Advantages/Disadvantages of aspect ratio/resolution changes

[Stelios Contos]

There are two questions I'd like to more about. Links, images and lengthy explanations are welcome.

 

 

1: In film or digitally what would be the benefits of changing Super 35mm aspect ratio to 35mm aspect ratio or any ratio that is smaller than super35mm?

 

2: What if I shoot digitally HD on super 35mm at 16:9 AR, then what are the pros&cons of aspect ratio changes & if lowering an aspect ratio originally shot at a higher higher AR & resolution would result in supersampling the master copy or render?

 

thnks,

 

SP

[Tyler Purcell]

Welcome to the forum!

 

On film; Super 35mm is the same ratio as academy (1.33:1 or 4:3). Super 35mm is just a slightly larger image, on film using up the space of the soundtrack.

 

In the digital world, the terminology is skewed towards digital cinema projection. So cameras produce 2k and 4k images which are 1.85:1 aspect ratio or WIDER then standard 1.75:1 (16:9) HD.

 

There are no other aspect ratios available without cropping the imager of MOST S35 cameras. So either you crop it on the sides to get 1.75:1 or even 1.33:1 (4:3) if thats your thing. Or you crop the top and bottom to get 2.40:1. The other option is to run 1.3x anamorphic lenses on a 1.85:1 aspect ratio S35mm imager and be done with.

 

One big side note, some cameras have old school 4:3 imagers in them (Alexa 4x3 for instance), but they are generally only used for 2X anamorphic shoots to achieve 2.40:1 wide screen without cropping. Most of the cameras today are formatted in either 1.75:1 or 1.85:1 NATIVE, even though there isn't much difference in pixel count between those two resolutions.

[Stelios Contos]

So, Tyler, If the a project was shot using the Alexa's 4x3 ratio to achieve 2:40:1 does that mean the final project (if shown in theaters or @ home) would fill up the whole screen as 1.75:1 does or would theaters & home tv sets still be cropped on top & bottom?

 

Also, side note.

 

Anyone, what would be the best way to achieve the highest possible resolution but still get 4:3 Aspect R?

 

The first thing that comes to mind is to mask off a monitor and record in the highest resolution available.

 

Cheers Tyler.

[Brian Drysdale]

How scope pictures are displayed depends on each theatre. Traditionally the screen tabs would move out. so that the height more or less remains the same, but the picture on the screen would be wider, multiplexes can tend to use the full screen width foe 1.85;1 so that the picture height is reduced, although some seem to do a combination of a slightly wider screen and slightly reduced picture hieght.

[Landon D. Parks]

The only real 'advantages' of aspect rations are that they fit your artistic style. The exception might be true anamorphic 2.40:1, also known as cinemascope. That ratio, when shot correctly produces a certain type of lens flare and overall look, and can generally result in a sharper image since more of the negative is being used.

 

I'd say in most cases, even most modern 'scope' movies are shot in either 16:9 or 1.85:1 (depending on the camera and rather it's film v digital), and then just cropped in post. Never shot anything anamoprhic, but my understanding is that the lenses are older, heavier, and harder to shoot with. That is just second-hand knowledge though, so take it with a grain of salt.

 

I know my GH4 can shoot native anamorphic via an anamorphic lens, and I know a few companies are starting to come out with Anamorphic adapters and even lenses... But that is a whole other subject.

 

1.85:1 aspect tends to be more dramatic, whereas 2.39:1 tends to be more epic and cinematic. Rarely do you find a romantic comedy shot at 2.39:1, just like you rarely find a blockbuster shot at 1.85:1.

 

16:9 and 4:3 are digital video specs and not cinema specs. If you are releasing in theatres via a DCP, you'll need to conver 16:9 to 1.85:1 for scope spec in DCI. My understanding is that DCI permits 16:9 with black bars, but that just looks weird to me, and I'd rather take a 1920x1080 image and slightly upscale it to 2048x1080 to get s 1.85:1 native ratio.

Edited April 29, 2016 by Landon D. Parks

[Brian Drysdale]

So, Tyler, If the a project was shot using the Alexa's 4x3 ratio to achieve 2:40:1 does that mean the final project (if shown in theaters or @ home) would fill up the whole screen as 1.75:1 does or would theaters & home tv sets still be cropped on top & bottom?

