Canon Speedlite Questions

[Roosta]

I'm after so more practicle advice than what I can take from the Canon Speedlite pages.

I would like to have a flash, I wouldn't use it much, so the 430EX 11 seems to fit the bill, add to that, at $284.00 from DWI rather than the Aussie price and a 580EX 11 that would be nice, but I have to be realastic and say I would hardly use it to it's fullest.

Can the 430 be fired off camera, as in mounted on its hotshoe plate supplied?

It says on the Canon Aus site Quote "--------------------------------------------------------------------------------

Wireless SlaveThe Speedlite 430EX II can be used as a wireless slave flash unit triggered by an appropriate master flash unit. The small size and high power output make it an ideal slave flash for creating a portable studio with multiple flashguns.
" end quote.

So can I use it off camera? If so, do I need to buy a trigger device, or will it have to be facing the camera and my 50D's in-built flash fire it (Not really what I want)
I see you can get a cable to trigger it, but that's not really the best for what I wan't to use it for.

My main thoughts for use would be a little for light bounce/fill in longer exp low light shots, maybe the odd time to use it at night, kids-family and the likes.

Can any one simply explain E-TTL to me to please, I under stand the acranim, but not the techknowledgly totaly.

Is there a viable third party brand/product I should consider?

Any advice would be greatly appreciated.

[Art Vandelay]

With a 50D you'd need a seperate triggering device to fire it off camera. The 7D & 60D are capable of triggering a flash via their built in flash.

Depending on use, a simple off camera shoe cord may suit.
Various aftermarket ones on ebay in different lengths for $20 to $30.

[Scotty72]

Basically, I speak as a layman - not a techno-boy.

E-TTL is a way of the camera transmitting what it knows about the light conditions and your camera settings to the flash. If it is mounted on the hot-shoe or connected to a cable plugged into the hot shoe - then that is easy.

I am not sure the 50D is capable of this transmission (I thought the 7D was the first Canon capable of that).

Those cameras that do transmit do this via a series of coded flashes (pre-flash) so, generally, the flash unit must be able to 'see' the camera's on board flash to work.

Wireless transmitters (at least the cheaper ones I have used) wont transmit the TLL info. I think you are getting into some serious $$$ to find ones that do.

Then again, I don't really find E-TTL that useful (for the situations I use) because the info the camera is calculating for the flash is at the point the camera is so, if you have the flash at a different distance to subject (or angle) then, the settings may not be appropriate.

Then, again, I've only ever used off camera flash manually - someone may be able to show I'm wrong or at least give more / better info.

I have the 580 exII so I can you it as the master too should I even want to get into e_TTL use but, my slaves are cheapo Yongnuo's that are manual and set off optically.

Cheers

Scotty

[MarkChap]

I will give it a go for you.
E-TTL - (not sure on the E)-Through The Lens
The camera causes the flash to fire a pre-flash that is used to determine the correct exposure for the scene in front of the camera, because the exposure is determined by the pre-flash it is quite accurate even off camera.

Of camera use of the 430 - If you want to to retain the E-TTL metering you will need to use either a 580EXII on camera as the master or anty up for the expensive Pocket Wizard triggers that do provide the E-TTL metering, the front red panel of the remote flash will have to be able to see the the flash commands from the 580 on camera,

If you want to use the flash in manual mode then you will need to get yourself some wireless triggers, these range in price from very cheap to very expensive, but are a lot more versatile, no issues with line of sight, you can put the flash pretty much where ever you want it. You just need to learn a few basic calculations and you are away

[Roosta]

With a 50D you'd need a seperate triggering device to fire it off camera. The 7D & 60D are capable of triggering a flash via their built in flash.

Depending on use, a simple off camera shoe cord may suit.
Various aftermarket ones on ebay in different lengths for $20 to $30.

Cheers Art, I was hoping it could be fired remotely, will look at the cords.


Basically, I speak as a layman - not a techno-boy.

