Category Archives: Hardware

Digital cameras, lenses, tripods, and more…

Crashing Waves

February 13, 2012 by Harold Davis | 2 Comments

Many things crash. Property that is overvalued. Waves on a storm-tossed sea. Computers that have outlasted their normal lifespan.

Storm-Tossed Sea © Harold Davis

Thus it was that my old Windows computer died in the middle of writing an email to a friend. I had been nursing it along on its last legs for longer than I care to say.

From this death there was no recovery. Suffice it to say I am writing this on a new computer, having put in many hours getting my systems up and running again. How unproductive! I would rather have spent my time doing something creative.

This fiasco made my weekend stormy, but it could have been worse—all my image editing and photography-related work takes place on another (and, dare I say it, better designed) system running OS-X.

I was able to take out some of my computer-driven frustrations by doodling the Turneresque seascape you see above (click to view a larger version) which shows another kind of crashing—that of waves on a stormy sea.

To create this image I made abundant use of the lovely Florabella textures library.

Also posted in Bemusements

Ruffles Have Ridges

March 26, 2009 by Harold Davis | 0 Comments

Ruffles Have Ridges, photo by Harold Davis. View this image larger.

I “discovered” (or perhaps “realized” would be the better verb) that there’s no reason I can’t combine flatbed scans at different exposures using hand HDR techniques. This Iris is from three flatbed scans.

No magnificent piece of equipment, the flatbed scanner is an older Epson 1660. Even so, it delivers wonderfully high resolution by camera standards (although of course there is no lens). Add to this the fact the software that comes with the scanner provides an RGB tone curve adjustment, a histogram that you can shove to the right or left, and a levels adjustment, and there’s plenty to play with.

To facilitate the capture, we constructed a black box, open on one side. I placed the Iris, fresh from the garden, face down on the scanner, and placed the black box over the Iris. I still had to mask out the background in Photoshop to fill it with true black, and (as always with scans) there was quite a bit of dust spotting.

The fun thing: this is really a digital era arts & crafts project, and pretty easy to do for anyone.

Capture: three combined RGB Epson 1660 flatbed scans at 1:1 and 3200 dpi.

Also posted in Flowers, Photography, Photoshop Techniques

Hexachrome Color

June 18, 2008 by Harold Davis | 2 Comments

The Lithographers Club of Chicago is a printing industry trade group. They selected an image of mine to use for the cover of their May/June 2008 magazine issue (the cover is shown below). Printing was contributed by Komori (they are a large manufacturer of printing presses) and demonstrates the Hexachrome process-color system. I’ll explain Hexachrome color later in this story.

View this cover larger.

Here’s my photo Wind, taken as a full horizontal, but cropped for this usage to fit the vertical cover format. You can read the story of how I came to make this image originally.

View this photograph larger.

Hexachrome color is a six-color process devised by Pantone in the 1990s. As you likely know, most process color printing is done with four process-color inks. The four process colors are Cyan, Yellow, Magenta, and Black (or CMYK for short).

The two colors that Hexachrome adds to CMYK are Orange and Green, so the six colors in Hexachrome process color are CMYKOG.

What’s the point of this? From the viewpoint of the digital photographer, the range of colors, called the gamut that CMYK can reproduce is limited. If you’ve ever had your photos reproduced via offset, you’ll know that some of them come out OK, but others lose a substantial part of their color range. CMYKOG (Hexachrome) has a much greater gamut than CMYK (see diagram below). In fact, the Hexachrome gamut falls somewhere between the sRGB and Adobe RBG 1998 gamuts, making photos reproduced via Hexachrome look very comparable to what you see on your RGB monitor (and your camera LCD). If you’ve ever flipped the color profile of an image in Photoshop from RGB to CMYK, and watched a huge color shift occur, you’ll know that this is potentially a big plus for digital photographers.

Commercial printers may not care so much about fidelity to an on-monitor RGB version of a photo. But they do have concerns about efficiency. For these printers, an important benefit of the Hexachrome process color system is that most of the solid colors included in the Pantone Matching System can be simulated using Hexachrome color. Simulating PMS colors means you don’t have to stop printing presses to prepare special plates for spot colors that have been specified using the PMS system (a common occurence in applications such as packaging). This translates to a potential boost in efficiency and cost savings.

