# Canon ST-E2 use as a Focus Assist only?



## danski0224 (Dec 7, 2011)

Is it possible to set up a camera to use the focus assist lamp on the ST-E2 and not fire a flash, and have correct white balance for natural light?


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## outsider (Dec 7, 2011)

Depends on which flash you're talking about. 
The ST-E2 has no flash built into it (at least not a visible light one; the flash it creates is a deep red in color and is used to communicate with other slave flashes).

White balance is controlled from your camera's white balance setting, so regardless of a flash firing or not, you can always set the white balance to whatever you want (or if shooting RAW decide after the picture is taken what white balance you want to select).

Many people use the ST-E2 purely as an autofocus assist light.


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## bycostello (Dec 7, 2011)

yes... but if u don't want flash just use the ste2 on its own... u can use a 580 too, and turn the flash off...


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## photogaz (Dec 7, 2011)

danski0224 said:


> Is it possible to set up a camera to use the focus assist lamp on the ST-E2 and not fire a flash, and have correct white balance for natural light?



I'm confused by the question. Surely you can just turn the other flash units off?

I often use mine for focus assist. You can actually do the same on a 580EX and just tell it not to fire the flash.


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## JR (Dec 7, 2011)

danski0224 said:


> Is it possible to set up a camera to use the focus assist lamp on the ST-E2 and not fire a flash, and have correct white balance for natural light?



Yes you can. I got one myself for that purpose. White Balance is not affected, however, because you cannot turn ETTL mode off on the ST-E2, the camera still thinks I have a flash which impacts exposure (shutter speed since I shoot in Av mode). The quick solution to this is when I shoot with the ST-E2, I do one test before and set the exposure on the camera to be ~ -1 to -1 1/2 stop less such that I get the same shutter speed with the transmitter as without. It is much easier to do then to explain!

There is also a High Speed Sync mode on the ST-E2 and I have not tried it. Not sure if I would have to still compensate exposure...

All that said, the transmitter does help with AF in certain condition. Your other solution is to use the AF assist from your flash but turn off the flash. In my case I did not choose this option because the ST-E2 is much lighter than my speedlite 580 on top on my camera...

hope this helps...


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## danski0224 (Dec 7, 2011)

JR said:


> danski0224 said:
> 
> 
> > Is it possible to set up a camera to use the focus assist lamp on the ST-E2 and not fire a flash, and have correct white balance for natural light?
> ...



Ahh. Wrong term on my part. Exposure.

I did not know you could turn off the flash and keep the AF assist lamp, but the ST-E2 is much smaller and lighter.

Guess I'll have to play with the exposure controls (on the camera).

It would be nice if the ETTL could be turned off on the ST-E2.

Anyone have experience with the off brand knockoffs?


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## Jettatore (Dec 8, 2011)

If you have a crop, you can do this with the pop up flash (have it assist focus but not actually fire). But I suspect you probably already know this.


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## neuroanatomist (Dec 8, 2011)

Jettatore said:


> If you have a crop, you can do this with the pop up flash (have it assist focus but not actually fire). But I suspect you probably already know this.



Yes, as long as you and your subject(s) don't mind a series of bright strobes. Personally, I find the popup assist (and that with low-end flashes) both distracting and annoying, and I much prefer the less obtrusive red assist lamp of the 430/580/ST-E2.


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## wickidwombat (Dec 8, 2011)

danski0224 said:


> JR said:
> 
> 
> > danski0224 said:
> ...



I got the Yongnuo one, its great, i havent tried using it without a flash purely for AF assist though. I shoot in manual so even if the remote flashes are off it should work fine, not a bad idea


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## danski0224 (Dec 8, 2011)

Jettatore said:


> If you have a crop, you can do this with the pop up flash (have it assist focus but not actually fire). But I suspect you probably already know this.



The popup assist is quite irritating, and it sucks the battery down.


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## Jettatore (Dec 8, 2011)

yup I agree, on the 7D, I use it when toying around in the dark to help me find focus though.


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## Flake (Dec 8, 2011)

"It would be nice if the ETTL could be turned off on the ST-E2."