E-TTL is a way of the camera transmitting what it knows about the light conditions and your camera settings to the flash. If it is mounted on the hot-shoe or connected to a cable plugged into the hot shoe - then that is easy.

I am not sure the 50D is capable of this transmission (I thought the 7D was the first Canon capable of that).

Those cameras that do transmit do this via a series of coded flashes (pre-flash) so, generally, the flash unit must be able to 'see' the camera's on board flash to work.

Wireless transmitters (at least the cheaper ones I have used) wont transmit the TLL info. I think you are getting into some serious $$$ to find ones that do.

Then again, I don't really find E-TTL that useful (for the situations I use) because the info the camera is calculating for the flash is at the point the camera is so, if you have the flash at a different distance to subject (or angle) then, the settings may not be appropriate.

Then, again, I've only ever used off camera flash manually - someone may be able to show I'm wrong or at least give more / better info.

I have the 580 exII so I can you it as the master too should I even want to get into e_TTL use but, my slaves are cheapo Yongnuo's that are manual and set off optically.

Cheers

Scotty

Thanks Scotty, My limited reading up on this subject was starting to get me lost, I have a basic understanding, know a fair bit better, I don't think my good old 50D will be able to process all the 580 can feed it, as Mark has mentioned, so thanks for the Laymans speak.


I will give it a go for you.
E-TTL - (not sure on the E)-Through The Lens
The camera causes the flash to fire a pre-flash that is used to determine the correct exposure for the scene in front of the camera, because the exposure is determined by the pre-flash it is quite accurate even off camera.

Of camera use of the 430 - If you want to to retain the E-TTL metering you will need to use either a 580EXII on camera as the master or anty up for the expensive Pocket Wizard triggers that do provide the E-TTL metering, the front red panel of the remote flash will have to be able to see the the flash commands from the 580 on camera,

If you want to use the flash in manual mode then you will need to get yourself some wireless triggers, these range in price from very cheap to very expensive, but are a lot more versatile, no issues with line of sight, you can put the flash pretty much where ever you want it. You just need to learn a few basic calculations and you are away

Cheers Mark, do these units move? or do you see more-so people buying the 580 EX II just because so to speak.


I guess what I was mainly thinking it's main use would be is to have the camera set-up on tripod, have object in FOV, and say hide the flash behind an object and use it to cast side on or from behind flash with varing strengths, not so much for straight up portraite stuff. More low light landscape stuff.

So with the 430 and a remote cable, this seems possible, also to hold it handheld and have a short lead to fire it.

Mark, Is there a good third party flash that would suit my needs say the "Yongnuo's" as scotty has mentioned? I don't need weather proofing, and the likes, but the ability to shoot with different power settings would be an advantage. As long as it can be remotely fired, It would be mainly a dead weight in my bag, and get only limited yearly use, but I'm not a cheap scate, so if the Canon is the way to go, well no worries.

Thanks to all for the information.

[agb]

I will give it a go for you.
E-TTL - (not sure on the E)-Through The Lens
The camera causes the flash to fire a pre-flash that is used to determine the correct exposure for the scene in front of the camera, because the exposure is determined by the pre-flash it is quite accurate even off camera.


Of camera use of the 430 - If you want to to retain the E-TTL metering you will need to use either a 580EXII on camera as the master or anty up for the expensive Pocket Wizard triggers that do provide the E-TTL metering, the front red panel of the remote flash will have to be able to see the the flash commands from the 580 on camera,

If you want to use the flash in manual mode then you will need to get yourself some wireless triggers, these range in price from very cheap to very expensive, but are a lot more versatile, no issues with line of sight, you can put the flash pretty much where ever you want it. You just need to learn a few basic calculations and you are away
E stands for Exposure. So it means that the Exposure is calculated by the camera via a through the lens system.

An interesting three part series about Canon flash is here.http://photonotes.org/articles/eos-flash/index.html#ttl

[kiwi]

Just get some phottix radio triggers - cheap as. You lose ettl, but, that really isnt such a big deal.