So how does my photo do in CMYKOG? This is an image that has been reproduced a number of times in books. Each time, I’ve had to work on the CMYK files. But this time the reproduction shows the full range of colors in my photo and looks pretty much just like it does on my calibrated monitor—straight from the RGB file, with no special prep work on my part. In other words, I like it.

Also posted in Photography, Photoshop Techniques

Blossoms and Sensitivity

March 2, 2008 by Harold Davis | 1 Comment

I’ve written about using noise for aesthetic purposes. I’ve also explored the possibility that noise generated by boosting a camera’s sensitivity (ISO) will become a historical artifact and thing of the past. I’ve also explained my strategies for effective noise post processing.

It’s time to take a look at a technical challenge that decreased noise generation at higher ISOs solves.

The other day I went down the block to photograph apple and cherry blossoms close-up on a sun-drenched but windy afternoon following days of rain. The challenge here is that for these extreme macros I almost always want as much depth as I can get so that reflections in water drops and the surface of the blossom all are in focus. At ISO 100, my typical setting for quality work, this implies a long shutter speed even on a bright day. Shutter speeds longer than a second just don’t work when there is a breeze!

If I could get acceptable results in terms of noise, boosting the ISO would seem to be the solution. At higher ISOs it would seem to be easy to get the shutter speed up from the 5-10 second range to something like 1/25 of second. At 1/25 of a second, I would need the Gods of timing with me, but I could wait for a still moment and have a decent chance.

I think noise isn’t a detrimental issue in these photos, so boosting the ISO for maximum depth of field at faster shutter speeds works to make these technically “impossible” photos possible.

You can judge for yourself from these results. All were taken using my Nikon D300, tripod mounted, with my 200mm f/4 macro lens and a 36mm extension tube. The lens was stopped down as far as possible (with slight variations in recorded aperture, as noted), so the only significant exposure differences between the photos were ISO, shutter speed (and, on the other side of the exposure equation, the amount of available light at the time of the photo because natural light does not stay constant in the late afternoon).

ISO 1,000 at 1/25 of a second and f/36:

View this image larger.

ISO 640 at 1/60 of a second and f/36:

View this image larger.

ISO 640 at 1/60 of a second and f/40:

View this image larger.

For comparison, here’s a ringer, shot conventionally at ISO 100 and 6 seconds and f/45. The blossom was relatively steady despite the wind because of its position relative to the tree trunk. This was my last shot of the series as the sun set. I like the soft quality of the blossom in the sunset light, but you’d be hard put to say that the noise characteristics are significantly better than its high ISO bethren.

View this image larger.

Also posted in Flowers, Photography, Water Drops

Physical Prints in a Virtual World

May 31, 2007 by Harold Davis | 1 Comment

When I came back to photography in early 2005, I confronted a world gone digital and virtual. On the whole, I thought this was a good thing, and I was pretty clear that digital photographs are different from film photographs. One thing I didn’t get yet: that physical prints had a place in this new virtual world.

View this image larger. Read the back story featuring this image.

Certainly, I was aware that great traditional print makers like John Sexton were still producing their luminous silver halide masterpieces. But it seemed to me that the place for a digital photo was in the virtual world: to illustrate a blog, to attach to an email, to save a screen, or to join a community like Flickr.

There’s something in this viewpoint, of course. But as time went by, I discovered both that there was some interest in collecting prints made from my digital images, and that the printing technology available to digital photographers was beyond anything I could even have dreamed of in my first career as a photographer.

Color inks like the Epson K3 are truly archival, there’s an astounding array of wonderful paper that you can use, and if you have the right software with good calibration you can accurately control the printmaking process. I’m someone who made my own color prints when this was a messy, unpredictable process. From this viewpoint, my Epson 4800 printer is a dream come true.

Aye, but there’s a virtual and physical rub. Creating great prints today takes working with technology. I prepare my image for printing in Photoshop and print them to the Colorburst RIP. The RIP actually communicates with my printer.

Turns out that Adobe changed the way page size info is written to the Postscript file in the Intel Mac version of PS3. So no matter what size print you make, the RIP thinks it is 8.5X11. Very frustrating, and wasteful of expensive paper, until you realize the problem. (The workarounds, if you run into this, are either to revert to CS2 for printing purposes, or to save your file out as a TIFF and import it directly into the RIP.)

