color temperature

Five Questions: Flashlight Filters, Night Photography with Film, Adobe Bridge and More

We like getting questions. Sometimes they challenge us, sometimes they fascinate us, and sometimes they allow us to fill in the gaps of the things we teach on workshops and in our blog.

This installment of our “Five Questions” series features inquiries about making custom filters for color-correcting flashlights, Pentax’s built-in equatorial tracking, film photography at night, Viltrox lenses and using Adobe Bridge with Lightroom.

If you have any questions you would like to throw our way, please contact us anytime. Questions could be about gear, national parks or other photo locations, post-processing techniques, field etiquette, or anything else related to night photography. #SeizeTheNight!


1. Making Custom Color-Correction Filters

Coast Portland LF100 flashlight filters.

Q: Thanks for your recent post on color temperature. Can you describe how you physically make a filter for the flashlight? Tons of gaffer tape? — Will

A: You could use gaffer tape, or you could just wrap the gel around the end of the flashlight and hold it there with your hand or a rubber band. But there’s a more elegant way. In Part I of that series, Tim told how he attaches the gel to the flashlight. Personally, I like to use double-sided tape to adhere the gel to the clear filter, which gives me a nice, clean piece of gear to work with.

However, the first time I did this, I used standard-size clear tape. It didn’t fit across the whole filter, so I needed to use three pieces side-by-side, which created shadow lines in my flashlight beam. Not a huge problem, but it wasn’t polished enough for me. Moreover, one of the reasons I love using a Coast HP7R to light paint is because the illumination is even across the whole beam. So, shadows from my filter wouldn’t do.

Because of that, I instead started using clear mounting sheets. They come in 8.5x11 sheets, from which I can cut a piece that covers the whole filter. I cut a square piece large enough to cover the clear plastic disc, then use sharp scissors to trim the edges to align with the circle. Then I peel off the backing, adhere a square of filter gel, and finish by trimming that as well. If I need two gels, I repeat the process on the other side of the disc.

Then I can pop my custom filter in the holder, and light paint with precise color with no fuss. — Chris

2. Equatorial Tracking with Pentax

Q: I rarely see anything about the use of equatorial mounts in general, or more specifically what Pentax claims to have with their K1 being able to simulate an equatorial mount for up to 3 minutes. I purchased the K1 thinking that this was the way to go, but as I am just starting in astro-landscape photography, I would be interested in your thoughts on these approaches to letting the shutter stay open a little while longer. — Ray B.

A: None of us have shot with a Pentax K1, but I have a couple of friends who have, and the AstroTracer feature does indeed perform as advertised. Since you already have the camera, I definitely recommend that you give it a go. Just bear in mind that you will still have to do a separate shot for the landscape or foreground, as it will be blurred in the tracer image. (The AstroTracer tracks the sky, so the camera will not be synchronous with the earth!)

For general astro-landscape photography, typical exposures are 20 seconds, f/2.8, ISO 6400. With the AstroTracer, you should be able to get 2 or 3 minutes at f/2.8 to f/3.5 and ISO 1600, depending on your lens.

We would love to see your results. Please send us a couple of images, or better yet, share on our Facebook page. — Lance

3. Film Photography at Night

Q: Greetings from Portugal! I make landscape photos with long exposures, including night photography. I shoot in black and white with digital, but also with film (Tri-X), and recently I got some Acros. What are your views about these two options? — Verissimo

Figure 1. Click to englarge.

A: Thank you for reaching out, all the way from Portugal! I’ve used film for night photography for over 20 years—less and less over the last 2 or 3, but lately I’ve been resurging. (Keep your eye out for a post about that soon!)

Figure 1 is an excerpt from my book Night Photography: From Snapshots to Great Shots, with a chart that compares the film reciprocity of Tri-X and Acros.

As you can see, Tri-X is not a good film for night photography, unless you want to be pushed to very long exposures very quickly. A 15-minute exposure for digital would need to be doubled for Acros (30 minutes), but quadrupled for Tri-X. That’s 1 hour, and anything over 15 minutes is not recommended for Tri-X. This means that with Tri-X at night, you can shoot only under full moon or in brightly lit urban conditions.

Last summer there was some very good news for film night photographers, as Fujifilm brought back Acros after a yearlong hiatus. One of our most beloved black-and-white films, Acros has very low reciprocity failure and can be used successfully under a variety of low-light conditions.

Another thing to consider is that when shooting film at night you are technically overexposing the lights to get a better burn into the silver. To compensate, I advise that you reduce your development times by 10 percent or so to get the best results. Use my chart and -10 percent as a starting point to cook up solutions that best fit your style and the chemicals you use. — Gabe

4. Viltrox 20mm

Q: In your recent blog post “How to Plan, Shoot and Edit a Milky Way Arch Panorama,” I have to say I am a bit confused by this statement: “Lately I’ve fallen in love with the Viltrox 20mm f/1.8, because it comes in a Nikon Z-mount and is crazy-easy to focus manually.” I am unable to find this lens in a non-Z-mount. Maybe you can point me in the right direction? Also, do you know how the Viltrox compares to the Nikon F-mount 20mm f/1.8G combined with the FTZ Adapter? — Eunice

The Viltrox 20mm f/1.8 Z-mount lens.

