Early Morning Shooting In Monument Valley’s Backcountry

Sunrise at Totem Pole and Yei Bi Chei, Monument Valley - One must have a Navajo guide to gain access to this scene for photography.

There we were, a fellow photographer (also from Los Angeles) and myself, at 5:40 in the morning one day in April 2009, waiting in the lobby of Monument Valley’s View Hotel. The native Navajo music playing over the lobby’s speakers filled the empty hotel lobby, and my fellow photographer and myself talked about what to expect as were going to go out into Monument Valley’s backcountry for four hours of early morning shooting. Very few people have access to Monument Valley the way we were about to have access to it in just a few short minutes that morning.

It was still dark and cold outside. At exactly 6:00 a.m., the bright headlights from Tom Phillips’ 4×4 SUV appeared within view through the hotel lobby’s doors. The legendary Navajo guide, Tom Phillips, who had led some of the best photographers around into Monument Valley’s backcountry to photograph its splendor had arrived, and with a quick “let’s go” we were off.

As we descended into the valley, Tom spoke about the history of Monument Valley, and told stories about the valley and its people. In particular, he spoke about the famous Navajo Code Talkers, bilingual Navajo speakers recruited during World War II to aid in the transmission of secret tactical messages. We passed by several of Monument Valley’s famous buttes and rock formations, including the Three Sisters. Light from the still present moon was the only light source illiminating these formations in the darkness.

Tom knew where to take us to get the best photos that morning. He knew exactly where to be and at what time.

He stopped his SUV in what seemed like out in the middle of the desert. It was still extremely cold and windy outside when my fellow photographer and I unloaded our photo gear out of Tom’s SUV. Tom led us out much further away, and told us to set up our cameras and tripods in a clearing on the desert floor.

We were about to photograph Totem Pole and Yei Bi Chei, at sunrise. According to Tom, we had only a few minutes to prepare for the sun to peak behind the rock formations. Time was of the essence.

iPhone shot of waiting for the sun to peak at Totem Pole and Yei Bi Chei

The resulting shot was the one that appears at the beginning of this blog post. We snapped away, and meanwhile, Tom was already thinking about the next destination. He yelled at us as he packed up for the walk back to his SUV, “you’re wasting your time!” Time was again, of the essence. With that, my fellow photographer and I also packed up.

The next destination was around the backside of Totem Pole and Yei Bi Chei, Monument Valley’s famous sand dunes. Upon arrival, Tom parked his SUV on high ground in the desert (so we could see it easily on the way back), and led us to a place where we could set up our tripods. There were many places to set up, and many different photo compositions were possible. I worked the area.

iPhone shot of setting up to photograph Monument Valley's sand dunes

I finally found a location and composition that I liked, and went for it.

Sand Dunes Near Totem Pole, Monument Valley

After the sand dunes, Tom took us to a number of different locations. The sun was very much out now, and it was not longer as cold as it had been earlier that morning. Ear of the Wind arch and some miscellaneous rocks with some petroglyphs were some of the highlights.

Ear of the Wind, Monument Valley

Monument Valley Petroglyph

Our four hours of early morning photography were drawing to a close. My fellow photographer was driving to Flagstaff that morning to catch a flight back to Los Angeles. Meanwhile, I still had two full days in Monument Valley. Tom Phillips and I discussed the possibility about taking me out at 3 p.m. that afternoon for some afternoon shooting. He mentioned that there was a possibility of a very strong sandstorm that afternoon, and we decided that it would be best to “play it by ear.” I was to meet him in the lobby of the View Hotel a 3 p.m. that afternoon and we would decide things from there. He made recommendations about other sights to photograph in the area between now and 3 p.m. that afternoon. I took notes. He dropped us off at the View Hotel, and I enjoyed a fabulous breakfast in the hotel’s restaurant. It was a very productive morning of shooting.

Tip: Most of the interesting parts of Monument Valley (ancient ruins, petroglyphs, beautiful arches, etc…) are restricted to the general public, and you need a Navajo guide to access them.  I came here to do only photography, so I charted Tom Phillips, who is well known, very knowledgeable, and has worked with many of the finest photographers around. While Tom works with photographers, and is typically well-booked, there are many guides available at the Visitor Center booth. More information is also available inside the Visitor Center and at the front desk of the View Hotel. Please be sure to tip your guide well. Invest in a guide to get the most out of your Monument Valley experience.

