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Finding the right diffusion


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Hi guys,

 

I was looking for a diffusion filter (needs to be circular, 77mm) to use with new digital sensor cameras. My goal is to take the edge off the 4k sensors, making the overall image more creamy, but without halation on the highlights. Something that would also help with fine lines that sometimes create aliasing would be nice (I know OLPF would be the best choice for that particular issue, but maybe a diffusion filter would also help with that).

 

The only diffusion I've tried was the Hollywood Black Magic 1/4 which I liked a lot, but found them to halate a bit too much. I also found that, when shooting against a light source, it creates flares in the form of tiny spots (which I assume has something to do with the inner pattern of the glass in the filter).

 

Any ideas? I was thinking something that would ressemble the look Paul Thomas Anderson got from his Phantom Thread. I know he used Low Cons but then again, he was shooting film, so that's a whole different ball game. Maybe Tiffen Ultra Contrast? Digi Con seems to be pretty popular, but they don't make them circular, do they?

 

Thanks!

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Thanks David. I've never read a lot about them. These come in multiple strengths from what I understand? How do they differ? I read at BH site that the FX3 is used to create a soft glow like a dream sort of image.

Edited by Tiago Pimentel
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The lightest is the #1/2 (though there is a rarer #1/4 that they made later). It is pretty subtle, has the least halation of any diffusion filter. I just used it the other day to shoot a scene where the camera is passing along a row of light bulbs in the frame and our normal Hollywood Black Magic filter was creating a too-dramatic halation.

 

Technically an UltraCon filter is not true diffusion though anything that lowers contrast by scattering light will also soften a little.

 

Go to 7:44 here:

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OP...order a bunch from B&H. Test them out, send back what does not work.

 

 

Should we be advising someone to abuse the very liberal return policy, from a very good store that has provided low prices to our industry for decades.. ??

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@ David

 

Thanks! So for my purpose of creating a more creamy image, without the apparent loss of sharpness, what strength would you advize? Maybe the 1/2 for wide shots and 1 for close ups and medium shots?

 

@ Daniel

 

Yeah, not sure I'd be comfortable doing that. And anyway, it's not an option for me, as I am located in Europe and any order from the US would be taxed by customs... The other option would be renting, but in my country it's extremely hard to find a good selection of filters for rent

Edited by Tiago Pimentel
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Diffusion is designed to soften and Im not sure what you mean by creamy. It sounds like you want a lower contrast image not a softer image. Simplest thing would probably be to time the image for less contrast, closer to the log look. Otherwise you could try UltraCons or DigiCons.

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David, when I say creamy, I mean something that would take out that videoish sharpness of these new 4k sensors when combined with modern lenses. I like sharpness, just not that video enhanced kind some sensors have. That's the main reason I use a lot of vintage lenses with 4k cameras. They produce beautiful images without that sharpness overkill that tends to distract.

 

Those Tiffen you mentioned seem exactly what I need. What would be the difference from the black nets?

 

Thanks!

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Black nets are good for diffusion too, you just have to deal with some issues with them. (1) It's hard to find a black net that is as light in strength as the lightest glass diffusion, (2) you have to avoid stopping down too much and seeing the net pattern, (3) you will get some sort of artifact around bright points of light, depending on the weave pattern, either a four point star or cross flare, or a rainbow flare in all directions, etc. (4) you have to avoid stray light hitting the net (if in front) and washing out the image.

 

Electronic sharpening is a signal processing effect post raw data, so make sure it's all dialed down to the level you want before you start adding diffusion to counteract it. You just may be seeing the effect of better resolution though, not increased edge enhancement. Also, contrast and sharpness are tied together so maybe you want less contrast, not less resolution.

 

Maybe you can find a Tiffen sales rep in Europe who will lend you the filters for testing.

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  • 2 months later...

Black nets are good for diffusion too, you just have to deal with some issues with them. (1) It's hard to find a black net that is as light in strength as the lightest glass diffusion, (2) you have to avoid stopping down too much and seeing the net pattern, (3) you will get some sort of artifact around bright points of light, depending on the weave pattern, either a four point star or cross flare, or a rainbow flare in all directions, etc. (4) you have to avoid stray light hitting the net (if in front) and washing out the image.

 

Electronic sharpening is a signal processing effect post raw data, so make sure it's all dialed down to the level you want before you start adding diffusion to counteract it. You just may be seeing the effect of better resolution though, not increased edge enhancement. Also, contrast and sharpness are tied together so maybe you want less contrast, not less resolution.

 

Maybe you can find a Tiffen sales rep in Europe who will lend you the filters for testing.

 

Hi David,

 

sorry to bring this thread back again, but I was wondering what you think about the Tiffen LC vs UC to get this effect we're talking about. Red cameras and BMD cameras are fantastic pieces of gear, but I feel they need some help in the highlights and shadows roll off to achieve that creamy Alexa look. Especially in skin tones. Do you think the UltraContrast or Low contrast might help? If so, which strength would you choose from each one?

 

Thanks!

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Tiffen UltraCons or Schneider DigiCons might be better if you are just looking for lowered contrast rather than a filtered-looking shot. LowCons are more like Fog filters, they bloom and soften focus more than UltraCons do.

 

The other day I was playing around, trying to match the softness of the #1/4 Schneider Hollywood Black Magic (which is a #1/8 Black Frost + #1/4 HD Classic Soft) but with more blooming and put a #1/4 Black Frost with a #1/2 Tiffen Black Diffusion/FX and thought it had a nice creamy quality. Probably similar in effect to a Tiffen Black Satin filter. There are also new filters called Radient Softs which I havent tried yet.