That’s a digital rub. I hit another rub when I started printing on a wonderful new paper, Crane’s Museo Portfolio Rag. Whoops. No Colorburst RIP profile for this paper (actually, not to pick on Colorburst, no one seems to have profiled it). Workaround: I used the Epson Enhanced Matte profile. This is a pretty similar paper, both have some texture and take the matte black ink rather than the more photographic gloss black ink, and the results came out pretty well.

Here’s a physical rub: my Portfolio Rag prints were coming out slightly uncentered. It turns out that this paper is a really thick, and the 4800 grippers seem to move it down .125 of an inch, so you’ve got to uncenter the paper, and set the software to manually over correct the left margin to get it actually centered.

My point here? Well, if you try to print on Portfolio Rag on an Epson 4800, or use an Intel Mac with CS3 and Colorburst RIP, reading this story will save you time and stop you from wasting alot of expensive paper.

More generally, even in the digital era there’s still an impressive amount of craft involved in creating a great photographic print. It’s just that the tools, methods, and techniques have changed. This is a situation that calls for experimentation, practice, and training.

Related story: a vanished pre-digital world, the World Trade Towers photo composed in camera without a computer.

Also posted in Photography

Bridge Time

April 28, 2007 by Harold Davis | 5 Comments

Bridge Time, photo by Harold Davis. View this image larger.

Coming up the trail from Kirby Cove, it was fully night. Not a pitch black night, because there was a sliver moon and light pollution from the bridge and city. But as dark as it was going to get.

Up on the fortifications of the Marin Headlands, I decided to see how long a time exposure I could make of the Golden Gate Bridge.

First I did some tests at 30 seconds to get the exposure right. My plan was to multiply out the exposure time once I had the right f/stop at this shutter speed (the maximum I can set on my Nikon D200 before going to Bulb). Based on what I was seeing in the LCD after exposure, 30 seconds and f/5.0 seemed about right.

Based on the 30 second exposure, I calculated that at f/22, the most stopped-down (smallest opening) of the lens I was using, 8 minutes would be about right.

Next I set the D200 to Bulb, which means the shutter will stay open as long as it is depressed. Since I really didn’t want to physically hold the shutter open for 8 minutes, I used the programmable Nikon MC-36 remote release.

It’s not too hard to set the MC-36 to whatever shutter time you’d like with the D200 on Bulb, although you need to remember to set Long to the time rather than Interval (it turns out that Interval means the time between multiple programmed exposures rather than the interval length of an exposure). Even though the MC-36 has a dim backlight, a headlamp really comes in handy for making settings in the dark.

I think the exposure as it came out is pretty interesting. A couple of things are worth noting. For some reason the camera’s EXIF data for the image shows an exposure of 479 seconds, one second shy of the 8 minutes I set using the control. Perhaps this is a round-off issue.

Also, you better have a great deal of patience for this kind of exposure, particualrly in cold and dark conditions. I’m using fast Sandisk Extreme III memory cards. Even so, each exposure took roughly 50% of the time the shutter speed time for writing to the card before I could use the camera again. This meant at least 12 minutes of standing around in the cold and dark for each exposure!

Also posted in Digital Night, Landscape, Photography, San Francisco Area

In the Bag

April 18, 2007 by Harold Davis | 4 Comments

In the Bag, photo by Harold Davis. View this image larger.

Photographers tend to collect gear bags. I have lots of camera bags. As photographer John Shaw once put it, I am a charter member of the “bag-of-the-month” club.

My favorite new bag is a LowePro Omni Trekker, shown above loaded with my photo gear and a camellia flower. I like this bag because it carries tons of stuff in a secure way and can be carried on my shoulder, using handles, or as a backpack. The bag also has a nifty feature that lets me pull my camera out without opening the whole bag via a kind of pass-through window.

As part of Lowepro’s Omni Extreme set, the bag fits in a waterproof case that can be used in conditions that are dangerous for photo gear. For example, I can pack this bag in the Extreme shell and take it on a white water rafting trip.

When I don’t need to carry so much gear, and I want something that fits well on my back, I carry a Lowepro Mini Trekker AW.

To create the black-and-white image of the camera bag loaded with my gear and a color flower, I first took an exposure straight down on the bag with the flower in position. I used a long exposure and a small f-stop for great depth of field (10 seconds at f/22).

In Photoshop, I duplicated the image, then converted one version to black and white. For information about how to convert digital color images to black and white, see Going with the Grain, More Black and White Conversion Fun, and Converting to Black and White.

My plan was to plop the color version of the image over the black and white version as a layer. Then I would need a layer mask (see From Filter Play to Layer Masking) to block out all the color portion of the image except the flower.

