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Got a Ring Flash :-) | by Victor W.
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Got a Ring Flash :-)

A few days ago perusing eBay as you do I came across an old 'Cobra Macroflash', (same as the Centon MR20 and the old Vivitar 5000). Marked as spares or repairs with a 99p bid start I placed a bid thinking if I got it and it was junk I'd only lose 99p. The auction ended Friday and I couldn't believe I'd won it for the 99p bid I put on!


You probably think I got ripped off with the P&P added to it, (why do people do that on eBay?!?!), but not a chance as this was from Cheshire Police and they only added a p&p of £2:00 for recorded delivery. It arrived Saturday!

So with the princely total sum of £2:99 I got myself a new toy :-)


With my own electronics experience I thought surely this bit of kit will be easy to repair, maybe a blown inverter transistor or a failed ignition transformer, so long as it wasn't the tube gone it should be fixable. Bit easier than I thought in the end. You'll never believe what was wrong with it - a broken battery door! As simple as that.


So with a rubber band for now to keep the battery door closed, (can't believe that was all was wrong with it!), I set about playing.


Now these ring flash units do have certain drawbacks - they're usually quite small so won't work on your wide angle lens without a massive sharp vignette. 1980's electronics technology means that they are quite slow to charge at about 10 seconds with the 2x ordinary AA's they take but none too shabby with Nimh recharging in about 4 seconds, (still won't be rattling off fast frame rates with that!) As they use the old 'quench tube' technology even in auto with a small flash burst the whole charge is lost and you have to wait another four seconds, (all relative, four seconds seems nothing to me). They only kick out about 15 watt/seconds at full plug but it was originally designed as a macro flash unit so not surprising.


But.......I could easily replace the circuitry with a modern inverter and a SCR or IGBT quench if I wanted, the tube can probably handle a lot more juice too. Couldn't buy a ring tube for 99p either!


I dug through my camera drawers and came across an old 49mm to 52mm step up ring, (the ringflash came with a series VII to 52mm ring fitted), so bolted it straight onto my old Olympus Zuiko 50mm f1.8 and set about experimenting. But not macro ;-)


For portraiture use my old zuiko works out as a crop of 100mm equivalent and being a fast-ish lens works quite well. Should be great with this old ring flash attached except that it was a lot more powerful than I first thought! On full power, (manual setting), exposure would have been around the f8 to f11 mark at this distance and on auto setting it was running about f5.6. Not a problem, I've got a collection of old filters and amongst them was a ND4 filter so I screwed that onto the lens. Now on 'auto' I had an exposure of f2.8. Brilliant.


Focusing with the zuiko even at f2.8 is a pain at the best of times especially when doing a self portrait, luckily I have an old Casio 'handheld' TV so with a video lead, the camera set to live view and zoomed I simply moved back and forth into focus by viewing the little TV screen strapped to the front of the camera tripod. Quick click on my remote and 'pop' got my first shot :-)


The halo shadow is the typical give away of a ring flash unit but the thing I did like was as this is a small ring you don't get that weird alien looking bright ring in the eyes. Personal preference really, some people like it just that I don't. If I hadn't got the grey background just behind me the halo shadow would have been missing but the light fall off is quite pleasing to me and I'd rather not have dark halos all the time anyway.


Some basic 'fixing' using my Linux Ubuntu system and all that free software again, (really growing to love GIMP!). Just reducing the redness in my skin tone, cropping and cloned out a big zit that was on my forehead, (Ha! Yuck!)

The DOF was left well alone, that's all down to the zuiko at f2.8, (none too shabby for a 4/3rds sensor either), and at this aperture what is in focus is very sharp.


Very happy with my bargain ring flash, in fact extremely happy :-)


Just need to find a 'fresh' model now, as willing and free as my usual one ;-)


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Taken on July 1, 2012