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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

ER on RED...

mmost said:
I really don't want to be shooting at f/9, regardless of the other characteristics, because the lens performance is just not the same as it is at f2.8 or f4.
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I think this essentially comes down to the fact that lenses for different formats have different sweet spots.

If you mean optical aberrations, then my experience doesn't match yours. While I'm sure there are some lenses that have more aberrations at narrow apertures than wide, I would think they are a rare exception. All my lenses get sharper and sharper as they're stopped down. A few are diffraction limited wide open (f/4), like the Canon supers.

If you mean diffraction instead of aberrations, then I would not agree. For a given 2K display size, diffraction scales with the f/number+format size. For RED ONE 2K Windowed, f/9 causes a visible loss of contrast at medium spatial frequencies. For RED ONE S35, f/9 only causes a visible loss of contrast at higher spatial frequencies (tiny details/high resolution, but you can certainly see it at 4K). f/9 on FF35 has an effect only at very high spatial frequencies: not enough to be noticed at 4K. It takes f/14 to get the same amount of diffraction in the final output.

If we judged the amount of diffraction by what we see in a 2K digital projection, all of these would have the same amount of diffraction, that is, practically none:

  • RED ONE 2K windowed: 25mm f/2.8
  • RED ONE 4K: 50mm f/5.6
  • FF35: 80mm f/9
  • 645: 120mm f/14

I think you will find that all the diffraction calculators back this up when set to the same display size, e.g. 2K theater.

You can see it from the point of view of physical aperture (where each lens, even the 120mm f/14, has 9mm aperture), so the "hole in space", which causes diffraction, is the same. If each format were enlarged by a factor of 10, it would be clear that f/14 is worse than f/9 is worse than f/5.6, etc. But they aren't enlarged the same, because some start out larger to begin with, like 645. It turns out that the enlargement factor perfectly scales with the f-number.

Similarly, if you take an aperture that would cause very visible loss of contrast and softening due to diffraction, such as 3.64mm, then you will see similar diffraction in all the formats:

  • RED ONE 2K windowed: 25mm f/7
  • RED ONE 4K: 50mm f/14
  • FF35: 80mm f/22
  • 645: 120mm f/33

The diffraction at f/7 on 2K windowed will be just as bad as the diffraction of f/33 on 645, when both are projected at 2K. (The OLPF and demosiac would throw off the results slightly, so Scarlet 2/3" 3K would be a better comparison than RED ONE 2K windowed, so that it's easier to separate diffraction MTF from OLPF MTF.)

There are some things that do scale with f-number but do not scale with physical aperture. Phase detect autofocus systems, for example. And within the discussion of a fixed format size (e.g. *only* S35 or *only* FF35), f-number accurately scales with many things. But as soon as you step back to look at the bigger picture of multiple format sizes, f-number doesn't cut it.

Diffraction, like DOF and total amount of light, scales with the physical aperture, not the size of the format medium or f-number, AOTBE.
 
Daniel Browning said:
I think this essentially comes down to the fact that lenses for different formats have different sweet spots......
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I'm going to take a breath for a moment and thank you for what has to be the most fascinating discussion I've been involved in on this forum.

Ok, I'm breathing again.

To return to David's focus on practicality, I think we're headed into some interesting times. There is clearly a focus (pardon the use of that term) on the part of Red to improve their technology and their products' utility, and one solution they are adopting is physically larger sensors. This in turn presents a need for new lenses to properly cover these formats, which in terms of cine lenses is not in great supply. The rebarreled still lenses that have been the mainstay of large format work - particularly Vistavision - are not well suited to the production techniques commonly used in single camera dramatic productions, which can typically involve lots of camera movement, choreography, and resultant rack focusing. So what I'm feeling is that the larger sensors are likely to be used in a windowed mode at first, at least for television production, which will allow the use of current 35mm glass, but which will also minimize the potential enhancements that a larger sensor can deliver. In that scenario, we're counting on new technology to provide an increase in sensitivity to allow the same size receptor to provide better performance. How all of this is delivered, and how the lens situation works itself out, should make the next year or so very interesting indeed.

