Thursday, December 5, 2013

Why Learn Good Photography Skills? ~

What keeps me the busiest throughout the year?  More than study group presentations, more than email correspondence, more than face-time sessions, are my in-clinic workshops for dentists and their staffs. And it's not surprising why this should be: competent photography skills, particularly when used in shade-matching practice, saves you a lot of time and money.

Even the general practice benefits from using photography regularly. Research shows a higher rate of patient acceptance of recommended procedures in practices that consistently use photography.

The great news is that the required skills are really accessible to anyone, and the camera systems are pretty easy to master. Teaching those skills is what I am passionate about, and darn good at, too.

Shade-matching is where photography really proves its worth. There's no way that a written description, even including a numbered shade tab, can convey the amount of information that a good photograph can. The camera, flash, and macro lens systems we've talked about in many previous posts here make incredibly sharp and color-accurate images. This is pure gold to a dental lab.

My on-location workshops are typically around four hours, and involved a lot of hands-on practice chair-side. My goal is to leave behind a staff that is comfortable and competent with the camera -- its settings and operations -- and able to continue mastering the intraoral and portrait techniques that make for a successful practice.
The cost? Just about what one re-make costs your practice. And now there'll be fewer of them.

Oh and, yes, it's a lot of fun, too. Photography should be! So send me a note. Let's get together and make it work.

It's what I do.

Later, amigos!


Friday, November 15, 2013

Get Out That Camera! ~

The digital camera system you're using in the clinic is a wonderfully creative tool; it can do so much more  than the intraoral photos you make every day. Whenever I do a photography training session in the clinic,  I usually get asked a lot of questions about using the camera to have fun outside the office. And it is fun!

In this post we're going to look at just two little things you can do with your camera that will make a big difference in your photography: controlling the shutter speed and controlling the aperture.

Here's that Command Dial on top of your camera; you'll recognize it from our training sessions. When we're making intraoral photos with the Macro Lens and Ringflash, we leave it on "M" (Manual) so that the flash can create proper TTL exposures for us. Let's remove that flash and go outside to explore our creative possibilities!

Let's first set it on "Tv" (Time Value) so we can set the shutter speed to capture the action of a fast-moving subject. As long as the overall light level is pretty good (a nice sunny day) the camera will automatically select an aperture that will yield a good exposure.

On the right is an extreme example of that:  the water fountain on the Stanford campus. I wanted to see what it would look like if I "froze" the water droplets with a really fast shutter speed. I jacked up the ISO to 6400 to take advantage of as much light as I could, and used a shutter speed of 1/8000 of a second! Think about other kinds of subjects that could use fast shutter times, such as racing bikes and football players, or the fastest subjects of them all: your kids.

Here are a couple examples of going in the opposite direction; very long (slow) shutter speeds that capture the flow of moving water. Of course, such long exposure time usually requires a tripod to keep the image sharp overall. The river was shot at 1/4 of a second, and the waterfall at 1/3. In human terms those don't seem like overly long durations, but in photo terms those are long exposure times indeed.

Now let's go in the opposite direction and set the camera to "Av" (Aperture value) which will allow us to control depth-of-field through aperture selection, and the camera will automatically set an appropriate shutter speed. The higher numbers (f 22, f 32 for example) give us a lot of depth-of-field, which we need in images such as landscapes. We use f 32 for all our intraoral imaging for exactly that reason, too. If you look closely at that picture of the waterfall, you'll see that in terms of sharpness, everything from the bush in the foreground to the hilltop in the distance is sharply in focus; that image was exposed at f16.

But what happens when we go in the other direction?

Here's an image showing the least amount of depth-of-field possible; it was photographed at f2.8, which is the "widest" that particular lens could go. Other lenses (considered "faster") may allow for f1.8, even f1.2!

This kind of imaging creates a lot of separation between the subject and the background, making the subject stand out dramatically. Portraits are nearly always taken in this manner, for example.

I know this is a pretty cursory description of the relationship between shutter speed and aperture, and you probably have more questions now than you did before. That's a good thing! Explore and try things out. You aren't going to break the camera, and you'll discover amazing things about photography -- and yourself! -- in the process.

We'll look at some other creative, outside-the-office techniques down the road. And I hope that road is a long, scenic drive.

Later, amigos! 


