Sunday, August 10, 2014

Further quantification of the Mavericks color management problem

I spent some time further quantifying the display problem that Mavericks introduced and that affects Lightroom, Aperture, and every other application that uses Apple color management libraries. In short, the problem is that shadows get crushed upon display. This is a serious bug that is remaining unfixed since OS X 10.9 and is apparently present even in the Yosemite beta. I am trying to raise awareness of this bug since I am getting no reply from Apple not from a bug report and not from directly emailing folks there. This should get fixed as it makes it tough to do serious work on Mavericks. You can work around it by using Photoshop which uses its own color management library or by using the soft proof feature in Lightroom. Mac OS X 10.8 and below do not have this problem and correctly show the shadows. This is independent of what color calibration you use and even shows up when you use Apple's supplied profile for your display.

I generated a simple photoshop file that has swatches of grey ranging from 1 to 100 in 8-bit scale and then used the system color taste dropper that you can get to if you open textedit and click the text color box. Then use "Show colors" and you can then "taste" any color on your screen and get the display values. These values are what is actually sent to the monitor and so are very useful for this purpose. Below I plot the values seen in Photoshop (correct), those in Lightroom Library and Lightroom Develop. I am not showing Aperture as those are the same as Lightroom Develop and also very wrong. I am using a double log scale to really show you the problem areas in the darker regions below r,g,b=25.

I did this using the nice plotly plotting service. The images sometimes take a short time to show up. You can find the data in the link on the bottom of the plot. Photoshop's light bump in the shadows is correct as sRGB has a little knee in the shadows. Lightroom Develop due to the Mavericks bug displays way lower intensity than it should leading to the crushed shadows that people are observing.

I also created the same swatch file in the color space of my monitor profile. The display of those swatches should happen at exactly the same display value as the input file. This really illustrates the problem I think.

Photoshop clearly does this correctly. The relation is almost exactly linear and any deviations are a single bit difference which is just a rounding error. Lightroom Develop shows way below. Lightroom Library is close but with a larger error than Photoshop. Below is the same data bit plotted as display error.

Mavericks causes Lightroom Library to be off by a full 8 points in the shadows! I hope this data is useful to somebody and helps some folks that have puzzled over dark shadows in Mavericks applications.

Saturday, August 2, 2014

Old Man and the mountain

Old man of the mountain flowers blooming at the shores of Andrews Tarn below Andrews Glacier in Rocky Mountain National Park. I visited this place after my visit to Sky Pond and Lake of Glass for sunrise. The mosquitoes were amazingly thick this morning and they were not impressed by the bug spray I was using ;-).

Old Man. Bigger. Flickr. Facebook. G+
Nikon D600, Tokina 16-28mm f/2.8 at 16mm, f/22, 1/60s, ISO 100, handheld.

Sunday, July 27, 2014

Cathedral Spires sunrise

Sunrise aplenglow on the majestic Cathedral Spires seen from the shore of Sky Pond.
Nikon D600, Tokina 16-28mm f/2.8 at 16mm, f/16, 1/5s, ISO 100

Cathedral Spires Glow. Sunrise casts alpenglow on the majestic spires over Sky Pond, a high alpine lake in Rocky Mountain National Park's Loch Vale.

Sunday, June 22, 2014

The many faces of Alstrom Point

My trip to the Southwest last April with a group of friends had three planned destinations. The Bisti Badlands/De-Na-Zin Wilderness, Alstrom Point and the White Pocket. I have pretty much gone through the Bisti Badlands images and posted those on my website except for a few that I am still working on. The Alstrom Point images are halfway done. For the White Pocket, I have a lot of work to do. I only posted two black and whites and the real stunners are still to come. This post is mostly about the Alstrom Point images. Alstrom Point is reached after a long drive over a dirt road and some four wheeling over a little slick rock. The location is a stunner though. You look out over Lake Powell and Gunsight Butte. We spent a single night there but even then it was amazing to see the different phases the view went through. I shot many different perspectives but the classical view is still what stood out. As always, click for bigger and for prints.

First sunset

Sunsight on gunsight butte.
Nikon D600. Nikon 24-85mm at 24mm, f/16, 1/25s, ISO 100. Grad ND filter.

The moon was out most of the night and very brightly illuminated the lake and rocks. The bright "star" in the middle is the planet Mars.
Moonlight illuminates Gunsight Butte and Lake Powell
Moonlight illuminates Gunsight Butte and Lake Powell
Nikon D600, Tokina 16-28mm f/2.8 at 16mm, f/2.8, 15s, ISO 1600.