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Thanks David! I don't mind halation. I actually like what it does to the highlights. But what I'm actually after is a filter that creates that nice rolloff to the highlights and the shadows, without making the image look filtered. I love Hollywood Blackmagic, but if you have a strong light source, the filter instantly gets all the protagonism :)

 

Between Ultracons, Digicons and Black Satin, what would you recommend? If I go with Ultracons, is the UC 3 too much for medium to close up shots?

 

Thanks!

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UltraCons or DigiCons. I dont know the strengths of the DigiCons and its been a decade since Ive used UltraCons but Id start with a #2.

Thanks David! Oddly, there is no stock of the Ultracon 2 for 77mm anywhere. I just called Tiffen and they told me they had to manufacture it. Is it too much to start with the UC 3? Maybe too strong of an effect

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  • 1 year later...
On 5/15/2018 at 8:05 PM, David Mullen ASC said:

But yes, I usually use the 1/2 Black Diffusion/FX for wides and the 1 for close-ups.

Hello David, 

Scrolling through these threads about diffusion and was very interested to see here how you increase the strength of your diffusion for CUs.   

I haven't used diffusion a great deal, and for my upcoming project I'm in the process of doing a bunch of testing. I've settled on using older Cooke Varotal zooms (20-100 & 18-90 Technovision or 18-100), but there will also be a Ruby 14-24mm for (very) wide shots & hand held, and most likely a couple of older Nikon primes for other hand-held.  I'm working to figure out how much diffusion I will need on which lenses to keep things consistent.

(Regarding your above comment, I am assuming one would, generally, be using a longer lens for close-ups.) 

My initial thinking was that a longer lens needs a stronger diffusion compared to the wide shot, as the longer lens will 'see past' anything intruding, but very close to, the lens surface vs. a wide, where the diffusion effect - or anything in front of the lens - will be more pronounced.

Hence, the elements inherent in diffusion filters would be less pronounced with a longer lens, and a stronger diffusion would be necessary.

Yet I came across the idea today that, in fact, the longer lens will magnify the diffusion effect inherent in diffusion filters, so one should be using a stronger diffusion for the wides and a lighter one for longer lens for consistency. 

Perhaps your reasoning for using a heavier diffusion for CUs is for a different reason altogether.  However, I'd love to clear this up if you can offer your insight. 

Thank you!

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It's the classic contradiction of diffusion filters -- if the idea is consistency of the degree of softening, the rule is that the longer the lens, the lighter the diffusion, because, as you say, you are magnifying the elements in the filter that are blurring detail when the filter is on the front. However, perceptually / psychologically, our eyes crave more detail in wide shots while in a close-up, we mainly want to see sharp eyes without seeing too much skin texture if it is unattractive, so you don't need to same level of fine detail compared to a wide landscape shot, let's say, so in that case, you'd increase the diffusion as you get tighter, and generally the tighter shots are on the longer focal lengths.

All of which to say is that if you are going onto a longer focal length on the zoom to get tighter, the simplest thing would probably be to leave the same diffusion strength on the lens, whereas if you are zooming in but the subject is still distant, you want a telephoto wide shot, you should reduce the diffusion.

Also, some diffusion filters on long lenses start to create magnified artifacts that can be distracting, which may lead you to use a different type of diffusion.  For example, a Classic Soft has little dimples, lenslets, in the glass to blur detail, and on a long lens those dimples get so large that you can get some odd blurry shapes around bright points of light.

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  • 4 weeks later...

For anyone interested in diffusion filters.. While on lockdown, we shot a simple practical test of using diffusion filters on budget anamorphic lenses (with 2 setups, modern and vintage). It is neither scientific nor perfect, should have been less enthusiastic about flares perhaps, yet it was fun and useful for our purposes. I think I have seen all filter tests on the internet, but could not find any on Double Fogs, for instance, even Tiffen does not have them, so..

Filters tested:

Schneider Hollywood Black Magic 1/8 and 1/4 (subtle, sharp, good contrast, the best skin smoothing effect, beautiful halation)

Tiffen GlimmerGlass 1/2 and 1 (also subtle and similar to HBM, even more beautiful halation – slightly wider and softer)

Tiffen Double Fog 1/8 and 1/4 (strong effect, perfect for dream or fantasy sequences – the instant classic 70s Brian de Palma look ?

Tiffen Smoque 1 (much less glow, more atmosphere, can be super useful in situations when real haze is not allowed)

Hoya Duto (I saw this weird highlight butterfly glint effect in classic 50s Doris Day movies, but the modern version looks way crazier)

DIY net (black bridal veil) – nothing gives the 30s-40s look better than nets, veils or stockings. Requires about half-stop exposure compensation and opening the aperture to soften the focus on the pattern. Also, produces beautiful glints. I really must shoot something black-and-white with it, someday.

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Alissa, thanks for sharing! I found it helpful. 

Lately, I’ve been splitting the effects of halation and diffusion into separate filters for more control. I think wider angle shots tend to need more halation/less diffusion, while longer lens close ups need more diffusion/less halation. Trying to perceptually match the same contrast level on close ups to the wides can be difficult if you can’t separate out these two effects.

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Yes, ideally I'd carry the Hollywood Black Magic line, the Black Frost line, and the HD Classic Soft line to have the ultimate control -- I sort of do that now except that I carry a set of Black Diffusion/FX instead of HD Classic Soft.

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