[Roosta]

Cool, Site sponsor as well, I'll give tham a call, Cheers Darren.

The TTL wont matter for what I want I'm pretty sure. Aslong as I can play around manually with flash power settings.

[Roosta]

E stands for Exposure. So it means that the Exposure is calculated by the camera via a through the lens system.

An interesting three part series about Canon flash is here.http://photonotes.org/articles/eos-flash/index.html#ttl

Thanks for that agb.. :th3:

[mikew09]

Hi Roosta, I was in pretty much the same opion when I bought my 430 speedlite. However, once I started to use it and discovere the greater usage of a flash unit I soon realised I should have bought the 580 II first up. I can see in the med term I wll want another flash or two to play, experiment and ustilise better lighting techniques etc so the 580 will provide the tricker unit and having some experience with it would be a bonus. Additionally, especially with equine photos and the nature of the beast it can be a challenge to get a well lite photo of a horse without the many shadows on the many curves etc on a horse body. I have often used the flash to lift the darker areas but have found the 430 a little weak at time and from what I have read the 580 is quite a bit more powerful.

I suppose it is a personal thing but I found once I started to utilise the flash I suddenly started using it more and more.

[Bennymiata]

I do a lot of flash work with my Canon D60, both outdoors and in a studio, and I use all my flashes wirelessly.

Not sure about the D50, but I discovered that my brother-in-law's D40 will wirelessly work another Canon flash unit by the use of the built-in pop-up flash.
Go into your menu and look for the setting called Flash Control.
Hit the set button, then scroll down to Built-In Flash Function setting, hit set, then you will see a menu down the list for Wireless Funct., scroll down and hit Enable.

I have a 580EXII that works brilliantly as eithr the master, when mounted on the camera, or as a slave, off-camera.
Usng Canon flashes will mean that the front of he external flash, ie the red plastic window, will have to face the camera, but it doesn't have to be dead on.

However, Canon flashes are expensive and there are much cheaper alternatives.
I needed a third flash and didn't want to pay much, so I bought a Nissin flash for $117, and I have found that it works very well wirelessly, and in fact, it is not really wireless, but goes off when it sees another flash go off, so it's very easy to set up. It also works very well with theCanon E-TTL exposure system too.

[Scotty72]

If you are using it to light backdrops etc, the e-ttl is (as far as I can tell) as useful as an ash tray on a motor cycle. :)

[Roosta]

Hi Roosta, I was in pretty much the same opion when I bought my 430 speedlite. However, once I started to use it and discovere the greater usage of a flash unit I soon realised I should have bought the 580 II first up. I can see in the med term I wll want another flash or two to play, experiment and ustilise better lighting techniques etc so the 580 will provide the tricker unit and having some experience with it would be a bonus. Additionally, especially with equine photos and the nature of the beast it can be a challenge to get a well lite photo of a horse without the many shadows on the many curves etc on a horse body. I have often used the flash to lift the darker areas but have found the 430 a little weak at time and from what I have read the 580 is quite a bit more powerful.

I suppose it is a personal thing but I found once I started to utilise the flash I suddenly started using it more and more.

Cheers Mike, Just been speaking to Stu @ Quality Camera and he has made my mind up with pretty much the same comments as yourself, added to that, its only about $130.00 more than to 430. I woul dhave to by a electronic hotshoe and other bits with the 430 to do what I want, so add that into the price and it hardly seem worth it, so 580 EX II it is.


I do a lot of flash work with my Canon D60, both outdoors and in a studio, and I use all my flashes wirelessly.

Not sure about the D50, but I discovered that my brother-in-law's D40 will wirelessly work another Canon flash unit by the use of the built-in pop-up flash.
Go into your menu and look for the setting called Flash Control.
Hit the set button, then scroll down to Built-In Flash Function setting, hit set, then you will see a menu down the list for Wireless Funct., scroll down and hit Enable.

I have a 580EXII that works brilliantly as eithr the master, when mounted on the camera, or as a slave, off-camera.
Usng Canon flashes will mean that the front of he external flash, ie the red plastic window, will have to face the camera, but it doesn't have to be dead on.

