Photoclubalpha

I just got one of the very cheap FS-1100 adaptors from eBay.(Seagull SC-5) Unfortunately they are not fully wired, having only the fire and ground connections wired through, despite having 4 pins at each end! - The consequence is that cameras do not detect that the flash is on the hotshoe and will not fire.
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 0280954225

With a great deal of difficulty I managed to prise the thing apart and solder in the two missing wires and it now functions with my old Minolta Program 1800AF flashgun. (Tried it with the Dynax 5 film SLR and it is recognised and fires). I have no idea if TTL is working on this or not, but my aim was to get the flash working in full power on the future A900 body.

The 1800AF AF illuminator does not work because the 5th pin for that is not implemented on the adaptor.

You can work out the wiring from this helpful page
http://www.mhohner.de/sony-minolta/flas ... hp#oldshoe

Anyone attempting this will need good eyesight , a soldering iron and some fine wire. (Also be willing to possibly completely break their cheap adaptor trying to take it apart).

Haver you worked out what state the flash ready signal needs to be? Hohner does not say whether for example flash ready is just a connection (I think it is not), or what voltage needs to be present across the flash ready pin to make the camera auto-set flash sync. This would be extremely useful with the A350/A300 (in fact, I need to convert a IR sync flash for this purpose - but it must be able to signal flash ready to the camera).

David

if you can open these adaptors and expose the connections then it would be pretty easy to see what the camera is waiting for.

I got one of those, and tried some wireless setup. Didn't work.
Maybe you answered my question, I'll look into it!

David Kilpatrick wrote:Haver you worked out what state the flash ready signal needs to be? Hohner does not say whether for example flash ready is just a connection (I think it is not), or what voltage needs to be present across the flash ready pin to make the camera auto-set flash sync. This would be extremely useful with the A350/A300 (in fact, I need to convert a IR sync flash for this purpose - but it must be able to signal flash ready to the camera).

David

From just switching on the flash and measuring between F2 and G, I see that the voltage goes from 0 to +3.65V, which is a logic 1 to the camera. It is steady, so that appears all you need to indicate to the camera that it has a flash ready.

I can easily get 3v by fitting two 1.5v cells inside an adaptor - they would not be 'on' until it was fitted, but then, it would be a short circuit through the camera. That worries me slightly, I'm not sure about the impedances involved and whether some kind of circuit would be needed. I don't know enough about these things to work out the implications.

David

I'll test something here with a variable DC power supply and a series resistor and my old Dynax 5 and find out what works with that, and report back.

David, I just checked what current my flashgun can give out on the flash ready pin (by shorting it with an AVO on the current range): About 1.5mA.
A rough calculation shows that the output impedance would be about 2.4K ohms. So you could safely use a 3.6V Lithium battery like the type used in Macintoshes for keeping the clock going, with a series resistor of 2.4K, though I suspect that the camera would be perfectly happy with higher voltage and most likely is protected from everything possible, like wrong polarity, dead shorts and some modest over voltage. It does makes sense to limit the current from a battery by fitting a series resistor.

Thanks. I have a whole box of components, dozens of cards of resistors but I long ago forgot my colour codes! There used to be radio rallies here in Kelso, and I bought bags of parts mainly for audio (where I do know how to roll off the top end on a loudspeaker using a capacitor - etc). I may also have some small batteries of the type you mention.

David

Yes, I used to visit the Kelso rallies also.
There is an online resistor colour code calculator:
http://www.dannyg.com/examples/res2/resistor.htm

I must admit I always double check resistors with an ohm-meter, even though I do still remember the colour code. I could manage the 4 band codes, but they now use 5 bands and I am not so quick at working those out.

A cheap Maplin digital multi-meter is something that everyone should have in their toolbox, if only for testing fuses.

The U.S. Navy Electronics School taught the color code with a crude mnemonic that sailors could learn in seconds and never forget:
"Bad Boys Rape Our Young Girls But Violet Gives Willingly".

We had something very similar that I won't quote in full - but ended in "But Virgins Grow Wise".

Hi there braeside!

I just got my "adaptor" in the mail today. I purchased mine from the same ebay store. I was supposed to set up a flash system using those cactus wireless triggers with my a100.

Would I need to do this wiring thing your referring to?

I was just wondering.

alissond wrote:Hi there braeside!

I just got my "adaptor" in the mail today. I purchased mine from the same ebay store. I was supposed to set up a flash system using those cactus wireless triggers with my a100.

Would I need to do this wiring thing your referring to?

I was just wondering.

Try it first without any mods and see. In my particular case it wouldn't work without the extra pins wired up as the camera (only tried a film 5) did not sense any flash fitted.

I have an A350 and one of those cheap hot shoe converters which looks like a proper four pin converter but only two are connected through. I'm still able to use it with my cheap Hong Kong radio flash trigger. The A350 sends the flash firing signal even if it thinks no flash is fitted.

But I'm proposing to wire in the extra flash-ready signal, because that would let me see things in amplified live view when the camera has been set to a short flash shutter duration in a dim place.