TO BE CONTINUED…

Early Morning in Monument Valley's Backcountry

Disclaimer: Monument Valley is a very rich place in terms of things to see and do. My blog postings related to Monument Valley are not intended to be a substitute for one’s own thorough travel research, but rather a “travelogue” of my experience with visiting and photographing Monument Valley, in order to provide some ideas and insights to others. Many ways to experience Monument Valley exist.

Mitten Sunset (and Shadow), Monument Valley

Monument Valley is one of my most favorite places on this planet.  It is quite a feat to find the words to appropriately describe this location, but in the next couple of blog postings, I am going to give it a shot. Few landscapes in the world come close to paralleling the mystical Monument Valley in terms of color, majesty and magic. It is truly an epic area, and a visit to this remote part of the American Southwest, near the Four Corners region, will never be forgotten.

You have to be crazy enough to come here – The mileages are staggering:
160 or so miles from the South Rim of the Grand Canyon
175 miles from Flagstaff, Arizona
318 miles from Phoenix, Arizona
401 miles from Las Vegas, Nevada
410 miles from Tucson, Arizona

Any other major city in the area that I missed? You get my point?
But those who make the long drive to the Navajo Indian Reservation (where Monument Valley is located and is administered under the tribe’s Parks and Recreation Department) will be rewarded with a landscape and experience that is undoubtedly unique.

When I visited Monument Valley in Spring 2009, I came from Page, Arizona, where I had just photographed Upper Antelope Canyon and Horseshoe Bend. I knew that I was getting close to Monument Valley when I stared out of my car’s window and saw the massive buttes and mesas appearing strikingly from out of nowhere and towering high above the ground. The weather in this part of the Southwest can be fickle and change in an instant. As I approached Agatha Peak (or El Capitan), I was just starting to get caught in a sudden snowstorm, while on my left, I experienced a gorgeous Southwestern sunset.

Mother Nature's Color Palette, North of Kayenta, AZ, on the approach to Monument Valley

I’ve heard of others describing the experience of being caught in one of the Southwest’s legendary and dramatic thunderstorms – an awesome light display that lights up the whole desert put on by Mother Nature to declare her power.

Upon arriving inside Monument Valley Navajo Tribal Park and settling into my room at the View Hotel, I felt as if I had just stepped into a movie. In fact, many movies, music videos, and television commercials have been filmed here over the years, including some westerns directed by John Ford. Despite the fact that Monument Valley has been featured in many forms of media, the location is not a sound stage – it is very real. The sights and vistas here represent some of the finest landscape images of the rugged West, which have been deeply engrained in the American psyche for years.  Say “American West,” and most likely, some images from Monument Valley come up.

Left Mitten, Monument Valley

Monument Valley is very rugged, so be prepared for it. There is a fine red dust in the air and all over the place that permeates everything, and it will eventually find its way onto your clothes and belongings.

The area near the new View Hotel, which opened in December 2008, is the centerpiece of tourism in the park. In addition to the View Hotel, there is a restaurant, an extensive gift shop, and a small convenience store/stand. In a future blog posting, I plan to talk about the View Hotel.  Near the hotel is also a Visitor Center, which was under renovation at the time of my visit, but I believe it is adjacent to the gift shop. Outside the Visitor Center is a small dirt lot, where one can find and charter a tour to explore Monument Valley. Just look for the small booth in the lot to ask for more information, including costs.

Also near the Visitor Center are two rather large boulders which stick out like bumps.  This is the site where Ansel Adams photographed his famous image of Monument Valley, with the three buttes in the background, in 1958.

Things really haven't changed much since Ansel Adams took his famous photograph of Monument Valley in 1958. Above is my version, shot from the same tripod location.

This area around the Visitor Center and the View Hotel is also probably the best area to catch the sunrise in the morning, unless you have a guide which may be able to grant you access to the interior of Monument Valley before the gates open in the morning (more about this in the next blog post).

In my next blog post related to Monument Valley, I will talk about some of the options that one has in order to explore the valley and what it has to offer. Hint: the best way to tour Monument Valley is to invest in and charter a guide.

TO BE CONTINUED…

Few experiences are as unreal and incredible as a Monument Valley sunrise. Taken from the balcony of my room at the View Hotel.