However, Canon flashes are expensive and there are much cheaper alternatives.
I needed a third flash and didn't want to pay much, so I bought a Nissin flash for $117, and I have found that it works very well wirelessly, and in fact, it is not really wireless, but goes off when it sees another flash go off, so it's very easy to set up. It also works very well with theCanon E-TTL exposure system too.

Thanks Benny, I got a fright when I'd only looked at the Canon.com.au web site pricing, but Quality Camera here in good old WA has them at a great price. Will look at the Nissan and the Yongano as well. Will look into the menu tips,as mentioned, I haven't really had a need yet to play with a flash, so it will be good to dig a little deeper.


If you are using it to light backdrops etc, the e-ttl is (as far as I can tell) as useful as an ash tray on a motor cycle. :)

Cheers Scotty, that's what I thought, this will be the main stay of what I'll use it for, light painting at different intentsities. Nice comment.. LOL :th3:

[Judyd]

I don't know if its any help Roosta but i started off using the 580exii on e-ttl and was totally bamboozled. And in one instance i couldn't get enough light into the image - thought i had a dud flash. I've since gone over to using everything in manual mode cos that way i can understand what's happening. as i change one variable - ie power on the flash, aperture etc, i can see exactly what's happening in the image. I do plan that when i've got a better handle on flash photography i'll give e-ttl another go. I gather there are situations that its very good for.

[Scotty72]

I hope someone will correct me if I'm wrong but, here goes: :cool:

If you use the flash in TTL mode: the camera shutter opens; the flash fires, the camera sensor decides when enough light has entered, it then tells the flash 'enough' and the flash stops.

All of this is coded within micro-flashes within the flash pulse (that our eyes don't notice). This is why you must have on camera flash (either a speed-light which is TTL master capable or the on board flash) for it to work.

When the flash is on camera, the camera measures the distance between camera and flash (focus) and tells the flash how strongly it ought to fire (all part of the pre-flash you do often notice when the camera is metring when you half press. The further the distance = the stronger the flash.

Am I right so far?

What I don't fully get, and where my off camera trials have been stuffed, is: when the flash is off camera and say 5 metres from the subject but the camera is 10 metres from the subject. It seems to me that the camera assumes the off camera flash is 10 metres (when it is only 5) and fires a far stronger pulse than it ought to. Being half the distance, this would be 4x the required strength???

The results I've had so far suggest this is the case. (I find it easy to set the off-camera flash manually).

Now, I do realize that the sensor will see that blast then, once the requisit light has entered, tell the flash to shut off. But, if you are trying to use off camera flash to side light (for eg), won't this blast of side light throw off the metering for the on camera flash (and probably drown it out).

God, getting my head around TTL flash hurts :lol:

[mikec]

That's correct for TTL mode, but your 580EX II doesn't have TTL, only E-TTL, which is different. Are you talking about your other cheaper flashes?

[agb]

I hope someone will correct me if I'm wrong but, here goes: :cool:

If you use the flash in TTL mode: the camera shutter opens; the flash fires, the camera sensor decides when enough light has entered, it then tells the flash 'enough' and the flash stops.

All of this is coded within micro-flashes within the flash pulse (that our eyes don't notice). This is why you must have on camera flash (either a speed-light which is TTL master capable or the on board flash) for it to work.

When the flash is on camera, the camera measures the distance between camera and flash (focus) and tells the flash how strongly it ought to fire (all part of the pre-flash you do often notice when the camera is metring when you half press. The further the distance = the stronger the flash.

Am I right so far?

What I don't fully get, and where my off camera trials have been stuffed, is: when the flash is off camera and say 5 metres from the subject but the camera is 10 metres from the subject. It seems to me that the camera assumes the off camera flash is 10 metres (when it is only 5) and fires a far stronger pulse than it ought to. Being half the distance, this would be 4x the required strength???