 

You'd need to use an anamorphic lens if using the 4 x 3 in the Alexa for scope..

[Tyler Purcell]

So, Tyler, If the a project was shot using the Alexa's 4x3 ratio to achieve 2:40:1 does that mean the final project (if shown in theaters or @ home) would fill up the whole screen as 1.75:1 does or would theaters & home tv sets still be cropped on top & bottom?

Cropped top and bottom. See, television is 1.75:1 and the theaters are 1.85:1.

 

With film, there is an encode and decode lens for 2.35:1 (anamorphic) which is used on the camera and projector. So when the projectionist changes lenses, the screen would need to be widened.

 

With digital, there are no decoding lenses. So you take the anamorphic or cropped image from the camera and push it through as black bars at the top and bottom of the 1.85:1 native image aspect ratio.

 

So again, television's are 1.75:1 aspect ratio. Theaters are 1.85:1 aspect ratio and you can put mattes on the image to get 2.40:1 aspect ratio. No matter what however, there will be bars on the top and bottom for any aspect ratio OVER 1.75:1 and bars on the sides for any aspect ratio UNDER 1.75:1 on standard televisions.

 

Anyone, what would be the best way to achieve the highest possible resolution but still get 4:3 Aspect R?

If you want to shoot 4:3 aspect ratio, you're always going to be loosing some resolution. It may not be the camera, but it will be the projection and distribution methods.

[Stelios Contos]

For all who decided to give information towards my question/topic, thanks sincerely.

 

Landon: Would there be quality loss associated with the upscale from 1920x1080 to 2048x1080 to get that 1:85:1 native ratio?

 

Brian: Could you expand on why an anamorphic lens is needed to shoot 4x3 to get cinemascope and you couldn't use a spherical lens and record at a different AspectR on the Alexa to gain some quality for example...if that sounds right?

 

Thanks for the knowledge Tyler.

[Landon D. Parks]

Landon: Would there be quality loss associated with the upscale from 1920x1080 to 2048x1080 to get that 1:85:1 native ratio?

 

Yes, there is a slight quality loss. If you're material is natively 1080p, you'll need to upscale it by about 128 horizontal pixels. It also means your top and bottom framing will be slightly cropped, but again only by about 60 pixels on top and 60 on bottom.

 

Most movies shot 1080p that are aimed for cinema upscale, since the amount is so slight that it's barely noticeable.

 

Important: The one thing to be careful of is to ensure that you upscale before adding text and graphics. The text and graphics should be done at the released resolution of 2048, not at 1080p. Upscaled text and things will be apparent.

 

Now if you're wanting to get a 2.39:1 DCI scope ratio from 16:9 1080p, you can simply up-convert by adding the 128 pixels horizontal. You'll then need to account for the top/bottom crop which will be substantial. Mostly, if you're aiming for a 2.39:1 release, you'll frame for that when shooting, using only the center 2.39:1 portion of your camera (you'll record the whole area of course, but your framing will be for the that center portion only). This can be achieved in most monitors that will display frame guidelines while shooting.

 

The other option if you're not aiming for cinema is to just crop the 1080p by placing the 1080p footage in a 2.39:1 1080p timeline, and scaling it back up to match the original resolution.

 

In terms of software, I have no idea how this is done in Premiere, Avid, or Final Cut. In Davinci Resolve, if you're aiming for a DCI-spec 2.39:1 ratio, you'll:

 

1. Create a new project

2. Chance timeline resolution to '2048x858 DCI Cinemascope' (it's a preset).

3. You'll then drop your 1080p clips from the media pool into the timeline. They will import as 1080p within the 2048 container, meaning they will appear to only use the center portion of the frame.

4. Click on the clip on the timeline and go to the inspector, find 'scaling'.

5. Change scaling to 'fill'. Magically, the clip will fill the 2048x858 timeline and you're done.

 

It's similar if you're wanting to just crop 1080p to 2.39:1.... Instead of changing the timeline resolution in step 2 above to DCI, just type in '1920' in the horizontal pixel box, and '805' in the vertical pixels box.

