Cobra 700AF Flash [Archive] - Talk Photography

Keltic Ice Man

26-06-2006, 16:47

Hi guys

I went out and got a Cobra 700AF flash and have been using it with the Canon 350D. It works great in Auto mode and in Manual - but has anyone managed to get it working in AV or TV mode?

And do you have any tips / tricks you could pass on when using it in Manual mode.

Thanks

Allan

Gandhi

26-06-2006, 18:34

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.

Keltic Ice Man

26-06-2006, 18:37

Sorry Spencer for not being to clear. Your right it is the Camera in Auto and in Manual.

Gandhi

26-06-2006, 19:26

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!

Keltic Ice Man

26-06-2006, 19:44

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.

namllihs

26-06-2006, 20:04

When the camera is in full auto mode it should set shutter speed to 1/60 when powered up

Gandhi

26-06-2006, 20:08

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

Keltic Ice Man

26-06-2006, 20:22

When the camera is in full auto mode it should set shutter speed to 1/60 when powered up

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

namllihs

26-06-2006, 20:24

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

namllihs

26-06-2006, 20:43

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
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

Keltic Ice Man

26-06-2006, 21:06

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.

http://img371.imageshack.us/img371/2929/bestoflot9xu.jpg

I think it maybe doesn't work too well in Manual mode on the 350D

26-06-2006, 21:24

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?

Keltic Ice Man

26-06-2006, 21:31

Hi CT

5 pins -4 in a square and one at the front

http://img355.imageshack.us/img355/2401/image14er.jpg

http://img355.imageshack.us/img355/55/image24gc.jpg

26-06-2006, 21:35

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? :)

namllihs

26-06-2006, 21:44

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.

Keltic Ice Man

26-06-2006, 21:45

Doh - :D

http://img355.imageshack.us/img355/1166/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

26-06-2006, 21:50

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

26-06-2006, 21:50

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.

Seems to be - I have the locking wheel rotated downwards and it seems snug in place, and the flash does flash when I click the shutter.

26-06-2006, 21:58

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

Allan

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. :)

Gandhi

26-06-2006, 22:01

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!

Gandhi

26-06-2006, 22:02

he just typed quicker than me!

26-06-2006, 22:04

LOL. :wave:

26-06-2006, 22:11

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.

Keltic Ice Man

26-06-2006, 22:18

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!

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

26-06-2006, 22:41

Keltic Ice Man

27-06-2006, 16:50

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.

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.

trip

27-06-2006, 17:18

think your problem here is that the flash wont sync with the camera, its a fairly common problem with older units on later digitals.

Keltic Ice Man

27-06-2006, 17:45

think your problem here is that the flash wont sync with the camera, its a fairly common problem with older units on later digitals.

Does that mean you think there isn't a way around it, so I should give up?

RobertP

27-06-2006, 17:58

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) :)

Kate

27-06-2006, 19:05

think your problem here is that the flash wont sync with the camera, its a fairly common problem with older units on later digitals.
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.

Keltic Ice Man

27-06-2006, 19:25

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

http://img368.imageshack.us/img368/8185/handflash4on.jpg

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

http://img368.imageshack.us/img368/696/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

mrgubby

27-06-2006, 19:56

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.

Got one as well , I had exactly the same problems :) , It makes you think about manual settings very carefully :)

RobertP

27-06-2006, 20:07

Keltic Ice Man

27-06-2006, 20:15

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.

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

RobertP

27-06-2006, 20:23

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.

Keltic Ice Man

27-06-2006, 20:35

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.

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)

RobertP

27-06-2006, 20:40

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 (http://groups.google.co.uk/group/rec.photo.digital.slr-systems/browse_thread/thread/e42038c0ef63617c/c77f827eacd4026c?lnk=st&q=350d+manual+flashgun&rnum=3&hl=en#c77f827eacd4026c)

ebay item that seems a bit expensive (http://cgi.ebay.co.uk/Flash-adapter-hot-shoe-to-PC-sync-for-Canon-350D_W0QQitemZ110000658457QQihZ001QQcategoryZ64354 QQrdZ1QQcmdZViewItem)

No guarantee it will work and cure the problem of course

Gandhi

27-06-2006, 21:07

Keltic Ice Man

27-06-2006, 21:51

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?

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!!

http://img308.imageshack.us/img308/7138/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! - *** the recycle time was longer after using it with the sticky tape.

Gandhi

27-06-2006, 22:00

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?