Thursday, October 10, 2013

RAW files: What, Why, & When? ~

Whenever we've talked about digital files here -- setting the camera, printing them, emailing them, and so on -- we've been talking exclusively about JPEG (.jpg) files. And these JPEG's are great, they record a lot of visual information. Every digital camera out there shoots JPEGs, and every digital imaging program can open them.  So, end of discussion.

And yet, and yet.....

You keep hearing about photographers, and other visual professionals, professing their undying love for the RAW file instead. And I know some dental labs are starting to request their clients to provide them with RAW files, so it's probably a good idea to spend a couple minutes here and take a quick look at them.

All digital cameras have a menu setting, such as the Canon shown here, that allows you to select what kind of file you wish to produce. The one highlighted here is the large, minimally-compressed JPEG, which I always recommend when you shoot JPEGs. These files "see", or record, 256 discreet brightness levels (or shades), which is a good deal of visual information. If you work with histograms, either in your camera or in a graphics program such as Photoshop, you'll see they display all 256 of those levels.

In that same menu you also see a lot of other possible file selections: smaller, more highly compressed JPEGs, and several RAW file + JPEG combinations, which are useful if you want an untouched RAW file to send to the lab but want an easy JPEG to keep on your desktop or in your patient files. They take up more room on your card and take a bit longer to process. I usually only set the RAW file by itself, as I've indicated with a yellow arrow.

But what are you setting? Well, unlike the 256 brightness levels the JPEG gives us (which is described as "8-bit") the RAW file on most digital SLR cameras records in 14-bit, which is over 4000 brightness levels. This gives the photographer far more control over the image in post-processing.

And of course, therein lies the rub. More control also means more work, so work-flow considerations have to be factored in any decision to start using RAW files. Going through an extra step while processing a handful of images is one thing, but working on several hundred will be something else entirely. When you shoot a JPEG, you set the camera to do most of that work: setting the exposure, the white-balance, sharpness, tone curves, and so on.  But all of these things -- everything, in fact, except ISO and shutter speed & aperture -- can be manipulated after the shot is taken, using the appropriate software. This picture shows the RAW converter you would use in Photoshop CS6 and Adobe Photoshop Elements. This means, of course, that unlike the JPEG, the RAW file cannot be opened universally; it absolutely requires software capable of doing so. (After the file is opened and worked on, it can then be saved as a JPEG.) Therefore, while some dental labs are starting to look closely at using RAW files, due to the advantage of having so much post-processing control over the image (and thus color quality), many labs can't afford that additional workflow. So don't start sending them RAWs unless they specifically request it!

Those of you who have been in one of my workshops or seminars know how much I love photography and want to share that enjoyment. Here's a great way to experience it at a whole new level. Download a copy of Photoshop Elements 12 (you can get it on Amazon for around $89), take your camera out of the office for a weekend, and play around with RAW files. Shoot whatever you like and let Elements open them in the RAW converter, then see where it can take you.

Nothing wrong with a good, creative hobby! Although the next step would be leafing through photo catalogs looking at all those nice $2000 lenses....

Share your thoughts -- and your photos!

Later, Amigos.

Thursday, September 5, 2013

A Few New Cameras ~

I've been in photography for a long, long time and have over the years acquired a lot of stuff: cameras of all sorts, countless lenses, strobes, and so on. And yet, (unlike some of my colleagues) I really don't consider myself a "gear-head". I use what I need to get the job done.

...but having said that...

...I do like to talk shop every now and then. I've had a couple recent workshops where our conversations turned to the new cameras that are out there, since these dentists were looking to replace some older ones that really weren't performing well. So here, in no particular order, are some of the latest offerings from our friends at Canon and Nikon that are appropriate for your clinical imaging. (Bear in mind, I don't sell cameras at all, so I don't make a push for any particular brand or model.)

Canon Rebel T5i.  Canon's latest offering in their impressive Rebel line-up, it's an 18-megapixel camera that also shoots  full 1080 p video. The Rebel line of DLSR cameras are smaller and lighter (the body only weighs a little over 18 oz) so it's easier for your staff members to handle than some of the upper-end pro models. Look for retail pricing, with a kit zoom lens, of around $900.