Daniel, thanks again for your participation. I'm still digesting some of what you wrote, and that's a very refreshing feeling.
 
Thanks, Mike.

mmost said:
How all of this is delivered, and how the lens situation works itself out, should make the next year or so very interesting indeed.
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I agree. Lens availability is the biggest issue in my mind, as David put it succinctly:

David Mullen ASC said:
I think the bigger issue will be what sort of optics come into widespread use for FF35 filmmaking, or whether more people will just use S35 cine lenses and crop the sensor most of the time.
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I just watched the episode on Hulu, so I can't really say much about the image quality. It looked as good as any of the other episodes on Hulu. Here's my constructive criticism, though. Skew on whip pans is very distracting to me. Did no one else notice it? Also, there was a scene where Noah Wyle is in an elevator with a patient and Angela Bassett sees the blood on his sleeve as the doors are closing. The long lens, rolling shutter, plus the speed of the doors closing made the doors look like they were angled. Pulled me right out of the story because it didn't follow reality. Just my experience and opinion.

Please have options for both global reads and side to side reads on the new sensors.
 
mmost said:
I'm going to take a breath for a moment and thank you for what has to be the most fascinating discussion I've been involved in on this forum.

Ok, I'm breathing again.

To return to David's focus on practicality, I think we're headed into some interesting times. There is clearly a focus (pardon the use of that term) on the part of Red to improve their technology and their products' utility, and one solution they are adopting is physically larger sensors. This in turn presents a need for new lenses to properly cover these formats, which in terms of cine lenses is not in great supply. The rebarreled still lenses that have been the mainstay of large format work - particularly Vistavision - are not well suited to the production techniques commonly used in single camera dramatic productions, which can typically involve lots of camera movement, choreography, and resultant rack focusing. So what I'm feeling is that the larger sensors are likely to be used in a windowed mode at first, at least for television production, which will allow the use of current 35mm glass, but which will also minimize the potential enhancements that a larger sensor can deliver. In that scenario, we're counting on new technology to provide an increase in sensitivity to allow the same size receptor to provide better performance. How all of this is delivered, and how the lens situation works itself out, should make the next year or so very interesting indeed.

Daniel, thanks again for your participation. I'm still digesting some of what you wrote, and that's a very refreshing feeling.
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Ummm is it me, or did mmost basically say "it's so nice to speak with someone on here who is not an idiot".

Ouch. What hurts worse is that he may be right.. At least where I'm concerned.

:sarcasm:

Jay
 
Skew if not excessive doesn't bother me any more than the blur itself in a whip pan, which is also a motion picture artifact, or judder, or lens flares, some grain, negative cut sparkles, the actual "cut" in movies . . .

As for David Mullen's practicality post - of course he's right, again. I posted this a few months ago:

Oh, here's why you get effectively a shallower depth of field with larger sensors/formats:

Let's say you are shooting with a 35mm movie sized sensor camera, like an Arri 235 or a RED. You have a nice head and shoulders shot of your lead actor, who is Mickey Rourke (seems to be the actor of the day). You're using a 30mm lens, or thereabouts, which is about a "normal" lens for that format.

Now, you pull out your "full frame" Scarlet, or Epic, which has a sensor about the same size as your old Nikon still film camera. To get that same head and shoulders shot of Mickey - that is, keeping the same head and shoulders composition of him - you have to use something like a 50mm lens. Your depth of field is shallower because you have to use a longer lens. The longer 50mm lens is "normal" - not telephoto or wide angle - for the full frame sensor.

And that's a bitch, because boy howdy it's already hard to keep actors in focus with 30mm lenses in 35mm 4 perf at 2-2.8. Even F4. Just watch Keifer Sutherland's ears have all the focus in 24, but not his eyes, on some shots!! Gadzooks. So going to a larger sensor is going to be that much more difficult - unless you can stop down, which means that for me, I'm really going to need a faster full frame sensor. Like, shoot all the interiors at 5.6-8 split. So, ASA 1600 would be nice. Fingers crossed.
 
