Cobra Auto 210


Link Posted 28/02/2012 - 22:25
I have a Cobra Auto 210 flash-gun which dates from when I bought my Ricoh KR10 Super kit in 1985 (from Cameo Cameras, anyone remember them?).

Does anyone know if it might be usable on my K5, K10 (or even MZ6)?

Thanks in advance,


Pentax K5
Pentax DA 18-55 Mk1, 50-200 (Samsung), 16-45, 55-300 Mk1, 35 f/2.4
Pentax MZ6 + FA28-90, FA50 f/1.4, M 50 f/1.7
Tamron 80-210mm & 28mm


Link Posted 29/02/2012 - 00:33
I wouldn't risk it until you've checked (and doublechecked) the voltage on the flashes shoe...
Pentax K5- Vivitar 19mm 3.8; FA35mm f2; D-Xenon 100mm macro f2.8; DA50-200mm WR...
Yongnuo YN-560; Vivitar 285HV; Cactus V4 triggers...
Pentax-MX & M50mm f1.4; Spottie & 55mm f1.8; MG & M40mm 2.8...

George Lazarette

Link Posted 29/02/2012 - 11:30
Certainly check the voltage, but if that's OK, you will also need to check the pin configuration on the hotshoe. It may not be compatible.

If there is just one contact, then you're fine.

Keywords: Charming, polite, and generally agreeable.


Link Posted 29/02/2012 - 13:37
I read some of the postings on flash modes on another thread and saw the references to voltage measurement there.

I used a small digital multimeter placed across the single contact at the flash-gun shoe and the socket where the sync lead plugs in.

After a little while charging, the voltage was in the region of 70V, so I suppose that would preclude use?

Is the danger from high voltages just for digital bodies or would my MZ6 be at risk too with this gun?

Pentax K5
Pentax DA 18-55 Mk1, 50-200 (Samsung), 16-45, 55-300 Mk1, 35 f/2.4
Pentax MZ6 + FA28-90, FA50 f/1.4, M 50 f/1.7
Tamron 80-210mm & 28mm


Link Posted 29/02/2012 - 15:32
I for one wouldn't put 70V onto my camera. To avoid the risk altogether I would look for a S/H Pentax gun on ebay.

There are frequently AF160; AF200; AF240; AF260 and so on with various suffixes for sale at 5 through to 20.

For this kind of price is it worth the possibility of paying for a camera repair.



Link Posted 29/02/2012 - 18:58
Thanks Dave, George & Bernard for your suggestions.

At present I don not feel any great need for a flash gun with the types of photography that I pursue.

In the future, I might be inclined to have a go at "light painting" with flash where I would mount the camera on a tripod and use a long exposure whilst walking around the subject, illuminating with flash from different angles (night shoots around static steam engines in a yard at preserved railways springs to mind).

As the flash would not be on the camera body, there would be no problem.

It was just a case of finding out if the flash-gun was of any use with my (mainly) digital kit.


Pentax K5
Pentax DA 18-55 Mk1, 50-200 (Samsung), 16-45, 55-300 Mk1, 35 f/2.4
Pentax MZ6 + FA28-90, FA50 f/1.4, M 50 f/1.7
Tamron 80-210mm & 28mm


Link Posted 06/04/2012 - 09:14
Can anyone please explain to me how to use one of these Cobra Auto210s? I got one with my K1000 off eBay (the flash was an unexpected bonus) but there is no manual with it.

As far as I can see, you do this:
- Set the ISO/ASA of the film with the slider
- Choose an aperture, shown by either the red or blue markers under the slider that corresponds to the desired distance range, and set the switch on the front to either red or blue to match
- OR, Set M on the front switch to just get full power (no idea how far that will illuminate)
- Shoot

But what happens if I want to use a different aperture? Is that not possible? Am I constrained to the two apertures the flash is suggesting?

If anyone has a manual they'd be willing to scan and email to me I'd be muchly grateful!


Asahi Pentax K1000, Pentax P30t, SMC-Pentax-M 50mm f/1.7, RMC Tokina 25-50mm f/4, RMC Tokina 400mm f/5.6

George Lazarette

Link Posted 06/04/2012 - 09:31
Buy this one, and you'll get a manual with it.


If you change the ISO, you can change the aperture.