The results I've had so far suggest this is the case. (I find it easy to set the off-camera flash manually).

Now, I do realize that the sensor will see that blast then, once the requisit light has entered, tell the flash to shut off. But, if you are trying to use off camera flash to side light (for eg), won't this blast of side light throw off the metering for the on camera flash (and probably drown it out).

God, getting my head around TTL flash hurts :lol:

Try reading this Scotty. Your head will hurt even more.
http://photonotes.org/articles/eos-flash/index.html#ttl

TTL cameras have a sensor in the camera body which measures the light returning from the flash and quenches the flash when it has measured that enough light has been received. A-TTL sends a preflash, but the duration and intensity of the flash is the same as in TTL. E-TTL sends out a preflash, measures that using the standard exposure meter, sets the exposure and the flash intensity then the shutter opens, the flash is fired.

[agb]

E stands for Exposure. So it means that the Exposure is calculated by the camera via a through the lens system.

An interesting three part series about Canon flash is here.http://photonotes.org/articles/eos-flash/index.html#ttl

I was wrong when I said that the E in E-TTL stands for exposure, it stands for EVALUATIVE through the lens. in E-TTL the normal camera exposure meter is doing the measuring of the exposure.

[Tannin]

What I don't fully get, and where my off camera trials have been stuffed, is: when the flash is off camera and say 5 metres from the subject but the camera is 10 metres from the subject. It seems to me that the camera assumes the off camera flash is 10 metres (when it is only 5) and fires a far stronger pulse than it ought to. Being half the distance, this would be 4x the required strength???

The flash system has neither the ability not the desire to measure distance, Scotty. It doesn't care how far away your subject is, only how bright it is.

The usual arrangement is that the flash system fires a very short pre-flash, measures the light coming back through the lens (this it the E-TTL part!), and from that, calculates how strong to make the main flash, which follows as soon as the flash system has finished doing its sums, i.e., a few milliseconds afterwards. The pre-flash can have unintended consequences in some cases - for example, when I'm working with small birds which get spooked by the pre-flash and take off before the main flash fires. (They have amazing reflexes!)

[MarkChap]

Tony has answered your question about on camera flash

Scotty, what you need to do, for off camera flash, is completely forget about where the camera is in relation to your flash or subject
The out put power and distance to your subject of the flash are the 2 things that then determine what aperture you need to shoot at, it is quite simple really

Aperture = Guide Number divided by distance
So lets just say that you are using full power on the 580EXII and your flash is 5 metres from your subject
Guide Number = 58, Distance = 5
Aperture = (GN) 58 / (distance) 5 - so therefore
Aperture = 11.6 (exact calculation)
So there fore an aperture of around f11 - f12 is going to what is needed for a correct flash exposure on your subject, the camera or sensor distance has NO relevance at all

[Scotty72]

The flash system has neither the ability not the desire to measure distance, Scotty. It doesn't care how far away your subject is, only how bright it is.

The usual arrangement is that the flash system fires a very short pre-flash, measures the light coming back through the lens (this it the E-TTL part!), and from that, calculates how strong to make the main flash, which follows as soon as the flash system has finished doing its sums, i.e., a few milliseconds afterwards. The pre-flash can have unintended consequences in some cases - for example, when I'm working with small birds which get spooked by the pre-flash and take off before the main flash fires. (They have amazing reflexes!)

Ok.. Thanks.

I think I'm almost there.

I do get the pre-flash (the E in E-TTL). That tells the main flash 'how hard to go'.

Q1: During the exposure: is the sensor still telling the camera when to stop (like normal TTL)? (I would think yes)

and

Q2: and, if I have an off camera flash too. Is this off camera flash also told how hard to go or does it just fire off a standard burst until told when to stop?

[mikec]

Q1: E-TTL system uses a different sensor in the camera, not the main imaging sensor I believe. I think the sensor for E-TTL is located near the view finder somewhere as it's getting light reflected off the mirror.