Why would you need to turn the ETTL off? If you are using the ST E2 on it's own then the camera will expose for the conditions. The ETTL works by firing a preflash to measure the light levels, if you don't have a flash then it won't be able to do a preflash!

Canons ST E2 is expensive and not particularly good especially in bright sunlight, it uses an odd and very expensive battery which doesn't last long, make sure you have a few spares for just in case. The Yongnuo unit is better in almost every way - it uses AA batteries and has a much better range, it works in bright sunshine. Unfortunately it has a weakness in the grid it projects for the autofocus is poor and although it will focus , it's a bit of a hit & miss affair. Using it as a commander for the Canon flash system is a much better choice than the OEM version.


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## wickidwombat (Dec 8, 2011)

Flake said:


> "It would be nice if the ETTL could be turned off on the ST-E2."
> 
> Why would you need to turn the ETTL off? If you are using the ST E2 on it's own then the camera will expose for the conditions. The ETTL works by firing a preflash to measure the light levels, if you don't have a flash then it won't be able to do a preflash!
> 
> Canons ST E2 is expensive and not particularly good especially in bright sunlight, it uses an odd and very expensive battery which doesn't last long, make sure you have a few spares for just in case. The Yongnuo unit is better in almost every way - it uses AA batteries and has a much better range, it works in bright sunshine. Unfortunately it has a weakness in the grid it projects for the autofocus is poor and although it will focus , it's a bit of a hit & miss affair. Using it as a commander for the Canon flash system is a much better choice than the OEM version.


I dont have a problem with the grid my yongnuo projects? it gives a massive benefit to the 5D in low light I also got soem 1.5v Lithium batteries for it and it recylces faster than using eneloops. I also got the yongnuo battery packs for my 580s and they boost recylce of the falshes massivley I think they recharge almost instantly all good value IMO. Maybe your yongnuo unit the grid is out of alignment, quite possible that QC isnt the best.


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## JR (Dec 9, 2011)

Flake said:


> Why would you need to turn the ETTL off? If you are using the ST E2 on it's own then the camera will expose for the conditions. The ETTL works by firing a preflash to measure the light levels, if you don't have a flash then it won't be able to do a preflash!



When you turn on the ST-E2, it automatically put itself into ETTL mode. So far in itself it is not too bad, the problem is that when connected to your camera, whether or not you have a flash setup to work with the ST-E2, the camera automatically assumes you have a flash plugged in with the ST-E2. As such, it impacts the exposure setting the camera will make because the camera will choose the same settings as if a flash was present. So you need to compensate by underexposing in order to get the proper shutter speed.

Looking in the manual of the ST-E2 I was not able to find a way to bybass this.


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## danski0224 (Dec 9, 2011)

JR said:


> When you turn on the ST-E2, it automatically put itself into ETTL mode. So far in itself it is not too bad, the problem is that when connected to your camera, whether or not you have a flash setup to work with the ST-E2, the camera automatically assumes you have a flash plugged in with the ST-E2. As such, it impacts the exposure setting the camera will make because the camera will choose the same settings as if a flash was present. So you need to compensate by underexposing in order to get the proper shutter speed.
> 
> Looking in the manual of the ST-E2 I was not able to find a way to bybass this.



Well, that explains why the images are different with the ST-E2 on and off.


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## wickidwombat (Dec 9, 2011)

JR said:


> Flake said:
> 
> 
> > Why would you need to turn the ETTL off? If you are using the ST E2 on it's own then the camera will expose for the conditions. The ETTL works by firing a preflash to measure the light levels, if you don't have a flash then it won't be able to do a preflash!
> ...



shoot in full manual then it controls nothing to do with exposure


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## D.Sim (Jan 11, 2012)

In response to this, can you use the 430 EXII and tell it NOT to fire the flash, but just the AF assist? Would be nice in low light if you wanted the artistic stuff...


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## neuroanatomist (Jan 11, 2012)

D.Sim said:


> In response to this, can you use the 430 EXII and tell it NOT to fire the flash, but just the AF assist? Would be nice in low light if you wanted the artistic stuff...



