Sunday, January 27, 2013

Right Angle Flash Mount For Photek Softlighter

In an earlier post, I described something I named the Black Plastic Thingy. Its purpose was to allow the positioning a speed light closer to the axis of an umbrella-based light modifier, specifically the Photek Softlighter. The BPT did just that, but was not very secure. This shortcoming left room for further investigation. As I mentioned in the earlier post, the trick is getting the flash as close to the umbrella shaft as possible.

One item that caught my eye was the Lastolite Brolly Grip. This device was a marriage of an umbrella bracket to a convenient carrying handle. It was unusual because it incorporated a special cold shoe that allowed for on-axis positioning of the speed light. Unfortunately, because it was designed to be hand held, there were no provisions for pitch control. I was tempted to purchase one, but instead decided to make something that would reposition the flash using bits and pieces I already had.

W. J. Wescott has introduced a number of reasonably priced light modifiers. Last year I purchased a Halo, which was essentially a shoot-through umbrella with a conical shroud that prevented flare from light back-splash. The big problem was mounting a speed light on the inside of the Halo. It utilizes a conventional umbrella bracket that positioned the flash in an upright position, forcing the placement of speedlight very close to the umbrella's inner surface. If I could mount a speed light along the umbrella axis, I would have more freedom to position the speed light further away from the diffusion surface. It just so happened that many of the Wescott light modifiers come with their own umbrella bracket with an integral cold shoe that employs a clamping action to secure the speed light foot. I decided to see if I could use clamping action to hold a right-angle bracket firmly in place. I would then add a second cold shoe to hold the speedlight.

First, I measured the width of the steel foot of a Nikon SB-800 and found that it was exactly 3/4 inches wide. I checked with a local hardware store and found some galvanized, right angle brackets with 3” arms made from 3/4 inch flat stock (Ace Hardware Corner Brace, Inside L). This would give me the right-angle repositioning I was looking for. But when I tried clamping it in the cold shoe's jaws, the bracket was too thick. This was quickly solved by filing a 45° bevel on the edges of the bracket to match those on the cold shoe.

Let’s talk about files. They come in different lengths, and different coarseness of cut. They range from bastard (coarsest) through second cut, to dead smooth (finest). My first cuts were made with a 12-inch bastard and were finished with a 10 inch dead smooth file. Remember that files only cut on the forward stroke. Do not allow the file to drag over the work surface during the backstroke or you will dull the teeth. Files should be cleaned with a special wire brush called a file card. A clean file allows its teeth to cut to their full depth, and for the chips to fall away while cutting. Best results will be achieved when your project is clamped in a vice. This minimizes "chatter" and will allow you to use both hands when using the file. While you have the file in your hand, lightly file all of the rough edges on the bracket, or anything else that might snag your umbrella’s fabric cover. Incidentally, I'm not particularly proud of my file work, but in this case, good enough is.

You can see that the bevels mesh nicely with the jaws of a clamp-type cold shoe. When tightened, I found the junction quite stable. The additional contact surface provided by the bevel made the difference. If you extend the bevel toward the "elbow", you can get some fore-and-aft adjustment, should you ever need it.

Once the bevels have been cut, you are pretty much done with the project. You can use the existing holes to mount the cold shoe using a ¼ x 20 thumbscrew. You can drill additional quarter-inch holes to provide additional positions for your mounting shoe. Depending on the type of cold shoe you use, you might find that the hole closest to the corner of the bracket does not provide enough clearance when the speedlight is installed. But if you’re using a clamp type shoe, you may be able to back the flash foot out slightly to gain some clearance.
Now if you’re using a conventional umbrella or a Photek Softlighter it is easy to establish a line-of-site relationship for optically triggering your flash (Nikon CLS or SU-4) because the sensor eye is on the "outside". But when  using the Halo,the flash is mounted on the inside and you will need to make other arrangements to trigger the flash. You could always use an extension cable, but with the availability of inexpensive radio trigger devices, you can well afford the luxury of wireless flash work. You get what you pay for, because unless you go with the more expensive Radio Poppers of the Pocket Wizard Flex series, you’ll lose TTL control over your flash. More on that later.

A final note on clamping cold shoes. I prefer the Stroboframe Shoe for the better build quality. I must admit that cheaper "Made In China" alternatives are out there, and I'm sure they will suffice. I have had some of Chinese versions strip their threads. You get what you pay for, I guess.

Sunday, January 20, 2013

To Flash Or Not To Flash...