Canon Rebel SL 1.  A brand-new entry from Canon, this is also an 18-megapixel model, but is lighter still than the T5i and more compact (around 13 oz for the body) yet has all the capabilities of its larger cousin. I think its design will make it easier for even those with very small hands to fit comfortably. Kits will retail for around $800.

Canon 70D.   This is a 20.2-megapixel "prosumer" model that will appeal to someone looking to do more with a camera outside the clinic as well as the day-to-day intraoral imaging. Consequently, a few more features, but also a little bigger (the body weighs a little over 23 oz) and more expensive (around $1200). Some of the in-camera imaging features won't necessarily translate into better clinical images but will impress a serious shooter, amateur or professional.

Just by way of comparison, here at our studio we shoot with the Canon 7D and the 5D Mk III.

To complete your system for intramural imaging, pair these up with the Canon 100 f2.8 AF IS Macro lens and either the MR-14 Ringflash or the MT-24 Twinlight.

Nikon D 5200.  I run into a lot of Nikon shooters in clinics (just returned this week from a workshop in Cleveland where we worked with a Nikon D3100) and this recent addition to Nikon's line-up is a 24-megapixel model with some nice features. I'm often critical of Nikon for having menu read-outs that are overly complicated for the novice user, but it seems they've nicely addressed that with the 5200. Weight is comparable to the Canon T5i, around 18 oz, and a comparable kit will retail for around $900.

Nikon D 7100.  Also 24-megapixels, this would be more of a "prosumer" camera, comparable to Canon's 70D: a few more features that will appeal to the serious shooter outside as well as inside the clinic. Thus a little heavier (around 24 oz) and more expensive (the body retails for around $1200).

To complete your system for intraoral imaging, pair these up with the Nikon 105 f2.8 AF VR Macro lens and the R1 Speedlight.

Clearly, these are the briefest of descriptions that only scratch the surface of all the features of these cameras. If there's a good pro camera dealer near you, it's worth the effort to go check these out in person.

Tell 'em Dave sent you.

Later, amigos!

Thursday, August 15, 2013

Color Temperature: Is It Warm Enough For You? ~

At first blush, there doesn't seem to be any obvious connection between temperature -- how warm or cold it is -- and color. So why is it that we photographers so freely throw around the term color temperature? Sounds like it must be something important, and in fact, it is.

The term itself comes to us from physics, and refers to black-body radiation; essentially, as a black body is heated, it glows in a color specific to that temperature, which is always measured in degrees Kelvin (K). In practical terms, any source of light will radiate at a particular color temperature, producing a predictable color in the visible spectrum. The chart on the left illustrates some examples. Traditional incandescent lightbulbs radiate at around 3000K, which is why their color is markedly yellow-orange. Fluorescent lamps, and some modern cool-white lightbulbs will radiate at much higher temperatures, above 6000K, and so will have a more bluish color to them. This has always been important to us in photography, as most color films were designed to "see"and record light in a normal daylight range, which is typically between 5000 - 6000K, and if the sources of light illuminating our photos varied from that, it resulted in images that didn't look natural. You've probably seen pictures that were either very yellow, or unnaturally blue-green. That's why.

Of course, painters and photographers have always confused the issue by defining colors, or color-casts, as being "warm" or "cool". This is almost certainly because we looked at a glowing fire, felt its warmth, and recognized the color it gave to anything it illuminated as a "warm" glow. And yet, the actual color temperature is at the cooler end of the spectrum, as you can see from the chart above. And those very high temperatures, above 6000K, are decidedly "cool" in appearance.

With color film, we used filters over the lens to add a compensating color in order to produce images that looked natural and daylight-balanced, or at least made sure to use light sources that were daylight-balanced. Most electronic flash units were fairly well color-balanced, or slightly biased to the "cool" end of the spectrum, which could easily be further improved in the printing process. Digital cameras can control for a wide range of color environments with their built-in white balance pre-sets, or the ability to  set a custom white-balance for a particular shooting environment. (This was covered in my last blog post; take a look).

Like so much in photography, color can be a very subjective thing; what looks pleasing to one may look odd to some one else.  But there are times when we need to work with objective, agreed-upon standards, too; and the best example of this is when we make shade-matching images for the dental lab. An understanding of color temperature, and control of the digital camera, is part of what makes it work successfully.

Are you getting good results with you color images, or still something of a challenge? Let's have a nice warm conversation.