But I didn’t want to have to hand generate the layer mask by painting the flower shape on the mask, a tough job. So I created the layer mask with no hand work by duplicating the color version of the image, converting it to LAB color, and discarding all the layers except the A channel (Magenta-Green). In the A channel, the camellia flower was almost white and everything else was dark, so it didn’t take much fiddling with the Curve to create an acceptable grayscale mask.

Finally, I used Image > Apply Image with the color layer of the layered version of the image active to add the layer mask so only the camellia appeared in color.

Also posted in Photography, Photoshop Techniques

World without End

December 19, 2006 by Harold Davis | 17 Comments

World without End, photo by Harold Davis. View this image larger.

There’s more to this picture than meets the eye. Put another way, no matter how hard you look at the on-screen version, even in its larger size, you won’t see everything that is in the image. Let me explain the alpha and omega of it.

The photo the image is based on started as a time exposure of the corridor in the Officer’s Quarters at Fort Point under the Golden Gate Bridge in San Francisco. (View the EXIF data here.) This was a normally-sized photo taken with my Nikon D200, so at 300 dpi (dots per inch) it measured 2592 X 3872 pixels (about 8.6 X 12.9 inches). I mention the dimensions of the image because they become an issue later in this story.

When I looked at the photo on my computer, I saw six “regressions”–or doorways on the corridor. At the end of the corridor was a dusty, dark, and unattractive display case.

I decided to replace this unattractive display case with a proportionally smaller version of the duplicated image itself, to make the corridor seem to go on longer (for twelve apparent regressions).

It wasn’t very hard to paste a smaller version of the image in, thus extending the corridor to twelve doorways. I duplicated the image, measured the size in the original image I needed, and resized the duplicate accordingly (to about 1/6 of the original dimensions, as it happens). Next, I dragged the small version of the image over the large version to position it in place, and dropped it to add it to a layer in the original image. I used a layer mask, the Paintbrush Tool, and blending modes to combine the smaller version fairly seamlessly into the large version. In addition, I realized that at the point in the process where I flattened the layers I’d need to do a bit more detailed retouching using cloning and related Photoshop tools.

It’s worth noting that as a matter of workflow I had to flatten the layers in my image a number of times. Each time I did this, I saved an archived version of the image with the layers still intact (except, as you’ll see later, when my layered versions exceeded Photoshop’s maximum file size of 2 Gigabytes). I did this archiving at every step of the way where it was possible, just in case I later decide to rework the image, and I won’t note that I did it each time (but you should do it too when you work with layers).

Looking at what I had, the thought occurred to me, why not repeat the process? So I resized the duplicate image once more, down to about 1/6 of the reduced size, or 1/36 of the original size, and added the new, small version in position as a layer to the original image. Once again, I used a layer mask, the Paintbrush Tool, and blending modes to combine the versions, with the understanding that further retouching would be needed eventually.

Now I was up to eighteen regressions, and the corridor with doorways looked pretty infinite to me. But, in fact, the corridor didn’t go on forever. I had to get up pretty close to it, but at 1600% magnification I could see a highly pixelated version of the ugly old display case.

It turns out that 1600% is Photoshop’s maximum magnification, so I couldn’t zoom in any closer. In addition, the corridor-end-within-a-corridor-end-within-a-corridor had shrunk to an area of about 12 X 18 pixels, so the physical limitations of the building blocks of my image seemed to prevent adding any more regressions. For those of you who don’t know from pixels, this is an area smaller than the proverbial pinhead upon with angels dance. As the Wikipedia notes, “A pixel (short for picture element, using the common abbreviation “pix” for “picture”) is a single point in a graphic image.”

Looking at this 12 X 18 pixel canvas at the end of the known world, I figured why not write something on it. True, no one would be able to see what I had written without being able to examine a full-size version of the image in Photoshop or comparable software at high magnification, or perhaps by vliewing a good, large print up close with a magnifying glass. But it seemed worthwhile to embed a secret in the corridors of apparent infinity.

Typography at this small scale proved to be surprisingly difficult, and I had some much appreciated help from Phyllis. I can’t tell you how much it helps my work having a spouse who is also a graphic design whiz!

