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InFusion: Normal Lenses
Posted May 4, 2010 Print Version     Page 1of 1

Normal lenses sound, well, normal: plain-Jane, boring, unimaginative, mundane. I could go on. But what I really think is that normal-angle lenses are valuable "sleepers"! Why? Because so much of the time when we're shooting at traditional events, presentations, or even just shooting on the street, the lowly normal-angle lens tells the story like it is. It's just right for an astonishing percentage of situations. The normal-angle lens reproduces the same relationship, proportion, and size of the objects that the eye sees. I can't imagine ever going out without a 50MM in my kit.

Here's what normal-angle lenses are good for:
• Very real appearance of capture
• Natural perspective; backgrounds don't look too near or too far away
• Basic crop without including too much extraneous material in the frame
• Great for small groups: 3-5 persons, 3/4 close-up, or formal wedding groups
• Fast ƒ/stop: great in low light, easy to focus in all situations
• Ease of use compared to moderate telephoto in fast situations or while following a moving subject
• Inexpensive

And here are the cons:
• Not tight enough for couples pictures: for instance, across a round banquet table
• Way too far away for speakers or workshop presenters and audience reaction shots
• Simplicity of size and use can make you lazy in choosing camera viewpoint

Dan Jahn
Dramatic bokeh is easily achievable with the right f/stop; just use a lower number such as f/2.8–f/5.6. At a close distance, a normal lens cropped Denver photographer Dan Jahn perfectly and focused on his hands as he framed a shot.

Ease of Focus
More needs to be said about the ease of focusing normal lenses. My favorite prime 50MM is an f/1.4. Top-model DSLRs now focus much more quickly than in the past, but they all are limited by the maximum aperture of the lens in use.

Focus is based on the amount of light that comes through the lens. This means if your lens is only an ƒ/4, it will take noticeably longer to focus than an ƒ/2 or ƒ/2.8. It bears repeating that progressive zoom lenses with maximum aperture of ƒ/3.5 at the widest MM typically decrease the opening to ƒ/5.6 as the MM lengthens.

It's easy to understand why progressives are the wrong choice for professional stills or video. Spending for the more expensive nonprogressive lenses will repay you with many good, sharp images in circumstances where a progressive could not autofocus in time, or perhaps at all.

Here’s a place where you can’t afford to blow the sharpness: a wedding recessional, using a normal-angle lens at about 15', prefocused, and allowing the couple to walk into the frame without riding the focus ring.

The weight factor of the lens comes into how long it takes to focus. Comparing my ƒ/1.4 50MM to the ƒ/1.2, which is four times more expensive, the difference in weight is almost a factor of two. The more costly lens, even though it's faster, will take significantly longer to focus because the lens motor needs time to move the extra weight. Of course, it's best to buy the most expensive glass you can afford, but follow all the guidelines about speed, weight, and cost to make informed purchase decisions.

The ability to grab focus has always been one of the three big things I consider to be the basic common denominators of good images, along with framing and exposure. When interviewing a potential employee, I ask for an entire wedding proof set. Film made critical review easier because you could see just how everything was taken. With digital, I can only guess at the manipulation that has been done, and I must rely more on the continuity of how well the person edits, organizes, and optimizes his or her work.

getting sharp focus outdoors
Sharpness outdoors can be critical, and the light-gathering ability of a normal lens makes focusing in shade or late daylight much easier.

The Physics of Focus
I'm always amazed at how hard it is to get sharp focus and that most image makers (film or still) seem to misunderstand the physics of focus. HDTV makes a merciless show of how often news and even feature videographers don't grab focus properly on their interview subjects. Don't you just hate it when the person with the microphone is fuzzy and the background is sharper in comparison?

Experience and confident equipment handling are a must if you're going to charge anything at all for your work. Static subjects should not be too hard to capture, but the moment action starts, the amateur will lose shot after panicked shot to blur and bad exposure. Here's where the practiced pro earns his or her money, and, incidentally, creates the impact of visual value and memories that please people for generations. Spontaneous wedding moments are more precious than gold.

Six elements control the precision of focus, in addition to pixel and chip size, and the quality of the glass:
• ISO or gain
• Stability: camera shake/subject motion
• White balance and exposure
• ƒ/stop selected
• Type of lighting
• Method of focusing

The higher the ISO or gain—in spite of phenomenal capability of the new DSLRs and HD video cameras—your image may be in focus, but it will not appear as sharp as lower range settings. Instability is a killer; shaky shooting or your subject moving too fast for the shutter speed/frame rate chosen will ruin your shot every time. Exposure and especially white balance, if they need to be corrected in post, will change the effective ISO and, in the worst-case scenario, will result in more noise. It can't help but look like the image is soft and blotchy.