 

In terms of 1.85:1 (your original question):

 

There would be some loss of quality, but not much. And only if you choose to go DCI-compliant 1.85:1, which I believe is 2048x1080. You can similarly change the aspect ratio of 1080p to 1.85:1 without doing the up-convert by simply cropping the timeline to '1920' horizontal by '1,013' pixels high. Effectually, you'll loose several pixels on the top and bottom, but won't have any resolution issues due to up-scaling.

 

Another important note: Many people might well just apply a 'black' mask on the top and bottom to 16:9 footage to get scope or 1.85:1 'look'... While this will work, it's much better to work natively in your format of choice, rather than relying on letter boxing. Many places will not accept a letter-boxed or pillar-boxed original for distribution.

Edited April 30, 2016 by Landon D. Parks

[David Mullen ASC]

I find the original question very confusing...

 

I think one has to clearly separate the origination issues with the mastering issues for digital cinema release and home video / broadcast.

 

2K and 4K DCP's for cinema release are 1.85 and 2.40, so if you wanted a 4x3 (1.33) release, it would probably be pillar-boxed (side matted) inside a 1.85 DCP.

 

You could shoot with a 4x3 Alexa as "Ida" did for a 1.33 release.

 

DCP's use max height for 1.85 (1080 pixels for 2K and 2160 for 4K) and max width for 2.40 (2048 pixels for 2K and 4096 pixels for 4K). This means that for a 1.85 DCP, the pixel dimensions are 1998 x 1080 for 2K and 3996 x 2160 for 4K.

 

And even though a 2.40 DCP does not have black bars in the file, many new screens today are built with 1.85 dimensions, so 2.40 movies are shown with black bars at the top & bottom of the screen -- those bars aren't in the DCP, that's just the image not filling the screen top & bottom. Personally I prefer screens to be 2.40 with curtains / black masks that come in to reduce the width for 1.85 movies -- CinemaScope was meant to be a wider image on screen, not a shorter one.

 

If you shoot in 2K 16:9 mode on an Alexa, recording in ProRes, your recording is 2048 x 1152 pixels. If you shot in HD 16x9 mode, you'd record 1920 x 1080.

 

So if you shot 2K mode, you'd slightly downsample the image to create a 1998 x 1080 1.85 2K DCP, and also downsample slightly to create a 1920 x 1080 HD master (with 1.85 letterboxing if you want that.) Now if you wanted to get fancy, you could create your own frame line guides so that your 1.85 composition was within a 1998 x 1080 area of the 2048 x 1152 recording, so you could just extract the 1998 x 1080 area for the 1.85 DCP with no scaling. But to make the HD master, you'd still have to deal some resampling to fit your 1.85 composition within 1920 x 1080.

 

If you shot HD 16x9 mode, you'd have a 1920 x 1080 recording, so to make a 1.85 2K DCP, you'd crop the top & bottom to 1920 x 1038 pixels and then upsample this to 1998 x 1080 pixels.

[David Mullen ASC]

You could record 4x3 with the Alexa and shoot with spherical lenses and crop to 2.40 -- I believe this is how Roger Deakins shot his Alexa movies for 2.40 release, until he started recording Open Gate, which is 1.55 : 1.

[Landon D. Parks]

David is right, I was wrong about the actual pixel dimension of 1.85:1 DCI. I never frame for that, always either shooting for 2.39:1 or 16:9. Frankly, 1.85:1 is so close to 16:9, I'd probably not bother with it unless I was planning on something going to cinema. Even then the ratios are so close that I'd probably still frame for 16:9 while shooting.

Edited April 30, 2016 by Landon D. Parks

[Landon D. Parks]

Personally I prefer screens to be 2.40 with curtains / black masks that come in to reduce the width for 1.85 movies -- CinemaScope was meant to be a wider image on screen, not a shorter one.

 

Use to, I would have said I liked 1.85:1 screens better (in fact, many years back I think I made that exact same argument on a similar thread). However, having now worked with the 2.39:1 ratio, I find myself using more than anything else, and really loving it. As of today, I'd love for there to be cinema-scope screens too, as I feel that they could fen-angle the sensors in the projectors to have better resolution at 2.39:1 by reshaping them.

 

Though, that probably won't happen, and I imagine the 16:9 digital chip is here to stay, this resulting in the taller 1.85:1 ratio to match the projector chips.

Edited April 30, 2016 by Landon D. Parks

[Stelios Contos]

Everyone has answered my questions & some.

