Black and White on Digital?

[Mark Kenfield]

Hey guys,

 

I'm prepping for a black and white feature at the moment that I'll be shooting on the Alexa Studio. Tested out some standard B+W Contrast Filters yesterday to see how they'd play on a digital sensor (I haven't used them since my darkroom days), and found the effect sort of worked, but certainly seemed to leave me with less capacity to push the image around than shooting clean and fiddling with my RGB channels.

 

So I'm leaning towards simply shooting clean now, and jacking my RGB channels around to create a really graphic look.

 

I was wondering if anyone had any 'best-practice' recommendations for this approach?

 

We don't mind gaining a bit of noise from messing the image up, but we're only recording ProRes4444 for this one, so I'm wondering about whether I should look into rating the camera around 200-320 ISO to keep things as noiseless as possible, to facilitate pushing the channels (particularly red) all the way up with as little adverse noise as possible?

 

Any thoughts or suggestions would be greatly appreciated.

 

Cheers,

 

Mark

[David Mullen ASC]

400 ISO is about as low as I'd go, that's clean enough on the Alexa. I'd use a pola outside to get better saturation and separation when the sky is blue with white clouds if you are going to go for that red filtered look in b&w.

[Kenny N Suleimanagich]

You should check out the May 2014 issue of American Cinematographer. Lukasz Zal talks about shooting with the Alexa for a black and white finish on “Ida". That movie looked great.

Edited March 8, 2017 by Kenny N Suleimanagich

[David Mullen ASC]

Here is an example of a color landscape photo I took with a polarizer on the lens to darken the blue skies before I turned it b&w:

[Satsuki Murashige]

That looks great David!

[Bruce Greene]

Hi Mark,

 

Like David, I wouldn't go below ISO 400. But I would shoot without color filters, and white balance fairly close to your light sources.

 

About the pola filter, I'd keep an eye out for what it might do to faces and reflections. Pola filters are often a give and take situation.

 

And something I don't normally have, a DIT colorist on set. It will be very hard to preview the monochrome image without constant color correction and desaturation. It so much effects the feel of the scene, that I'd really want to preview and record the corrections for dailies and/or color grading.

 

Lastly, you may want to set the camera to the highest level of ProRes it can record. (not sure about an older Alexa Studio for ProResHX) as you'll find that pushing the color channels in grading shows banding pretty quickly in B&W conversions.

 

PS. ... when you do your grade, consider making a duotone "monochrome" result, rather than just single channel B&W. You could even adjust the "color" scene by scene....

 

Have fun!!!!

[Mark Kenfield]

400 ISO is about as low as I'd go, that's clean enough on the Alexa. I'd use a pola outside to get better saturation and separation when the sky is blue with white clouds if you are going to go for that red filtered look in b&w.

 

Thanks David, I've shot some test comparing the results of the red channel push at different ISOs, and there's a BIG jump in noise from 400 to 800 ISO, and again from 800 to 1600 ISO. The shift is much subtler from 400 ISO downwards, but there is certainly still a difference between 400 and 200 ISO.

 

Because we're only shooting in ProRes, I think I'll probably try to shoot at 200 ISO wherever I can (highlights allowing), but I'll bump back up to 400 without much hesitation if need be.

 

You should check out the May 2014 issue of American Cinematographer. Lukasz Zal talks about shooting with the Alexa for a black and white finish on “Ida". That movie looked great.

 

Ida was gorgeous, a very different and much softer look than we're going for though. Thanks Kenny.

 

About the pola filter, I'd keep an eye out for what it might do to faces and reflections. Pola filters are often a give and take situation.

 

And something I don't normally have, a DIT colorist on set. It will be very hard to preview the monochrome image without constant color correction and desaturation. It so much effects the feel of the scene, that I'd really want to preview and record the corrections for dailies and/or color grading.

 

Yeah, as I mentioned to you earlier Bruce, I'm a little hesitant on what a polariser might do to the specularity in the image (which seems to have a particularly big impact in B+W when you push the channels around), but I think I'll treat as a case-by-case thing. Still have more tests to do on that front.

 

I've already built a couple of show LUTs that I can push through both my EVF and video village (I'm switching out the Studio's OVF for a Zacuto Gratical for this film for this reason), this will hopefully help a great deal, by forcing me to alway lighting to the LUT (and to the most extreme artifacts that the red channel can give me).

[Mark Kenfield]

For an idea of the sort of look I'm going for, here's a test sample:

 

This is with the standard Arri Rec709 LUT applied and a conversion to monochrome:

 

 

And this is with the LUT I've built pushing the colour channels:

 

[John E Clark]

For an idea of the sort of look I'm going for, here's a test sample:

 

And this is with the LUT I've built pushing the colour channels:

 

 

To me there's a bit of 'ringing' on the edges. Don't know if that is due to the 'push' or if in addition you are using some sort of edge enhancement filter...

 

In any case, I use the 'channel mixer' feature of Premiere to form my 'monochrome' out put. Film film B&W had a varying response to colors, and the channel mixer filter allows RGB to be 'weighted'. This is where you can also simulate the effect of a B&W filter. I tend not to put too much filtering in the capture. Perhaps the polarizing filter that David Mullen mentions, would be about it.

 

If I recall from one of the writeups on B&W from digital, perhaps it was the film "Ida"(2013), in any case, the use of a 'blue filter'(cut red...) was used to cut down 'reds' due to the inherent sensitivity of the digital sensor to reds.