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dubzee

Digital Sensors = Anamorphic Redundant?

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So here's a thought... and sorry for the long post but this has been on my mind for a while.

 

We keep talking about how an anamorphic lens uses the entire imaging sensor and is then compressed in post.  We always follow up by saying that just cropping isn't the same.  But isn't it?

 

Let me explain.  With my camera, the 5D Mark 3, there's a fixed number of horizontal and vertical pixels which are available to be exposed.  There's no in-between or random arrangement like there'd be with silver halide grains in analog film.  When I record MLV at 1920 x 1080 I'm getting 2,073,600 pixels.  When I record 1920 x 804 (scope) I get 1,543,680.  So yes, 25.56% less pixels. But!  An imaging sensor isn't a perfect pickup mechanism. It doesn't have pixels all over it. That's why it's digital - it's quantized.  It's a representation, as best as possible, of an analogic wave, which turns into a stair-stepping wave when it goes through the ADC due to there being no infinite quanta (even the current standard 64 bit is "only" 18,446,744,073,709,551,616 steps).

 

What happens when you squeeze an image from 1920x1080 to 1920 x 804? You don't gain any resolution. In fact you may introduce aliasing due to lines being squeezed which weren't squeezed before, and the stair-stepping we're all familiar with (jaggies) comes out.  Yes, we started with more pixels, and I understand the value in starting with more instead of starting with less. Analog mediums - sure - squeezing leads to resolution advantages. But digital is a fixed number of lines.

 

But if in the end it all has the same aspect ratio, just one didn't have any squeezing done to it (and thus no pixels deformed and/or aliased), wouldn't just cropping make sense?

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Anamorphic isn't just about the aspect ratio, do some more research and look at more samples, the whole image, composition, rendering of the lens, flare, depth compression and look of out of focus areas is different.

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In this case I'm only speaking about the resolution. I have a Cinemorph anamorphic bokeh/flare filter so I'm sorted in terms of the optical aberrations. In front of the filter I have a huge 0.7x wide - angle adapter which provides h+v compression (as opposed to just horizontal with the anamorphic lens). Side benefit is I get a 40mm f/2 Helios and a 60mm f/1.4 Rokinon due to the compression.

As you can tell I know my stuff. I'm just trying to figure out why I'd spend the money on a real anamorphic instead of my poor man's hack job.

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Have you tried uploading 2592x1080? With anamorphic adapter you don't really gain any resolution. Something similar is squezing 1920x1080 ordinary footage to 960x1080 and back, you'll see what happens in terms of resolution. Otherwise 1920x804 is just a way of presenting your footage, I prefer 800 or 816 (dividable by 16)....

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Sorry a bit confused about this post - digital sensors = anamorphic redundant - when the pixel count is a mere aside to the qualities the different lenses offer. A cinemorph stuck on a normal lens can't match the wonderful and organic aesthetic of a Bolex Moller for example. Try some real anamorphics and see how they feel...

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You're right about the resolution. You don't gain any resolution by using an anamorphic lens especially for 1.5x or 2x anamorphic lenses. And that's because your camera's sensor is not 4:3 format like film cameras in the past that anamorphic lenses are built for. That way, they get beautifully anamorphic widescreen ratio without cropping the top and bottom of 4:3 aspect ratio.

 

If you're shooting a 16:9 sensor and just want to get 2.40:1 then just crop the top and the bottom a bit then you're fine. If you need real anamorphic artifacts like oval bokeh, horizontal flares and barrel distortions then you have to sacrifice some (a lot of) pixels.

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I disagree.  anamorphic still allows attainment of greater resolutions, even if the exported piece is 1080p.  you're using all of your sensors real estate and if your timeline is 1080x 2550 you're then applying your post workflow to a lot more pixels - sharpening processes benefit most from this.  then the downsizing of 800x 1920 during export then squeezes all of that additional real estate into a smaller area. rather than binning 1/3rd of it.  Cinemorph fronts impart incredible amounts of light loss to obtain the oval distortion.  and also impact on the overall image sharpness due to hindering the front light gathering surface of your lens.  Additionally the flares look stuck on.     