Landon, thanks for that bit about upscaling first w/o the titles or it would be noticeable from previous exposure to text this I know can true.

 

David. When you said:

2K and 4K DCP's for cinema release are 1.85 and 2.40, so if you wanted a 4x3 (1.33) release, it would probably be pillar-boxed (side matted) inside a 1.85 DCP.

 

Do you mean that regardless of what the aspect ratio of the finished project comes it at (E.G: 1.33) the cinema would display the 1.33 pillared boxed footage wrapped in a 1.85 or 2.40 AspectR?

 

P.S: I understand what you were saying about the cinema screens different Aspect R.

 

Also,David, by one shooting 4x3 on the Alexa with a spherical lens they would be still taking full advantage of the film/sensor so and the end of the tunnel there Master would for DCP would be a 2.40 release?

Please expand on the relationship between the resolution of 4x3 AspectR & its resolution & how for the final projection we get to that 1.85 or 2.40 cinema experience?

[Tyler Purcell]

You're still a bit confused.

 

Digital cinema projectors have a 16x9 1.75:1 aspect ratio imager, but the delivery format is scaled to make 1.85:1 the "base" aspect ratio.

 

When a movie is at a different ratio, the screen mattes are changed to compensate.

 

For 2.40:1, the top and bottom would change so there wouldn't be black bars at the top and bottom.

 

For 1.33:1 the right and left would change so there won't be black bars on the sides.

 

There are TWO ways to shoot for different aspect ratios... One is to use lenses which compress and expand the image (anamorphic) and the other is to simply crop the image in post production. When you use anamorphic lenses, you are using the full potential of the imager, all of it's pixels, to create a wider image.

 

When you crop in post production, either from the top/bottom or sides, you are loosing pixels. Most cameras have a native ratio of 1.75:1 16:9. This is because most people shoot in that ratio OR narrower. So it only makes sense for efficiency, to make the imager the same size as MOST people will want when shooting.

 

If you release your movie in the same native aspect ratio as the camera, you will then be using the full imager. Otherwise, you will always be cropping.

[Brian Drysdale]

To make full use of the pixels in the camera for scope, you'd use the anamorphic lens with the 4 x 3 sensor (which is roughly simllar to how they're used on 35mm film cameras), otherwise you're cropping, which uses less pixels.

 

http://www.arri.com/news/news/alexa-plus-43-for-anamorphic/

[David Mullen ASC]

I'm saying that for digital cinema release, you'd have to place your 1.33 image inside a 1.85 DCP.

 

Of course, you could release it in a 35mm film print that was in the old 1.37 Academy format... but you'd have to show it in art house theaters and museums that had the right focal length lens to fit Academy onto the screen. Most first run theaters with 35mm projectors only have lenses to fit 1.85 images on the screen using a 1.85 mask in the projector to matte the 4-perf 35mm print image, or they have anamorphic (scope) projector lenses to stretch the image to fill a 2.40 screen.

 

So the problem with bringing in a 1.37 Academy print is that even if the theater could pull out their 1.85 mask in the projector and replace it with a less-cropped 1.37 mask, the taller image would spill over the top & bottom of the 1.85 screen unless the theater switched lenses on the projector to shrink the image to fit. Because of this, some 1.33 or 1.37 movies in the past, or re-releases of old 1.37 Academy movies, had to be printed reduced to fit inside a 1.85 area of the 35mm print so they could be shown in first-run theaters.

 

You could shoot with a 4x3 Alexa and frame for cropping to 2.40 just as you could before when shooting in 4-perf Super-35 film, which is also 4x3 -- but either way, you are cropping to get a 2.40 image and thus losing vertical resolution.

 

Or you could shoot with anamorphic lenses and squeeze a 2.40 image into most of the 4x3 sensor area (or film area) -- a 2X squeeze means that you are using a 1.20 : 1 area to get a final 2.40 image.

 

4x3 aspect ratios, or aspect ratios in general, do not have resolutions. They are just ratios between height and width. Shooting 4x3 on a 4x3 Alexa has a certain resolution in terms of the sensor area used and then in terms of the recording format (2.88K ARRIRAW versus 2K ProRes), but using a 4x3 area of a different camera would give you different resolutions.

