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Changing from 4K to 2K on Red Epic instead of changing lenses???


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#1 Robert Gardner

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Posted 07 September 2014 - 11:32 AM

Hi,

 

I heard something odd today. I was told by a camera assistant that he was working with a DP last week who instead of changing lenses just changed from 4K to 2 K on the Epic to crop his shot so he could get the right composition.

 

Is that OK just to jump around like that instead of changing the lense to your desired composition.

 

I was a bit confused when I heard that.

 

Any thoughts or experience with that?

 

Many Thanks,

 

Rob


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#2 Steven Wyatt

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Posted 07 September 2014 - 11:46 AM

Hi Rob, 

 

Long time no speak it's Steve! Hope your well. 

 

Regarding your question, I dunno, that sounds very strange to me, but it's possible to do that. In terms of going from 4k to 2k, the resolution does crop down, so I suppose in essence you can alter your composition changing your resolution.

 

I'd just stick to either one of the resolutions depending on what your project doing, so for example if you have 35mm pl lenses, just stick to 4k but if you got s16mm lenses go 2k, as i'm sure your aware.

 

Hope this helps

Steve


Edited by Steven Wyatt, 07 September 2014 - 11:48 AM.

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#3 Steven Wyatt

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Posted 07 September 2014 - 11:49 AM

Just forgot to add, if your end project/ finish was 1080p, then you could alternate between 4k and 2k no problem, it would mean you could shoot at higher frame rates in 2k mode if necessary.


Edited by Steven Wyatt, 07 September 2014 - 11:50 AM.

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#4 Robert Gardner

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Posted 07 September 2014 - 12:09 PM

Hi Steven,

 

good to hear from you.

I am aware of these things, just was confused why he would just go from 4K to 2K to crop his field of view rather than changing the lense let's say from a 50mm to a 85mm?

Was he just being lazy? Prob he was outputting on 1080p, just thought it was odd. Never seen anyone doing that.

Anyhow, was just being curios if other people do that  as common practice?

 

Greets from Doha,

Rob


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#5 David Mullen ASC

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Posted 07 September 2014 - 12:46 PM

I think it's a bit lazy if you already have the lenses -- you really should avoid 2K on the Red Epic except when there is no other alternative, like for extreme slow-motion.  At 2K, you are enlarging noise artifacts plus losing resolution (obviously.)  Also 2K Raw doesn't make for great HD RGB, you are under-sampled on your red and blue information. I mean, if this was a situation where for a documentary shooting quickly it was faster to change to 2K from 4K rather than miss the shot by changing a lens, but on the other hand, you'd probably use a zoom in that situation anyway, plus it doesn't take that much time to switch a prime lens.

 

Why would cropping to 2K get you the "right composition" as opposed to using a lens that was twice as long???


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#6 Robert Gardner

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Posted 07 September 2014 - 12:52 PM

Hi David,

 

thanks for your thoughts. I was thinking the same. Was just a bit puzzeled when I heard that from a camera assistant I work with quite a lot. He was also puzzeled.

 

We figured it was lazyness.

 

Cheers,

 

Rob


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#7 cole t parzenn

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Posted 07 September 2014 - 06:50 PM

Also 2K Raw doesn't make for great HD RGB, you are under-sampled on your red and blue information.

 

I was going to ask about this. In theory, 2K down sampled from 4K has more color information per pixel (and fewer or less severe artifacts), so would there be a visible difference between the two, viewing at 2K or 1080?


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#8 David Mullen ASC

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Posted 07 September 2014 - 07:54 PM

It's mainly just a resolution issue, you'll get more from converting 4K raw to 1080P RGB than from converting from 2K raw.  I don't think it's a matter of getting "better" colors one way or the other, just better resolution in red and blue areas of the image if ending up at 1080P RGB.


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