Stroboscopic flash is when a series of flashes are fired continuously in a single exposure. The multiple bursts of light allow you to freeze a moving subject multiple times as it moves through the frame. The results are very similar to that of combining multiple exposures. This tutorial is a brief overview of how stroboscopic flash works.

How Do I Access Stroboscopic Flash?

Many of today’s high-end Speedlights such as the Canon 580EX/EX II and Nikon SB-800/900 have this feature built in. Canon refers to this feature as Multi Mode while Nikon calls it Repeating Flash (RPT). We’ll be using a Nikon SB-800 for this tutorial, but all of these concepts can be applied to any flash with a stroboscopic mode.

Stroboscopic flash is first controlled by the flash output, frequency, and number of frames. First, you set the power level of your flash just as you would in manual mode. Frequency, expressed in Hz, represents the number of flashes per second. The number of flashes represents exactly how many times your flash will fire at a given frequency. Keep in mind, the lower the output, the more flashes you can get at a given frequency.

Setting the Exposure

Once you have your output, frequency, and number of flashes set, you’ll need to set the exposure. You can determine the aperture by using a light meter, using the guide number table in your flash’s manual (f/stop = Guide number x ISO factor / Subject Distance), or simply by experimenting.

Keep in mind that if you have a portion of the frame overlapping (i.e. still part of the frame), the repeating flash may result in overexposure. For example: If you flash a still subject at 1/2 power two times, your exposure would be almost exactly like flashing that subject once at full power. This generally doesn’t affect moving subjects but is an important thing to consider when setting up your shot and calculating exposure.

The minimum shutter speed is determined by dividing the frequency of flashes into the number of flash frames (shutter speed = number of flashes / frequency (Hz)). For example: If your number of flashes per frame was 10 and the frequency is 5Hz, you would need a shutter speed of 2 seconds or slower. You can also use the bulb exposure if you are trying to time a particular action.

Setting Up for the Shot

Stroboscopic flash pictures work best in a dark setting. Because the shutter speeds can be very long, it’s also best to work on a tripod. You can trigger the flash from the camera’s hot-shoe, from an off-camera cable, or using a radio trigger. For this demonstration I used the latter. The main reason for this is when you fire the camera, it immediately fires the flash. By using the PocketWizard on the flash, I could delay when the flash was firing and manually trigger it as the object was in the frame. Here is a shot of the setup:

(1) Nikon SB-800 Speedlight (2) PocketWizard Plus II Transceiver with PC-sync connection (3) Camera with shutter release attached (4) Reflector on other side of “drop area” for fill (5) Black background (6) Step ladder to drop subject from.

I pre-focused to where the “drop zone” would be, and marked it on the floor with gaffer’s tape. I used a larger aperture to get a little leeway with the depth of field and to allow a longer shutter speed. Once the camera was set up and focused, I turned off all the lights and hit the shutter. I then dropped the object and triggered the PocketWizard as the subject passed through the frame. Here are the results:

Nikon D200, 35mm f/2, 3.0 sec @ f/11, ISO 100; Flash Setting: 1/32, 10x40Hz

Nikon D200, 35mm f/2, 3.0 sec @ f/11, ISO 100; Flash Setting: 1/32, 10x40Hz

Nikon D200, 35mm f/2, 3.0 sec @ f/11, ISO 100; Flash Setting: 1/32, 10x40Hz

Nikon D200, 50mm f/1.8, 3.0 sec @ f/5.6, ISO 100; Flash Setting: 1/64, 10x40Hz

You might have to do a lot of experimenting to get the results that you want, but stroboscopic flash can be a lot of fun. Hopefully the provided frequency, number of flashes, and power settings will give you a starting point.

Other Methods

There are also ways of achieving the same effect using traditional strobes or speedlights without a stroboscopic mode. You can always open the shutter and manually trigger the flash as many times as you’d like. Triggering systems like the PocketWizard Multimax transceivers feature a mode called multipop that allows a flash to trigger multiple times within an exposure.

There are also infrared and sound triggers available for high speed photography. These devices fire your flash when a particular action happens and can be a lot of fun to experiment with.

The Olympus PEN E-P1 is a camera that many photo enthusiasts have been dreaming about for a long time. It’s a relatively small camera with a decent sized sensor and interchangeable lenses. The question on everyone’s mind is how does it stack up? I had the chance to get some hands-on experience with the PEN E-P1; continue reading to find out how it handles.