I was showing my friend a collection of some photos I had taken for the Journal. She paged through the samples, and stopped at two that I had taken and placed on facing pages. This was not an accident, I explained, as I had imagined that I could casually comment that one shot was taken with available light, while the other with the judicious use of an on-camera accessory flash. At this point, she asked, “How do you know when to use flash?”

This is an interesting question. While I might have answered “I use flash when the light levels are too low”, this is really no longer true, since the current crop of cameras is capable of insanely high ISO ratings. In theory, there aren’t many environments where a high ISO couldn't produce a usable image. There must be some other issues governing if, or when, one should pull out a speed light. I believe that the addition of a flash can completely change the appearance of a photo, allowing the photographer to direct the viewer’s attention to important areas in the photograph. I am therefore more likely to utilize a flash or two in my photographs than not.

I often find myself alone in my approach, since it appears that most photographers assume that there will always be enough available light to produce a proper exposure. This may be so, but relying on what is available puts you at the mercy of your lighting environment. Harsh, ceiling mounted light sources will create dark shadows devoid of detail.

It boils down to two basic questions: Is flash permitted, and if so, how will it improve the overall appearance of the image?

Permission To Flash: Let’s dispense with permissions. There are times when flash is inappropriate. Indoor stage performances are a universal no-no, especially when animals are involved. Frequent bursts of light will distract both the performers and the rest of the audience, so the best advice I can give is when in doubt, Don't. In other instances, particularly museums, exposure to bright lights could potentially accelerate the deterioration of the displays, so consider museums as absolute no-flash territory.

There will be some exceptions. The obligatory “picket fence” or “handshake” photos are fair game for flash work since the subjects expect it, and more importantly, the photos must turn out. I can’t say that I have never blown a handshake, but I have had some close calls where the image squeaked by through to the grace of post processing. Now, when I enter a new venue, I ask myself, “If I had to take a handshake photo, where would I stand?” If I can find a position with a nice bounce surface behind me and an appropriate background, I’ll remember it for possible use later on.

If flash is permitted, I must now consider whether flash will help, or hurt. In some instances, the available light will be satisfactory both in appearance and quantity. This is why my first test shot is usually an aperture priority available light shot. I have occasionally encountered professionally lit venues where the existing light was perfectly fine.

Once the decision is made to “flash”, the next decision is how it will contribute to the finished photo. Flash can contribute as a Key Light, a Fill Light, or an Accent Light.

Produces the shadows that give the photo a three –dimensional appearance.
Appropriate when ambient is relatively even. It adds “snap” to cloudy-bright outdoor photography.
Provides details in shadow areas. Remember fill light will add to the ambient light, so overexposed highlights will sometimes occur.
Appropriate when the existing light produces dark shadows. Think fill flash on a sunny day.
Applied when you want light in a specific region of the photograph to draw the viewer’s attention.
When used as a background light, be sure the exposure compliments the key light exposure. When used as a “kicker”, use a gobo* to minimize lens flare.

Outdoor Flash Key Lighting: Under bright sunlit conditions, you’ll need lots and LOTS of light to overpower the sun. If you apply the “Sunny Sixteen Rule” to a possible outdoor shooting situation, you’ll know that on a sunny day, if you use an ISO of 200 and a shutter speed of 1/200 of a second, your shooting aperture will be F 16. With most speed lights, you’ll need a flash to subject distance of about five feet, which isn’t always easy to accomplish.

It is easier to use a key light flash if the ambient levels are less than "full sunlight". This shot was made in the early evening. The performer is essentially in the shadow of several buildings and has no direct sunlight illuminating him. If you look at his white shirt, you can still see some detail in the shadows. Light was provided by an 800 w/s Norman powerpack powering a flash head placed on a light stand 12 feet in the air and securely lashed to a flag pole 20 feet from the subjects. Exposure was 6.3 @ 1/125 of a second, ISO 200.

Outdoor Fill Lighting: Whenever you attempt to  balance flash with ambient, you have to consider the contribution the fill light will make to the overall exposure of your subject. When photographing for a newspaper, one should try to keep the contrast between the highlights and the shadows to a minimum. Deep shadows ultimately become large blobs of black on the printed page. Fill light will go a long way in cutting the contrast. But be careful: the addition of fill light not only brightens the shadows but also adds the the brightness of you highlights. Over-filling the shadows often results in overexposed or "blown" highlights.

