July 04, 2009

The Vanishing "Sweet Spot"

When it comes to the choices people make in photographic equipment I'm generally a live-and-let-live kind of guy. "Use whatever you can afford and that makes you happy," is my motto. That said, I sometimes shake my head in wonderment at the popularity of so-called "walkaround" zooms for DSLRs. These are zooms that start out somewhere around 17mm (wide angle on an APSC sensor camera) and stop at 100mm or so (medium telephoto). A few even go up to 200 or 250mm.

EF17-85_586x225 I am not singling this particular lens out for criticism. It's a wonderful product and if you own one you made a brilliant choice. It just happens to be an example of the type of lens I'm referring to, that's all.

It's not the zoom ratio that bothers me. I "get" the convenience of having one lens that replaces many. What bothers me is the maximum aperture. At the wide end its generally something like f/3.5. At the long end it's almost always f/5.6. Not so coincidentally, that's the smallest aperture at which most autofocusing systems can still function in low light.

What most photographers using these lenses don't realize is that most DSLRs these days with resolutions above 10 megapixels are diffraction-limited at roughly f/8. That means that when you stop down to f/11 or f/16 you loose image resolution and contrast simply from the effect of light diffracting off the edges of the aperture blades. It's a function of the physical size of the aperture opening itself, so compact digicams with tiny lenses and aperture openings are often diffraction-limited at f/5.6.

But back to DSLRs attached to slow zooms. The effect of using a lens that has a maximum aperture of f/5.6 is that you have a "sweet spot" of only two full apertures (i.e. f/5.6 and f/8.0) before you start to lose image quality--and that's assuming the image quality is good at f/5.6!
       
Now some of you may ask "What about the wide end? That's still f/3.5 or so, right?" To which my response is, "That depends." What often happens is that if you're in Program mode and your lens is at maximum aperture (f/3.5) the maximum aperture will automatically decrease (to f/5.6) when you zoom to the maximum focal length. But when you zoom back to the wide end, some cameras will keep the aperture at f/5.6. Clever, eh? No wonder so many of these lenses come with image stabilization: The resulting shutter speeds are slow there's no other way you could get a reasonably sharp image unless you cranked up the ISO or mounted the camera on a tripod.

Contrast this with the situation you're in if you're using a reasonably good prime lens. Let's say the maximum aperture is f/2.0. Let's say the corners don't catch up with the center resolution until you stop down to f/2.8. Even so, you'd have a "sweet spot" with a range of four full stops (f/2.8 - f/8.0) rather than two. That gives you a lot more options for shutter speeds and depth-of-field, which translate into more creative options. You'd have only one option for focal length though--but if it was the right focal length you might find you'd miss the ability to zoom less than you'd miss having a broader choice of apertures.

Another option is to switch to a zoom with a constant aperture of f/2.8; however, if you've priced such lenses you don't need me to tell you that they tend to be rather pricey, not to mention large and heavy.

In photography as in life, you don't get something for nothing. If you want a small, affordable lens you can carry everywhere and that has a wide zoom range, you're going to have to live with a very small sweet spot. Only you can decide if the trade-off is worth it. I've already made my decision and I suspect don't have to tell you what it is.

June 28, 2009

What Do Your Photos Say About You?

2009_0616_1175_Scowl
If you look at enough of my work you'll see I'm a sucker for compositions like this one, with strong yet simple geometric shapes, bold contrasts, and dynamic tension with an element of mystery. But then what would you expect from someone who has worked as a graphic designer, technical writer and instructional designer? I know the world is chaotic and often absurd but I still like putting a neat frame around it. So sue me.

You can tell a lot about a person simply by observing the choices they make in food, friends, clothing, music, cameras... the list could go on indefinitely. A few caveats apply, of course: You can't tell everything there is to know about someone based on any one choice. It's also important to remember that  traits are relative, not absolute. Just because someone is more conservative than you doesn't mean they are a Conservative and you are a Liberal, it only means you are at different points of a continuum. With these qualifiers in mind, however, if you look at a series of related choices you'll soon have a pretty good idea of what sort of person is making them.

When it comes to photographic choices, someone who prefers to shoot with a large-format view camera is a very different person than someone who uses a 35mm rangefinder or even a full-frame DSLR. They are likely to shoot different subjects. Even when the subject is the same their working methods will be quite different--and therefore the results.

If your camera forces you to work slowly and methodically and to limit your exposures because of the cost and bulk of the media, you're going to put a lot more thought into each photograph before you release the shutter. In contrast, if your camera allows you to work quickly and at no incremental cost for each exposure, it can be easy to fall into the habit of clicking first and thinking later.

This is not to imply that digital photographers are lazy or that owning a digital camera leads to sloppy technique. If that's what I was trying to say I'd just come out and say it. What I am saying is that when the cost of shooting is so low you can choose to shoot a lot more,  when you shoot more there's more evidence of what choices you tend to make and it's therefore easier to determine your strengths and weaknesses as a photographer.  (Yes, I know, I could have put all that into the first paragraph, but I like to take my time.)

Now here's the good part: If others can gain insights into who you are and what you're about by looking at a collection of your photographs, so can you. Are you the sort of person who likes to play it safe or are you constantly pushing the envelope? Do you keep making the same mistakes, and if so, why? What impressions do people express when they look at your work? Are they the impressions you were expecting? Are they seeing something you don't, or not seeing something you thought was obvious? These are questions worth asking because it's otherwise hard to expect others to see something in your work that you can't see yourself.

June 21, 2009

Happy Father's Day

Edward Lewis It's Father's Day here in the U.S.--a day to honor and celebrate fatherhood. (And for merchants to sell more watches, cologne, greeting cards, ties, and so on. But that's another story.) I got breakfast in bed and the chance to read the morning paper in relative peace and quiet. The real gift of course was seeing the delight in my family's eyes as they opened the door and showered me with their love and appreciation.

My own father died of lung cancer when I was sixteen years old. He himself was only in his mid-thirties. It was only when I reached my mid-thirties that it really struck me how young he was when he died. It was only when I had children of my own (my first was born when I was forty-six) that I gained insight into how hard it must have been for him to support a wife and seven children on his working man's salary--and then to have leave us all at such an early age.

If you're wondering what any of this has to do with photography, here's your answer: My father worked as a photo-lab technician. I remember being fascinated with the magical process of putting a blank piece of paper into a tray and watching it develop into a photograph before my very eyes. The darkroom process still fascinates me to this day. (Sorry folks, but watching a print ease out of an inkjet printer doesn't deliver quite the same thrill.)

It's not as if my father tried to steer me towards photography or that he was a photographer himself; it's that he did something I considered magical and did it well. We all have our own individual reasons for buying cameras and producing photographs. Mine was my father and what better day to honor his memory than today?

June 18, 2009

Canon Posts Part Three of My Flash Tips

ThreeSpeedlites
I just wanted to let you folks know that Canon has posted the third of a three-part series I wrote about Canon's Speedlites. Part One was about why you might need an accessory flash unit and how to decide which one to choose. Part Two explained how to use some of the more esoteric features that are poorly explained in the owner's manual. Part Three is about how the benefits of using Canon's wireless E-TTL II system.

My motivation for writing this series was the relative scarcity of information about Canon Speedlites (or any brand other than Nikon, for that matter). What you find tends to be very specific to how a particular photographer uses them. My goal was to collect what I thought were the most useful tidbits and present them on Canon's Digital Learning Center. I'd be very interested to know whether you find this information useful or not.

If you'd like to learn more, whole books and chapters have been written about how to use off-camera flash. There's even a blog or two devoted to this topic. It can seem overwhelming at first, but even a little knowledge and skill goes a long way. There are photographers who've built a whole career and lighting style based on using only one light. All it takes to join their ranks is a light source and the will to learn how to use it.

June 13, 2009

A Focus on Focus


2009_0610_933

Most broad-area AF systems I've encountered are biased toward focusing on whatever is closest to the camera. In this case it's the guy with the binoculars.

During my brief vacation Massachusetts I decided to experiment with the way I normally focus. Instead of using only the center AF point and then recomposing I decided to try using all nine of the AF points in my EOS 30D so I wouldn't have to recompose.

In theory this should be faster and more accurate. In practice it was neither. Because it's difficult to gauge the visual sharpness of the focusing screen, I found I had to pay close attention to which focusing points lit up. They stay lit for less than a second and aren't always easy to see in bright light, so confirming focus is often easier said than done.

And then there's the tendency of automatic systems to focus on whatever is closest to the camera or offers the highest edge-contrast. This isn't much of a problem when you're focusing on a flat surface. When you're focusing on three-dimensional objects though, you'll often find that the camera focuses on the foreground when you really wanted to focus on the background--or vice-versa. The accompanying photos illustrate this nicely.

2009_0610_934

In case you're wondering whether it might have been better to focus on the guy in the background, here's the result. The question is, which do you prefer? Or would you have stopped down enough that they were both in focus?

If you shoot with a small aperture, say f/11 or so, you'll often have enough depth-of-field that you can focus somewhere in-between the foreground and background so that both will look reasonably sharp on screen or in print. But once again, targeting a specific area isn't easy when you're using nine or more focus points.

Finally, as mentioned in a previous post, it's not easy to assess depth-of-field through the viewfinder. Things look more in focus than they really are, especially when you're using medium or short focal length lenses at medium-to-far distances and shooting at wider apertures such as f/4 or f/2.8. There's not enough depth-of-field for everything to look in focus, but not so little that you're obviously using a selective focus technique.

The bottom line here is that as wonderful as automation can be, there's still no substitute for keeping your brain fully and actively engaged while photographing. Put some thought into what you're trying to achieve and the most effective way of achieving it, then make sure your camera is doing what you want it to.

As for me, I'm going back to focusing in the center, then recomposing (except when it doesn't make sense to do so, of course). I'm also going to be a lot more careful about how I choose apertures. (No more Program mode, thank you.) I'm going for either obvious selective focus or generous depth-of-field, without much in-between. It's time to show these damned cameras who's the boss. Wish me luck.

To Filter or Not to Filter

One of the easiest ways to get an argument started among photographers is to ask whether or not it's a good idea to use a UV or Skylight 1A on your lenses. Those who say yes argue that such filters help protect the front element. Those who say no argue that a filter degrades the optical quality of the lens. If you care to know what I say, read on.

Continue reading "To Filter or Not to Filter" »

June 07, 2009

I'm Traveling Light

Sorry folks, there's no photo this time. I've been attending my 35th college reunion at fair Harvard and am now visiting with family on Martha's Vineyard--which, by the way, is not a vineyard but an island off the coast of Massachusetts. Don't worry though. By the time I'm back at home I'll have plenty of great photos to dole out to you.

The reason there's no photo is that I'm traveling light. This is being written on a borrowed laptop. I brought along my Canon EOS 30D and two lenses (a Sigma 30mm f/1.4 and a Canon 50mm f/1.4) but I left my card reader and other non-necessities back at home. That's because I learned a long time ago that the heavier the equipment I take with me on a vacation, the less likely I am to carry it around.

My attitude and approach would be different if I had been hired to take travel photos, but in the absence of financial compensation, my preference is to travel light: one medium-sized body, one or two lenses, a couple of batteries and flash cards, a small, minimally-padded shoulder bag and that's it. I can sling it all over my shoulder and walk continously for three or four hours without being exhausted. Tired yes, but not exhausted.

Before anyone feels obliged to point this out to me, I'm well aware that I could travel even lighter with a compact digital camera. If I owned one I'd probably carry it instead of my DSLR, if only for situations where there was plenty of light. Since I don't own one and have more important spending priorities at the moment though, it's a moot issue.

But I digress. I'm really just advising you to stay tuned. I'll be back from my travels on Tuesday and ready to get back into the groove on Wednesday. In the meantime, the photographic adventures continue.

May 31, 2009

Are You Working Too Hard?

Costly Reflection
It took me roughly five minutes to convert this from color to black and white and then adjust the contrast and tonality to my liking. If it grows on me over time I may go back and spend and extra ten. Would it be a better photograph if I had spent five hours on it? I'll never know. I just don't have that kind of time.

One of the most important aspects of digital photography is how you manage your workflow—that is, how you structure the flow of work involved in producing a digital photograph.

“Producing a digital photograph” can mean different things to different photographers. For some it means ending up with a Photoshop file that has a minimum of six layers, backed up onto three different media and printed at 11 x 17 inches on an inkjet printer. For others it simply means printing the JPEGs from their memory card at the local drug store.

Some of those who do the former often sneer at those who do the latter because, after all, any “real” photographer knows how essential it is to shoot raw, use Lightroom or Aperture for global adjustments, and then move the best images into Photoshop for local adjustments and fine-tuning, with perhaps a few special filters and curves applied for good measure.

To this my response is that it’s possible, just possible, that there is no strict relationship between the time you spend on your photos and the ultimate quality of said photos. You could work for hours to improve a mediocre photograph only to end up with an improved version of a mediocre photograph.

This could be worth the time and effort if you were doing it as a learning exercise. If not, you might want to ask yourself if there might be a better way. Digital cameras and computers are, after all, supposed to be labor-saving devices. Why not use them to reduce the amount of time and effort it takes to produce photographs?

For example, instead of shooting raw, then converting the images to JPEGs for printing or distribution, why not set your camera to raw+JPEG and let you camera do the conversions for you? To make the JPEGs look good you’d have to get your white balance and exposure right from the start, but this too saves you time in the long run.

Other time-savers include automating the process of ingesting, naming and storing your image files, assigning metadata, and sorting the best from the rest. Anything you do often that takes more time than you’d like is a good candidate for automating. Look at it this way: The less time you spend sitting in front of your computer, the more you can spend shooting, or maybe even interacting with other people. You don’t have to use your camera or be social, of course. It’s just a suggestion.

May 27, 2009

I'm Feeling Better Now, Thank You.

2009_0523_658_Pinwheel
Spring is starting to merge into summer. This pinwheel thrust into the morning breeze by my son represented this joyful feeling perfectly. But wouldn't you know it, the breeze stopped as soon as I raised my camera--and so did the pinwheel's spinning. Oh well. Pastel colors and creamy smooth bokeh will have to suffice.

Thanks to everyone who sent comments of support and especially to those who surprised me by dropping contributions into my tip jar. I'm not the sort of fellow who suffers from insecurity or who has a strong need be acknowledged by others. That said, I appreciate being appreciated. As long as you continue to be interested and I've got the will, I plan to carry on. Meanwhile, it's time to get my shutter finger in shape for the summer. I suggest you do the same.

May 23, 2009

State of the Blog Address

Dino Bike
I'm on a selective focus kick these days. My 30mm f/1.4 Sigma lens is only too happy to accommodate. This was shot with a Canon 30D at ISO and f/2.8. Sweeet!

Those of you who have been following me for the past year or so have probably noticed that my postings have slowed down to about once per week--not that the pace was ever that torrid to begin with. I try to post often enough to maintain your interest yet not so often that it begins to feel like an uncompensated burden.

Burden or not, it is uncompensated. I state this not to complain but as a simple matter of fact. There are no ads, just a simple tip jar. So far I have received one tip. That's right, one. If any wags out there are of the opinion that even this was overly generous, please keep it to yourselves.

Also bear in mind I know what I should be doing if I wanted to make a buck at this. For one thing, I should write a lot more about equipment and less about photography itself. With few exceptions, I get far more comments on my postings about cameras, lenses, and lighting techniques that I do about what motivates me or anyone else to actually use any of it.

Another thing is that I should narrow my focus. This might seem counter-intuitive considering my already small readership, but here's the logic: There are fewer people interested in a blog about using and maintaining classic film cameras than a blog about photography in general, but those few would have fewer options to choose from and would be more intensely interested in the choices available.

An intensely focused readership would have a strong appeal for similarly focused advertisers. Given enough readers, the fore-mentioned blog about using classic film cameras could be an appealing advertising medium for businesses selling film, camera repair services, vintage equipment and so on.

As you can see, I've obviously been giving this some thought. There are two reasons why I haven't followed through. The first is that I've written about photo equipment for money before. It's not as fun as you might think. Sometimes it's no fun at all.

The second reason is that I can make a hell of a lot more money writing about things other than photography. The time and effort it would take to create a profitable blog could be much more profitably invested in finding and writing for business clients.

If you want to contribute any opinions to this mental dialogue I've been having, please feel free. For all I know, this little indulgence of mine is more (or less) important to others than I realize. One thing is for sure though: I'm going to keep taking pictures. I've been at it so long now I'm just too damned stubborn to quit.