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Diffusion Filter to soften digital sensor


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#1 Tiago Pimentel

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Posted 12 August 2016 - 05:31 AM

Hello, 

 

I'm about to buy a Ursa mini camera (probably the 4.6k). I love the look but I feel most modern digital cameras, can benefit from soft diffusion especially under specific kind of lights, to take a bit of that digital edge of the ultra sharp sensors. 

 

I was wondering about the perfect diffusion filter that would take that video-y look and soften the light, give more flattering skin tones and more cinematic highlights. I'm not looking for a filter that would give me a dreamy look, but more of softlight image. Maybe the Hollywood Blackmagic? Two sets of 1/4 and 1/2 or would the effect be too much at 1/2?

 

thank you!!

Tiago


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#2 Michael Rodin

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Posted 12 August 2016 - 06:03 AM

I used to put the good old Schneider White Frost on a Sony F900 when shooting HD. 1/2 for close ups, 1/4 for medium, 1/8 for wide shots. Used lighter grades on 35mm digital cameras. The main reason was smearing highlights so that clipping is less obvious. When I had a strong backlight  or some lights in frame, I changed to HD Classing soft. I think I've hardly ever shot without diffusion on digital. Film is different story: I use very little diffusion on that.

White Promist can be used to remove that artificial digital sharpness, but I'd rather pick a Frost if I want halation. Black Promist halates less, but Soft/FX looks a bit more natural to me. Sadly there are only 3 grades of them and the thickest one is pretty useless.

If your shooting style is to diffuse everything, you need some 'invisible' diffusion like Black Diffusion for wide-and-bright exteriors.

You might try low-contrast filters, a Soft-Contrast for instance. Shoot some sunny exteriors, underexpose and see if you like the results.


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#3 Tiago Pimentel

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Posted 12 August 2016 - 08:15 AM

Thanks for your answer! Well, I'm really looking to get the most organic image I can get from a digital S35 sensor such as the Blackmagic Ursa Mini 4.6k. The sensor is very sharp and I fear it may be overly sharp (video-y) when is shooting under specific lighting conditions. I wanted to soften that ultrasharp edges that scream video instead of film and get great skintones and soft highlights. So which would you strongly recommend to get the job done? The Soft Fx or the White Frost? Hollywood Blackmagic? Which densities?

 

Thanks once again!


Edited by Tiago Pimentel, 12 August 2016 - 08:16 AM.

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#4 David Mullen ASC

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Posted 12 August 2016 - 10:34 AM

Just depends on the look you want. Some diffusion filters are designed to be "mistier" than others, or are combination filters that add a mist filter to a softening filter -- the Hollywood Black Magic, for example, is a combination of a Schneider #1/8 Black Frost base + degrees of HD Classic Soft.  The Tiffen Black Satins are combinations of some mild GlimmerGlass (like a Pro-Mist) base + degrees of some softening filter like the Diffusion-FX.

 

You may find that the halation from a mist filter (frosts, pro-mists, etc.) helps lift up some shadow detail by lowering contrast, but other people don't like to see that glow around points of light and just want a filter that softens definition (such as a Tiffen Black Diffusion-FX) without any glow effects.

 

Also depends on if you want to filter everything or only want to filter a select close-up now and then, so that shot shouldn't feel "filtered".

 

Since there is always a slight halation effect from a Schneider Hollywood Black Magic, I always carry a #1/8 Schneider Black Frost as well, since it is one step lighter in strength than a #1/8 Hollywood Black Magic, which is a #1/8 Black Frost + #1/8 HD Classic Soft.  That ways I always have a consistent amount of halation but I can vary the degrees of softening.


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#5 Tiago Pimentel

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Posted 12 August 2016 - 11:23 AM

Thanks david. Well, i wasn't thinking of using the diffusion so much to achieve a look, but more to avoid the digital look of ultra sharp sensors. I like that slight halation as long as it doesn't call atention to itself. I want to get a more organic image by softening unrealistic sharpened details. So, maybe the hollywood blackmagic then? Is 1/8 enough? For closeups as well?

Thanks!
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#6 David Mullen ASC

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Posted 12 August 2016 - 02:19 PM

If all you want is a little bit of halation and a little bit of softening, then the #1/8 Hollywood Black Magic is a good choice.

 

As to whether you want even softer close-ups, that's a matter of taste... but getting a #1/4 isn't a bad idea.

 

One's tolerance for sharpness is a bit like one's tolerance for salt or spices in a dish, it can be rather personal.

 

Also, sometimes you are softening a close-up to hide a problem or de-age an actor so you might need something heavier or just have to plan on using post color-correction tools to help out.

 

And the lenses themselves will also be a factor.


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#7 Michael Rodin

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Posted 12 August 2016 - 02:20 PM

You should test various kinds diffusion before buying anyway. I find 1/8 Frosts too thin for closeups, even with additional softening.


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#8 David Mullen ASC

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Posted 12 August 2016 - 02:25 PM

The images are a bit too small to judge, but if you look at these frames from "Extant", you can see something shot with Hollywood Black Magics, mostly the #1/8, on a Alexa (usually with the lightweight Ang. Optimo zooms):

 

http://www.davidmull...d-21/index.html


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#9 Tiago Pimentel

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Posted 12 August 2016 - 02:39 PM

I guess the most important would be to perceive how the ursa mini 4.6ks image needs more or less softening than the alexa. So maybe i'll get both 1/8 and 1/4 to get a more cinematic and less digitally sharpened image. Do you agree?
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#10 David Mullen ASC

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Posted 12 August 2016 - 02:45 PM

Sure, but as Michael suggests, it would be better to shoot a test before you spend the money on such expensive filters.  Talk to a sales rep at Schneider Optics and see if they can loan you some filters or maybe you can visit a store or rental house with some and put them on your camera.


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#11 Tiago Pimentel

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Posted 12 August 2016 - 03:13 PM

Problem is, in my country is not that easy to find that kind of stuff. Basically, my brother is going to nyc at the end of the month and he's bringing me a lot of filters: nds, ir cuts (a necessity for bmd cams) and diffusion filters. I'm getting all formatt firecrest except for the diffusors which apparently are going to be hollywood blackmagic :)
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#12 Tiago Pimentel

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Posted 13 August 2016 - 05:16 AM

Btw, do the firecrest filters still suffer from quality control issues? I need some very neutral nd filters with minimal ir pollution and firecrest seem to deliver, but not sure about their quality control...
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#13 Mark Kenfield

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Posted 13 August 2016 - 11:45 AM

Btw, do the firecrest filters still suffer from quality control issues? I need some very neutral nd filters with minimal ir pollution and firecrest seem to deliver, but not sure about their quality control...

 

I just got hold of a full set, 0.3-3.0 and 0.6-1.2 grads, and colour-wise they're exceptional. Easily the most neutral NDs I've used to date (especially in the higher grades).

My only caveat, is that I'm seeing some apparent inconsistencies between the rated stop of the filters and how much light they appear to actually cut. I need to test them under controlled conditions however to confirm what's happening - and controlled conditions aren't really a possibility over here in India at the moment.


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#14 Robbie Fatt

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Posted 14 August 2016 - 09:49 PM

I tested out a Black Satin 1 here on the 4.6k:
 


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