Olympus PEN System

Olympus PEN System

Controls and Menus

Most of the camera’s main controls are positioned so you can easily access them with your right hand while you steady the camera, adjust zoom, or focus with your left. The controls you’ll probably be using the most are the command dial and wheel. The command dial is very conveniently located just to the right of where you would naturally rest your thumb, making it very easy to get to. The command wheel surrounds the selector pad and takes a little bit of getting used to. I can’t help but say it feels very awkward at first. Although I did eventually get used to it, I would have rather seen another command dial in the front of the camera for things like aperture control, exposure compensation, etc.

One of my biggest gripes with the camera is its menu and interface. For a camera that looks so simple, the E-P1 can get very complicated when it comes to changing certain functions.

One prime example I faced is moving the selected AF point. By default you have to access the Live Control menu, scroll down, select the AF targets function, then select the point you want. Now you can customize the controls to make the selector pad move the focus point when you press it, but then it won’t work to adjust the ISO, AF, WB, or advance mode. It would have been nice to be able to map the INFO or Fn button as a focus point selector mode so you could retain the quick functions on the selector point (although you can program the Fn button to re-center the focus point).

Olympus PEN E-P1 Controls

E-P1 Rear Controls

Fortunately there is a pretty extensive “Super Control Panel” that you can access a lot of the most common functions (it looks similar to the shooting settings on the back of an E-VOLT camera). You could call this the Super Secret Control Panel because I stumbled upon it accidentally and there is no indication of how to access it in the menu or the Live Control. To access this “Super” menu, first press the OK button, then the INFO button, and voila! Oddly enough, when you are in the Super Control Panel, there is a reference to get back to the Live Control panel (press INFO) but there is no reference in Live Control to get to the Super Control Panel. It is, however, referenced in the manual, pages 6-7.

The menu itself is pretty extensive, which is not the problem. The main problem is some of the options are not exactly easy to recognize off the bat without referencing the manual (ie: AF Loop, AF Spiral). Some of the functions that you would think would be in the same part of the menu are split into different tabs (ie: picture mode, quality, and gradation are in a completely different part of the menu from noise reduction, white balance, and color space).

These gripes might seem a little nit-picky but should be addressed. The last thing a photographer wants is to miss a shot because he/she is digging through the menu to change or find a particular function. These issues may not be “deal-breakers” for most but will take some getting accustomed to.

Lenses

Olympus launched the camera with two lenses: a 17mm f/2.8 and a 14-42mm f/3.5-5.6. With the 2x multiplication factor of the 4/3 sensor, these equate to a 34mm and 28-84mm respectively in 35mm terms.

The 14-42mm is unique because of its size. Fully expanded, it’s just shy of 3.5 inches, but you can contract the lens down to just under 2 inches for storage. This makes it much easier to pack in a small case rather than a full-sized camera bag.

14-42mm Contracted and Expanded

14-42mm Contracted and Expanded (mouse over to compare).

The lens itself covers the standard “kit lens” range you would expect – decent wide angle to medium telephoto. Olympus is very well known for making top quality optics, and this one is no exception. The build of the lens is not quite like the body, but it does have a metal mount and feels very solid. Kit lenses are notorious for getting a bad rep, but this one is excellent.

Next up is my personal favorite: the 17mm f/2.8. Mounted to the camera, the lens is less than an inch long, making it a great compact and lightweight walk-around kit. Obviously, being a fixed lens, it will require a little more work to frame up your subject compared to a zoom lens, but the work can result in a much different type of picture. There’s also a pretty nice external viewfinder available to cover the field-of-view of the lens. The viewfinder is included in the E-P1 17mm f/2.8 kit but can also be purchased separately.

If these two mounts don’t fit your needs, there are other lenses available for the Micro 4/3 mount from Panasonic. You can also use existing 4/3 lenses with an adapter, but depending on the lens, you might lose some functionality. There is also a slew of 3rd party adapters on the market for common mounts such as Leica M and R, Nikon F, Olympus OM, and many more. Usually these adapters are limited manual focus and stop-down metering but can be very useful if you have an extensive collection of old lenses.