Q2: No, unless you are using something that allows E-TTL transmission like the new PW system. If using E-TTL the camera needs to tell the flash what the flash burst needs to be. If you are using dumb triggers (non E-TTL) you need to use manual mode on the flash.

Pretty sure the link posted above explains E-TTL too, it's just a little further down the page.

[agb]

Q1: E-TTL system uses a different sensor in the camera, not the main imaging sensor I believe. I think the sensor for E-TTL is located near the view finder somewhere as it's getting light reflected off the mirror.

Q2: No, unless you are using something that allows E-TTL transmission like the new PW system. If using E-TTL the camera needs to tell the flash what the flash burst needs to be. If you are using dumb triggers (non E-TTL) you need to use manual mode on the flash.

Pretty sure the link posted above explains E-TTL too, it's just a little further down the page.

From the link I posted.

The reflected light from this preflash is analyzed by the same evaluative metering system that the camera uses for metering ambient light levels. The appropriate power output (ie: flash duration) of the flash is determined and stored in memory. The entire sensor area is evaluated and compared to the ambient metering, and the area around the active focus point is emphasized. If you are in manual focus mode then either the central focus point or averaged metering is used.

[Scotty72]

Sorry, maybe I wasn't clear enough... :confused013

If I have an E-TTL master (ex 580II) and a 2nd E-TTL flash (another ex 580II) off camera. Will the camera tell the 2nd flash how strong it needs to fire and if yes, how does the camera know how far the 2nd flash is from the subject and therefore compensate?

And. TTL senses how much light gets into the sensor then shut off the flash once the exposure is deemed correct. In E-TTL, after all the pre-flash calculations, will it still use a similar process to TTL to shut off the flashes (both of them) if (for whatever reason) that second flash pours in too much light. Or once the pre-calculations are done, that's it?

I hope my question is better phrased this time :p

Scotty

Scotty

[mikec]

Yep if you are using something that can transmit the ETTL then it will send the info to other flash. But it won't know how to adjust it suit your desired lighting, you'll need to use ratios.

All the ETTL calcs are completed before the shutter opens, no more are done once the shutter us exposed to my knowledge.

[Tannin]

Maybe I wasn't clear enough!


how does the camera know how far the 2nd flash is from the subject and therefore compensate?

It doesn't know. And it doesn't care.

It just fires a tiny pre-flash, measures the light coming back into the lens, and adjusts the power of the flash accordingly. It doesn't matter if there is one slave flash or 100 of them, if it is one metre from the subject or one kilometre - it just measures the exposure from the pre-flash and adjusts.

kilometer

[Scotty72]

Maybe I wasn't clear enough!



It doesn't know. And it doesn't care.

It just fires a tiny pre-flash, measures the light coming back into the lens, and adjusts the power of the flash accordingly. It doesn't matter if there is one slave flash or 100 of them, if it is one metre from the subject or one kilometre - it just measures the exposure from the pre-flash and adjusts.

kilometer

Ok, I think I get it. :cool:

Now, in the spirit of, 'It's only a dumb question if you don't ask it.' :D

What if you have a subject that is well lit on one side but dark on the other (eg a face half in shadow)? And you have two flashes off camera - one on either side.

Will the E-TTL be able to tell one flash to be stronger than the other to even out the face? Or do I have to dial up the flash compensation by a stop or two?

I ask because this is where I have had spectacular failures. I've given up and resorted to trial and error using manual :)

Scotty

[mikec]

I don't believe so because the flashes and camera do not know where they are relative to the subject and each other. Also lighting ratios are subjective. Just like camera settings, there is no "correct" exposure, same goes for lighting. So the flash / camera can't determine what is "correct"

You'll need to use the ratio function to get it correct. Since the same ETTL settings would be sent to both flashes to control the individual output you need to the ratio function.

[Tannin]

In one word, no. :)

In more words, you will get roughly the same result as you'd get if those flashes were spotlights or windows letting in daylight and you were using aperture priority or full auto - the exposure system (the flash system rather than the camera's exposure system, but they work much the same way) does its best to get a good overall exposure with an average figure.