You can avoid the blown highlights by underexposing your subject slightly and allowing the fill light "take up the slack". In this photo, I decreased the metered exposure by about 2/3 of a stop before apply a TTL adjusted at my normal +2/3 stop. The shot, incidentally, was done at very close range using a wide angle lens. Keeping things level minimizes the disturbing effects of perspective distortion.

Accent Lighting: Accents can be added to provide additional detail in the background. You have a little more freedom about coverage, just a puddle of light to add some detail to the image. Certainly, we see accent lighting and accept that perfectly even lighting is not only difficult to create, but just a little boring.

In this case, I used my usual Zumbrella for the foreground lighting. I noticed that the light fell off quickly, due in part to the angle of the wall. I placed a second remote SB-800 on a nearby staircase and aimed it directly at the painting, perpendicular to the surface. I didn't have a grid at the time, relying on a narrow beam angle adjustment to contain the light. It wasn't entirely successful because there is a definite hot spot below the center of the painting. If I had the time I could have fixed this, but with dinner guests just minutes away, my timely exit was probably more appreciated.

*Gobo is short for “Go Between Light”. They shield the lens from direct light coming toward the camera.

Sunday, January 6, 2013

Battle Of Inches

Funny. I was watching Joe McNally's DVD on lighting this morning, just hours before this shot was taken. Joe (like I really KNOW him) stated that sometimes lighting is a Battle of Inches, meaning that an inch or two can make a big difference in the final appearance of a photograph. In viewing this photo, it is clear that if I had only seen my mistake, I could have easily corrected it.

The assignment brought my editor and me to the Redwood City Courthouse to gather background information for an upcoming story on the Sheriff's Department. Their responsibilities cover a much wider range than most of us realize, and my job was to try to illustrate some aspect of the department's responsibilities that would get the viewer quickly to the point.

After spending nearly an hour touring the Sheriff's "turf", it was time to make a photo. With so many different aspects, my editor and I did a quick evaluation of how we should approach the shot. Due to privacy issues, I was decided that only our designated subject should appear in the photograph.

Since I had the full cooperation of the department, I was able to get Officer Heindel to pose for the shot. In order to minimize my impact on his day, I said I'd call for him after I had a chance to stage the shot. I now had five minutes to evaluate the environment for useful visual elements. First came the door. "Presiding Judge - Criminal" seemed a natural, since the presence of an armed member of the sheriff's department surely indicated that something ominous was in the air. But the normal comings and goings would mean that the door would open and shut randomly, so we had to be fast and flexible. Then came the ambient light. Indirect sunlight was coming in from a window on the far wall, leaving the tell-tale glare on the wooden benches. I decided to include that in the image, as it gave a sense of depth without adding any distracting details. There was no way I could have arranged for the lights to be turned off, so I decided I would just have to live with them. By underexposing the ambient by 1 stop, I lessened the impact of the color temperature mismatch.

During the test phase, I "choked up" on my Zumbrella by sliding the umbrella shaft so that the flash was much closer to the diffusion surface. This effectively reduced the diameter of the light source, giving me a harder, more direct light. Also, it eliminated edge spill which could have allowed stray light to get past the umbrella's edges. Used in this manner, I gained some control over the light at the expense of soft edge shadows. Considering the demeanor of my subject, "soft" was the last thing on his mind!

Immediately after I took this shot, I noticed that the door handle was interfering with a clean line on the sign. By moving to my right, I could get some distance between the handle and the sign, and improve the perspective to boot. But in doing so, my subject appears to move closer to the dark wood door, something I didn't catch. Incidentally, the person at the end of the hall killed the shot for publication, even though he would have been impossible to recognize.

After I re-positioned myself to address the door issues, I moved my light closer to me so I could get some light on Officer Heindel's right eye. I finally asked him to give me a look that said, "You'll have to get past me", which he did.

Now back to the chosen image. Notice that Officer Heindel's dark uniform blended in with the wood frame. Even though he is several inches away from the wall, it looks like he's leaning against the door, detracting for the strong image I had hoped to create.

I know this is putting a very fine point on the subject, but it bothers me a tiny bit, primarily because I didn't notice it during the shoot. But I have to admit that Joe was right: It is a Battle of Inches.

Addendum: After I wrote this article, I went back to see if there was something to be learned about composition for future reference. Since I could not include anybody in the photo other than my subject, the benches had to be empty. But what if the number of people waiting on the benches was an issue?

I was surprised at how complete this photo could have been if I had people on the benches and a full view of the name on the door. Certainly this alternate composition is worth considering, should a similar opportunity arise.