My first thought was to write my name, but “Harold” simply wouldn’t fit in the space I had, even with the strokes only one pixel wide. So a single letter would have to do. In a representation of infinity, perhaps α (alpha) or ω (omega) would have been most apt, but I settled for the more egocentric “H”. (I am, after all, at the core of my own solipsistic universe!) As I’ve said, you’d need to view the original Photoshop file at maximum magnification to see this character. But wait! The plot thickens (or thins)! Things get even crazier.

It occurred to me that although I couldn’t paste in another smaller copy of the image there was nothing to stop me from blowing up a copy of the current large image to make it bigger, and then pasting the current large image into the even larger version.

After the flattening the image with type layer and the layers with the two smaller versions, I duplicated it. Next, I used the SI Pro 2 (Stair Interpolation Pro) Photoshop plugin from Fred Miranda Software to blow the image up. As you may know, there are quite a few Photoshop plugins that automate the process of stepping an image up without appreciable quality degradation; I’ve had good luck with SI Pro.

If you are interested in using the SI Pro 2 plugin, it costs about $25 to download from Fred Miranda Software (you’ll find the link about half way down the page on the left). I’ve used it successfully to upsize images, and also to size images precisely for printing with margin areas on particular paper sizes.

I figured I needed to blow the image up 6X to be able proportionally to fit the 18 doorways into it, for a new total of 24 regressions (I am fondly calling each doorway a “regression”, although of course technically it is no such thing).

After enlarging the duplicate six times, the new dimensions were 15,300 X 22,857 pixels at 300 dpi (or about 51 X 71 inches at 300 dpi). It still looked pretty crisp on my monitor. I was bumping up against a Photoshop limitation, namely a maximum image size of 30,000 X 30,000 pixels, and a maximum Photoshop file size of 2 Gigabytes. I was to find out about the file size limitation when I tried to save a layered version of the large-size image.

And now, a word about my hardware. I noted in an earlier story that it takes quite a bit “under the hood” for me to post-process my images, particularly when complex channel operations are involved. Specifically, I do my image processing these days on a Mac Pro with 2 X 3 Dual-Core Intel Xeon processors (four processors in total), 5 GB of blazingly fast 667 MHz DDR2 RAM, about a terrabyte of SATA disk storage, and a 30 inch Apple Cinema monitor. True, Adobe hasn’t come out yet with a native version of Photoshop, but even in simulation mode this is pretty good hardware.

On the large-sized image, things slowed to less than a crawl. Simple operations, like displaying a histogram, or adjusting a curve, took minutes. While I waited for each operation to complete, I could not only twiddle my thumbs and drink a cup of coffee, I could brew the coffee as well! A good thing I also have my Windows XP machine going for mundane tasks like email, word processing, and blog writing! Here’s to multitasking if saving a file takes half an a hour!

So now I took the 2592 X 3872 pixel image, with the 18 regressions, and pasted it in position as a layer into the 15,300 X 22,857 pixel large version. As I’ve noted, when I tried to archive a version of this image with the layers intact I hit the 2 Gigabyte file size limitation of Photoshop, but fortunately I could work on the image in Photoshop with the layers even if I couldn’t save it, and I just squeaked by just under the 2 GB limit when saving layer-flattened versions.

Besides simply elongating the corridor, an interesting optical effect happened when I combined the images. The doorways start sharp, and gradually lose apparent sharpness as the eye goes down the passage (and the image gets magnified). But at six doorways in, where the pasted original version takes over, the doorways get sharp again. This effect creates an illusion that the passage is even longer than it is, because it doesn’t seem to lose definition as the eye travels down it.

You won’t really be able to see all the doorways in the version on the web. You certainly won’t be able to see the H embedded at the end of the World without End. There simply isn’t enough resolution. To fully see my image, you’ll need to come visit me and look at it on my monitor. You could then inspect the end of the corridor at 1600% magnification and see the H.

Of course, I’d also like to make a print that is close to one-to-one. Alas, my Epson 4800 only goes up to 17 inches wide. There are a number of places around here where I can get my hands on a 9600, with a maximum width of 44 inches. A little smaller than I’d like, the print on a 9600 would end up about 40 X 60 inches. I’ll bet that with a magnifiying glass you could even see the end of the corridor.

How’s that for finding infinity’s end?

Also posted in Bemusements, Photography, Photoshop Techniques

My Favorite Worlds

August 5, 2006 by Harold Davis | 6 Comments

Getting the Drop, photo by Harold Davis. View this photograph larger.