Later amigos!


Thursday, July 18, 2013

And now, a word about White Balance....

My last post here (I think I must be on a summer hiatus?) discussed Picture Style; the differences among them, and which of them was most appropriate for intraoral imaging. Now I'd like to take a closer look at White Balance, which can just as easily be a source of some confusion for the non-professional shooter.
White balance (sometimes called gray balance, or color balance; all the same thing) refers to the process of removing an unwanted or unnatural color cast in a scene so that objects that appear white to our eyes will look white in the photograph. Our eyes are great compensators and will correct for environmental conditions, reflections, color temperature, and so on, but unless we make those  adjustments in our camera, we'll get poor color images that are difficult to correct in post-processing. This is much easier to do with digital cameras than when we were all using film and our options were much more limited.

Here's a good example of that. Viewed individually, we may not see anything terribly "wrong" with any of the pictures of this lady with a guitar, but side-by-side we can make a more critical assessment. While the image in the middle has more natural and neutral tones, the one on the left is distinctly "warm" (strongly tending towards the reds and yellows) and the one on the right appears distinctly "cool" (tending more towards the blues and greens).

Now let's look at how we control for this in the camera settings:

AWB: Auto White Balance; this mode calculates an average color temperature for an entire scene. While I often find this problematic in a scene that has multiple sources of light, each with its own strong influence, it works well with one dominant light source -- as when we are shooting intraoral images using a ringflash. I typically use this mode for exactly that reason. In the sample above, and in the following, the color chart on the left was shot using available, natural daylight. The ones on the right are shot using on-camera flash.
DAYLIGHT: usually useful for making available-light exposures on bright, sunny days. (Since I live in Oregon, I probably don't get to use this one very much!)

SHADE: open shady areas on an otherwise sunny day with blue sky will tend to shoot somewhat cool, so this mode adds more reds and yellows to the scene.
CLOUDY: This may be a bit more Oregonian (maybe with a little rain?).  Here, too, the thought is that cloudy days produce cooler exposures, so this warms it up a little. You can certainly use this anytime on a sunny day if you like a slightly warmer touch to your pictures. Everything is worth experimenting with.

TUNGSTEN: Have you ever seen old photographs that were taken indoors, and they all look intensely yellow? That's because color film was usually "Daylight" balanced, and common light bulbs -- tungsten bulbs -- produce a low color temperature, yellow-orange color cast. This camera setting compensates for that.

FLUORESCENT: Traditionally, fluorescent lighting was distinctly magenta-blue, in the same way that tungsten lighting is distinctly yellow. However, most modern fluorescent bulbs are now designed to produce a more natural color balance.

FLASH: Most on-camera flash units produce a color temperature at or above 6000K, which is cooler in tone than standard daylight, so this setting adds some warmth. In practice, I find this usually adds too much warmth, and flashes can vary quite a bit in color temperature as well, so I rarely if ever use this.

These last two settings in your White Balance menu are CUSTOM and, below that, KELVIN setting.  Photographers will frequently "custom balance" their jpeg images to minimize post-production time when shooting a large number of images under the same lighting conditions (think outdoor wedding). This can often improve the overall color quality as well, but intraoral images made with  the macro lens and ringflash cannot be custom white balanced.
And finally, setting an actual Kelvin value can be useful in creating precisely defined color images. This is very useful to commercial photographers.

Since we're on the subject of color, on my next post I'll try to discuss in greater detail some of the broader color issues like color temperature and environmental effects on how we perceive and record color information. In the meantime, play with your camera and experiment with these settings. You can't break anything, and you'll have fun looking at the different results you can end up with.

And post your pictures -- and questions -- right here!

Later, amigos!


Sunday, May 5, 2013

"Picture Style" Setting in the Camera

I was giving a talk recently, going over the many setting options presented in the camera's selection menu, when the question arose as to which "picture style" setting was appropriate for clinical photography. It's a good question, but one that's hard to answer in words alone, so I thought I should try to post an illustration of the differences between them.

I tend to think of it as something similar to choosing the right kind of film for a particular image quality we're looking to get. It's a quick way to select for a set level of sharpness, contrast, color saturation, and color tone, as you can see in the menu. You can go with the default settings in the camera (which I think works fine for our intraoral imaging) or make slight adjustments within them. Digital technology gives us a lot more control over these factors than we ever had before.

