Steve and Antonio had a great conversation about red filters on black and white photographs, I go on a rant about how every one of my Apple tech toys is fiddly. I tell a fun story about how I used what I learned in Taming the Terminal to finally tame my Drobos.
Hi this is Allison Sheridan of the NosillaCast Mac Podcast, hosted at Podfeet.com, a technology geek podcast with an EVER so slight Macintosh bias. Today is Sunday December 20, 2015 and this is show number 534.
The holidays are upon us and every other show is taking a break (my podcatcher is almost empty right when I have long drives!) but the NosillaCast just might go off without missing a show. Timing is going to be tricky for next week though. Bart and I are going to try and record while I’m at Steve’s family’s house so we might get a Security Lite and a Chit Chat Across the Pond out of that but I’m not sure. In any case there will definitely be no live show next Sunday and the show may not come out until Monday or Tuesday. Mark your calendars!
Chit Chat Across the Pond
This week’s Chit Chat Across the Pond was so much fun, Chris Ashley of the SMR Podcast joined me to talk about “The New Hotness” from Microsoft. Chris is brilliant and funny and thoughtful and a dear friend who I’ve never met in real life. We had a blast chatting and I think our enjoyment will be infectious. Like me, you may have to set your “Ever so slight Macintosh bias” aside but if you do it’s great fun.
One warning – I originally put the previous weeks’ Chit Chat Across the Pond into the feed so if you didn’t get Chris attached to the latest episode, you may have to resubscribe to the show. With any luck your podcatcher has a refresh feed thingy though. Several people were kind enough to notify me of my error and I gave them all a free month podcast subscription to both the NosillaCast and Chit Chat Across the Pond. Remember that next time you think I might already know I goofed up!
Speaking of Chit Chat Across the Pond, last week I had Antonio Rosario on to talk about black and white photography. Steve had a question about something Antonio said, and then engaged in some conversation over on the blog about it. I’d like to read you some excerpts because it was really really interesting and I learned even more.
I really enjoyed your talk with Allison about B&W photography. Even as a novice photographer I got some good tips out of it.
Your discussion with Allison about using color filters to enhance photos was intriguing and made sense, but left me with a question about how digital color filters work. I hadn’t thought about using a color filter to highlight an object or subject in a B&W photo. The example you gave was using a red filter to enhance skin tones in B&W photos. You explained this works because many people’s skin has red tones in it so using a red filter on a color photo while converting it to B&W “lightens” their skin tone in the photo. That’s a marvelous tip that can be extended to highlight other objects using color filters.
However, this got me thinking about your use of the word “lighten” in this context. The way I understand it, analog color filters block all colors except one which gets through the filter. So a red filter blocks all colors except red which passes through the filter. In other words, filters can only block light, they can’t add light or lighten an image. I know that filters aren’t perfect so 1) some light from other colors will get through the red filter, just at a much reduced intensity, and 2) although red light passes through a red filter, it is slightly attenuated. So from my perspective, a red filter doesn’t lighten the skin tones, but instead reduces the red skin tones significantly less than other tones in the photo resulting in emphasized skin tones relative to other parts of the photo.
So my question is do digital color filters behave as analog color filters and only block light? Or do they also bring up the average level of the photo after filtering resulting in a true lightening of the color which passes through the filter?
Antonio replied back:
So Steve, great question.
I should have mentioned that my brain still works in the world of film sometimes and this was one of those times. When I mentioned that red filters lighten skin, it’s because when you use one when shooting black and white *negative* film, the result is that more red light hits the negative film and is going to exposure the film longer. Longer exposure on negative film,… means a brighter image. So if a red filter is letting in more light, then those parts that are red in the original scene will show as lighter when viewed on the negative (and resulting print).
Digital color filters on a black and white image simulate this phenomenon. How they do it, I have no idea. Digital magic I suppose. In Lightroom, you basically can convert your RAW file to B&W then have access to the color filter sliders where you can darken or lighten the different major colors in the image and have them lighten or darken in the B&W conversion. In SnapSeed, you can convert a color image to B&W using a straight conversion or one of three or four simulated color filters. Also, on the Fuji X-series cameras, you can shoot B&W with a simulated red, green or yellow filter. It’s nice to see this in a preview LCD because you can understand what tones will be affected by whichever filters you use.
When I did B&W film photography, the major color filters I would use were red, orange, yellow, or green. Never blue. Red was great for getting dark skies, but when used on people, they’d glow white, almost like infrared photography. Orange was also good for skies but wasn’t as intense as red. Yellow was good for skies, getting rid of haze (since there was a lot of blue light in haze) and also good on foliage.
I thought this was really interesting. Steve and I talked through it ourselves and it’s a bit of a mind bender. He pointed out that a red filter looks red to us not because IT is red, but because the only light that passes through it is red. That took me a few minutes to get into my brain.
In reading Antonio’s comment about how his Fuji XT100 camera could apply colored filters in camera so that as you took a photo sounded really cool. He can take a black and white photo in camera that already has the red filter applied for example. I went poking around in the menus on my Olympus E-M10 and it turns out this camera can do it too. I did a few experiments to prove to myself what he was talking about, pretty cool stuff. I think Antonio is dragging me into his madness!
ANYWAY, if you’re not already subscribed to Chit Chat Across the Pond, be sure to search in your podcatcher for it, or you’ll miss all this fun! Steve and Antonio went back and forth a bit longer on the blog so go check that out too.
That’s going to wind this up for this week. Don’t forget to send in your Dumb Questions, comments and suggestions by emailing me at firstname.lastname@example.org, follow me on twitter @podfeet. Check out the NosillaCast Google Plus Community too – lots of fun over there! If you want to join in the fun of the live show, head on over to podfeet.com/live on Sunday nights at 5pm Pacific Time (except not next week) and join the friendly and enthusiastic NosillaCastaways. Thanks for listening, and stay subscribed.