(There are various different ways it can calculate that average - the camera uses centre-weighted, matrix/evaluative, plain all-over average, highlight tone priority, and so on - but they are all the same thing in broad, they differ only in the details. The Canon flash system has fewer variations on offer, and they probably work in ways slightly different from the in-camera equivalent, but the overall thrust is the same - try to average out the exposure with a medium, pleases-everyone number.)

[Jules]

Personally, I have never liked the results from leaving my strobes on ETTL, despite doing a lot of experimenting with various ratio and FEC settings (flash exposure compensation). I find it far simpler to leave the speedlights on Manual and adjust the power output myself after a couple of test shots. Of course, I work in fairly controlled conditions, so have the luxury of being able to employ this approach.

I'm just saying this because I nearly did my head in trying to understand ETTL. Once I switched to Manual, OCF became much easier to understand and implement.

[Roosta]

I don't know if its any help Roosta but i started off using the 580exii on e-ttl and was totally bamboozled. And in one instance i couldn't get enough light into the image - thought i had a dud flash. I've since gone over to using everything in manual mode cos that way i can understand what's happening. as i change one variable - ie power on the flash, aperture etc, i can see exactly what's happening in the image. I do plan that when i've got a better handle on flash photography i'll give e-ttl another go. I gather there are situations that its very good for.

Thanks JudyD, that,s what I had in mind, get use to the thing first, like using the camera in scary manual for the first week or so, that's the way to learn.

Cheers.

[Roosta]

Personally, I have never liked the results from leaving my strobes on ETTL, despite doing a lot of experimenting with various ratio and FEC settings (flash exposure compensation). I find it far simpler to leave the speedlights on Manual and adjust the power output myself after a couple of test shots. Of course, I work in fairly controlled conditions, so have the luxury of being able to employ this approach.

I'm just saying this because I nearly did my head in trying to understand ETTL. Once I switched to Manual, OCF became much easier to understand and implement.

Cheers to all above, very interesting conversation, I'm with Jules to the end so far, the shooting I'm going to be using the flash for is for backlighting a subject in low light situations, go figure, but with the manual setting and say a tree, that has plenty of time on it's hands, well for me, I think manual adjustment will be the way to go. (as in my mirrored tree series I posted in Land/sea)

Thanks you all for so great ideas/knowledege sharing. Now to get the 580 ex II.

[Michaela]

This has been very helpful and informative - thanks for asking the question, Roosta! :th3:

[Scotty72]

Thanks guys.

I think I am down with it now :)

Was good to clear up a few mis-conceptions I had. :th3:

[strictfunctor]

No-one's mentioned the STE2, a commander unit that's cheaper and less clumsy than putting 580 on top of the camera. Not needed any more with the 7D and 60D, of course. It makes it easy to control the ratio between 2 groups if you're using E-TTL.

+1 for using manual if you have a controlled situation and time to futz about, but otherwise E-TTL is what you want, and off-brand flashes aren't going to do that as well, if at all.

[andylo]

Hmm... Canon ST-E2 is expensive and it's crap!! It has a very limited range and use hard to find battery to power.

Get the Chinese made YN branded ST-E2! Double the range, use 2 x 2AA battery to power up! More importantly, 1/2 the price :) I got one and it's awwwwesome!

[GTP 290]

Maybe I wasn't clear enough!



It doesn't know. And it doesn't care.

It just fires a tiny pre-flash, measures the light coming back into the lens, and adjusts the power of the flash accordingly. It doesn't matter if there is one slave flash or 100 of them, if it is one metre from the subject or one kilometre - it just measures the exposure from the pre-flash and adjusts.

kilometer

I have a 50D with a 430 EX II and have never had a pre-flash come off my flash unit. I do however hear a small motor operation when a half push my shutter button down I also notice 3 red vertical bars one the subject before the motor sounds comes from the unit. I use it in E-TTL for most of my nightclub work and every images comes out as desired (well lit).