If you’ve been reading my blog, you’ll know that I’ve been photographing water drops. And that for me, each water drop is a world, as Blake put it, in a grain of sand. (Here’s a fairly complete selection of my water drop photos on Flickr.)

The two photos in this story are among my favorites of my recent water drop worlds. Everything seems to come together in the photograph of a single drop above: sharp focus on the drop, a nice sunburst, and a nice inner world showing the white Scabiosa atropurnea (“Snow Maiden”) that hosts the water drops and shows drops within the drop.

The photograph below shows a cosmos full of water drops, each caught by the thin filament of a spider’s web, and on and on into an apparent infinity.

Both photographs were captured with the same gear, and roughly the same setup. That is, my wonderful Nikon D200, my stupendous Nikkor 200mm f/4 macro lens, a 36mm extension tube and a +4 diopter close-up filter, mirror lockup, and a remote trigger. The single drop (above) was exposed at f/36 for 0.2 of a second, and the multiple drops (below) at f/40 and 0.8 of a second (both ISO 100).

To digress for a second, the 200mm f/4 Nikkor macro is as heavy as big telephoto lens (which it kind of is at 300mm 35mm equivalence). One of the things about it that really makes my life easier is the built-in tripod collar. The tripod collar lets me shift the center of gravity forward on the tripod (by mounted the lens rather than the camera). It also lets me change the orientation of the photograph by loosening the screw that holds the collar in place and rotating the lens. Meaning that I don’t have to move the camera at all. A big, expensive, special purpose lens. But well worth the price if you do much macro work.

View this photograph larger.

Also posted in Patterns, Photography, Water Drops

McClamp Bubble

July 27, 2006 by Harold Davis | 3 Comments

McClamp Bubble, photo by Harold Davis. View this photograph larger.

If you’ve been reading my blog, you probably know that about a year ago, I started a series of extreme close-ups of water drops on the flowers in my garden. You can see some of these photos on my blog in my Water Drop category.

Of course, one of the main technical challenges with this kind of photography (when I’m using available light rather than a strobe) is the motion of the flower and water drop. A partial answer to this problem is to use my McClamp The Stick (click here for the McClamp website). This piece of equipment keeps flowers from swaying in the breeze using a stake to anchor into the ground, flexible plastic piping, and a padded clamp to hold the flower. If you are really careful, it won’t even damage the flower!

In my photo “McClamp Bubble” (above), I attached the McClamp stick to a dahlia, and after it was attached turned on my irrigation system to get a natural looking set of drops (if I had attached the McClamp after spraying the flower, the drops would gave shaken off).

I was pleased to see how sharp this water drop looked when I opened the RAW file on my computer, and amused to see the McClamp stick reflected in it. At first I was going to discard the photo because of of the way you can see The Stick in it.

But, “on reflection,” the reflection of The Stick makes the photo more interesting to me (rather than less), because it helps to show within the photo the tools I used to make the photograph. I’m glad I kept it, and I hope you enjoy it!

Also posted in Bemusements, Photography, Water Drops

Beyond the Visible

June 25, 2006 by Harold Davis | 3 Comments

Indian Paintbrush, photo by Harold Davis. View this photograph larger.

It’s fairly well known that digital sensors are more sensitive to infrared (IR) than either film or the human eye. In fact, this is so much the case that digital cameras are equipped with a filter that screens out IR. You can capture IR photographs either by removing this factory-supplied CCD filter, or by adding your own filter to the camera.

Less appreciated is that digital sensors also can pick up more ultravioltet (UV) light waves than film or the human eye. As with IR, this effect can be amplified using filters. At the lower end of the UV spectrum, you’ll find xrays—so the ability to harness UV waves lets one “see” through, or inside things, a facility used in snooping and military devices that provide night vision.

Altogether, photographing light waves one cannot see is a crap shoot—you don’t really know what you are going to get. But in some circumstances so is taking normal photos with a digital camera, this photo being a case in point. It has been minimally processed in Photoshop from the RAW version.

Phyllis and I were hiking on the Chimney Rock Trail on Point Reyes (probably the most western trail in the continental United States). Rachel was taking care of the kids. We figured we hadn’t been hiking alone together in, well, eight or nine years—so a memorable occassion. It was early evening with a bright but low fog. This Indian Paintbrush was sitting by the edge of a headland cliff. The reds and greens of the flower glowed with an incredible intensity, and almost seemed to smolder, or vibrate. The image does not capture these colors. At the same time, the blue tendrils in the photo were not apparent to our human vision.