Disclaimer: Monument Valley is a very rich place in terms of things to see and do. My blog postings related to Monument Valley are not intended to be a substitute for one’s own thorough travel research, but rather a “travelogue” of my experience with visiting and photographing Monument Valley, in order to provide some ideas and insights to others. Many ways to experience Monument Valley exist.

Horseshoe Bend in Arizona, USA

The landscape of the American Southwest abounds with crazy and whimsical rock and geologic formations. There are rocks that look like pancakes (or UFO saucers), a Mexican sombrero, mittens, a mother with her child, and more. There is even a geologic formation just north of the Mexican hat that resembles a long gooseneck, scrunched up in a very small area.

Needless to say, they are very interesting to look at. One of my favorite geologic formations is located about four miles south of Page, Arizona. It is a horseshoe-shaped meander of the Colorado River, appropriately named Horseshoe Bend.  It is just simply amazing and something that has to be experienced in person.

From the center of Page, AZ, the Horseshoe Bend is relatively easy to reach. From Page, travel about four miles south on Highway 89 until you reach the entrance to the small dirt parking area for Horseshoe Bend on your right.  It is marked with a sign.

GPS Coordinates for Horseshoe Bend: N 36° 52.599′, W 111° 30.173′ (Parking lot); N 36° 52.765′, W 111° 30.637′ (General overlook area)

Horseshoe Bend Overlook trailhead

From the parking area, it is about a 3/4 mile hike to the viewpoint.  The trail starts from the parking lot with a ascend up a small hill, then a descend into the desert. The rest of the trail is relatively flat, but sandy and with a few curves and ups/downs, as it makes its way to the overlook.  The Horseshoe Bend comes into view as you approach the overlook. You can’t miss it.

Approaching Horseshoe Bend

Once you reach Horseshoe Bend, you come to realize that the scale of the bend is massive, beyond proportions, and standing there at the edge of the cliff, you just feel completely miniscule in the world.  You feel like a tiny ant. No picture can do it justice. It looks small when you see it in a book or photograph, but when you are viewing it in person, you come to realize just how huge this bend is. Horseshoe Bend is something that must be experienced in person.

Take your time, and take it all in.  Look over the cliff, and you see the boats and rafts floating down the Colorado River as little specks (seriously!).  It’s just that phenomenal, from the view to the feelings and sensations.

This place is truly scary and not a place for anybody who is scared of heights.  You can’t really stand at the edge, but rather get down on your stomach and look over the edge while lying down.  It’s hard to describe.  But the vertigo factor here is high.  Try to stand at the edge of the cliff and you’ll see what I mean.  The wind and sand blowing against your body just adds to the overpowering sensation. You have to be really, really careful here.  It’s about a 1,000 sheer foot drop to the Colorado River below, and there are absolutely no guard rails, wind strong, the terrain ragged and strenuous around the very edge.  Hold on to those little ones.

The rugged edge of the cliff overlooking Horseshoe Bend

Due to the immensity of Horseshoe Bend, it is not possible to get the entire bend in one frame using a standard point and shoot camera, unless you use a stitching method.  It is best to shoot Horseshoe Bend with a professional DLSR (preferably full-frame) to take a proper image, and the widest lens that you got – we’re talking 15mm (even 14mm or fish-eye) here (on a 35mm scale). You might be able to get away with 24mm, but probably no more.

To take a picture here, I’d recommend mounting your camera on a tripod, lying down on your stomach at the very edge, and (believe it or not) dangling your tripod with camera attached over the edge, kind of like a fishing pole. Use a cable release to trip the shutter. It worked very well for me.

Some other miscellaneous photography tips:

• The best time to photograph Horseshoe Bend is late morning to early noon, when the sun is behind you. In the afternoon the sun will be directly in front of you.
• Consider using a polarizer to remove any haze and reflection.
• HDR or blending multiple exposures in post-processing would work here if there are strong contrasts between different elements of the scene.
• Leave all the multiple lenses and other gadgets in your car back at the trailhead. Seriously, the only things you need here are your camera and your widest lens. And maybe your tripod and cable release (if you want to try my “fishing pole” method).

Horseshoe Bend is well worth visiting if you’re ever in the Page, AZ/Lake Powell Area. While you’re in the area, don’t forget to visit the other popular photography hotspot in the area – the slot canyons at Upper and Lower Antelope Canyon.