We have all these ƒ/stops available, but for optimal sharpness, we use only the lower range of generally ƒ/2-ƒ/8. High ƒ numbers introduce diffraction, which always makes an image seem fuzzy. Type of lighting is something that many videographers and photographers completely forget. A dark room lit with candlelight will never look as sharply focused as an outdoor portrait and even less so than illumination with flash or powerful hot lights.

Focus Methodology
The method of focus makes all the difference in the world. My husband and partner, Karl Arndt, demands to jump in at this point to say that peaking and double zebras in his Sony EX3 have changed his life with deftly proficient focus and exposure. He's got this wired, and the difference in method has made a noticeable refinement. The broadcast-approved HD capture fits really well with the huge file size and beauty of the still/video coming off my Canon 5D Mark II.

Here are three focus tips with DSLRs for still shooting that will make your life easier:
• Setting the focus sensor
• What to focus on
• Separating the shutter and focus functions

sushi baby
Sushi baby was just 3 weeks old when this portrait advertising his parents’ restaurant was taken. The normal-angle lens allows a bit of size distortion on the dishes to make them look extra big in comparison to the little samurai.

Auto focus rules, but you've got to set it right to make it work for you. The strongest point is the center one, when used by itself. It functions quickly and more accurately on any camera. Using all focus points together can result in grabbing the sharpest focus on a close object that may not be the one you prefer to feature. I find the flash-and-beep focus confirmation is essential, particularly since I'm so often working in low light or, perhaps, paying more attention to the subject's expression than to mechanics. I'm reminded to wait for the confirmation, rather than getting excited and shooting too quickly before the lens has had time to function. A subject with wide depth of field will usually confuse the auto focus if it's set to all points, and you may not be able to achieve any focus whatever. This is true in either single-shot or continuous-focus mode.

If you're into continuous shooting for action/sports-dancing at a wedding is in this same category—a high-speed card allows your camera to write from the buffer more quickly and get back to the business of focusing for the next shot.

Things were simpler in the heyday of range-finder focus, but the good workmanship remains the same. You must decide what the important element is that must be sharp-unless it's the overall frame. If you don't place the focal point fully over the specific spot-for instance, just off a person's ear or shoulder-you risk blur on the subject with a sharp background. Zeroing in on any detail with contrast makes focus quick and accurate. For portraits, the eyes are usually what we want pinpoint sharp; sometimes that calls for changing the focal point for vertical capture to the point that is right over the face. Of course, we focus on the subject and then recompose to frame the shot for meaning.

bokeh with beauty
Bokeh with beauty: You can practically smell the flowers and feel the sunshine in this image.

Separating Focus and Shutter
A secret that instantly improved my image capture was introduced to me many years ago by Ed Pierce, the mastermind behind the PhotoVision Video tutorials and the inventor of the invaluable three-panel exposure and white-balance target. After separating the functions of focus and shutter on my camera, my accuracy of focus is almost 100%! This means that you press the shutter with your forefinger and control focus with your thumb on a different button on the back of the body. The rocker motion between thumb and forefinger is very stable, ergonomic, and precise. Once you focus and release that button, focus is locked.

You can fire a number of frames at a subject that are reasonably motionless without refocusing at all. Of course, when the subject moves, you must press the button again. For continuous shooting, simply hold the button down all the time. On the Canon 5D Mark II, go to Custom Function IV and select option 2 to separate focus from the shutter to the AF/ON button. I guarantee you'll be amazed!

In LiveView video mode, there's another preferred setting that will help your focus. In dark and difficult environments, I really want to take advantage of auto focus when I can. I select the Live mode setting, rather than Quick mode. Before starting a clip, I auto focus on my subject. If I need to shift depth of field, I note the focus pull necessary, because I'm going to have to do this myself, and then shift to manual focus.

If the subject moves, I move too, keeping about the same physical distance between us to avoid blurry capture. (A little shaky-cam is preferable to just plain fuzzy.) Then, I drop right back into auto focus to start the process for the next clip or to transfer into stills. You can also auto focus during a clip-it takes a second or more-keep rolling and use a dissolve to create bokeh.

Next time, I'll discuss my favorite medium telephoto lenses.

Sara FrancesSara Frances (studio at photomirage.com) and husband/partner Karl Arndt collaborate in their own unique brand of Fusion as “Foto-Griots” whose work has evolved past photojournalism into what they call “Storytelling from the Heart.”

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