I have two Metz 45 CT-5s (one well used, one little used) and now I'm in the process of starting to use them again. In the past I used them with V-series Hasselblads, mainly for weddings, they were powerful and reliable. After a long pause I'm doing some more serious photography again, but with a Canon 5D III and a lot of lenses (converted FD, EF and Zeiss ZE). My favourites are: FD 24mm f1.4 (Lens Doctor conversion), mini-magic drainpipe, Zeiss ZE 100mm f2 macro.
I recently bought a new Canon 430EX III-RT flash, it's handy to carry round in a camera bag but it's not exactly powerful. That's where the Metzs come in. The old nicad battery packs no longer work properly, that figures. It is possible to use loose AA batteries in the empty battery-holders but in my experience that can be a bit hit and miss. Fortunately there is a very good solution. Metz now offer the B46 charger and battery set, it's expensive and it isn't. At first I thought £75 (fotosense) was a lot to pay for a charger and six batteries in a holder, but having received a set, made in Germany, I can appreciate the quality. A second set is on order.
Like many people I have read the scare stories about old flashguns frying the circuitry of modern DSLRs, so I bought a Wein HSHS 990-560 to get round that. I imported that from the USA (B+H) to the UK, a hot-shoe adaptor arrived in a large box that Customs decided duty should be paid on, so that ended up costing around £65 in total. Ouch!
While that was going on I contacted Metz in Germany about using my old SCA 511 adaptor to connect camera and flash. Their reply (3 March 2017) surprised me, and I quote: ‘Basically the flash units Mecablitz 45 CT-5 are equipped with a low-voltage ignition (ISO 10330) in any case. Therefore these flash units can be connected to the digital camera Canon EOS 5D Mark III. The camera can't be damaged by the Mecablitz 45 CT-5
I haven’t tried the Wein or a direct connection yet, I might play safe and check with a test meter first, but it seems that my Metzs can ride again, and I have a Wein adaptor that might come in handy for something else one day, e.g. a circuit-frying Metz 30B-3 (http://dpanswers.com/roztr/volt_finder.php
). The Wein leaflet says that it will drop voltages of up to 400V down to just 6V, clever stuff.
I was toying with buying a more powerful Canon flash, perhaps a nice secondhand 600EX-RT, but then I started reading up on the supposed guide number of 60(m). To me that is very misleading as the guide number varies as the flash head zooms, with a wide-angle lens it can be as low as 26(m) (http://www.the-digital-picture.com/Reviews/Canon-600EX-RT-Speedlite-Flash-Review.aspx
), which confirms my instinct that the Metz is a much more powerful flash. For what I have in mind I am quite happy to set my camera to manual and let the flash control the exposure, I did that for decades at weddings, and that was working blind with film to be processed later.