A: Viltrox is a relative newcomer to the lens market. They presently make the 20mm f/1.8 lens only in a Sony E-mount and a Nikon Z-mount. The latter is not yet available through U.S. retailers, but you can order one directly through Viltrox on Amazon. The Viltrox website is not so up-to-date, but here is some information about the two focal lengths they make (20mm and 85mm). For most of what they manufacture that is available in the U.S., check out B&H Photo.

As for your other question, I have not compared those two lenses directly, so I cannot comment about the optics. But I can comment on the physical attributes.

The Nikon 20mm f/1.8G is substantially lighter, but then you do need to factor in the FTZ Adapter, which adds a little weight. The 20mm is very sharp, though it does suffer from more coma than the Nikon 14-24mm f/2.8, which is why the latter is legendary among night photographers.

Here’s the breakdown:

  • Viltrox: heavier, manual focus only, has coma until stopped down to at least f/2.8, all metal lens barrel, comes with adapter to use screw-on filters 

  • Nikon: lighter, requires adapter, auto and manual focus, also has coma until stopped down to at least f/2.8, plastic lens housing, can use screw-on filters natively

Matt

5. Bridge to Lightroom?

Adobe Bridge—meant for using with Photoshop, not generally with Lightroom.

Q: At a recent workshop you said not to use Adobe Bridge to edit photos before importing them into Lightroom, but rather use just Lightroom. If you import from Bridge, that changes the equation somewhat? Most folks in my camera club swear by Bridge. — Brien R.

A: If someone is not using Lightroom, then by all means they should be using Bridge. But there just isn’t any good reason I can think of to use Bridge before Lightroom. Everything that Bridge does is something that’s built into Lightroom, so using Bridge beforehand is just adding extra steps to accomplish the same tasks.

I’m not claiming that there’s not some truly efficacious reason out there to use Bridge first, but it would be a major exception to the rule, something that would fit a very specific, out-of-the-ordinary need. As an indication of how unusual that need would be, know that between Lance, Tim and I, we don’t know any professional photographer who uses Bridge before Lightroom. — Chris

Chris Nicholson is a partner and workshop leader with National Parks at Night, and author of Photographing National Parks (Sidelight Books, 2015). Learn more about national parks as photography destinations, subscribe to Chris' free e-newsletter, and more at www.PhotographingNationalParks.com.

UPCOMING WORKSHOPS FROM NATIONAL PARKS AT NIGHT

The Color of Night: The Proliferation of LEDs and its Effects on How We Photograph

If you’ve been paying attention, you may have noticed that it’s gotten much cooler at night in recent years––about 3000 degrees cooler!

The nighttime world has transitioned from one that was overwhelmingly lit by yellow-orange sodium vapor lamps to one lit primarily by daylight-balanced LEDs. It’s happened quickly and it’s had a huge impact on night photography, especially in urban areas. Even night photography in national parks is impacted, as the distant glow on the horizon shifts from orange to white.

While there’s no doubt that LED lighting is more energy-efficient, and generally easier on the eyes, it is making for much more mundane and ordinary-looking night photographs.

Figure 1. Trona Pinnacles, California. November 2014. Canon 5D Mark II with a Nikon PC Nikkor 28mm f/3.5 lens. 30 seconds, f/8, ISO 6400. White balance: tungsten. Foreground lighting with a Four Sevens Quark 123 LED flashlight. Sky glow from mostly sodium vapor lights in the nearby small city of Ridgecrest.

Back in the 1990s I was living in San Francisco, and much of my night photography was done in and around industrial sites in the Bay Area. My friend Tom Paiva and I explored the abandoned piers along the Third Street corridor in the south of San Francisco, and the Southern Pacific rail yards across the Bay Bridge in Oakland. We were drawn to the strange machinery and architecture of these sites, but most of all it was the odd mixture of high and low pressure sodium vapor, mercury vapor and metal halide lights that we found so irresistible. We sought scenes lit with multiple light sources that created surreal colors when combined with long exposures on our film (Figure 2). These were exactly the kind of situations that I tried hard to avoid or to correct for in my commercial architectural work.

And there’s the rub––mixed lighting can be both a curse and a blessing depending on the situation at hand. To the artist, it makes for worlds of possibilities, and to the commercial photographer concerned with color accuracy, nothing but headaches.

Figure 2. Petaluma, circa 1994. Shot on Fuji NPL color negative film (tungsten), exposure unrecorded. A combination of sodium and mercury vapor lights illuminates separate parts of this image making for areas with radically different color balances—not to mention that crazy purple sky. Note the light on either side of the pole in the foreground.

Photographing mixed-lighting scenes with digital cameras and adjusting the white balance in post-processing allows for great flexibility in how an image is presented, and in turn the feelings or moods it elicits. We have it easy today being able to fine-tune (or even dramatically shift) the white balance after an image is made, and local adjustments make it even easier to “correct” for different colored light sources in the same frame.