Keltic Ice Man

27-06-2006, 22:08

seems to work great now Gandhi with the tape in place. - Real Big thank you - and to everyone else along the way!!

Now the decisions - keep with the sticky tape, get a non-canon sync cable or sell the flash and put the money towards a sigma flash

Think I'll keep with the flash for the mo - use with the sticky tape, and save up for a different flash later in the year or early next.

YOU GUYS ARE BRILLIANT - THANKS :)

Gandhi

27-06-2006, 22:22

No worries. I really enjoy a bit of investigative problem solving, keeps the old noggin alive.

Marcel

20-07-2006, 11:52

KIM how are you getting on with this flash now? Used it any more?

Billyboy

24-11-2008, 10:39

Having used a Minolta Dedicated Cobra Flashgun for many years with my Minolta (film) SLR, I naturally assumed a Canon dedicated Cobra 700AF unit would be just as good. Obviously I goofed. Sadly, I didn't get a User Manual with it when I bought it off e-bay, but I see 'Kate' has offered to provide a scanned copy at the end of the relevant thread. Please, is it possible to make contact with her to ask if she would be so kind as to provide one for me? I should very much appreciate it. How do I give her my e-mail address?

Keltic Ice Man

28-11-2008, 18:23

SCAREY THREAD REVIVAL!! - Did I really take those pics in 2006!

Can't remember if i got a manual or not, will look though, if you hear nothing from me in the next few days pm me to remind me.

Gramayr

29-11-2008, 10:13

Blimey, that's a flashback.. I had one of these with the side mount hand-grip for my old Minolta Dynax 5000i.

Wonder what the trigger voltage is?

Billyboy

30-11-2008, 02:08

Sadly, I haven't yet received any indication of anyone actually having a User Manual for the Canon dedicated Cobra 700AF. The flash gun works perfectly on test, but when fired via the camera, it gives a very weak flash – probably about quarter power, whatever the camera programme is set on. I wish someone could help.

The weird thing is that after searching the internet for a Canon dedicated flash unit, there seems to be very little on offer, apart from some very pricey 'speedlight' units at £180 and above.

The Cobra 700AF slides into a special connecting bracket (looks exactly like my old Minolta connection system!) on top of the hand grip of a bracket arm which is screwed to the base of the camera. A cable connects the bracket to the hot shoe via a small box-like gizmo which appears to have two sensor windows, like the flash ubnit itself. I haven't a clue what the purpose is of these things. Can anyone shed any light on this?

Chuckurbarla

30-11-2008, 05:50

I've got a Cobra 700AF flash, Canon dedicated and I've got the manual. If anyone wants a copy of it I'll scan it and email it. Just email me at chris.twofridges(at)gmail.com.

Billyboy

30-11-2008, 12:42

Took up Chuckurbaria's kind offer re the Canon dedicated Cobra 700AF's User Manual and received it from him today. Many thanks, Chris! It explained some things I was not aware of. Also tried blanking off the rear four pins of the hotshoe connecting module – which resulted in full flash (far too much!) so I'm currently experimenting with different settings. One workaround solution seems to be to set the flash unit to ISO 1000, and the camera to 100 and point the flash towards the ceiling, so giving the 'bounced' flash effect, which is quite nice. I'll look into setting the f-stop whilst maintaining shutter speeds from 1/60 to 1/1000 to see which works best, if at all. Will let you know!

Gramayr

30-11-2008, 22:50

..which appears to have two sensor windows, like the flash ubnit itself. I haven't a clue what the purpose is of these things. Can anyone shed any light on this?

They help the camera focus in low light by shining red lights onto the subject so the camera can lock on.

Mitzyboy

17-02-2012, 09:56

It's an awfully old thread but just an indicator of how useful old threads can be ......
I went to a Photography Club meet last night and it reminded me how important flash can be outside on occasion.

So I dug out my Cobra 700AF, got on the internet to check voltage etc, and ended up on this thread. The Cobra now works perfectly (and surprisingly) on my Canon 7D, so thanks for the helpful thread, even if some of you aren't here any more :-)

Ive asked for a manual as well, so hopefully that will be forthcoming

cosmicma

17-02-2012, 22:05

i have one of the cobra 700AF flash units sat in it's box with manual, coloured filters and wide angle diffuser also another filter that looks bigger than the other 4
unfortunately it's a minolta / nikon dedicated flash unit and i use canon :(

Kate

23-02-2012, 21:39