Tag: Tone Mapping (page 1 of 2)

Four Peaks at Night

I took this shot from my balcony earlier this evening and tone mapped it with Mantiuk ’06 Contrast Equalization (using -e 0.6).  The exposure lasted nearly 20 minutes.  It’s not as sharp as I’d like, but I don’t think I had the lens focused correctly.  (I couldn’t see anything in the viewfinder to focus it at all!)

Sigma 50-500mm lens at 140mm.  f/11, 1179 seconds, ISO 100.

Red Mountain and Saguaro

I got this photo yesterday while hiking the Sunrise Trail with Nick and Marilyn.

Nick had asked me, yesterday, about the “enhancements” used to create some of my photos.  The answer was highly technical, so I just said “a lot”.  For the above photo, I did the following.

  1. I processed the RAW file with the photo twice and brought each image into GIMP as a separate layer.  I used an appropriate exposure compensation value for the background with the white balance set to “Daylight”.  I processed the image a second time for the saguaro with the white balance set to either “Cloudy” or “Shade”.  I probably used “Cloudy” because “Shade” usually makes things too red for my liking.  For some photos, I may process the RAW file additional times with different exposure values or I may use one of the (exposure) bracketed files showing (roughly) the same shot.  (Additional work – alignment – is required when I process a different exposure.)
  2. I placed the saguaro layer on top and carefully created a layer mask so that just the saguaro would be visible from that layer.  The underlying layer had a very dark, almost black, saguaro due to being underexposed.
  3. When this is done, there is frequently some light fringing around the border of the mask.  I touch this up by painting into the layer mask with a partially opaque brush.  I’ll vary the brush size and degree of transparency depending upon the area under consideration.
  4. At this point, I hopefully have an image which could stand on its own without any additional work.  However, I’ve found that detail is increased if I add a tone layer created using the Mantiuk ’06 tone mapping operator.  So, I run the tone mapping operator on the RAW file and bring that result into GIMP as yet another layer.  This layer is placed on top.
  5. I disable the tone layer momentarily and create a “color” layer from the bottom-most two layers.  These were the layers that I had originally processed from the RAW file. I set the layer mode on the “color” layer to Color.
  6. The resulting image often looks too harsh.  In particular, there are frequently some white areas, often in sand or foliage, that appear too bright.  I create a layer mask for the tone layer and partially mask these areas exposing the results of the original two layers.   I will also often mask out the sky as it often appears quite blotchy.  If the sky has interesting clouds, tone mapping will sometimes help to explicate those clouds; in those situations, I’ll often leave some or all of it in place.  But even then, tone mapping can cause excessive sharpening.  Experimentation is required to find just the right level of masking.
  7. I create another new layer using “New from Visible”.  This layer will combine everything that can be seen in the image so far.  I use the “Curves” tool on this layer and make minor tonal adjustments.  I try to keep these minor though because some color changes will often occur at the same time.
  8. The top layer (upon which I had made tonal adjustments) is duplicated again.  I sharpen this layer using “Unsharp Mask”.  Portions of the image will often appear too sharp.  I create a layer mask and mask those portions out, exposing or partially exposing the unsharpened layer underneath.
  9. The image is written out three times, once in GIMP’s native (XCF) format, once as a JPEG file at full resolution, and a third time as a JPEG file that’s 1080 pixels high.  I’ll use this latter file in my blog posts.  All layers that I used in creating the image are preserved in the XCF file.  This allows me to go back and tweak parts of the image if I should decide that I don’t like it for some reason.  (This happens with some frequency.)

This is what the layer dialog looked like when I was done with this photo.  For some photos, I will end up with ten layers or more.

