Monthly Archives: July 2005

Pile of Marbles

Here’s what $8.50 can get you on eBay if you like marbles…

Aren’t They Marbelous!

I bought five pounds of old marbles on eBay, and cleaned them today.
I photographed a few of these marbles on a mirror using one of my new Kenko extension tubes to get close.

There was some dust on the mirror, but the marbles looked good. Phyllis helped me make something of the image in Photoshop. First we used the Glowing Edges filter to give the marbles their distinctive, electric, other-wordly look. Then we selected the background (Magic Wand, Lasso, etc.) We filled the background with black. After that it was cleanup with the Clone Stamp Tool.

More experiments with the extension tubes and more “marbelous photos” to come…

Fog Rolling In Across the Bay

I took this picture yesterday when I was out with Nicky. It’s cropped and the colors are boosted using the Photoshop Hue/Saturation dialog.

I like the effect, sort of like a Japanese screen. The image shows fog rolling over San Francisco Bay, with Mount Tamalpais in the background.

Photoshop and Digital Photography Techniques

June Lake

I seem to be writing about digital photography techniques, workflow, photography, and Photoshop. Here’s what I’ve written recently in Photoblog 2.0 about these things:

The Evolution of Photography



Wet Rose, photo by Harold Davis.

I love my digital cameras, and am blown away by the intelligence built into them. My Nikon D70 gets a great many things right in one of its auto exposure modes. This picture was taken in aperture-preferred mode on a tripod, where I set the aperture and the camera picked the shutter speed, but this is an exception that proves the rule.

For the most part, digital cameras even as elegant as the D70 are old-style SLRs grafted onto a sensor-based digital capture array (instead of film). Why can’t camera manufacturers start thinking about a camera that leaves the evolution of photography behind – and recognizes the reality of digital photography?

I’d like to see:

  • A reasonable language and interface for programming my digital camera.
  • A mechanism for saving my images directly to my computer via USB when I’m in the studio (this would be faster than Flash card storage, and save a workflow step).
  • The three exposure control variables in a camera are ISO, aperture, and shutter speed. You can easily control aperture and shutter speed, but not ISO. This is a holdhover from the days of film, in which the film selected pretty much controlled the ISO you used. In the digital era, ISO should be set via a dial on the surface of the camera, just like aperture and shutter speed.
  • A way to easily program bracketing for greater flexibility with exposure

Do you have any suggestions about what a digital camera should be? Please add them as a comment here. Maybe the camera manufacturers will listen to us…

A Lost Hiker

In the stillness of the early morning at the beginning of July of this year I stood by my campsite high on a ridge admiring the snowy view of the high Sierras. Later that same day, by a snow-covered Thousand Islands Lake, I photographed these wild flowers in a rock outcropping that was emerging from the snow.

You can read the story of this adventure of mine in three parts:

I was reminded of my difficult, but beautiful, trip yesterday when I got a call from a National Park Service ranger asking whether I’d seen missing hiker Hyundo Ahn. Ahn would have been coming south along the John Muir Trail; according to his wilderness permit and mine we would have been in roughly the same place at the same time (the upper Rush Creek basin). The ranger tracked me down on the basis of the dates and locations shown in my wilderness permit.

I didn’t see Hyundo Ahn, a lingusitics student at U.C. Davis, when I was in the Ansel Adams Wilderness back country. Considering the snow conditions, I doubt he made it out over Donahue Pass from Yosemite National Park. I am deeply sorry for his family and friends, and offer this photo of mountain flowers as a testament to the beauty and purety that hides amid the remoteness of the wild – and why it is worth sometimes putting aside the safety net of civilization and exploring these difficult places.

Update (8/19/05): Hyundo Ahn’s body has been found in Tenaya Canyon. The exact cause of death is unknown. He never even made it as far as Tuolomne Meadows, and was not in the area I hiked. Condolences to his friends and family.

