Lockdown boredom led me to wondering which, if any, of my old 'spud-masher' or hammerhead flashguns to hold on to. The collection includes old Metzes, Sunpaks and oddball Osram/Wotan models. I set up a small 'still life' and placed the tripod 5.6 metres away from it, as measured by an ultrasonic gizmo. Methodology: In each case I determined the optimum aperture by centring the histogram of the included Kodak grey card. As near as possible. If the 1/3rd stop steps didn't hit centre exactly, I used the f-stop that was slightly higher, rather than lower. I left the camera WB on daylight, since that would better show how suitable the flash was for synchro-sun use. In each case the flash was fired at full 'power', with at least 30 seconds allowed between firings for the capacitor to recharge. All weights quoted include rechargeable battery or AA cells. The text on each picture is a neutral 18% grey in sRGB space. First up, the 2.4Kg Metz 60CT-4. As you can see from the aperture needed, the Guide Number isn't 60 at all. More like 50. Trigger voltage is a safe 4.6V. Next, a Metz 45CT-4, weighing a shade over 1Kg. This time the 45 GN is pretty much spot on. Now for the 'lesser' brands. Starting with a Sunpak 'Autozoom' 3600. Weighing in at a fairly hefty 1.3 Kg with needed hotshoe adapter. Note that the ISO used is 200 this time, meaning this flash has a true GN of 36 as implied by the model number. Trigger voltage without dedicated hotshoe adapter is a naughty open-circuit 350 volts! The adapter drops that to a tolerable 11.2V. Next up is a Sunpak 455 - weight 1040 grams. It has a slightly higher GN of close to 40 and a much safer trigger voltage of 6.6V. I also tested a Sunpak 555, but the results and stats are so similar that it only duplicates the above. Now for the Maverick in the pack. A Wotan S440, with a unique design that swivels only the reflector for bounce. It has a built in diffuser that also swivels into place and boasts a built-in slave trigger. lt weighs only 800g. The exact same flash was sold under the Osram brand name (also tested - with identical results) Again the GN is 40 and not the 44 implied by its model number. Trigger voltage with SCA300 adapter is 10V. To round things out I threw in a few hostshoe mounted speedlights. A Nikon SB-28 zoomed to 35mm coverage angle. Weight 426g. Guide Number 36. Trigger voltage 4.4V. An SB-800 at 483g including 5th AA cell 'power bulge' gave visually identical results. Trigger voltage measured a bit lower at 3.6V. A 'cheap' Yong Nuo 560-III weighed 475g and gave this result. GN = 36. Trigger voltage 4.2V. The YN560 also offers built-in slave triggering. Just for fun, I doubled up the hotshoe mounted YN560 with the Wotan S440 in slave mode and got this result. We're back down to 100 ISO again now, with a combined GN of 50 - same as the Metz 60CT-4, but at about half the weight! That includes the metal bracket supplied with the S440. The double shadow with both flashes direct is a bit ugly, but the bounced result is quite nice. With the added advantage that the aim of the separate heads can be varied to give a better spread of light. Conclusions: The Sunpak AZ3600 gives probably the worst 'power-to-weight' ratio, and its high trigger voltage without a dedicated adapter is definitely to be avoided with a digital camera. The runner-up Sunpak hammerheads (455 and 555) probably aren't worth their weight for a paltry 1/3rd stop over a speedlight either. The behemoth 60CT-4 can be got rid of too. For me, the quirky Osram/Wotan S440 is a keeper. As is the Metz 45CT-4 with a useful 2/3rds extra stop.... maybe; since boosting the digital ISO by 2/3rds of a stop is no big deal these days. So, there's my evidence. It's up to you, but all I'm saying is; don't be impressed by the size and weight of old hammerhead flashes. Size really isn't everything. And I haven't even touched on the niceties like built-in diffusers, allowable head rotation, nasty tilt detents, automated exposure options, ability to fit in a softbox, mounting convenience, etc.