The Standard setting, as seen here on the left, has some sharpness applied and usually has a nice, crisp look to it. It's not over-sharpened or over-saturated for most imaging, and is appropriate for clinical applications. I generally use this setting for my dental photography.

The Portrait setting reduces the level of sharpening somewhat, and tone and saturation are thought to be more complimentary to skin tones in general portrait photography. You can experiment with it, but I never use this setting in my clinical work.

The Landscape setting increases the level of sharpening, tone, and saturation. This usually is seen in more vivid blues and greens in the image, which landscape photographers sometimes prefer, but I think is too much for general clinical imaging.

The Neutral setting doesn't have any sharpening applied, and can look a little flat. The idea is that you're going to apply some processing yourself in imaging software, but not such a good idea if you're shooting jpeg files.

The Faithful setting is almost the same as Neutral, but can achieve somewhat better color results when you're shooting under ideal daylight (approx. 5200 degrees K) conditions.

And, of course, you can choose to shoot a black & white image by selecting the Monochrome setting. You can even control for filter effects in this setting, so it's fun to play around with, but remember that an image shot in Monochrome has no color information at all and can't be converted into a color file later on, so don't use this in the clinic!

There are further selection options in the Picture Style menu that let you create your own custom-made style. Like everything else with your digital camera, it can be fun to experiment with these. But when you just need to get some work done, go ahead and set it on Standard. You'll get fine results.

And now that we're getting some nice Spring weather, take that camera out this weekend and have fun!

Later amigos (oh, and Feliz Cinco de Mayo!)


Thursday, April 4, 2013

40 ... And Counting!

We count down our time in decades, I guess because we have ten fingers. This is what I'm counting down now. A simple reflection: It was in the spring of 1973 that I apprenticed at a portrait studio in Cheyenne Wyoming, and am proud to look back on a career in professional photography that has spanned, for better or worse, these four decades.
Thousands, certainly, of portraits; many hundreds of commercial assignments, and more weddings than I care to count. But what I remember most clearly are those first couple years at that studio, living and breathing photography every hour of every day, and acquiring the skills and techniques that I would continue to hone in studios and darkrooms for many years.
Mercifully, there aren't many pictures of me from those days, but of the few I can still find (and admit to) this one by my friend and classmate Terry McCarthy is the one I most enjoy sharing. And that was my dad's Nikon Photomic F.  That was one sweet camera!

My own humble little possession when I began was this Nikkormat FTN and a plain old 50mm lens, which I bought used in Casper Wyoming for about a hundred bucks. I think I must have run a million rolls of film through it; in any event I completely wore it out and gave it an honorable retirement. I was addicted to Tri-X (and Edwal FG-7) along with venerable Ektachrome 64.

We had large-format cameras of all sorts at that studio, and medium-format ones as well. All these were new and wondrous to me, portals to incredible worlds of art and creativity. Eventually I saved up all my nickels and dimes and bought this Mamiya RB 67 and a couple lenses.  I had that baby for years too, and even wore that one out. I guess I'm a little hard on my gear, but then again, these are tools, not art objects. I sometimes wish I still had them, but it's mostly digital now and that technology has taken my career to entirely new places. No regrets.

Would I do it all over again? In a heartbeat! Photography has taken me to fascinating places, to meet incredible artists, and work with wonderful people.  And it brought me here.

My favorite writer Douglas Adams once wrote, "I may not have gone where I intended to go, but I think I ended up where I intended to be".

Amen, brother.


Thursday, March 28, 2013

(Color) Space ... The Final Frontier ~

There are few subjects in photography less well-understood by the average shooter. Color Space. Or Gamut. It's an understanding of the range of colors a given device, like a camera, can "see" and record, or what a printer may be able to produce. Obviously you don't need to be an expert on color (I certainly don't claim to be) to be a good photographer, but since our digital cameras want us to make a decision on which color space to shoot in, we should try to distill down a few of the essentials here to better understand what we're doing.

In other words, what on earth is the difference between using sRGB and Adobe RGB??

Most of what we shoot will be viewed on a monitor, either as we share our photos or post them to a website. This world sees in sRGB; shooting in this mode generally reproduces better saturation, particularly in the reds (at one end of the spectrum) and the deep violets (at the other). But why? Isn't Adobe RGB a larger color space?
Technically yes, it is, but it doesn't actually make more colors, it spreads those colors over a wider area. Since our monitor "sees" these colors in the smaller, more compressed sRGB space, those reds and violets get "cut off" and the program we're viewing the image in has to figure out on its own what those colors are. As a result, you end up with images that, by comparison, looked a bit washed-out. The reds don't pop, everything can look a little flat.

Alright, so when do we use Adobe RGB? I have usually recommended this to dentists who were shooting for high-quality shade matching, and working with labs that were using software which took advantage of this color gamut. It's also preferred when you're making custom prints and likewise are familiar with the imaging and printing software involved; typically you'd be shooting RAW files to fully take advantage of this. (A topic for a new blog post!). So, as I've always said, there's no more effective tool than communication. Work with your lab to see how they would prefer the image files you send them.

Are you getting the color quality you want in all your shots? You might not be, and maybe it's because you're not shooting in the appropriate color space. Check it out.

And let me know. I'd love to hear what's been working for you!

later, amigos!         Dave            

Tuesday, March 19, 2013

Keeping Your Photos Safe, Safer, Safest ~

As a photographer, I know of one particularly scary horror story: a crashed hard drive, photos not backed up anywhere, photos gone...forever. In the past, we had been meticulous to the point of obsession about the care and archiving of our negatives. We had to be; they were our bread and butter. We don't use negatives much any more, but instead we have digital files. And I'm afraid too many of us have become complacent about how we consider their long-term care. Any good computer you buy these days will have at least a half-terabyte (500 Gb) of hard drive space, so it's easy to save our photos there with little concern to running out of room for them. But room isn't the issue. Just ask anyone who has lived through that crashed hard drive horror story.

So, let's talk about some good digital archiving strategies. In the not-so-distant past, we commonly burned our files to CD's (and later, DVD's) to store them. They stacked pretty easily on our bookshelves. But even back in the day there were suspicions about the long-term stability of this media. And -- have you looked at new computers these days? Solid-state is the state-of-the-art, due to greater speed and efficiency; this means no more optical drives for CD's (unless you buy additional hardware. Blech!) So I don't look at this media as a good solution any more. 
Besides, they don't have a lot of capacity. A CD only holds around 750 Mb of data, a DVD around 3Gb. Your typical thumb drive? Easily 8, 16, 32 Gb's. I recently saw a 64Gb thumb drive on Amazon for around $30! I use these all the time to upload everything from entire folders to my Keynote programs. They're especially good if you need to share those files, too, since the USB port is universal. So yes, these are good solutions. But.....

They are not the best alternative, mainly because the very quality that makes them so convenient also makes them vulnerable: if they're easy to carry around, they're easy to lose. What you'll find every photographer relying on are external hard drives. They're stable, have high capacity, and can easily be transported. Plus, they're fairly inexpensive. I use several. As a Mac guy, I have a large (1Tb) external HD dedicated to Time Machine, which keeps my computer's entire content continually backed up. Additionally, I use portable HD's to upload all my photos, Keynote programs, Word documents and other data in a way that makes it easy for me to retrieve them later on when I need to work with them. Since I know that all my important data is redundantly stored (on thumb drives, on Time Machine, and on portable HD's) I can confidently delete them off of my computer's hard drive and not take up space there. 

Yeah, it would definitely be a drag if my computer hard drive crashed. Those are never inexpensive events. But losing my data? Never. I sleep well at night.

Your thoughts? Let's archive them here!

Monday, March 11, 2013

Accurate Color ~

As a commercial photographer and printer, I have always taken color very, very seriously. Capturing it on film, in a print, or in a digital image requires precision on many levels.
This is all the more critical in shade-matching, where we convey color information to the dental lab. Using digital technology, this task is much more reliable and accessible. Quality camera equipment -- a good digital SLR camera, macro lens, twin-light flash source  -- makes this possible. Other essential tools are the grey neutralizing tab and a reliable shade tab.

Dr. Dave and I normally shoot RAW files, and this totally unposed (!) picture shows the software we use to process them. But since most labs require jpeg images (they're a lot easier to email and work with) it's good to know that critical color accuracy is just as reliable with these.

Are you getting the color results you need? I might not be rosy, but I'm all ears!