Flowers and Reflections

More flowers from my garden photographed as a still life. I can’t help myself, I enjoy working with flowers so much…

Faulty Towers Cake

Happy Birthday, Julian. It’s numero 8.

His mom made this great cake that melted in the heat. The knight defended the castle valiantly against threats known and unknown, including the shadow of the lens.

Julian had a great time at his party:

Julian

Flowers on Mirror

What is it about photographing flowers that is so satisfying to me? I will never get tired of photographing flowers – or of looking at flowers and enjoying their colors and smells.

From a technique perspective, it works well indoors to put the flowers on a mirror and shine a slightly warm light through the flowers (from behind and to the right of the arrangement in this picture). I had my camera mounted on the tripod (of course), and I used a cross piece on top of the tripod so I could easily move the camera perpendicular (straight down) on the composition.

I’ve had a strenuous day – up early with the kids, a time consuming and peculiar consulting project, and an interaction with the editor of my current book project that was upsetting – so it’s nice to be able to be comforted with something as simple as photographing flwrs on the mirrr (and to get a smile by eviscerating vowels, er, vwls, just like flickr!).

Opening Camera RAW in Photoshop CS2

Opening a camera raw image in photoshop cs2

In a previous post I explained the basics of my workflow for processing a digital image in Photoshop. The first step in this process is to open the image in Photoshop, use the Camera RAW adjustment dialog to process the raw image when it is imported, and save the image off as a PSD file (so you can archive the RAW original).

If you haven’t already seen it, take a look at the dialog that opens in Photoshop CS2 when you open a photo saved in Camera RAW format (shown above). It’s a great deal more powerful than the comparable dialog in CS1, and from the viewpoint of digital photographers everywhere this power and flexibility is a Very Good Thing.

Hey – don’t be put off if you haven’t been using your camera’s RAW file format. You should be. For the time being, you can just accept the default / Auto settings in the CS2 dialog, and you’ll get pretty good results — better certainly than shooting in JPEG. It’s fair to say that this window in CS2 is a complex as you need it to be, or as simple. If you are in a hurry, and don’t want to worry too much about tweaking the color balance of your image, as I’ve said, you’ll do pretty well with the Auto and default settings most of the time.

Here are some pointers to help you get started with the wonderful (but complex) RAW Settings files in cs2.

You can open a RAW photo, and get the CS2 RAW Settings dialog to open either from Photoshop itself, or from the Bridge (the new implementation of file browsing in the Photoshop universe).

First, you can save (and open) camera RAW settings. These are the .XMP files you may have seen in the same directories as your RAW images (each one is named the same as a RAW image but with a .Xmp suffix, for example DSC_0001.Nef and DSC_0001.Xmp). These files are written in XML (so you can open them in a text editor and take a look at them) . It’s useful to know about this if you have a number of images from the same batch that you want to treat in the same way.

The title bar of the RAW Settings dialog shows you Exif information for the photo: ISO, lens, and exposure.

Right below the title bar, you have controls that allow you to easily zoom in on an image, crop the image, rotate the image, straighten the image, and take a color sample.

Histogram in RAW Settings dialog in photoshop cs2 The Histogram, in the upper right of the RAW Settings dialog, and shown to the left, is a visual representation of the spectrum of RGB color values in your photo, and will also show you the exact RGB values for any point in your image (by holding one of the controls over the point).

The Workflow Options, at the bottom of the RAW Settinsg dialog, lets you set target color space profile, bit depth, pixel dimension, and resolution. (These settings can also be changed once the image is opened in Photoshop.)

To load a previously saved RAW settings to the current photo, click the triangle to the right of the Settings drop-down list (below the histogram), and choose Load Settings from the context menu (browse for an XMP file). You can also use this context menu to save the current settings.

Now for the fun stuff! Most often, if you want to play with anything other then the default and automatic settings, you’ll want to do this with the sliders on the Adjust tab. I’ll discuss the most important of the settings these sliders control below, as well as giving you an idea of what you can do with the four tabs beneath the Adjust tab.

Tonal Adjustments The Adjust tab, shown to the left, is used for tonal adjustments to a camera RAW photo. First, you can set the white balance of the photo from the drop-down list of preset white balances. White balance is the setting used to make something white appear neutral (without a color cast) in a given light.

If you leave this to “As Shot,” then the camera’s white balance settings will be used. Otherwise, you can choose from Auto, Daylight, Cloudy, Shadows, Tungsten, Flouresecnt, Flash, and Custom.

Generally, you’ll find that either As Shot, or Auto does a pretty good job. But depending on the photo, you may want to tweak white balance a bit.

Temperature adjusts the color temperature on the Kelvin scale. The higher the Kelvin number, the “warmer” (more red) the image looks, and the lower the Kelvin number the “cooler” (bluer) the image.

Tint fine-tunes the white balance to compensate for a green or magenta tint. Move the slider to the left (negative values) to add green to the photo; move it to the right (positive values) to add magenta.

If you use the Temperature and Tint sliders to tweak the white balance even slightly, the drop-down white balance setting will change to Custom.

If you check the Auto box for each tonal slider, Photoshop will do its best to find the optimal tonal settings for you. Otherwise use the sliders in order from top to bottom to adjust the image as described:

  • Exposure adjusts the brightness or darkness of the image. Move the slider to the left to darken the image; move it to the right to brighten the image. The values are in increments equivalent to f‑stops. An adjustment of +1.00 is similar to widening the aperture one stops. Conversely, an adjustment of –2.0 is similar to reducing the aperture 2 f-stops.
  • Shadows specifies which input levels are mapped to black in the final image. Moving the slider to the right increases the areas that are mapped to black. This sometimes creates the impression of increased contrast in the image.
  • Brightness adjusts the brightness or darkness of the image, much as the Exposure slider does. However, instead of changing the image in the highlights (areas that are completely white, no detail) or shadows (areas that are completely black, no detail), Brightness compresses the highlights and expands the shadows when you move the slider to the right. In general, you should use the Brightness slider to adjust the overall brightness or darkness after you set the white and black ranges with the Exposure and Shadow sliders.
  • Contrast adjusts the midtones in an image. Higher values increase the midtone contrast, and lower values produce an image with less contrast. Generally, you use the Contrast slider to adjust the contrast of the midtones after setting the Exposure, Shadow, and Brightness values.
  • Saturation, or color intensity, adjusts the color saturation of the image from –100 (pure monochrome) to +100 (double the saturation). No Auto check box is available for Saturation, so this is something you have to adjust manually depending on how it looks to you.
Sharpness A Camera RAW image as shot has had no sharpening algorithms applied to it. The Details tab is used to adjust sharpness, essentially using the Unsharp Mask filter. You can see the impact of your sharpening on the image that you are opening, provided the Preview box is checked.

The default sharpness is 25%, but can certainly see what a greater percentage will do for your image (it may look surprisingly good). (Of course, you can also apply sharpening once an image is loaded in Photoshop.)

The two other sliders on the Detail tab are used to reduce noise — the random appearance of pixels that degrade image quality and often appear when images are shot at high ISOs that are analagous to film grain.

The Luminance Smoothing slider reduces grayscale noise, which makes an image look grainy, and the Color Noise Reduction slider reduces chroma noise, which usually shows up as random colored pixels. Moving a slider to zero turns off its noise reduction.

Lens You can use the sliders on the Lens Tab to compensate for chromatic abberation introduced by digital camera lense. One slider is used to compensate for red/cyan color fringing by adjusting the size of the red channel compared to the green channel. The other slider is used to compensate for blue/yellow color fringing by adjusting the size of the blue channel compared to the green channel.