Yes, you can set the 430 or 580 flashes for AF assist only.


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## D.Sim (Jan 12, 2012)

You wouldn't happen to know how to set it up for that on the 430 would you? I'd need to get my AF Assist beam to start working again, but it would be good information to have =)


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## wickidwombat (Jan 12, 2012)

you can use the custom flash functions on the camera in menu and enable disable fireing the flash etc I think in there is the AF assist only option thats how it works for 580s anyway the 430 should be identical


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## neuroanatomist (Jan 12, 2012)

D.Sim said:


> You wouldn't happen to know how to set it up for that on the 430 would you? I'd need to get my AF Assist beam to start working again, but it would be good information to have =)



In the Flash Control menu (with the flash attached and powered on), set the flash to Disable (top menu item), then under External Flash C.Fns, set the C.Fn for the AF assist lamp (C.Fn 8) to Enable.

You might also check the C.Fn 8 setting on your flash - hold the C.Fn button for 2 s, then arrow to #8, make sure it's enabled. With a setting that can be changed on both the camera and the flash, if they differ the one you set most recently will be used.


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## D.Sim (Jan 13, 2012)

AF assist still isn't firing... gotta send it to Canon Malaysia to repair (thank goodness for 1+1 guarantee!)

Thanks for that info on the disabling flash, totally forgot about that menu...


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## Quasimodo (Mar 25, 2012)

I have a question. I will say beforehand that my knowledge both intelectually and as bodily experience with flash and that world to be limited. I have read the postings on this thread, and I think I understand half of it

I have a 580 EX II and a 430 EX II. I reason I got the ST-E2 was for its ability to master the other two flashes, and that it would give me the possibility to set the white balance correctly when shooting portraits. The way (at least in my head) that I would get the best white balance was to set up the flashes first, then to use an expodisc or if I had forgotten to bring it, a white/grey paper next to the subjects face, and use the ST-E2 to fire it off, while I have the camera and lens next to them to get the most correct reading. Is this a good way to go?

Second. I keep reading here about using the ST-E2 without firing off the flashes.... What some of the postings here say is that it helps with focus assist.. Does it do anything that the AF does not do from the camera at its vantage point? I am a bit confused here. Ar you saying that the ST-E2 and the 580 EX II can help with additional focus readings. Or is this all wrong on my part, and that the focus you are talking about is: reading (focus) to get the right amount of light strenght?

As you can see, I am quite confused here. The use of flash is new to me, since I normally shoot without it. And while I am at it, do you have suggestions for good books to learn the art of lighting, both on an entry level (I have Scott Kelby books on it), and intermediate level books that I can read after the entry level?

Thank you in advance


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## neuroanatomist (Mar 25, 2012)

Quasimodo said:


> I have a 580 EX II and a 430 EX II. I reason I got the ST-E2 was for its ability to master the other two flashes, and that it would give me the possibility to set the white balance correctly when shooting portraits. The way (at least in my head) that I would get the best white balance was to set up the flashes first, then to use an expodisc or if I had forgotten to bring it, a white/grey paper next to the subjects face, and use the ST-E2 to fire it off, while I have the camera and lens next to them to get the most correct reading. Is this a good way to go?



Seems reasonable to me. Personally, I just include a ColorChecker or SpyderCube in one shot of a series, shoot RAW, and set the WB in post. 



Quasimodo said:


> I keep reading here about using the ST-E2 without firing off the flashes.... What some of the postings here say is that it helps with focus assist.. Does it do anything that the AF does not do from the camera at its vantage point? I am a bit confused here. Ar you saying that the ST-E2 and the 580 EX II can help with additional focus readings. Or is this all wrong on my part, and that the focus you are talking about is: reading (focus) to get the right amount of light strenght?



The ST-E2, 600EX-RT, 580, and 430 flashes have a focus assist lamp - they project a deep red grid pattern of light that gives the AF system something to lock onto in dim light. Other flashes (320EX, 270EX, popup flashes) provide the assist by flashing the main strobe light, which many (including me) find distracting and annoying. FWIW, the new ST-E3 doesn't provide any focus assist.


