PSA: Used Gear Caution, High End Strobe Pack Profoto Pro6 Hiding in Pro7 Clothing

The Profoto Pro-7a power pack probably one of the most ubiquitous strobe packs in high-end photography studios around the world. Despite two newer models replacing it, the Pro-7a is still widely available for rental at photo studios and equipment houses. Several Pro-7a packs have been popping up on the used market at very appealing prices. The problem is that they are actually Profoto Pro-6 Freeze packs with a few cosmetic updates.

Without question, the Profoto Pro-6 Freeze strobe generator is an awesome pack and was at the top of the industry when it was newly launched in 1993. Popular with fashion photographers for its quick recycle, it was equally popular with still-life photographers for the short flash duration. These packs stacked up against the Broncolor's Pulso line of packs. Pulsos were tech-y and slick with the power setting in glowing LEDs and smooth touch controls on top. The Pro-6 was more blunt and simple with chunky dials and white push-buttons on top that belied the technology inside.

The Pro-6’s control layout carried over completely to the Pro-7 line's design. Both units also have the same overall dimensions and weight. Most of the improvements made to the Pro-7 were on the inside. This is where the opportunity for confusion arises. On the outside, the differences were a softer rubber bumper around the top and base, a more ergonomic handle, and a new name plate.

How Did This Happen?

When the Pro-7a came out in 1998, many rental studios and equipment rental houses already had a supply of Pro-6 Freeze packs for rental. Faced with the choice of replacing a number of working Pro-6 packs with the new Pro-7a at a cost of more than $6000 each, some companies decided to be creative. By installing new rubber and a new name plate, several Pro-6 freeze packs became Pro-7a packs and were used alongside the genuine packs. Those older imposter packs started making their way into the used market in places like eBay and Craigslist.

Pro-6 packs could be fully converted by rewiring each strobe socket to power additional pins and be safely compatible with Pro-7 heads and the later ProHead. The Pro-6 uses two wires to carry high voltage to each socket, but the Pro-7 uses four high-voltage wires going to each socket to handle higher voltage and higher draw. The four-wire configuration allowed the Pro-7 series to have a slightly faster flash duration. Unfortunately, not all conversions were complete, and the cosmetic-only conversions are not forward-compatible with Pro-7 and later heads. The result can be dangerous arcing that can potentially damage both pack and head.

How to Tell the Difference

The tell-tale sign of a conversion on the outside is the handle. That is the external change that couldn’t be transferred to the older pack. There are two details to look at to quickly determine if a Pro-7a is genuine. The real handle is curved across the top and more ergonomic at the grip. The Pro-6 handle has more squared corners and the Profoto logo stamped into the hard rubber. A more subtle clue is that the strobe channel identifiers are printed above the strobe sockets on the Pro-6 while they are printed below the sockets on the Pro-7a, and the Autobracket feature is printed slightly differently from one to the other. Even a knowledgeable bidder could be fooled in smaller listing photos without careful attention.

Sellers in the used market might not even be aware of the conversions. I recently encountered a seller who acquired four Profoto packs in an storage locker sale. Three of the packs were authentic Pro-7 units, but one was a conversion pack. I don’t blame the seller since they were listed in as-is condition. I was fortunate to pick up the genuine units. I even saw a Pro-6 Freeze recently listed as a Pro-7a by a well-known camera seller. To be sure, the older Pro-6 packs and conversion packs still have value, but an informed buyer will be able to navigate the auctions and sales with more confidence.