Vignetting is a defect that causes the edges of photos — particuarly the corners — to be darker than the center of the image. (A common cause is mounting your lens shade incorrectly.)

You can use the vignetting sliders to fix a vignetting flaw — or to add some vignetting as a special effect.

The Amount slider controls how much vignetting there is (how dark it is), and the Midpoint slider controls the size of the area of the overall vignetting.

Tone Curve The Tone Curve tab adjusts tonality using a curves adjustment. You can use the Tone Curve menu to choose a preset adjustment. I’ll be writing more about how to use curves to adjust the tonality of an image loaded in Photoshop in a future entry.
Calibration The Calibrate tab lets you correct a color cast in the shadows and adjust non-neutral colors to compensate for the difference between the behavior of your camera and the Photoshop Camera RAW conversion built‑in profile for your camera model.

Sometimes a color cast remains in the shadow areas after you adjust the highlight white balance using the Temperature and Tint sliders. The Calibrate tab has a Shadow Tint slider to correct this remaining shadow color cast.

In the Calibrate tab, move the Shadow Tint slider to remove the color cast in the shadows. Usually, moving the slider to the left (negative values) adds green to the shadow areas, and moving the slider to the right (positive values) adds magenta.

Here’s a link to an entry showing the finished photo after opening in Photoshop and processing, and saving (as a JPEG) for the web. The settings I used to open this Camera RAW photo into Photoshop were a custom Kelvin temperature of 6050 degrees, Tint +6, Exposure – 1.1, Shadows 17, Brightness 130, Contrast +25, and Saturation +24.

Mud Hollow

Julian and I drove out to Limantaur Beach on Pt Reyes. We walked on the Mud Hollow Trail for half a mile or so until the sign said “Hazardous Conditions: Trail Under Water.” We couldn’t really go any further, but these boats in the Mud Hollow pond were quite pretty.

Afterwards, we went to Limantour Beach, and Julian cackled with joy as he built sand castle after sand castle – and each fortification was swept away by the waves. Limantour is a lovely beach!

Heroic Fantasy

This heroic (and somewhat bizarre) bronze sculpture of a lithesome lady holding onto a taloned eagle has recently been placed in Oakland’s Jack London Square.

I enjoy the fantasy that as I look up towards the eagle rider she comes to life…I will not pretend this is an entirely innocent fantasy!

Earth in a Glass

The question of scale in photography is crucial, particularly in macro photographs. Is this a marble on a mirror, or is earth suspended in the ether? (Or neither?)

And is this an alien space ship, or perhaps a small, delicate sea shell in a glass?

Shell Glass Game

The Hills Turn Brown in the Summer

There’s an amazing wilderness less than a mile from me consisting of Tilden Park, Wildcat Canyon Regional Park, some other East Bay parks, and municipal water supply land. True, the water supply land (“EBMUD”) has its own private police force, and you need a special permit to hike in it.

But the rest of the area is accessed by beautiful trails. Once this was grazing and ranch lands, and you still find cows along with wild turkeys, the occassional mountain lion, and a wonderful variety of animals. It’s amazing that this is so close to San Francisco.

As folk singer and song writer Kate Wolf wrote in memorable lyrics:

Here in California fruit hangs heavy on the vines
There’s no gold I thought I’d warn you
And the hills turn brown in the summertime

The hills are indeed golden brown, and Julian and I went for a wonderful and strenuous hike in these golden hills in the wilderness in our back yard!

Thistle

Valley of the Dolls

At Nicky’s pre-school, the dolls were dirty. These dolls played hard, and who knows what they do after the kids go home to Mom and Dad. Probably they party even harder when no one is watching, and maybe even disco when night comes.

Anyhow, these dolls got a good wash down, with a shampoo for each and every one of them, and then they were dried with towels. When I photographed them, they were chatting and drying the rest of the way in the late afternoon sun, soaking up some rays, and seeming much calmer. Clothing optional. Life is good in the valley of the dolls!