Professional digital cameras generally provide two formats for writing and downloading image files: jpeg and RAW. 

Jpeg files have important advantages for photographic work. Because they are compressed, they are much smaller in size than RAW files. This facilitates sending them as attachments to emails, incorporating them in websites and printing them, actions for which the much larger RAW files might not be feasible. 

But RAW files have advantages that make them much more flexible as capture formats, that is, as the format which the camera actually writes to the memory card. Compared to jpeg, RAW files have a wider dynamic range- the range of tones which they can capture. Also, RAW files allow much broader color correction than jpeg; in fact, the color balance is not even defined in the RAW file until it is processed. This means that whatever color light in which you expose your image, the color of gray is not defined until the file is processed in a RAW editing program. 

Say that your subject is lit with flourescent light, which is quite green compared to daylight or incandescent lighting. This is very easy to correct in processing the RAW file: just select the color balance tool in the RAW processing program, click on an area that you know to be neutral gray and it’s done- your color is accurate. In comparison, adjusting color balance for jpeg files is difficult and may not even achieve satisfactory results. 

This is not to say that jpeg files don’t have their place as a capture format. A news photographer who must capture files and immediately transmit them to an agency or newspaper doesn’t have the luxury of using the RAW format. Also if  a photographer needs to expose large numbers of images in a controlled studio environment, such as for catalog work, then the quality of the jpeg file can be optimized and much time can be saved by eliminating RAW processing. 

But in situations in which images must be captured quickly without the opportunity to fine tune white balance and exposure, such as in environmental portrait and wedding photography, the RAW format can provide a path to the highest quality image production.

There has been a lot of interest recently in the use of small, battery-operated flash units for off-camera lighting. While the benefits of off-camera lighting are obvious, the advantages of the use of camera flashes for this purpose is not so clear. At this time, the flash units available for this purpose are not well designed for use off-camera, except in limited ways. As a result, they require modification through the use of radio adaptors which are clumsy in their implementation and unreliable in operation.

In addition to the radio system, you’ll need an adaptor to fit the flash to a light stand and support an umbrella or softbox. By the time you’ve jury-rigged your electronic flash unit to operate off-camera, with an umbrella on a light stand, you’ve come up with a complicated, clumsy and expensive system that takes a long time to set up and doesn’t work reliably. I suggest an alternative.

The Alien Bees B400 mono strobe light, made by Paul C. Buff, is an AC operated flash with several advantages for location work. It is fairly light weight, not very large and has a continuously variable power output over its entire range. The unit supports an umbrella or one of a special series of softboxes made by the same manufacturer which have a built-in speedring and set up very easily. The flash is available for two hundred and twenty-five dollars. For an additional two hundred and forty dollars there is an optional rechargeable lithium battery pack which weighs only three and one half pounds. So for less than the price of a top-of-the-line Canon or Nikon speedlite you can have an Alien Bees B400 with a battery pack.

You’ll still want a radio trigger of some brand to facilitate working with the rig, but you won’t need a complicated and expensive ETTL trigger system. A Pocket Wizard Plus X or my choice, the Impact Power Sync will suffice.

Of course the Alien Bees is not an automatic flash; you will need to take test exposures or flash meter readings to set the power levels. I don’t regard this as a disadvantage. In my experience trying to get ETTL flashes to expose correctly an exercise in futility: I find I’m always having to adjust the flash for over or under exposure. I’d rather take a reading and know my exposures will be correct.

An easy method for quickly setting the correct flash-to-subject distance is through the use of a cord. Put a loop in the end of the cord that can be easily slipped over a knob on the light stand. Take readings from the flash to give you the desired exposure at a particular distance, measure that distance on the cord and tie a knot to indicate the position. Then, when you’re working, simply pull out the cord to measure the distance from the flash to the subject and move the light stand accordingly. In the case of portrait photography, it’s likely you’ll be taking a number of shots with the light at a particular distance from the subject, so this technique can save you having to take unnecessary meter readings or test exposures. When you change to a new set-up, measure the flash output again and tie a new knot.

Another advantage of using a portable monolite as opposed to a speedlite is that you’ve got plenty of power available when you need it. Say you’re taking a group portrait in an outdoor location and need to move the flash to a considerable distance from the subjects to keep it out of the frame. With a monolite you’ll have the power you need to bridge that distance.

Speedlites are made to be used for direct flash on top of the camera. Trying to modify them for off camera use is, in my opinion, more trouble than it’s worth. A lightweight monolight such as the Alien Bees B400, coupled with a lightweight battery pack can be a much more effective solution for location flash.