Cobra 700AF Flash

The camera in manual or the flash gun?

If it's the camera, then you just need to remember that aperture controls the amount of flash and shutter speed controls the ambient lighting, if you want get a balanced exposure.
 
Is it a dedicated flash? or a normal one? and in what way is not working, just not firing or under/over exposing?

Sorry for the barrage of questions but trying to help. honest guv!
 
Hi Spencer - not sure what a dedicated flash is (but I remembered putting it in the Glossary - so guess where I just checked) - Its a normal One - but I wondered if the camera was clever enough to pick up that I had an external flash on and so would adjust shutter or aperture automatically if I was in AV or TV mode.

On just trying it now - I see it doesn't do it for Auto - I must have imagined it yesterday. So I think I'm persuading myself that it only works properly in Manual mode. It fires in the other modes but the shutter or aperture is set wrong for flash. - so maybe my question should be how do I determine the correct shutter and Aperture speeds in Camera manual mode for Flash.
 
When the camera is in full auto mode it should set shutter speed to 1/60 when powered up
 
You need to find the guide number for the flash. Then divide that by the distance to the subject and that will give you the correct f-stop to use at iso 100. I don't know what the range of sync speeds are for the canons so you will have to experiment to get the effect you want.

The flash should have a non-dedicated auto mode that uses a sensor on the flash to determine the output by measuring the amount of light returned. You will probably need to set the aperture you're using on the flash-gun for it to do this calculation properly as the flash wont talk to the camera. As far I can tell, even if it's a dedicated canon model it won't talk to the canon digital models.

If you want to do fill flash, you will need to meter for the brightest part of the background (camera and flash in manual) as you would normally and then adjust the power output of the flash to give the desired amount of fill, only trial and error will help here.

TTL flash is a very good modern invention but sometimes it's fooled by light conditions, so it's good to have this knowledge to fall back on
 
namllihs said:
When the camera is in full auto mode it should set shutter speed to 1/60 when powered up
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Namllihs - the shutter in auto mode is still around 1/8th and is the same whether I have the flash on (and with the red lightning sign - I assume this is fully powered up) or switch off.

Do the Iso or 28/35/50/85 switches need to be anywhere specific?

Also should I be able to see the little flash symbol in my viewfinder? as I don't

Thanks for the help

Allan
 
With the camera in manual mode set the shutter speed between 1/60 to 1/200 fand set the lens length and ISO on the back of the flash unit and you can read off the aperture required for the distance
 
Keltic Ice Man said:
Namllihs - the shutter in auto mode is still around 1/8th and is the same whether I have the flash on (and with the red lightning sign - I assume this is fully powered up) or switch off.

Do the Iso or 28/35/50/85 switches need to be anywhere specific?

Also should I be able to see the little flash symbol in my viewfinder? as I don't

Thanks for the help

Allan
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The ISO and focal length switches on the back will give you a guide to the aperture required, yes there should be a symbol in the view finder when the flash is charged at least it does on the 300D and 300 film cameras that I have used it with
 
thats interesting - No green light in viewfinder, and just looked at the pics and they say Flash did not fire (off) in the exif.

This was the brightest of the lot - 1/60 F5.6 ISO400 - anything less than 400 showed just black.

bestoflot9xu.jpg


I think it maybe doesn't work too well in Manual mode on the 350D
 
Allan, how many contacts are there in the foot of the flash shoe?

Any chance you can post a pic of the back of the flash head?
 
LOL sorry Allan. Can you post a shot of the display panel on the back of the unit, so we can see what's going on there? :)
 
Is the flash unit pushed right into the hot shoe? when I first got mine I had not located it properly and had the same problem.
 
Doh - :D

image35gu.jpg


Must admit the instructions mention the eos 650,620,600,1,5,10,100,500,1000, 1000f, 1000fn, 850, 750, 700 RT so wondering if it maybe doesn't work with the EOS 350D

Manual also says This scale can be used as a guide to maximum shooting distances. The scale is not electronically connected to the flash unit and its use will not affect the flash output, which is completely controlled by the camera
 
Well you gotta remember that this flash pre-dates the 350D and probably all DSLRs for that matter, so you have to expect some compatibilty issues. You're doing well if you have a manual for it, from what I can gather, they're as rare as hens teeth.

Is the flash actually firing when you press the shutter?
 
