Studio Flash Explained
Monolights Vs. Power Packs

Monolights Vs. Power Packs
Both of these systems have their place in professional photography. The preference is usually a function of the type of shooting contemplated.

In small to medium studios involved in portraiture, fashion, small-product photography and similar, monolights offer certain advantages over power pack systems. These include:

Better adjustability of individual light levels and modeling lamps. Each monolight unit has its own controls and adjusting one light does not affect the other lights. With the exception of very expensive power pack systems, monolights generally have a wider range of adjustment.

Ease of light placement. Each monolight can be located wherever there is an AC outlet, so there are fewer cords running across the set and no distance limitations between lights.

Redundancy. If one monolight should fail, the others will continue to operate and workarounds can be more easily found. There is no limitation on the number of lights needed. If you have four monolights and need a fifth, you can just add another unit. If a repair is needed, your entire system is not down – only the unit being repaired.

The primary disadvantage of monolights lies in size and weight limitations. Since the power supply is located in the light itself, monolights capable of power in excess of around 1000 Ws tend to get large and heavy. This is important for overhead or boom mounted lights where the presence of an extremely bulky light can be hazardous and difficult to maneuver.

Also, when monolights are mounted in relatively inaccessible areas, they can be difficult to get to for adjustment of power, etc. - because of this, a remote control mechanism capable of adjusting the operating parameters is advisable.

Since the power pack is usually located on the floor, it is an easy matter to get high amounts of flashpower from relatively small, light weight flash heads. And the sheer flashpower available from power pack systems exceeds that obtainable from monolights.

The output from a power pack can be shared across several flash heads. Putting multiple heads on a power pack can be an effective means of shortening flash durations for stop-action work.

When extreme power levels are needed from a small flash head, special bi-tube or quad-tube heads may be connected to multiple power packs.

When multiple flash heads are connected to a central power pack there are limitations of placement since all cables must run across the set. Extension pack-to-head cables are quite expensive and can result in lower efficiency and output.

If multiple heads are connected there are limitations in the ability to set lighting ratios. When one head is adjusted, it affects the power of the other heads (except in the most expensive systems). Most low to mid priced power pack systems limit the user to simple fixed power ratios such as 1:1, 2:1, 3:1, etc. between heads.

If you are using a single power pack with multiple heads, a failure in the pack takes down the entire system.