are many papers out there) typically show projected resolutions in theatres to be extremely overrated. Here are some examples.

http://www.etconsult.com/papers/Technical Issues in Cinema Resolution.pdf

http://www.fixetdefix.fr/IMG/pdf/35mm_resolution_english.pdf

I feel that if Imax footage isn't handled much differently then 35 mm film then I'm not sure how likely it is to produce the numbers they are quoting.
Given about 800 Max lines vertical resolution of 35mm projected times about 2.5 for IMax neg size gives around 2000 lines vertical resolution. Not far off your FF I would think. Bayer conversion will throw 30 percent away or so, a heavy loss.
The differences in focal plane size (imaging chip) may well be made up for in the fact that so many FF lenses are much faster than Medium format lenses. Thus reducing the differences in DoF between the two systems given the same relative field of view.
I must admit to knowing nothing about Imax lenses. F2 or faster in medium format is a rarity though some faster lenses exist. Noritar 1.4 135 rings a bell but is made of unobtainium. Most Imax lenses are 2.8 or slower. Much much slower.

This would be a drawback to the 645... slow lenses.

I'm talking out of my fanny here, just noodling.
Bring on the 6K projectors!

Now if FF Epic had a 20 megapix imager....

 

[Michael Hastings]

Now if FF Epic had a 20 megapix imager....

Actually, Epic FF35 is 24 megapixel in 3:2 aspect and 21 MP in Imax 4:3 aspect.

But Epic 645 is 65 megapixel in Imax 4:3 (that's it's native format).

With that said I had forgotten that FF35 is the monstro sensor, so a pretty big difference over epic-x

However, I still think, if 645 is only 3 months later and your real goal is IMAX then that is the most likely thing an IMAX producer or funding executive is going to use to make a decision. You also have to remember that 645 is only $10K more (not trivial to a lot of us but in the IMAX world that's just a few rolls of film) and AFAIK should be able to do any of the sizes and speeds of the FF.

Iannis, I don't mean to contradict Imax's technical people, but research in 35 mm projection (there are many papers out there) typically show projected resolutions in theatres to be extremely overrated.

But I would think that with IMAX - where you are basically trying to give that awesome/overwhelming experience - then you would be trying to improve on it if anything. I.E. if 8K digital projection would give real world improvement over film projection then you would go for the improvement rather than saving 3 months and $10K. Same would seem to hold true even if you are talking film out for current theaters over the next few years. Why not wait an extra 3 months and spend the extra $10K (camera owners investment - not really a cost to the individual production.)

I'm talking out of my fanny here, just noodling.

Me too, but it's more fun than doing the same on the 2/3" scarlet.

BTW is this chart still the current sizes?

 

[Tom Lowe]

Just to be totally clear... I am in no way discounting nor overlooking how nice and ideal 645 will be for IMAX. No one really questions that at this point. I'm down for it.

I do think that James makes a couple very good points. First, tested resolutions of IMAX projection are nowhere near 8K, if I recall. It's something to do with both the acquisition lenses, the optical finish and print, and the projection lenses, in the same way that these same factors cause 35mm multiplex releases to test poorly (under 1080p resolution). Honestly I cannot remember the details or the average numbers for IMAX, though.

Another point James makes is about lenses, both the quality, and the speed. The real eye-opener for me came this June when I had a chance to shoot side-by-side comparisons using two 5D2s filming FF35 5.6K RAW timelapse on both a Panavision anamorphic Primo 25mm (the ones used on The Thin Red Line, etc!) and a Canon 50mm 1.2. No question, in terms of pure image quality (detail, sharpness), the $1,600 Canon lens smoked the $100,000 Primo!

Some Master Primes on the wider end will not cover the FF35, but many MPs will, so imagine the quality gains and speed gains lenses like those can offer. And don't count out the rehoused Nikon 14-24s either. They are the still equivalent of MPs, and could offer incredibly compact and light Epic FF35 "IMAX" rigs! :yesnod:

And finally, another thing to consider here. The FF35 Monstro actually overcranks to 100fps at 6K!!! That could be incredibly epic for IMAX films.

 

[Michael Hastings]

I just bought a Pentax 645N and their 35mm lens (older version - the new version is very rare) so when I get it I will try some comparison shots with a full frame dslr just to see where we sit with the lenses (I have access to some of the newer normal focal lengths.

Re the frame rates: It is unclear to me whether the 645 will let you window to full frame size and do the same frame rates - anybody know? Because if it doesn't you have probably convinced me to go FF35 - because I agree the high frame rates are essential!