Horseshoe Bend as seen on Google Maps Satellite View

Calcite Springs, Calcite Springs Overlook, Roosevelt area, between Tower-Roosevelt Junction and Canyon Junction, Yellowstone National Park - Processed using the "exposure blending" technique, but using GND filters in the field could have yielded a different result

In the previous and first post from this series, My Experience Using Singh-Ray GND Filters, Part 1: Introduction, I wrote about the so-called dynamic range problem in photography, and the various solutions that exist to overcome it.  Graduated Neutral Density (GND) filters are one possible solution.

In this second posting, I describe the filters and accompanying equipment I chose, and attach the filters to my camera for the first time and share.

What are Graduated Neutral Density (GND) filters?

Graduated Neutral Density (GND) filters are optical filters that are clear on one half, and dark on the other. They are used to bring an overly bright part of a scene (for example, a bright sky) into the dynamic range of the camera’s sensor. They come in different shapes, including round filters that you screw onto the end of a camera’s lens like you would a polarizer. They also come in square (or rectangular) shapes, which most photographers tend to favor, as they allow you to adjust and move the filter to make the ND cut-off line meet the horizon, making square GND filters more flexible. With round GND filters, the ND cut-off line is directly in the center of the image, and many photographers do not frame their images with the horizon line at the center. Because of the flexibility that square filters allow, I decided to go down this route.

Aside from the square and round distinction, GND filters come in two categories: soft-edge and hard-edge. These terms are used to describe the transition between the clear and dark halves of the filter. A soft-edge transition is a more gradual transition. One would commonly use soft-edge filters when photographing scenes where the horizon line is not so easily defined, like some mountain or seaside landscapes. A hard-edge transition is a sudden transition. One would commonly use hard-edge filters when photographing scenes where the change in light is defined (some desert landscapes, for example).

Image courtesy of Wikipedia

The GND filters come in different strengths. These strengths refer to the amount of light that the dark portion of the filter cuts out, from one to five stops more dense than the clear part. Different manufacturers use different methods for measuring the density (or strength) of their GND filters. Singh-Ray sells filters in one, two, three, four, and even five stop strengths. Lee uses the filter grades 0.3, 0.6, and 0.9, corresponding to one, two, three stops respectively. Based on my research, Singh-Ray is unique in that they sell GND filters with a strength of four and five stops. The most popular strengths of filters are two and three stops, especially two stops. For unique lighting situations, one can always combine two filters together.

GND filters can be used with your camera in the following ways: You can get a filter holder (such as the ones from Cokin), which is a device that attaches to a lens, and that holds each GND filter in place. The filter holder is helpful to obtain a precise, exact placement of the GND filter. Some photographers, however, prefer to hand-hold their filter(s) in front of the camera, without the need to use a filter holder. The advantages of hand-holding are that it helps to reduce vignetting, offers more control, is faster, and doesn’t require the photographer to carry and work with extra gear in the field. Note that the filter holder option does allow you to place multiple filters in its slots (see pictures below).

Different manufacturers make and sell the filters themselves. Based on my research, I concluded that while Singh-Ray filters are the most expensive, they are also the highest in quality. They were designed by the late prominent landscape photographer Galen Rowell, and they are used by some of the leading landscape and nature photographers in the world. However, Lee also makes some excellent GND filters, and many photographers have been happy with the results that they have obtained using them. Cokin also makes GND filters, however I cannot comment as to their quality.

My chosen GND setup

The three components of a filter system. Image courtesy of Cokin

A filter system consists of three major parts, as shown in the illustration above: an adaptor ring, a filter holder, and the filters themselves. Let us look at each part one by one, and also look at which parts I chose.

Cokin Z-Pro Filter Holder

While different manufacturers make filter holders, I chose to go with the Cokin Z-Pro Filter Holder. Cokin makes filter holders in multiple sizes to accommodate the gamut of consumer and professional DSLR and video cameras. For the purposes of digital photography up to DSLR, Cokin makes filter holders in two sizes: P and Z size. For more details about the sizes, visit the page on Cokin’s Web site. Basically, the P size is a smaller filter, and the Z size is a bigger filter. I chose the Z size because my camera is a full-frame DLSR. I also plan to use this filter system with a wide-angle lens, and wanted the best setup to minimize vignetting that is possible when using this type of lens with a full-frame sensor.