Scottsdale, after Sunset, from the Sunrise Trail

I got this shot on Saturday while hiking back on the Sunset Trail with Marilyn.  We came to an overlook area and saw the lights of Scottsdale along with a colorful, post-sunset sky.  I rested my camera on a large metal toolbox that the city keeps out there.  Presumably it has shovels, picks, and the like for trail maintenance purposes.  Anyway, the first several tries didn’t work out because I still had to level the camera and I was trying to do so by supporting the camera and lens with my fingers.  I finally got two rocks that I positioned in between the top of that metal toolbox and the camera.  It wasn’t perfect, but it allowed me to hold the camera steady enough to get the photo below.

This photo was created using three exposures at ISO 200, f/4.0, with exposure times of 1/2 second, 2 seconds, and 6 seconds.  I first blended the exposures together by hand.  From this, I created a color layer.  I interposed a tone layer set at 50% opacity above the original three layers that I had blended earlier and below the color layer.

The tone layer was created by running the Mantiuk ’06 contrast equalization algorithm on the RAW file from the lightest (longest) exposure.  Ideally, you’d use all three exposures to create the tone layer.  I had tried this, but did not get good results due to a slight misalignment of the three images.  I mainly wanted the tone layer to explicate foreground detail, so I used that exposure to create the tone layer.

I have been asked about that big barren space is between the lights near the horizon and the lights nearer to the camera.  This is what I’ve figured out…

First, it’s important to know that we’re looking south and somewhat west in this photo. You can see that the sky is brighter at the far right in the photo. That’s where the sun had set perhaps 20-30 minutes before the photo was taken. (It got quite dark perhaps another 20 minutes after taking that photo – dark enough that we got out our headlamps so that we could be more certain of our footing on the way back. We thought we were locked in at the parking lot too, but luckily the gate senses vehicles that are trying to get out and automatically opens.)

Shea Blvd is the big, well lit road in the photo. If you start at the left edge of the photo, it starts a little over half way up and extends across most of the photo, angling slightly upward as you follow it to the right. The hill to the right in the immediate foreground eventually blocks our view of Shea Blvd. If you follow Shea Blvd from the left of the photo, you’ll see the lower slope of a small mountain just above the road – to the south. There is a small road which intersects Shea that’s visible in the photo. It goes south (and north) of Shea and runs between that small mountain and a hill to the west. That small road is 136th Street.

The big cluster of lights in the center of the photo, just to the north of Shea Blvd is Mayo Clinic. There are some residential areas which are part of Scottsdale just south of Shea in that photo, but they don’t extend very far south. Once I found these landmarks, I was able to look at a map to figure out the rest. Here’s a link to a map showing Shea and 136th St. You’ll have to zoom out a bit to see more of the surrounding area.

There is a big empty looking area south of those residential areas which are, in turn, south of Shea.  This sizable tract land used mostly for agricultural purposes.  There are some homes there too, but it’s much less densely populated than the cities which surround it. It belongs to the Salt River Pima-Maricopa Indian Community. To the south of that – i.e. the lights further on up the photo towards the horizon – are the cities of Mesa and Tempe. Mesa is more to the left and Tempe is more to the right. I can’t say for certain where one ends and the other begins – it may even be that Tempe isn’t visible at all in the photo. I think too that some of the southern portions of Scottsdale are visible off to the right. If you look to the far right, you can see a small portion of Camelback Mountain at the edge of the photo.

Here is another photo looking in the same direction, but taken from a different overlook.  I don’t like this shot as well, but it does show what the area looks like in the daylight.

Hiking the Dixie Mine Trail with Marilyn and Joe

Joe, Marilyn, and I went out late Sunday afternoon and hiked out a ways on the Dixie Mine Trail.

There were several contrails that hung around for the duration of our hike.  Here’s a photo where they seem to form a “V” emanating from behind one of the McDowells.

Weaver’s Needle is off in the distance in the photo below.  You can also see a part of Dixie Mine Trail in the foreground.  It’s a nice trail in that section.  There’s not a lot of elevation gain or loss, but numerous small hills and washes give texture to the terrain.

The half-moon and a nearby saguaro:

A particularly scenic section of the Dixie Mine Trail:

Mother and son hiking together just after sunset.