[David Mullen ASC]

Actually a DCI-complient projector has a chip that is either 2K (2048 x 1080) or 4K (4096 x 2160) -- that's a 1.896 : 1 aspect ratio. (And some digital cameras have sensors close to this native shape, the Red cameras and the Sony F65 mainly.)

 

You can see the specs for a small 2K Barco projector here for example:

https://www.barco.com/en/Products/Projectors/Postproduction-projectors/2K-digital-postproduction-projector.aspx#!specs

 

This way 1.85 movies can use maximum pixel height (1080 or 2160) and 2.40 movies can use maximum pixel width (2048 or 4096).

 

And many theaters today do not have moveable black screen masking or curtains, so if the screen is 1.85-shaped, then 2.40 movies have visible black bars top & bottom (not baked into the image, it's just the projected image not filling the physical screen) and if the screen is 2.40-shaped, then 1.85 movies have black bars visible on the sides. And definitely most would show a 1.33 image with black bars on the sides if they can't bring in the curtains or the screen masking.

 

You're still a bit confused.

Digital cinema projectors have a 16x9 1.75:1 aspect ratio imager, but the delivery format is scaled to make 1.85:1 the "base" aspect ratio.

When a movie is at a different ratio, the screen mattes are changed to compensate.

For 2.40:1, the top and bottom would change so there wouldn't be black bars at the top and bottom.

For 1.33:1 the right and left would change so there won't be black bars on the sides.

There are TWO ways to shoot for different aspect ratios... One is to use lenses which compress and expand the image (anamorphic) and the other is to simply crop the image in post production. When you use anamorphic lenses, you are using the full potential of the imager, all of it's pixels, to create a wider image.

When you crop in post production, either from the top/bottom or sides, you are loosing pixels. Most cameras have a native ratio of 1.75:1 16:9. This is because most people shoot in that ratio OR narrower. So it only makes sense for efficiency, to make the imager the same size as MOST people will want when shooting.

If you release your movie in the same native aspect ratio as the camera, you will then be using the full imager. Otherwise, you will always be cropping.

[Tyler Purcell]

It's hard to find exact specs on the digital cinema projector imagers. The manufacturers list DCP compliant max resolution, which is an electronics spec, not necessarily imager spec. Like a cameras imager that has "effective" pixels, DLP imagers can do the same thing. This is why you can send them multiple aspect ratio's and the outlying information is non-active pixels. In the past, all the cinema DLP imagers have been 16x9 with inactive pixels. They do this so they can move the image up and down/left and right electronically, for calibration purposes.

 

I didn't know about the immovable curtains. I haven't personally noticed that before. If I ever go to the movies again, I will make a point to pay more attention. I know the last scope movie I saw projected digitally, the matte fit it perfectly. Of course, I see film prints all the time and those always have perfect screen mattes.

[Landon D. Parks]

And many theaters today do not have moveable black screen masking or curtains, so if the screen is 1.85-shaped, then 2.40 movies have visible black bars top & bottom (not baked into the image, it's just the projected image not filling the physical screen) and if the screen is 2.40-shaped, then 1.85 movies have black bars visible on the sides. And definitely most would show a 1.33 image with black bars on the sides if they can't bring in the curtains or the screen masking.

 

Sadly, this is true. Since most screens are now 1.85:1 and don't mask, it can actually be pretty annoying watching a cinemascope film on those screens. It's for that reason alone I avoid theaters that have taken that route. Locally I have an 18 screen AMC (built last year) and an 18 screen Showcase Cinema De Lux... I'll nearly always see the film at the De Lux for the precise reason they still mask the screen. Frankly, I'm not a fan of 'grey bars' - which when projected onto a massive screen is what they look like. The De Lux also has nicer seats, but that is not the subject of this thread. Though both theater's have 1.85:1 screens throughout, at least De Lux bothers to mask them.

 

The funny thing is, The Showcase recently retrofitted (well, within the past 6 years) their screens. They use to have 2.39:1 screen in a lot of their auditoriums. Then they got a "LieMax' screen and they replaced ALL their screens with 1.85:1.

Edited April 30, 2016 by Landon D. Parks

[Stelios Contos]

Well, thanks everyone.

Im out of questions and I know more than when I began.

 

cheers.