Cokin Z-Pro 82mm Adaptor Ring (for use with my Canon 16-35mm lens)

Once I chose the filter holder, the need came to choose adaptor rings that will fit each of the lens that I plan to use with the GND filters. This decision wasn’t too difficult at all. I plan to use my GND filters with both my Canon EF 24-105mm f/4 L IS USM lens (which has a filter size of 77mm) and my Canon EF 16-35mm f/2.8 L USM (which has a filter size of 82mm). I simply chose the adaptor rings that will fit these two lens: two adaptor rings, one size 77mm, and the other size 82mm. I had no trouble finding the 82mm. However, I am having some trouble finding the 77mm. Apparently, Cokin is known for having delays in shipping their products to retailers.

One very nice thing about the Cokin filter system (or any other filter system), is that if one uses the square-shaped filters, it is possible to use them on a variety of lens of different sizes without having to invest in individual filters for each size lens. This keeps the cost down when purchasing filters. The rings themselves are reasonably priced at about $30 each size.

So now I had the filter holder and adapter rings chosen. I now had to choose the filters themselves. As said before, I decided to go with Singh-Ray GND filters. I purchased two filters: a tw0-stop soft grad, and a three-stop soft grad. I felt that this is a good starting set, especially for my upcoming trip to Grand Teton National Park. With time, I will purchase hard grads, when I return to the American Southwest for more shooting. Two-stop and three-stop strengths are just good numbers to have in a kit, in my opinion. We’ll see what results I am able to obtain using this “introductory kit.”

Singh-Ray packages the GND filters very nicely

Singh-Ray even provides a protective case with an optical-cloth liner for the each filter's storage

My recently-aquired Singh-Ray GND filters

That’s it!  That’s my basic “introductory” GND filter kit. Now, let’s put them on my camera…

How my GND filters attach to my camera

The Cokin Adaptor Ring screws on to the end of a lens (or the end of a UV filter if it has threads)

Each Cokin Adaptor Ring attaches to the threads located at end of the lens. If you’re using a UV filter that has threads like me (I’m using one manufactured by Heliopan), then the adaptor ring screws right over the UV filter. (a side note: I never, ever leave the glass of the lens exposed while shooting. I always have either a UV filter or polarizer on my lens at all times. Just good practice to prevent damage to the lens’ glass. It’s much cheaper to replace a UV filter than it is a lens’ glass!)

The Cokin Z-Pro Filter Holder slides down over the Adaptor Ring. Pins built into the holder prevent it from moving any further than it needs to

With the adaptor ring attached to the lens, the filter holder slides down over the ring. The peg located at the top of the filter holder helps to prevent it from slipping off the ring/lens assembly.

The assembled Z-Pro Filter Holder and Adaptor Ring

When the filter holder is securely attached to the ring/lens assembly, it’s time to slide the individual filters in. The Cokin Z-Pro filter holder provides slots for three filters. Some photographers prefer to cut off two of the slots, in an effort to prevent vignetting. As mentioned below, my final setup did not produce any visible vignetting, and at this time, I am leaving the three slots intact.

Sliding the GND filters in

A quick word about using polarizing filters with this setup: My polarizers do not have threads etched on the outside of them. As a result, it is not possible to stack anything else (like an adaptor ring) beyond a polarizer. If you need to use a polarizer for your shot, Cokin manufactures a drop-in polarizer that fits into one of the slots on the filter holder. You should see Cokin’s Web site for more details. Also see the illustration below:

Image courtesy of Cokin

The completed Z-Pro Filter Holder, Adaptor Ring, and GND filter assembly, ready for shooting

The Z-Pro Filter Holder with GND filter can be rotated along the Adaptor Ring, which in turn rotates the division between the graduated and clear parts of the GND filter - allowing for flexibility in composing your landscapes

Observed effects of vignetting: My above setup, which uses a Canon EF 16-35mm f/2.8 L USM (the widest of my lenses that I would ever use a GND with), a full-frame digital DSLR, and a Z-size filter system, yielded no observable vignetting at the time of this initial test and writing. Please note, however, there are many different combinations of cameras and lenses, and that vignetting can occur in some of these combinations, but not in others.

A side-view of the completed filter system

That’s all for now. I hope that this posting provided some useful information to anyone researching filter systems for their cameras.