Olympus PEN E-P1 Mount and  Exposed Sensor

E-P1 Lens Mount and Exposed Sensor

One thing that might make some nervous is how exposed the sensor is when you remove the lens. Because of the nature of the camera, the sensor is completely exposed most of the time, even when you remove the lens. I didn’t encounter any dust problems, but you definitely need to be careful when changing lenses with the E-P1. The camera does have a shutter so many have asked why it doesn’t cover the sensor when the camera is off. I suspect it is because a sensor cleaning is much cheaper than a shutter repair.

Flash

The camera does not have any kind of built-in flash, but there is an optional FL-14 flash available. The flash itself works well, but you will need to make some menu adjustments if you plan to use it extensively. In the Custom Settings Menu, you will most likely want to re-assign the command dial or wheel to adjust flash compensation for each shooting mode (except manual, which already utilizes both of those dials). The other alternative would be to access flash compensation through the Super Control Panel.

FL-14 Flash in action

The FL-14 flash in action

The flash does a pretty decent job considering its size. It’s not exactly the most powerful little unit, but it certainly gets the job done. My only complaint is the fact that it utilizes AAA batteries instead of AAs. I would rather have a slightly larger flash that takes AA batteries instead of a small unit with AAA batteries.

Performance

The E-P1 produces excellent images. I found that the image quality was better than even the best point and shoots out there, and definitely on par with most of the consumer to midrange DSLRs. Of course, the Zuiko lenses in combination with the sensor produce a lot of detail and very sharp images. High ISO performance was good even up to 1600. Anything higher really starts to show the noise, but 3200 could certainly be used in a pinch.

One thing I was a little disappointed with was the LCD screen performance in bright light. It can be very difficult to see in full sunlight, which is tough for a camera that relies on the screen so much. Shooting with the optional viewfinder for the 17mm lens definitely helps, but doesn’t allow critical focusing or menu adjustments. Perhaps we will see some sort of external electronic viewfinder for future PEN cameras, similar to what Panasonic is doing on their upcoming GF1.

Autofocus

[Editor’s Note: I decided to delay my initial publication of this article because Olympus released a firmware update the day I was going to post it. This update specifically addresses the AF performance. I’ve left some of my initial findings and those after the 1.1 Firmware Update.]

The autofocus system is somewhat hit or miss on the E-P1. The good news is it performs pretty well in bright shooting conditions in S-AF. It’s able to lock on and capture subjects pretty quickly. In C-AF or for fast moving subjects, it can have some problems. This is definitely not a huge issue since the E-P1 is not exactly designed to be a “fast” camera for sports or action.

In low or dimly-lit situations, the autofocus can be very sluggish and prone to hunting – even against static subjects. The camera does not have any kind of built-in AF-illuminator, which seems like a pretty big oversight. In these darker situations, even some point and shoot cameras can potentially outperform the E-P1. It’s a shame because Olympus really pioneered Live View in a lot of their early EVOLT cameras and is still one of the leaders of the technology in the full-size DSLRs.

[AF Performance After 1.1 Firmware Update]

A word about the firmware update process on the E-P1: Unlike most other manufacturers, you cannot simply load an empty memory card with the firmware update to load it into the camera. You will need to install the Master/Studio software provided with the camera to access the firmware. To load the firmware to the camera, you have to connect it via the provided USB cable (not a standard USB cable). As with any firmware update, you’ll want to have a full battery. This is a little tedious compared to other manufacturers, but the process itself runs pretty quickly. Keep in mind, you will want to run an update for both the camera and the lenses.

Once the update was completed, there wasn’t a night and day difference in the focus speed but definitely a marked improvement. The S-AF seemed to snap in a little quicker with both lenses, in both bright and dim lighting. C-AF was less prone to hunting for the subject and tracked focus slightly better but is still slow overall.

I would still stick with my initial comments on the camera after the firmware: it’s great for static or slow subjects but is definitely not suited for fast moving subjects or action. I personally don’t find that to be an issue at all because in reality, I don’t think the E-P1 was really designed with that type of shooting in mind.

Images

Here are a few images from the E-P1.