So intead of “beyond the visible,” maybe I should have called this story “making the unseen visible, and making the visible disappear.”

Also posted in Digital Night, Flowers, Photography

Slow Flash

June 13, 2006 by Harold Davis | 0 Comments

Dahlia Glowing, photo by Harold Davis. View this photograph larger.

“Slow flash” is an oxymoron because there can be no such thing as a slow flash exposure. A flash duration is usually between 1/1000 of a second and 1/20,000 of a second, depending on the strobe. By most normal definitions, a flash burst cannot be slow.

In default camera modes it usually synchronizes with a camera shutter speed of 1/60 of a second or 1/125 of a second (1/60 of a second with the Nikon dSLRs such as the Nikon D70 or Nikon D200). Whatever the shutter synch speed, the light from the flash is fundementally controlling the exposure, although depending on circumstances ambient light can play a role as well.

Nikon uses “slow flash,” along with “slow synch,” as their rather obscure terms for an exposure that combines a flash burst with a long time exposure (of up to thirty seconds). With this technique, you’ve got to set the flash into this synch mode. Next, you need to know that it will only work when exposure is set to automatic or aperture-preferred modes.

Even in slow flash mode, of course, the flash isn’t slow: it’s the exposure that is used in conjunction with the flash that is slow.

The idea is that you could put the camera on a tripod, stop the aperture all the way down (say to f/40), and take a time exposure of a couple of seconds combined with a flash burst.

Once I figured out how to set the camera up in slow flash mode—and I think you can believe me when I say the Nikon manuals are not a model of good expository technical writing, this documentation is difficult to decode—it occured to me that I could use slow flash to create a stained-glass effect using the natural translucence of flower petals. In other words, my idea was to use the flash part of the slow-flash exposure to create seriously intense backlighting.

The photograph of the dahlia at the top of this story used the technique, with a Nikon SB-800 unit mounted on a tripod directly behind the flower (and pointed straight at it) and connected via wireless at the camera, which controlled the exposure in aperture-priorty mode. The overall exposure of the camera, which also was tripod mounted, was at ISO 100, for 1.3 seconds, at f/36 using my 105mm macro lens.

This extreme macro photo of a Salpiglossis sinuata (“Painted tongue”) really shows the stained glass effect:

View this photograph larger.

For this photo, both the camera and strobe were tripod-mounted and connected via wireless. I used the less powerful SB-R200 unit (rather than the SB-800) to create the backlighting. My overall exposure was 2.2 seconds, f/40, at ISO 100 with my 105mm Nikon macro lens with extension tubes and a close-up filter.

Also posted in Flowers, Photography

My New Toy

January 10, 2006 by Harold Davis | 4 Comments

Monitor Lizard, photo by Harold Davis. View this photo larger.

I photographed this monitor lizard at the Vivarium in Berkeley with my new toy. My new toy is a Pentax Optio WPi. It measures about 3½ X 1½ X 1 inches and weighes a couple of ounces. The thing is waterproof. It takes six megapixel Jpegs. The cost, with an appropriate SD memory card, is a little more than $300.00.

The waterproof feature is worth the price of admission, at least at dinner parties. (Watch me drop it in a glass of ice water, and then take pictures!) However, as you might expect, the camera is a little hard to use precisely, and it’s too bad it won’t do a RAW capture.

My thinking in buying this “toy” was born from frustration about not wanting to take my expensive equipment out in wet and dusty conditions. There’s no problem with dust or water with this “little guy”, you just wipe it off. Just slip it in a pocket, it’s a far cry from schlepping my usual thirty pounds of gear.

And it does pretty decent pictures once you figure out how to use the manual modes.

I also bear in mind something that photographer Ruth Orkin once explained: she could get in and take photos with a consumer point-and-shoot in places she never could use her professional gear. My little guy goes anywhere and does not shout “pro photographer.”

Oh yeah, he also is an alarm clock, a voice recorder, and (for your inner spy) has a document photography mode.

I’ll be posting more photos from my little guy in the fullness of time.

Also posted in Bemusements, Photography

To dSLR or Not to dSLR

December 7, 2005 by Harold Davis | 0 Comments

Pink Mallow, photo by Harold Davis. View photo larger.

I took this close-up using the macro setting of my Canon PowerShot G3 mounted on a tripod.