Here are some additional useful resources:

http://www.great-landscape-photography.com/graduated-filters.html

http://en.wikipedia.org/wiki/Graduated_neutral_density_filter

http://www.my-photo-blog.com/graduated-neutral-density-filters

http://timsastroblog.blogspot.com/2008/12/cokin-z-pro-filter-holder.html (another great look at the Cokin Z-Pro Filter Holder)

———-

This is the second blog posting in a series of three postings that describe my initial experience with shooting landscapes using Singh-Ray Filters.

In the first posting, I wrote about the so-called dynamic range problem in photography, and the various solutions that exist to overcome it.  Graduated Neutral Density (GND) filters are one possible solution.

In the third posting, to follow after my upcoming fall 2009 trip to Grand Teton National Park, I report back on the results of shooting landscapes in GTNP using the filters.

Snake River Overlook, Grand Teton National Park - this landscape, processed using the exposure blending technique, could have been improved by using Graduated Neutral Density (GND) filters in the field

The Dynamic Range Problem

Most scenes that a landscape photographer would photograph contain elements that fall into one of two categories: bright and dark. For example, a landscape scene where the sunset is the main subject (like Snake River Overlook, Grand Teton National Park above) might include both bright and dark elements when photographed using only one exposure. The foreground (which might contain a buck and pole fence, a river, trees, bushes, etc…) might be dark, while the sky (containing dynamic clouds or a dynamic sunset) might be very bright. The difference between the brightest and darkest parts of an image is known as its dynamic range. If a shot has very bright highlights, dark shadows and everything else in between, it is said to have a wide dynamic range. The human eye is very powerful. It has the ability to perceive a very large dynamic range. It can perceive a scene with both bright and dark elements.  Unfortunately, our cameras cannot. As a result, without knowing much about dynamic range and how it works, one would either expose for the bright spots of a scene, or the dark ones.

Snake River Overlook - RAW unprocessed exposure, exposed for the bright spots

Snake River Overlook - RAW unprocessed exposure, exposed for the dark spots

As one can see, the top image which is exposed for the bright spots in the scene, shows some detail in the sunset and sky, but elements and detail in the foreground are lost (the foreground is underexposed).  The bottom image, which is exposed for the dark spots in the scene, shows the foreground detail, but the detail in the sky is washed out or lost (the sky is overexposed).  In both of these exposures, it would be very difficult (if not downright impossible) to restore the lost detail in post-processing.

There are several solutions to the dynamic range problem in photography:

1. Use the “exposure blending” technique (which I used for my Snake River Overlook, Grand Teton National Park composition above)
2. Use High Dynamic Range Imaging (HDR), a technique which is becoming widely popular
3. Use Graduated Neutral Density (GND) filters

Numbers 1 and 2 above require creating several exposures of a scene in the field, and later combining them using computer software (a program like HDRsoft’s Photomatix Pro) in post-processing.  I can do this, and I’ve done it before. However, my goal moving forward is to explore the use of GND filters (option number 3) and how they can improve my landscapes.

Why use Graduated Neutral Density (GND) filters?

Using GND filters, you are able to bring to the camera what your eyes see, both bright and dark elements. This without using any Photoshop or software post-processing. Taking photos of landscape scenes which include moving water (a waterfall or river, for example), can also be a problem if you intend to take multiple exposures to either blend them together or create an HDR in post-processing. The same problem applies to fast-moving clouds in a scene. GND filters help curb these problems. And of course, they help diminish the amount of time spent in front of a computer in post-processing. Flat out, GND filters are indispensable when the need arises to control the contrast range in any landscape image to avoid blowing out highlights, like dramatic skies. Many professional photographers attest to their usefulness and some say that they are among the best investments they have made for their cameras.

The outstanding, beautiful, and jaw-dropping work of photographer Patrick Smith inspired me to look into GND filters, and explore how they can help improve the quality of my landscapes.

———-

This is the first blog posting in a series of three postings that describe my initial experience with shooting landscapes using Singh-Ray Filters.

In the second posting, coming soon, I describe the filters and accompanying equipment I chose, and attach the filters to my camera for the first time and share.

In the third posting, to follow after my upcoming fall 2009 trip to Grand Teton National Park, I report back on the results of shooting landscapes in GTNP using the filters.