 

And we have not even started talking about the fact that in order for you to get the same fov I can from a 85mm f2, you need a 50mm f1.2 to match the depth of field/field of view ratio without an anamorphic, and even then the look of your cropped image will look like it was captured with a sensor 1/3rd the size of the material shot using the longer lens, the larger imaging area and the anamorphic lens.

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And I disagree with you. If you're recording in HD and then doing post at 2560x1080, you're stretching the image since it was captured at 1920x1080.  Read another way: you're blowing up and the computer is interpolating what's in between.  Like I said early in the post: yes there is more data, but it's still limited by quantization.

 

I stuck a 0.7x wide-angle adapter on the front. It's got a 93mm front filter AKA it's huge. So I get the advantage of both horizontal AND vertical compression so that there's no need to further manipulate the image and dither/cause aliasing.  Added bonus is my lenses take advantage of the shallow depth of field with a 1.42857x wider FOV.

 

The footage I've captured on my 5D Mark 3 in MLV, with the Cinemorph, the WA adapter, and the Helios 58mm f/2 looks absolutely incredible.  Once I've got it rendered I'll provide proof.

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David Mullen will have been talking about 2x anamorphic since this is the normality in motion picture work he is involved in- in which case their 3.55:1 ratios resulting from a 16:9 sensor and 2x anamorphic will need cropping off the sides to obtain 2.35:1, and therefore the sensor area is removed in the same way you are doing, only from the sides instead of the top and bottom.  but with a 1.33x or 1.5x anamorphic you're not needing to crop any or very much at all from the sides. - way less than the 1/3rd of the sensor you are throwing away.

 

Only once you have used an Iscorama and an 85mm on a full frame sensor will you be able to consider what we are telling you.  Until then you simply will not be able to comprehend.  

 

Anyway, my primary point is that you will never be able to match the aesthetic of a 85mm and anamorphic on full frame simply by using a wider lens and cropping.  depth of field is ultimately determined by sensor area.  and the lack of need for such harsh cropping when using a 1.5x anamorphic means more sensor area is seen by the viewer.  It's the aesthetic that your setup will be missing - you won't notice it's missing since you haven't used an iscorama/85mm on your camera. 

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Out of curiosity i searched for some test footage of the cinemorph in partnership wit ha wide angle adaptor just to check to see if I was maybe being a bit harsh on the setup you propose.

 

This video seems to back up what I mean :-

 

http://youtube.com/watch?v=fbiNdfHTtfU

 

Yes, the defocus distortion is there like anamorphic - almost, but damn it looks forced.  Even at 1080p you can see how both the cinemorph and the wide angle adaptor are degrading the image quality to the point where discussion about resolution are null and void.  Now, maybe you have a higher quality wide angle adaptor and a better taking lens combination than what this test was shot on, but if we now go to something shot on a 5dmk3, helios 44 and iscorama 36 you will see a stark difference in the overall image - expose differences aside, even in then sun, the setup in the link above will never, and i mean never compete in resolution, cinematic aesthetic , or in overall beauty terms.

 

 

 

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I guess we just have to wait and see... going to run a bunch of tests tomorrow and see how close I can get. At the end of the day it's all about experimentation and having fun.

 

You deleted your poor example I see?  and changed your username?  Come on man, why are you here other than to try and play devils advocate?  Your discussion was moot over at the cinematogray.com forums.  If you're going to come onto a forum signing up specifically to try and belittle enthusiasts of anamorphics at least have something to back up your bold statements.  Until we see you provide a direct comparison of your solution versus a well arranged anamorphic solution such as those i have mentioned, your debate is moot.      

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YouTube disabled my sound cuz I used a copywritten song so I took it down. I'm off to High Park to see how this works out in the field.  There's no belittling going on, just sound technical discussion. Perhaps you have a passion for arguing on the internet but I don't share it.

I don't have to justify but I will, changing my user name to the user name I use on all bulletin boards and release dance music as. Shocking as it may be, I'm not doing any of this to mess with you. Just hate how my default user name was my Facebook name which is hidden from the world :-)

 

Cheers

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It looks not too bad, nice job. I don't think it's rendering real anamorphics redundant though, but seems like a cool hack if you don't want to spend a fortune. Have you seen DSO oval aperture lenses? I think they fake the anamorphic bokeh a little more convincingly.

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