The moonlight was so bright that it was easy to photograph the surroundings. I put my headlamp in my tent to obtain this:
moonlight lights the desert near Alstrom point. A headlight illuminates the inside of my tent.
moonlight lights the desert near Alstrom point.
Nikon D600, Tokina 16-28mm f/2.8 at 16mm, f/2.8, 15s, ISO 1600.

Close to sunrise, the milky way had come out very brightly and we had a lot of fun shooting images of it. I created two views - one vertical and one horizontal, by combining two exposures. One for the stars and one much longer for the foreground. You can already see the sunrise light starting to pour over. The bright star is the planet Venus in this case.
Milky Way and planet Venus rising over Gunsight Butte and Lake Powell as seen from Alstrom Point in the Grand Staircase, Escalante Wilderness. Vertical version.
Milky Way and planet Venus rising over Gunsight Butte and Lake Powell
Nikon D600. Tokina 16-28mm f/2.8 at 16mm, f/2.8, ISO 1600, Two exposures at 15s and 246s.

I also created a horizontal version:
Milky Way and planet Venus rising over Gunsight Butte and Lake Powell as seen from Alstrom Point in the Grand Staircase, Escalante Wilderness.
Milky Way and planet Venus rising over Gunsight Butte and Lake Powell horizontal.
Nikon D600. Tokina 16-28mm f/2.8 at 16mm, f/2.8, ISO 1600, Two exposures at 15s and 221s.

Close to sunrise, the glow started to drown out the stars but the pinks were coming out in force.

Nikon D600, Tokina 16-28mm f/2.8 at 16mm, f/11, 1/6s, ISO 100.

I also created some panoramics of which this is my favorite. It really should be seen much bigger in the link.

The grey before dawn.
stitched from 4 images from Nikon D600, Nikon 24-85mm at 24mm, f/11, 1/6s, ISO 100

Closer to sunrise, the glow turned red and orange:

Nikon D600, Tokina 16-28mm f/2.8 at 20mm, f/11, 1/20s, ISO 100.

And finally the sun peeked over and gave a nice sunstar: The sun peers over gunsight butte seen from Alstrom Point.
The moment.
Nikon D600, Tokina 16-28mm f/2.8 at 19mm, f/22, 1/20s, ISO 100.

Again, enjoy these images bigger in the links behind the images.

Saturday, June 21, 2014

The Polar Vortex - Star Wings

When I was at the Bisti Badlands/De-Na-Zin Wilderness this April, we decided to leave our cameras for star trail images. The location we chose was the Wings, which is an amazing formation. We set up our cameras each in our own way. I chose a horizontal composition with the pole star being pointed at by one of the Wings. My reasoning for a horizontal image was that I could also turn it into a time lapse. I shot 30 seconds exposures on the built-in interval timer in the camera. I used my Tokina 16-28 mm lens at 16 mm, f/5.6 (to get more of the wings in focus) and ISO 1600. The battery lasted for a little over three hours. We left the cameras and hiked back to the cars to have dinner and returned for the cameras. These were extremely difficult to find as in the mean time the moon had set and this place is a complete maze. Finally with some help of a GPS waypoint and the red lights on my friends' Canon cameras, we were able to retrieve them. At home the fun started. I combined all 300-some raw images in Photoshop in batches of 10 using the lighten mode. I cloned out all the jet trails, sensor hot pixels, and a few distracting meteor trails. I then took the 30-some remaining images and combined them in Photoshop, again using lighten mode, but now using progressively increasing opacity. This created the comet effect you see below.

Moonlight illuminates The Wings formation and stars form trails at Bisti badlands
Moonlight illuminates The Wings formation and stars form trails at Bisti badlands.
This image is also on Flickr, Facebook, and Google+.

I also created some time-lapse movies using the individual frames. If you click through you can get to the HD versions that use a HTML5 (i.e. tablet and phone friendly) display. You can see a in the lens reflection from the very bright moon move in the frame. This disappeared in the composite image luckily.

And this is the same thing but without the pan and zoom of the previous.

I find it amazing how many planes you can see come by. The music was "composed" by me using Garageband.

Saturday, April 26, 2014

The cracked eggs

In the beginning of April I spent some time in the Bisti Badlands/De-Na-Zin Wilderness. This is an extraordinary place which one could explore for days and days. We did a sunset around the area people call "Stone Wings" and I shot a very nice star trail image there (more on that later - it takes quite a bit of explaining). The next morning, we went for sunrise to an area called the "Cracked Eggs". It is exactly as the name implies. Below is a small slideshow of images from this extraordinarily nice location. For those on iOS or Android tablets, you should be able to see the slideshow here by clicking slideshow in the link. I'll post detail on the images later.