 

[Tom Lowe]

I just bought a Pentax 645N and their 35mm lens (older version - the new version is very rare) so when I get it I will try some comparison shots with a full frame dslr just to see where we sit with the lenses.

Re the frame rates: It is unclear to me whether the 645 will late you window to full frame size and do the same frame rates - anybody know? Because if it doesn't you have probably convinced me to go FF35 - because I agree the high frame rates are essential!

Success! :thumbsup:

One thing I love on internet forums is when people keep an open mind. I know for sure that I could do a lot better in that myself. So, respect, Michael!

 

[Michael Hastings]

Success! :thumbsup:

One thing I love on internet forums is when people keep an open mind. I know for sure that I could do a lot better in that myself. So, respect, Michael!

And I want to learn how to do all that cool timelapse stuff too!

 

[Iannis Holwech]

No doubt that FF35 will be an improvement, but I think it will rather be an improvement over s35 which I always have seen as sub-par format for big screens.
I think that downplaying the IMAX quality too much is going in the wrong direction. It can easily be like trying to contributing to "dumbing down" the best image quality on the planet, and that I believe IMAX is quite able to do on their own.
IMAX claim over 100 megapixel. I pulled it down to 64mpx (9K) or even as low as 33mpx (8K).
But remember that we talk about huge screen sizes and IMAX has a big film frame to project from. They also do few prints, so it is nothing like 35mm distribution. In addition, the IMAX projectors uses a special form of vacuum technology to hold the frame flat and quiet during projection so they get more out of the frame than conventional 35mm film.

On smaller screens we will not see so much difference, but IMAX full size screens are a very different matter.
But nobody can answer this, as I wrote in my first post, before somebody does a side by side comparison.

It will also be many years before we see 8K digital projectors powerful enough to even light a conventional screen, so the best we can hope for is those Mini IMAX's with stacked DCI projectors for FF35 .

Another better place where I think FF35 will make a much larger impression than on a huge IMAX screen is in features and nature documentaries on regular size screens shot at 48fps.

Now, they do some blow up of 35mm for IMAX so it is if course possible to shoot FF35 digital and print it to film and blow it up to IMAX size/resolution , but how good that looks compared to shot 15/70 I don't know, but I guess not too good.
How Regular Movies Become "IMAX" Films

Just so people who are interested can get an idea of the complication with high resolution, here are the article posted previously in another thread;
Delivering 8K VFX Shots for The Dark Knight; 4K Was Just Too Small for Those Large-Gauge IMAX Sequences

I did some Photo-shopping on an image I found and added a FF35 frame and moved the s35 frame into the IMAX frame, just to give people an idea of the size difference. Hope it is not too inaccurate. :aureola:

Original image is here; http://www.slashfilm.com/2008/07/14/how-the-dark-knight-went-imax/

 

[Iannis Holwech]

Here are some other comparisons;

 

[Tom Lowe]

Another reason I think FF35 6K RAW is viable as IMAX is by looking at how well FF35 5.6K RAW compares with 65mm film scanned at 8K, when both images have been downsampled to 1080p with similar compression.

I have pixel-peeped the new BARAKA 8K>1080p remaster (done under opitimal conditions), and frankly, if we are talking about strictly image quality, ie clarity, detail, resolution (not dynamic range nor any artistic issues), the FF35 5.6K smokes the 65mm 8K, IMHO. It's not even close. And I could post 20 more side-by sides if anyone is interested.

65mm scanned at 8K:

FF35 5.6K RAW:

So.... if FF35 5.6K RAW smokes 65mm 5-perf, how much of a stretch is it to think that 6K RAW could potentially be cut against 15-perf?

 

[Tom Lowe]

Just so people who are interested can get an idea of the complication with high resolution, here are the article posted previously in another thread;
Delivering 8K VFX Shots for The Dark Knight; 4K Was Just Too Small for Those Large-Gauge IMAX Sequences

This article seems to be saying that the 15-perf IMAX effects shots for Dark Knight were done at 5.6K, which seems to support my case. That puts the resolution in the same ballpark with the Epic FF35.

 

[David Mullen ASC]

Yes, but remember that's 5.6K RGB, not 5.6K RAW. You'd need nearly an 8K RAW sensor to get 6K RGB resolution.

Also remember "Baraka" was shot in 5-perf 65mm, 1/3 of the size of the 15-perf 65mm IMAX frame.