Not too long ago that would have been an unimaginable luxury. Back in the days of 4x5 transparency film, I shot assignments where I would have to make multiple exposures on the same sheet of film for each light source. Testing was required to find the right filtration to put in front of the lens for fluorescent, incandescent, sodium, halide and other light sources, and if daylight was involved, windows would often have to be blacked out and then exposed for separately with all of the other light sources turned off. All of this had to be done while making sure the camera didn’t move between exposures. The gas discharge lamps often took 5 to 10 minutes to warm up after being turned off, so testing and exposing Polaroids and film might have taken 2 or 3 hours for a single image. In some instances, I could filter the lights directly and make a single exposure, but putting filter sleeves on a sea of fluorescent tubes in a large office space wasn’t much fun either. This is what it was like in the days before digital photography and even Photoshop.

But, back to our future …

In the images below of an old textile mill in Pawtucket, Rhode Island, the overall scene is lit with high pressure sodium vapor lights, and there’s a metal halide light out of sight behind the building on the right side of the frame. The interior is lit with either incandescent or possibly more sodium vapor lights.

In each version, I’ve set the white balance differently by using Lightroom’s eyedropper tool to click on an area lit by one of the light sources. As is usually the case, my preferred white balance is somewhere between the neutral points used in the first two examples. After using the eyedropper tool to check various white balances (Figures 3a and 3b), I pick the one that is closest to what I want and then use the temperature and tint sliders to further refine the color (Figure 3c). In this kind of situation, the “right” white balance is the one that looks best, not a perfectly neutral setting.

Figure 3a: Pawtucket Textile Mill. December 2015. Nikon D750 with a Nikon PC Nikkor 28mm f/3.5 lens. 10 seconds, f/8, ISO 400. White balance neutralizing the metal halide light: 3100 K, +15 Magenta.

Figure 3b: The same image with the white balance neutralizing the sodium vapor light: 2050 K, +4 Magenta.

Figure 3c: The same image with the white balance set to personal taste: 2450 K, +7 Magenta.

Figure 4: An LED streetlight casting multiple shadows in Los Angeles, December 2013.

LEDs in the Modern World

In my recent travels, I’ve noticed that in both large cities and small towns around the country, most places have almost fully transitioned to LED lighting within the last 2 or 3 years. Lighting technology has evolved quickly, and early adapters—such as the city of Los Angeles (Figure 4), which converted to LED in 2012 and 2013—now find themselves with outdated fixtures that use multiple diodes and cast weird repeating shadows. Newer lights are brighter, and don’t require multiple diodes for adequate brightness. Even my tiny hometown of Hinesburg, Vermont, has completely transitioned to LED streetlights, casting the town in a naturalistic—but boring—neutral glow.

I had the great fortune to lead National Parks at Night’s Easter Island and Morocco photo tours this winter, and observed that relatively poor and extremely remote Easter Island (Figure 6) has converted to LED lighting, but Morocco, which generally has better infrastructure, is still lit mostly by sodium vapor. Granted, there’s only one town on Easter Island, while Morocco (Figure 5) is a country that is slightly larger than California with several major cities! I guess it’s not a fair comparison, but it was interesting to see. I haven’t been to Cuba since 2015, but I’m guessing that when Gabe returns next week, he’ll report that Havana still glows orange at night!

Figure 5. Essaouira, Morocco. March 2019. Nikon D750 with a Nikon PC Nikkor 28mm f/3.5 lens. 13 seconds, f/11, ISO 100. White balance was set to auto, which used 4350 K, +36 Magenta. I adjusted it to 3950 K, +37 Magenta by clicking the eyedropper tool just above the archway in the foreground. The orange light is high pressure sodium vapor, the green is from mercury vapor, and the archway was lit by either metal halide or LED. The window in the tower is most likely an LED bulb.

Have you noticed the Color of Night in your town lately? Has it changed, and if so, was it for better or worse? Let us know in the comments below or on our Facebook page.

Figure 6: Tahai, Rapa Nui. February 2019. Nikon D750 with a Sigma 24mm f/1.4 lens. 20 seconds, f/2.2, ISO 3200. White balance was set to auto, recorded as 3550 K, +2 Magenta, and adjusted to 3300 K, +6 Magenta. Six vertical images, merged to panorama in Adobe Lightroom. The Moai at Tahai are just at the edge of Hanga Roa, the only town on Rapa Nui, or Easter Island. They are the only Moai that are (indirectly) lit by artificial light, and one of them told me that they were not pleased at being lit up all night every night. Most of the light in this scene is from LED street lighting, but there is one sodium light casting a yellow tinge on the right side of the image. The rock platform in the foreground on the left was lit with a Luxli Viola set at 3200 K.

Lance Keimig is a partner and workshop leader with National Parks at Night. He has been photographing at night for 30 years, and is the author of Night Photography and Light Painting: Finding Your Way in the Dark (Focal Press, 2015). Learn more about his images and workshops at www.thenightskye.com.

UPCOMING WORKSHOPS FROM NATIONAL PARKS AT NIGHT