Although sophisticated enough in its own right, this camera is now a couple of years old, and no match for my Nikon D70 dSLR (“digital Single Lens Reflex”).

I have a couple of points to make here:

You don’t need to have hugely expensive camera equipment to take good photos. It’s the eye and feeling, and understanding of the craft of digital photography that really count.
In some ways, less expensive cameras can be better than fancy digital SLRs.

Besides being, well, less expensive, a camera like the PowerShot is also much lighter to carry. This means that you are more likely to have it with you when you need it.

The fact that a camera is not an SLR means that you can’t change lenses, or view directly through the lens. But special modes, like macro modes, can actually be better. In addition, the LCD screen is bigger than on SLRs, and can be used for composition, not just for reviewing photos (as with a dSLR).

So think carefully about how you intend to use your camera before springing for that expensive and heavy digital SLR. Something more portable, and, well, less like a digital recreation of a film camera, might just serve you better!

Also posted in Flowers, Photography

Working that Lens Baby Macro

November 29, 2005 by Harold Davis | 11 Comments

Yellow Greeting Red, photo by Harold Davis. Click to view in large size.

A reader writes:

I’ve read your piece on photographing the lobelia flower with your lens baby, as well as the item you refer to with more information about this set up, and I still don’t get it. Could you please be a little more explicit?

OK. There’s nothing like a straightforward request, and the whole Lens Baby thing is pretty straightforward. But, before I get started, another photo:

You get a Lens Baby from Lensbabies.com. It costs $150 plus shipping for the Lens Baby 2.0, and you need to specify the lens mount (Nikon or Canon and some others). The Canon version provides some exposure automation (I think), but there is absolutely no automation with the Nikon version.

Here’s another photo:

The macro kit for the Lens Baby consists of two glass filters that screw on the end. One is +10 and one is +4 diopters, and you can stack them together to get within 2-3 inches of your subject. These filters will run you another $29 bucks and come with absolutely no documentation. They do arrive in a sweet little carrying pouch that says “Lensbabies” in a kool typeface. (You gotta love this kind of packaging, elevating form far over function, as all of us visual people do from time to time!)

Here’s another lens, baby macro:

The Lens Baby itself has no ability to focus. Essentially, you have a “sweet spot” towards the center of the thing that is more-or-less in focus, and all the rest of the image is sweetly and pleasantly blurred.

The exact location of the sweet spot is impacted by a couple of factors. First, the end of the Lens Baby is flexible and bellows-like, so you can bend it around. This changes both the size and location of the sweet spot (although I’ve found that the way the photo comes out looking does differ from the way I see things through the viewfinder, through-the-lens viewing or not). In other words, chance and its guardian angel Sarah Dipity (serendipity) play a role with Lens Baby photos.

Here’s another photo:

The other factor that influences focus also influences exposure. The Lens Baby 2.0 comes with a bunch of different magnetic rings that you plop into place inside the barrel of the Lens Baby lens. (The Lens Baby comes with a little tool that allows you to easily remove the rings.)

These rings set the aperture of the lens. The smaller the opening in the magnetic ring, the smaller the aperture, and–to some extent–the greater the apparent sharpness of the Lens Baby due to higher depth of field.

At best, how sharp are we? Not very. That’s not the point of the Lens Baby:

As a practical matter, once you have the macro filters in place, particularly if you are using both of them, you probably don’t want to be bothered with changing the aperture rings (you’d have to take the macro filters off to change the aperture ring). I find myself using the Lens Baby “wide open” with no aperture ring, since it’s not the point of the thing to be sharp, and with the widest aperture you are most likely to get acceptable results hand holding in the part of the image that is sharp (because the wider the effective aperture, the faster the shutter speed you can use).

So, all the photos that accompany this story were taken with my Nikon D70 mounted with the Lens Baby, no aperture ring, and both +4 and +10 macro filters. There’s no focusing, and no exposure automation.

What you have to do is set the camera to manual (M on the dial for those of you who are acronym tone-deaf). The only control you have over exposure is setting the shutter speed.

The photos that accompany this story were taken at shutter speeds between 1/60 and 1/200 of a second in overcast, but bright, conditions. But trial and error is required. You’ll also need to review the results on your LCD display as you take the photos, and give praise for the bracketing inherent in the Raw format.

Having set the shutter speed where I guestimate it ought to be, the process of taking one of these photos is pretty intuitive: I get close, wiggle the Lens Baby, and when I like what I think I see, press the shutter release.