Another view of the contrails as the sun was setting:

A short while later, we turned to see that the setting sun had turned the contrails a brilliant reddish orange:

Another edit of the above photo using the Mantiuk ’06 contrast mapping algorithm.  All of the above photos use the Mantiuk ’06 contrast equalization algorithm.  In the tests that I’ve done, contrast mapping seems to produce more realistic looking results, but I often like the look obtained using contrast equalization.  The sky in the photo below is fairly close to the image obtained out-of-camera, but the out-of-camera foreground detail is very dark; so dark in fact that it appears to be mostly black.


The Gossips

Below is a photo of The Gossips in Arches National Park.  I have other edits of this photo and I may have even posted one in the past, but they all look a lot different.  The sun is behind the gossips in this photo creating a very bright sky.  The out-of-camera photo is considerably darker, making it difficult to see much detail.

Marie with a Dog on the Moab Rim Trail

This photo was taken last June during our trip to the Moab area.  On our way up the Moab Rim Trail, we saw two dogs bounding up the hill.  In this picture, Marie has stopped to take a photo of one of the dogs.

Friday Fitness Hike

Today’s hike started at the Trailhead Staging Area.  In addition to regulars, Bob, Linda, and Janet, two other hikers joined us today: Elma and Connie.  Elma and Connie told us that they do a lot of hiking at South Mountain; this was their first visit to McDowell Mountain Park.

We hiked out about a mile on the Pemberton and came back on the Scenic Trail.  Total distance for that segment was a little over 4.3 miles.

As we started up the Scenic, I took this photo of the sun coming up over the hill.  Tone mapping it gave it an interesting look – the photo was kind of boring otherwise.

A short ways further, I turned around and took a photo of the clouds with Little Granite Mountain (I think) off in the distance.

Janet, Linda, Elma, and Connie:

A view of Four Peaks from midway along the Scenic Trail:

When we got to the wash, Bob pointed out this Red-tailed Hawk:

When we got back to the staging area, Bob found this spider in the bathroom!

Bob, Linda, Janet, and I then started on the second part of our hike.  We hiked out the Pemberton in the other direction.  Janet turned back just after we crossed Stoneman Wash.  (She had other errands to do…)

Bob, Linda, and I continued on and took a look at this wash:

We also hiked a bit of the Tonto Tank Trail.   Here is Linda taking a photo of some cacti and an ocotillo at the top of the steep section near the beginning of the trail.

Here’s my own photo of that scene:

Bob, Linda, and I hiked a total of 9.35 miles today.


A Small Hill at the Edge of the Island

Below is another photo taken during our visit to the Island in the Sky in Canyonlands National Park.  I eventually hiked around that hill to the edge of the rim to get some other photos.

This one was tone mapped with Mantiuk ’06.  I set the opacity of the tone layer to 85 percent and did some further partial masking of the sky and some of the overly white areas in the foreground.

Here’s a crop which is interesting too…

Candlestick Tower in Canyonlands National Park

I had a rather dingy looking picture of Candlestick Tower that I took during our visit to the Moab area last June.  I decided to see what tone mapping using Mantiuk ’06 would do for it…

Below is the cleaned up and cropped version that I started with.  I edited out the sensor dust to make an image to feed the tone mapping operator.  It seems that Mantiuk ’06 is really good at finding sensor dust in the sky.  When used on a person, it’ll find the smallest skin blemishes or even perspiration that you might not even notice in the starting photo.

As a consequence, I often do a significant amount of masking.  If the image has people in it, I’ll mask them out of the tone layer.  In the above photo, I masked the sky out entirely as it had entirely too much noise for my liking.  I will sometimes partially mask some of the really intense highlights too.

Red Mountain through Ocotillo Branches

I took this photo back on July 14 just after a big storm swept had swept through the area.  I had tried editing it several times, but wasn’t happy with the results.  Today, I tone mapped the image and then applied some other small edits resulting in the image below.  I’m also including a crop which is interesting too.