Douglas Underdahl said:
So going to a larger sensor is going to be that much more difficult - unless you can stop down, which means that for me, I'm really going to need a faster full frame sensor. Like, shoot all the interiors at 5.6-8 split. So, ASA 1600 would be nice. Fingers crossed.
Click to expand...

This is a circular solution though. By solving the focus problem you also simultaneously remove most needs for a FF35 sensor. Which also solves your focus problem by allowing you to shoot S35 again.

Improving the ASA directly improves the latitude of the sensor.

If RED did create larger format sensors so that it could make higher sensitivity sensors then increasing the sensitivity of the sensor also simultaneously removes the need for a large sensor. :D

Which is why I still want a 3k S35 sized sensor. Nice big fat pixel sites.
 
  • RED ONE in 4K mode, 640 ISO, 50mm f/4.0: aperture is 12.5mm
  • RED ONE in 2K windowed, 320 ISO, 25mm f/2.0: aperture is 12.5mm

If both were projected at the same size, then both would have:

  • The same field of view.
  • The same depth of field.
  • The same total amount of light.
  • The same aperture (12.5mm).
  • The same amount of noise.
  • The same "brightness".
  • Different resolution.
  • Different available frame rates.
  • Different compression (maybe).
  • Different read noise (maybe).

So, moving up from 2k to 4k, to maintain depth of field, I would have to iris down two stops, but only

A) double the amount of light on the set, or

B) "push" the asa from 320 to 640.

And, moving from s35 to FF35, to maintain depth of field, I would also have to

A) double the amount of light on the set, or

B) push the asa from 640 to 1280.

So for this to work, I would need a FF35 sensor from RED that was higher. I would think, as I stated in my last post, that 1600 would be a nice asa, one that would allow us to cope with the difficult, shallow depth of field when working with actors in most dramatic, narrative features. As David says, most DPs working today shoot about a 2.8 at asa 500, so going to 320 makes for harder job for the focus puller (set the lens at 2-2.8 split).

If we don't get that faster sensor, then for most interior work, FF35 will be less attractive for narrative feature work.

Doubling the amount of light on the set is expensive, time consuming and often uncomfortable for actors. Often it just isn't possible, given time and budget constraints, and it will also have the tendency to overpower practicals, street lights, and monitors on set that who's output simply cannot be increased. I would think that the 2/3 chip in the Viper with it's increased depth of field over 35mm sized sensor cameras was one reason Fincher used it to shoot ZODIAC for all those city night scenes.

When David uses the word "practical", it just might behoove us to make an attempt to understand the realities of feature filmmaking rather than use technical studies to try to justify other approaches not based in on set realities. The man has shot 22 features.
 
Gavin Greenwalt said:
This is a circular solution though. By solving the focus problem you also simultaneously remove most needs for a FF35 sensor. Which also solves your focus problem by allowing you to shoot S35 again.

Improving the ASA directly improves the latitude of the sensor.

If RED did create larger format sensors so that it could make higher sensitivity sensors then increasing the sensitivity of the sensor also simultaneously removes the need for a large sensor. :D

Which is why I still want a 3k S35 sized sensor. Nice big fat pixel sites.
Click to expand...

Not sure I understand your "circular solution" argument. But yes, I don't see any need for a larger sensor, unless it has increased sensitivity AND wider latitude, which are not the same. If I get wider latitude from the 4k sensor, that's great. But if I have to go to a FF35 sensor to get more latitude, then it will have to be a considerable increase in latitude to offset the problems caused by shallower depth of field from the larger sensor. Unless the sensor has higher sensitivity too, which lets us stop down and regain that depth of field.

Shallow depth of field is interesting and sometimes useful, but it's become the latest fad and for my work, actor's freedom is much more important. And besides, there are times when I want lots of depth of field. It can be stunning - check out CITIZEN KANE.
 
Sounds right to me, Douglas.

Douglas Underdahl said:
If we don't get that faster sensor, then for most interior work, FF35 will be less attractive for narrative feature work.
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If the FF35 can be rated ~2.6X faster and still get the same noise as RED ONE, it will have achieved equal DOF and equal noise. I'm confident that will happen.

The biggest factor that will affect narrative feature work, of course, is (the lack of) FF35 cine lens availability.

Douglas Underdahl said:
I would think that the 2/3 chip in the Viper with it's increased depth of field over 35mm sized sensor cameras was one reason Fincher used it to shoot ZODIAC for all those city night scenes.
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3-chip cameras have three times the sensor area without any change in DOF. FF35 has 2.6X times the area, but DOF changes with it. For that reason, I think 3-chip cameras will always have superior sensitivity and noise when compared to any other camera at equal DOF. (Though there are plenty of other things to dislike about 3-chip.)
 
3-chip pros:
  • Three times the area means higher sensitivity,
  • lower noise,
  • without changing DOF (i.e. deep DOF)
3-chip cons:
  • 2/3" is the largest practical size.
  • Lens compatibility.
  • Sometimes thinner DOF is desired.
  • Longer flange focal distance.
  • Prism artifacts.
  • Color is not as accurate as CFA.

Color accuracy (metamerism) is an important difference. Although 3-chip color is accurate "enough" for most purposes, it can never be as good as a CFA-based system.

The fundamental reason is that a prism splits light in a way that is different from human vision. Even with heavy processing it can't match all colors to the way a human sees, and there is no way to modify the prism to more closely match the ideal spectral response.

That is, you can't choose a certain slope over the certain portions of the visible spectrum. For example, so that the green channel gets 0.5 of a certain part of the spectrum (say, 598nm) as well as 0.2 of another part. Once that light is filtered by the prism (e.g. the entire slope of the visible spectrum from blue to red is flattened to a single value for "green"), there is no way to go back and get it.

CFA, on the other hand, can be tuned for much greater similarity to human vision.

EDIT:
USlatin said:
But wouldn't a CMOS with microprisms that catch 100% of the light then make use of the same amount of light a 3-CCD would use given the same lens was mounted on both setups?
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Yes, if the microprism-based sensor had three times the area, it would be the same amount of light, but I don't know how or if it could be done. Despite Sony's patent last year, microprisms still seem to be a long way off (even for a sensor of the same area).
 
Oh... I was under the impression that Red had something like that going on on their CMOS. Long way off? That sounds a bit discouraging. Dang... Serious? Do you think we might be surprised by Red or is that 100% out of the question?

Thanks about the explanation of color reproduction and the impact of the prism! That really means 3-CCD will eventually be phased out. Noise will continue to drop across the board as electronics get more efficient, but the laws of optics won't change.

So the 30mm x 15mm S35 DSMC sensor will have a total area of 0.697, call it 0.7 inches. Whereas a 3-CCD 2/3 chip has a full inch. Then again FF35 DSMC will have 1.34 square inches.

Does the F35 use S35 sized 3-CCDs?
 
USlatin said:
Do you think we might be surprised by Red or is that 100% out of the question?
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I don't know, but my guess is that the technology will be perfected sometime between Jericho and Blade Runner.

There is a lot of lower-hanging fruit to pick first, such as reducing read noise and simulating increased full well capacity for more dynamic range.

USlatin said:
That really means 3-CCD will eventually be phased out.
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I don't think so. Advancements in technology can only reduce read noise; photon shot noise will always be limited by the amount of light, and there is little room for improvement there, so 3CCD will always have an advantage for a given sensor size. It may dwindle for applications where larger sizes are acceptable, but there will always be applications where small size is vital.
 
So... I just got back from vacation and caught last week's ER, which I assume was also shot on RED (wasn't it the final 6 episodes?).

Did anybody notice the hand-held shot of Carter running in to the ambulance bay seemed to exhibit sme significant skew? (the ambulance seemed to compress/stretch with the rapid cam movement).

It also so happens that the scene was shot with what seems to be a relatively low shutter angle. Any thoughts on how much of the shutter angle choice was to convey a specific mood (which the scene seemed to call for), versus to attempt to reduce the skew?

-Steve
 
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