Keltic Ice Man said:
Do the Iso or 28/35/50/85 switches need to be anywhere specific?

Allan
Click to expand...

Yes.

The 28/35/50/85 settings refer to the focal length of the lens you're using and need to be the same or smaller than the focal length to get proper flash coverage to match the field of view of the lens. If you were using a 100mm lens then set it at 85.

The ISO setting needs to match the ISO setting in the camera. :)
 
ok, so you set the Iso on the slider, the zoom position on the bottom slider, then select the relevant aperture for the distance to subject shown on the back of the flash, this should all be with the camera in manual mode. If it's firing when you press the shutter then all is good.

You may need to go into a custom function on the cameras menu to set the flash sync speed, you can do this on the Nikon and I would expect it to be the same with the canon. It may also be worth having a quick flick through the cameras manual to see what it says about using non-dedicated flashes!
 
Going by Namllihs post (who's used one) you should be OK Allan. There appears to be a sensor on the front of the flash head. What this does is it gives you a degree of automation in that light bouncing back from the flash is picked up by the sensor which quenches the flash when it deems exposure is correct. This is assuming you've set the ISO and zoom settings on the back.

Not as sophisticated as modernTTL flashes but they can give pretty good results providing you're using them within the range indicated by the scale on the back of the gun.
 
Gandhi said:
You may need to go into a custom function on the cameras menu to set the flash sync speed, you can do this on the Nikon and I would expect it to be the same with the canon. It may also be worth having a quick flick through the cameras manual to see what it says about using non-dedicated flashes!
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On the sliders on the back I've had it set to 400, and to 50 as my lens is the kit 18-55mm and the tv and gamecube are 3.5m away so the scale says 11m, 35 feet at 5.6F down to 3.2M at 16F so I tried all the different aperture settings. I expected it to be well over exposed.

But you're right Gandhi I think there must be something in the camera I need to set to tell it I'm using a non-dedicated flash. had a look in the manual but can't see anything
 
Try setting the camera to Manual mode and 1/60 second. Set the aperture the same - both in the camera and on the back of the flashgun e.g. f8. Set the ISO to 400 both in the camera and on the flashgun. Match the zoom setting to the lens obviously. I don't see any reason why that shouldn't work.
 
CT said:
Try setting the camera to Manual mode and 1/60 second. Set the aperture the same - both in the camera and on the back of the flashgun e.g. f8. Set the ISO to 400 both in the camera and on the flashgun. Match the zoom setting to the lens obviously. I don't see any reason why that shouldn't work.
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Thanks CT - that what I tried on the pic that I've posted - but I'll try some more tonight. I read the camera and the flash manual and they didnt give me any other pointers.
 
think your problem here is that the flash wont sync with the camera, its a fairly common problem with older units on later digitals.
 
Just as a test....

set the camera to f8 100 iso and 5 seconds + manual focus in a darkened room on a tripod or on a table. With the flash OFF the camera shoe press the button to manually fire the flash sometime during the 5 seconds exposure.

You can then try again with a different f stop until you get a good exposure. Once you know say f8 gives a good picture you can put the flash back on the camera and experiment (and maybe prove it does not work with it).

At least you will know the flash makes the light needed and the problem is communication or something.

Not used a manual flash in many years but the sliders thing is just a ready reconer - if you are on 100 iso at 16 feet use f8 kind of thing... no connection or influence on the flash (i think) :)
 
trip said:
think your problem here is that the flash wont sync with the camera, its a fairly common problem with older units on later digitals.
Click to expand...
Bang on. This is not a dedicated flash.

I have this flash and you need to use it in manual 100% of the time. It will not communicate with the camera. You just need to put it in manual and either adjust the exposure or shutter speed to compensate.

It's a cracking little budget flash and I take all my macro shots with it. I would, however, recommend that you buy a Sto-Fen diffuser for it as it really helps to soften the flash.

Finally, did you get a manual with it? If not, gimme your email and I'll send you a scanned copy.
 
Hi Kate

Are you using this flash with the Canon EOS 350D? Thanks for the offer of the manual but I've gone one with it thanks.

Robertp

Took this pic with 5 sec exposure and hand flashed

handflash4on.jpg


then this is using the exact same settings but with the flash connected to the camera

cameraflash8lk.jpg


Tried other adjustments of the aperture but nothing better than this - the flash seems to illuminate as soon as the shutter opens. So thinking the sync is wrong with the 350.