E-P1 Sample Image

Olyumpus E-P1, 17mm f/2.8, 1/10 sec @ f/3.5, ISO 800

E-P1 Sample Image

Olyumpus E-P1, 17mm f/2.8, 1/25 sec @ f/2.8, ISO 3200, Grainy B&W Art Filter

E-P1 Sample Image

Olyumpus E-P1, 17mm f/2.8, 1/30 sec @ f/2.8, ISO 800

E-P1 Sample Image

Olyumpus E-P1, 17mm f/2.8, 1/25 sec @ f/5, ISO 800, FL-14 Flash

E-P1 Sample Image

Olyumpus E-P1, 17mm f/2.8, 1/250 sec @ f/2.8, ISO 400

E-P1 Sample Image

Olyumpus E-P1, 14-42mm f/3.5-5.6, 1/500 sec @ f/8, ISO 100

E-P1 Sample Image

Olyumpus E-P1, 14-42mm f/3.5-5.6, 1/250 sec @ f/8, ISO 100

Conclusion

Despite some of its quirks, I really enjoyed the E-P1. The menu and interface take some getting used to, but that can be overcome with time. This is definitely a “read the manual” type of camera, even for seasoned vets. Some of this is somewhat expected from a first generation camera in a particular system – just look at any early DSLR or point and shoot camera compared to a camera from today.

When it comes right down to it, the camera produces great images and is on par with a lot of the low to middle range DSLRs that it competes with in terms of price. It can be a great alternative for users wanting to carry something other than their big DSLR system but still having something comparable in terms of image quality.

Right off the bat, there are some minor changes that would be very welcome for the next generation PEN camera:

External Electronic Viewfinder. For a camera that relies so heavily on Live View, this would be extremely helpful. The viewfinder for the 17mm f/2.8 definitely makes things easier, but what about the rest of the lenses? If it was implemented similar to the Ricoh GX-200 or recently announced Panasonic GF1, it could increase the flexibility of the camera in brightly lit situations.

AF-Assist Lamp. This is something that even the most basic cameras have, and I was very surprised to see it missing from the E-P1. Unless the contrast-detect AF system in low light dramatically improves in the next camera, this is a necessity.

Simplified Controls. As I mentioned earlier, for such a simple looking camera, the E-P1 has a lot of complex controls. I think making the menu selections and interface a little more intuitive, or taking a “less is more” approach, might be the right way to go on the E-P1.

I would say the Olympus PEN E-P1 is a great camera, but it may not be the camera for everyone. The bottom line is it’s able to produce wonderful images, but it will take a little bit of getting used to for some users. If nothing else, it shows a massive amount of potential for the future of Micro Four Thirds cameras.

The Hot Shoe Diaries: Big Light From Small Flashes

Fresh off the success of his last book, “The Moment It Clicks,” Joe McNally has returned with “The Hot Shoe Diaries: Big Light From Small Flashes.” His last book mainly focused on the images and the stories and obstacles behind them, along with some technical details. “The Hot Shoe Diaries,” as the name implies, is completely about shooting and making the most out of hot shoe Speedlights.

The book starts off with the basics. A lot is covered in this section including camera and flash functionality, technique and lighting principals. Joe also talks a little bit about some of his tools of the trade and the rationale behind why he uses them. He does a great job of taking some of the more complex subjects and explaining them in a very simple manner. He also interjects his very funny humor here and throughout the book to keep things interesting.

Once you’ve got the basics down, the book works in a very logical manner: one light at a time. Joe shows what you can do with a single speedlight and stresses the importance of getting the light off the camera in most situations. As the book moves on, more and more speedlights are added into the equation, with the number topping out at a whopping 47 in one scene.

There are a variety of different scenes and each one is broken down in technical (but not overly complex) detail. You’ll see behind-the-scenes shots, before/after comparisons, camera settings, flash settings and diagrams. On top of that, Joe is an excellent storyteller and does a great job explaining why he uses a particular modifier or positioning in each situation.

“The Hot Shoe Diaries” is an absolute must-read for anyone who uses or is interested in using Nikon’s Creative Lighting System. There’s even a very useful appendix that breaks down how to set up all of the CLS-compatible lights for wireless use. While most of the information is Nikon-centric, a lot of it can be applied or translated to any hot shoe flash, making it an important read for anyone who uses multiple flashes on-location.

The Hot Shoe Diaries: Big Light From Small Flashes is available at Amazon.com. If you liked this book, check out our review of A Hands-On Guide to Creative Lighting by Nikon School, a DVD that features behind the scenes video of several of the chapters of this book.