B&W, the Low-light Savior

by Joseph Linaschke

We've said it before and I'll say it again — converting to B&W can be a great way to save an otherwise way-too-noisy high-ISO photograph. I have the privilege right now of playing with a handful of small cameras, and one I'm really, really enjoying is the Olympus OM-D E-M5. It's a micro four-thirds camera, which means the sensor is considerably smaller than my Fuji X100. I really didn't think I'd like the camera much because of it, but it turns out I really do. It focuses extremely fast, even in low light, and can shoot up to a somewhat ridiculous 25,600 ISO. More importantly, the images are actually very sharp and detailed at that point, if not understandably noisy. And of course, as would be expected, it's the kind of colorized noise that's really quite icky. Enter the B&W conversion.

Let's start with two relatively low ISO images, shot at a paltry 6400. These are shot by the mixed lighting of candles, Christmas lights, and dimmed overhead lighting. So you know, a veritable porridge of color temperatures.

Iris | Olympus OM-D E-M5, 45mm ƒ/1.8 lens — ISO 6400, 1/100th @ ƒ/2.2

Here's the same photo as it came out of the camera (well, as Aperture interpreted the RAW file), followed by an auto enhanced version, then a manually enhanced one, and finally the in-camera JPEG (shooting RAW+JPEG). These aren't unusable, but the colors aren't fabulous.

The original RAW file, as interpreted by Aperture

The original RAW file, as interpreted by Aperture

Aperture's auto enhance did a reasonable job, but not a great one

Aperture's auto enhance did a reasonable job, but not a great one

I think this manual adjustment is better, but really at this point we're splitting pixels

I think this manual adjustment is better, but really at this point we're splitting pixels

Here's what the camera produced. To be fair, I have a little color tweaking dialed into the camera, which in this case didn't do it any favors!

Here's what the camera produced. To be fair, I have a little color tweaking dialed into the camera, which in this case didn't do it any favors!

Here's another ISO 6400 example, converted to B&W with a splash of sepia. I felt the faint sepia returned the warmth of the evening to the images, which was lost by going to B&W.

Felicia | Olympus OM-D E-M5, 45mm ƒ/1.8 lens — ISO 6400, 1/100th @ ƒ/2.2

Now let's see something at the extreme end. These next two shots are both at ISO 25,600!

Iris, playing kid games | Olympus OM-D E-M5, 45mm ƒ/1.8 lens — ISO 25,600, 1/40th @ ƒ/3.5

Austyn, playing kid games | Olympus OM-D E-M5, 45mm ƒ/1.8 lens — ISO 25,600, 1/50th @ ƒ/3.5

The detail is amazing! I'm really blown away by this camera. But the point here of course is about the color noise. So let's see the last image before conversion. I've cropped it because the bokeh highlights went really weird in the conversion — more on that below under "technique".

The original file is not very pretty; the color noise has turned blotchy and made his skin look artificially red. But c'mon… it's friggin' ISO 25,600!!

Depending on where you're viewing this, you may not be able to see this full size, so here's a crop at 100% zoom, as grabbed in Aperture.

Original image, zoomed in 100% in Aperture

The Technique

The B&W conversion was all done with Aperture. I'm including a custom preset here for you Aperture users, and I'd love to hear how this works on other images. Notice in this preset, one of the oddities here is that instead of adjusting exposure to save/restore highlight detail, I changed the color temperature. Since color temp doesn't matter for a B&W image, I was able to use it to my advantage here, and at least in this collection of photos, it allowed me to maintain a really nice skin texture.

However a bi-product of this on these specific images was that some of the highlight rings around the Christmas light bokeh went really, really weird. Like this kind of weird:

Original image; bokeh highlight with color fringing from a Christmas light. Clearly there's a halo but it's livable.

Original image; bokeh highlight with color fringing from a Christmas light. Clearly there's a halo but it's livable.

Treated image. Most of the dark halo goes away with an increase in color temperature, but skin tones look better with the temp low.

Treated image. Most of the dark halo goes away with an increase in color temperature, but skin tones look better with the temp low.

I was able to crop them out or retouch them on all the images, but still, that's something I'd rather not have to do.

Anyhow, there you have it… this holiday season, when shooting in crazy low light and you want to avoid using flash, keep in mind the B&W conversion to save those noisy photos! :-)

Happy holidays, everyone.