PS. Big Thanks for your time and thoughts
 
Kate said:
Bang on. This is not a dedicated flash.

I have this flash and you need to use it in manual 100% of the time. It will not communicate with the camera. You just need to put it in manual and either adjust the exposure or shutter speed to compensate.

It's a cracking little budget flash and I take all my macro shots with it. I would, however, recommend that you buy a Sto-Fen diffuser for it as it really helps to soften the flash.

Finally, did you get a manual with it? If not, gimme your email and I'll send you a scanned copy.
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Got one as well , I had exactly the same problems :) , It makes you think about manual settings very carefully :)
 
Well it can produce the light OK. When it is mounted on the camera does the flash go off with the same power or does it flash less powerfully?

If its just as bright then the shutter timing is off compared to the flash being triggered.

If it is less bright then something is telling the flash to shut down early ...and that may be fixable.
 
RobertP said:
Well it can produce the light OK. When it is mounted on the camera does the flash go off with the same power or does it flash less powerfully?

If its just as bright then the shutter timing is off compared to the flash being triggered.

If it is less bright then something is telling the flash to shut down early ...and that may be fixable.
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Seems to flash with the same brightness

Messaged MrGubby - and he's using the 300D, think Kate is too so wondering still if anyone has it working with the 350D
 
As it was dark on the long exposure the flash seems to fire too soon?

Might be worth trying 2nd curtain sync before giving up. custom function 15 (?) on my 20D.
 
RobertP said:
As it was dark on the long exposure the flash seems to fire too soon?

Might be worth trying 2nd curtain sync before giving up. custom function 15 (?) on my 20D.
Click to expand...

Thanks Robert

Just given this a try - Custom Function 9 on the 350D - and .... sorry same result. Flash flashes when the shutter fires - the auto light stays on, on the flash, but doesn't fire again before the shutter closes. - when the auto light on the flash goes off.

I can sense an item to sell coming on here, I'll try it till the end of the week and then see if I can sell. (then start saving up for the sigma maybe)
 
Just had a quick google and found something that seems to imply it will work but only via a sync cable not the hotshoe. You get an adaptor to go in the hotshoe with a sync cable connector on it then connect the sync cable to the flash to trigger it.

I read it quick...could be wrong :)

Google groups (usenet) messages

ebay item that seems a bit expensive

No guarantee it will work and cure the problem of course
 
Weird one. If it will only work on a sync cable I would imagine it's the extra pins causing the problems, try covering the four extra pins with tape to allow just the main central pin to contact the shoe. Do any of these extra ones line up with the contacts on the 350?

So if I've got this correct, with the flash on auto and the camera set to iso100 and 1/60th of a second, if you vary the aperture on the camera, the exposures all come out the same?
 
Gandhi said:
Weird one. If it will only work on a sync cable I would imagine it's the extra pins causing the problems, try covering the four extra pins with tape to allow just the main central pin to contact the shoe. Do any of these extra ones line up with the contacts on the 350?

So if I've got this correct, with the flash on auto and the camera set to iso100 and 1/60th of a second, if you vary the aperture on the camera, the exposures all come out the same?
Click to expand...

Just tried using the flash with the 4 extra pins covered over and... IT WORKED - a shot that is a bit over exposed - but WOW thats the first time ever!!

fix5ow.jpg


Now other than telling me that it works great if I put sticky tape over the other 4 pins - what does it tell me? that it will work with a sync cable? that thats the only way? (sorry to sound a bit vague)

And RobertP think I got it wrong before - the flash must not have been as bright when mounted! - coz the recycle time was longer after using it with the sticky tape.
 
Thing to do ow is try it properly. Stick the flash on auto and match the settings to the camera. (iso and focal length) I'd leave it on 100iso and 1/200th of a second at the moment as that's the x-sync speed of the 350d.

If you want to, you should still be able set the camera to slow-sync and rear-curtain slow sync as the camera should still trigger the flash at the correct point.

The result of the experiment with the tape just tells you that the extra pins are fooling the camera into thinking it can communicate whith it when it can't. there's nothing to stop you using it like this permanently I guess. A standard non-canon sync cable only as the two basic connections to make a circuit so removes the need for the sticky tape, if you see what I mean?
 
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