So, if the gun suggests f5.6 at 100 ISO, you can use f8 at 200 ISO.

Good luck


PS: Just noticed you are a film man. You'll obviously have to change film too!
Keywords: Charming, polite, and generally agreeable.
Last Edited by George Lazarette on 06/04/2012 - 09:35


Link Posted 06/04/2012 - 17:52
Hi Mark,

The 'Auto' apertures (red/blue etc.) use the sensor on the front to kill the flash output when it detects the right amount of light has been received by the subject. The distance associated with these apertures are maximum and if closer the flash automatically reduces the duration of the flash to get correct exposure.

In manual, it always discharges at full power, so if the subject is closer than required it will be over-exposed, if further it will be under-exposed. There's usually a table or calculator with ISO, aperture and distance figures. Pick (or set your ISO), work out how far your subject is from the flash, where these two meet on the table/calculator should give you the aperture to use.

Alternatively if it has a GuideNumber (GN) (usually for ISO 100) which will be in meters or feet, simply divide this by the subject distance to get the aperture:

i.e. GN10m at ISO 100, subject is 2.5m away, use f/4

PPG Flickr
Last Edited by johnha on 06/04/2012 - 17:54


Link Posted 02/05/2012 - 15:49
Hey thanks George and John - that's very helpful. Sorry for being tardy with a response. I kind of assumed that I'd get an email or something when this thread updates, so only just seen your posts....

As George has spotted I use film (on Pentax anyway - also have an EOS600D but not using the Cobra on that as it might kill it), so changing the film is not an option for odd shots.

Doing a bit of Googling leads me to believe the GN for the Cobra may be 21, so at ISO100, with a subject 3m away I would use ~f/7, right? So what happens if I have ISO400 film in the camera in that case? Would I then just stop down two stops as the 400 film is 4x as sensitive as 100?

I think what I need to do is get some cheap film and have a play about!

Many thanks

Asahi Pentax K1000, Pentax P30t, SMC-Pentax-M 50mm f/1.7, RMC Tokina 25-50mm f/4, RMC Tokina 400mm f/5.6


Link Posted 04/05/2012 - 02:24
Just to add to an earlier post in this thread - I was interested to see if I could use my Auto 210 on my Canon EOS600D, so I brought it to work today and measured the trigger voltage.....

I got 234V!! So, needless to say, it will be going NOWHERE near the hotshoe on the Canon!
Asahi Pentax K1000, Pentax P30t, SMC-Pentax-M 50mm f/1.7, RMC Tokina 25-50mm f/4, RMC Tokina 400mm f/5.6


Link Posted 04/05/2012 - 15:48
200V is fairly typical for older flashes.
It is possible to get / make a little isolating circuit to go between the flash & the camera (effectivly a relay). It's been on my to do list for a couple of years but I find TTL too useful so I probably won't every bother.

Another possibility is to use an optical slave to trigger the old flash. I've seen slaves going for under 5 and the older ones were designed for higher trigger voltages. If I ever play around with multiple flashes (more than just the inbuilt flash & one remote) I'll probably be looking for where I left my slaves & flashes...
Pentax:K5ii, K7, K100D, DA18-55, DA10-17, DA55-300, DA50-200, F100-300, F50, DA35 AL, 4* M50, 2* M135, Helicoid extension, Tak 300 f4 (& 6 film bodies)
3rd Party: Bigmos (Sigma 150-500mm OS HSM),2* 28mm, 100mm macro, 28-200 zoom, 35-80 zoom, 80-200 zoom, 80-210 zoom, 300mm M42, 600 mirror, 1000-4000 scope, 50mm M42, enlarger lenses, Sony & micro 4/3 cameras with various PK mounts, Zenit E...
Far to many tele-converters, adapters, project parts & extension tubes etc.

.[size=11:].Flickr WPF Panoramio


Link Posted 05/05/2012 - 21:41
I have one of these and have used it manually with a K10D and Samsung GX20 with no problems.I eventually even figured out how to use the different modes apart from M


Link Posted 05/05/2012 - 22:04
I'm forming the impression that Pentax DSLR's can handle higher voltages than the under-24V voltages that people tend to be most comfortable with. The problem is that Pentax do not officially confirm a 'safe' voltage. Still, using a 200V flash regularly would worry me a little...
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