[Scotty72]

I have a 50D with a 430 EX II and have never had a pre-flash come off my flash unit. I do however hear a small motor operation when a half push my shutter button down I also notice 3 red vertical bars one the subject before the motor sounds comes from the unit. I use it in E-TTL for most of my nightclub work and every images comes out as desired (well lit).

The pre flash lasts a few milliseconds so, unless you have particularly sharp eyes, you wont notice a thing.

[GTP 290]

The pre flash lasts a few milliseconds so, unless you have particularly sharp eyes, you wont notice a thing.

I've just gone outside and tested this and it can't be correct. I took 2 photos, the first photo I covered the flash with my hand while half pushing the button down and letting the camera focus (effectively blocking out any possible pre-flash). I heard the motor inside the flash unit makes it's little noise. I then remove my hand and pushed the button the rest of the way down. The second photo I just took the photo normally and then compared the two images. Both had almost identicle tone curves.

From my understanding the flash communicates with the camera using the apature, shutter speed, ISO and current light meter reading to adjust the power of the flash unit to suit the condition (almost as if the flash can see Through The Lens and take the information it needs for the shot)

[Scotty72]

Didn't we just go through all this earlier in this thread?

There is no way that, after pressing the shutter release you could move your hand so quickly.

The half press flashes are not e-TTL flashes. They may be the focus assist flashes.

[GTP 290]

*facepalm

Step 1: Cover the flash with your hand.
Step 2: Press the shutter button half way.
Step 3: Allow the camera to focus.
Now this bit is tricky so read carefully.
Step 4: Remove hand from flash unit while still holding the shutter button half way down.
Step 5: Once you hand has been removed press the shutter button the rest of the way down.

[Scotty72]

And... the pre flashes only happen at stage 5

So, steps 1-4 are completely, utterly, totally, absolutely (clear) irrelevant.

[Scotty72]

If you are still not convinced, try this.

Put the camera in manual mode (or TV)

set the shutter speed for 2 secs (so there is a huge delay that is obvious)

set your flash to 2nd (rear) curtain sync (so the main flash is at the end of the exposure and pre-flash is just prior to it)

make sure your 430ex is ready

do the half press and focus the camera (where you put your other hand is your business :eek:)

keeping your shutter button half pressed, pause to make sure that operation has finished.

then, when you're ready fully press the shutter button.

You will then notice (a distinct but, small and short) pre-flash.

Count two seconds (or whatever the shutter speed you choose is) then you will notice the main flash pulse.

Normally, if you have a shutter speed of 1/10 th or faster, the gap between pre-flash and main flash is too short for anyone to notice.

Scotty

[Scotty72]

If you need yet more convincing

Use the FEL lock to set the pre-flash off (and lock that reading in) prior to the exposure, then, turn the room lights off. You will find that because your flash setting is locked, that it wont react to the lights going off - so the flash will be a fraction of what's required.

[Scotty72]

If you remain sceptical, I can think of one more test.

You might be thinking that pre-flash in the 2 sec, rear curtain test was part of the exposure.

Try this. (you'll need a tripod)

Set the shutter speed to 20 secs (long enough to do what I am suggesting) - make sure rear curtain is still on

Pre focus. pause etc just like the other test.

Only this time, once the pre-flash has gone off, turn off the flash head - remove it, smash it, burn it and place a curse on it before launching it into deep space - so it will not go off and ruin this test.

After 20 seconds (by the way, turning the flash off is sufficient - you don;t have to smash it to atoms), the exposure will end but, obviously, the main flash (that the camera was expecting) never happens - the photo will be massively underexposed.

Why, because that pre-flash was just that - pre the shutter movement. So, no light from it entered the shutter.

All it did was tell the flash how strong it needs to be.

Scotty

[Scotty72]

:)

Well, in fairness. It is very difficult to get your head around modern flash technology.

Sometimes, I know what the flash is doing but am not sure how it is done - thus my questions earlier in the thread.

I know that the more I learn about flashes, the less I know about it. :eek: