GH4 help me with anamorphic logic in a 4k world

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wwjd

Well-known member
Let's assume I am making a full blown movie to be projected at a 4K equipped theater, desired aspect ratio of 2.40:1. NOT relying on the lens of the projector, but reating a 4096x1707 in the file.

ALL the silly little things aside - oval bokeh, horizontal lens flares, DOF changes etc.... - I'm trying to work through the possible logic of squeezing down anamorphic shot 4k digital in post.

If my goal is 4096 x 1707 (2.40:1 aspect roughly) Am I REALLY gaining better resolution of the image by shrinking 2160 down to 1707, post process of the anamorphic image? Or is it a wash?

I can fathom that 2160 IS more pixels, more detail than shooting normal and cropping down to 1707, but I'm trying to grasp if that extra detail translates DOWN INTO the 1707 from 2160 when squished in post?

Thoughts, ideas, comments, anyone shooting anamorphic on GH4?
 
and a corollary: since technically, anamorphic pushes MORE scene in from the left and right sides... is that REDUCING resolution? putting more info across less pixels, if ya follow?
 
Unless looking for anamorphic artifacts avoid the hassle, plus expense, & just crop.

Been on two extended national commercials recently that delivered in 'Scope & though we had full sets of anamorphics, filmed at least half on sphericals.
 
Let me try and grasp the sparrow by the tail (a t'ai chi reference :smile:)

Don't know the technical answer to your question but it crosses my mind occasionally while shooting. However, to my eye the process of anamorphic shooting is not a matter of how many pixels or lines are involved, especially when in comes to 4K, where there is already an abundance of information. Rather, it is a particular aesthetic that cropping a 16:9 image does not achieve (I appreciate that C4K is slightly wider).

To me there is an added sense of depth in the image, with the linear perspective in the image seeming more detailed. Sort of the opposite effect of a telephoto lens where the background is compressed. Here the background sits more naturally and not so flat. This is of course very subjective, but what is not is the additional character that an anamorphic lens or adapter can add to the overall image. I do like the clean look of the SLR Magic Anamorphot, but I know other people love the unique characteristics of other systems.

So basically I work with what I've got and don't worry too much about the math.
 
I just read Bern's post after submitting my reply. Yes, it is less hassle to just crop and for commercials and such he's right, especially if budget issues get in the way. I'd even warrant that some "narrative" stuff is delivered the same way. However, I stand by my feelings, especially when it comes to cinema. It's a personal preference and I'm willing to put up with additional work involved. YMMV.
 
Yeah, seems a hassle. Just wondering.... you know how crunching 4k into 1080HD seems to deliver much better detail out of the HD, than regular HD.... wondered if that effect works going Anamorph 2160 down into 1707? USING the extra verticle pixels detail instead of cutting them off. I'll probably just save my money - just wondered if there is some science there to extract more of the whole 4k in a 2.40:1 aspect.

Anyone else chime in here?
 
stoneinapond said:
It's a personal preference and I'm willing to put up with additional work involved. YMMV.
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Anamorphic (especially 2x) has a special look that I love, & used the term "artifact" as a description, not a detraction.

Even own a Letus Anamorphx 1.33x adapter that I picked up for a high frame rate job on the Alexa but don't use often (so should sell).
 
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A great anamorphic lens will give your video footage a genuinely cinematic look that cannot be simulated by cropping an image shot by a standard lens. Scaling the image down from 2160 to 1707 lines gives you an opportunity to adjust sharpness at the same time, allowing you to control how much detail you want to see. Scaling can, however, introduce moire effects with certain patterns that you'll need to avoid. Bear in mind that if your anamorphic lens ratio is wider than 1.33x, you'll have to crop off the sides of the anamorphic frame to get the 2.40:1 screen aspect ratio you need. While that may eliminate some anamorphic corner distortion, it will also reduce the subjective cinemascope effect of a wide-angle anamorphic lens.
 
wwjd said:
Let's assume I am making a full blown movie to be projected at a 4K equipped theater, desired aspect ratio of 2.40:1. NOT relying on the lens of the projector, but reating a 4096x1707 in the file.

ALL the silly little things aside - oval bokeh, horizontal lens flares, DOF changes etc.... - I'm trying to work through the possible logic of squeezing down anamorphic shot 4k digital in post.

If my goal is 4096 x 1707 (2.40:1 aspect roughly) Am I REALLY gaining better resolution of the image by shrinking 2160 down to 1707, post process of the anamorphic image? Or is it a wash?

I can fathom that 2160 IS more pixels, more detail than shooting normal and cropping down to 1707, but I'm trying to grasp if that extra detail translates DOWN INTO the 1707 from 2160 when squished in post?

Thoughts, ideas, comments, anyone shooting anamorphic on GH4?
Click to expand...


Anamorphic lenses in the 'digital' world have different characteristics than what was the goal for Film film. In the case of Film film, the anamorphic lens recorded the wider angle of view on the 35mm full frame (movie FF...). The final film was then projected through a projector with a comparable anamorphic lens to restore the image to it's correct width. Otherwise, circles would be ovals and everyone would look like they had lost 50 or more... pounds...

In the digital world, 'anamorphic' really is used more for the 'look', since one can get the 'wide' screen look by cropping top and bottom of the frame to the desired aspect ratio. If one were to use an anamorphic lens, then one would crop the sides to obtain the desired aspect ratio, given one is using a 2x anamorphic lens.

One could use a lower value of anamorphic, say 1.33x, and perhaps eliminate the side to side crop... but then you'd have to crop top and bottom...

In any case you would still have to 'stretch' the image back into correct 'shape'. Do digital theater systems use actual anamorphic lenses? Or do they 'stretch' on the fly given the media is so marked?

At which point, the difference between spherical and anamorphic really does become a choice on The Artifacts.

Since I don't care for those artifacts for the most part... I would use a spherical to obtain a wide angle of view, even if I were to shoot in 2.40 (or whatever). As it is, most of the stories I have an interest in can live in 1.76/1.85.
 
Keep in mind that DCI standards for 4k Scope are actually 4096 x 1716. Also keep in mind that, even though many theaters have 4k projection, almost all films are finished in 2k because rendering VFX in 4k is still very expensive. Even "Godzilla" is only 2k. Most all films shot in the Cinemascope aspect ratio are 2048x858.
 
I'd never considered the ADDING MOIRE/ALIASING part. That is a very good point, and definitely something to consider. This camera looks fantastic, so I'm not worried about that, but I was trying to think about all the extra detail I LOP off masking it in post .... maybe anamorphic could make that part more useful, make a great look, recover detail.
I have yet to shoot and mask with this camera and suspect it will still look epic with 1716 (is that 2.35:1?) being almost double 1080 :)
Having seen how well regular old HD looks projected in a theater, I think it is ALL uphill from here! :)
 
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