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## justsomedude (Mar 25, 2012)

wickidwombat said:


> you can use the custom flash functions on the camera in menu and enable disable fireing the flash etc I think in there is the AF assist only option thats how it works for 580s anyway the 430 should be identical



+1

Disable flash firing
Enable AF assist

Your camera will not consider the flash when it meters and your images will be exposed only for ambient light. AND, you'll get the benefit of the AF beam. This can be done with the 580EXII, and the ST-E2. Don't know about the 430EXII, since I've never tested it.


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## Quasimodo (Mar 25, 2012)

neuroanatomist said:


> Quasimodo said:
> 
> 
> > I have a 580 EX II and a 430 EX II. I reason I got the ST-E2 was for its ability to master the other two flashes, and that it would give me the possibility to set the white balance correctly when shooting portraits. The way (at least in my head) that I would get the best white balance was to set up the flashes first, then to use an expodisc or if I had forgotten to bring it, a white/grey paper next to the subjects face, and use the ST-E2 to fire it off, while I have the camera and lens next to them to get the most correct reading. Is this a good way to go?
> ...



Thank you Neuro and justsomeguy. That helps. 

while I have you here.... A friend of mine and I did some shooting the other night (picture inclued below) and he did something that I never saw before. We used my gear and the ST-E2 was on, and he pushed the button normally used for dof at the front of the 5D mk II and the flash gave continous light. He said that he does this seldom given that it might shorten the flashs' lifespan. Is this true? Because to me, this is an excellent help in order to see if I have placed my flashes correct. I don't mind burning through batteries, but would mind to kill my flashes


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## Axel Reefman (Mar 25, 2012)

I use the ST-E2 for Focus Assist on my 5D MKII especially during rock concerts. It definitely helps, trust me!


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## neuroanatomist (Mar 25, 2012)

Quasimodo said:


> [A friend of mine and I did some shooting the other night (picture inclued below) and he did something that I never saw before. We used my gear and the ST-E2 was on, and he pushed the button normally used for dof at the front of the 5D mk II and the flash gave continous light. He said that he does this seldom given that it might shorten the flashs' lifespan. Is this true? Because to me, this is an excellent help in order to see if I have placed my flashes correct. I don't mind burning through batteries, but would mind to kill my flashes



It's called modeling flash, can be turned on/off in C.Fn's. IIRC, the manual warns against doing it more than 10 times in a row, and in that case it needs a 10 minute rest.


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## Quasimodo (Mar 25, 2012)

neuroanatomist said:


> Quasimodo said:
> 
> 
> > [A friend of mine and I did some shooting the other night (picture inclued below) and he did something that I never saw before. We used my gear and the ST-E2 was on, and he pushed the button normally used for dof at the front of the 5D mk II and the flash gave continous light. He said that he does this seldom given that it might shorten the flashs' lifespan. Is this true? Because to me, this is an excellent help in order to see if I have placed my flashes correct. I don't mind burning through batteries, but would mind to kill my flashes
> ...



Thank you Neuro. So basically you're saying is that my friend is correct, as far as killing the flash with too much use.


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## neuroanatomist (Mar 26, 2012)

Too much of a specific kind of use, yes. There's a similar warning for using the 580 with an external power pack. The bottom line is that with use, the flash tube gets hot, and if it gets too hot it suffers damage.


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## tag (Jul 20, 2012)

justsomedude said:


> wickidwombat said:
> 
> 
> > you can use the custom flash functions on the camera in menu and enable disable fireing the flash etc I think in there is the AF assist only option thats how it works for 580s anyway the 430 should be identical
> ...



justsomedude - Are you saying that the ST-E2 can be used as a focus assist without a flash, and not impact the camera's metering? I can't figure out how to do this, the metering is always expecting that an off-camera flash will be firing.


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## tag (Jul 20, 2012)

tag said:


> justsomedude said:
> 
> 
> > wickidwombat said:
> ...



Nevermind, I figured it out! On a 5d3, there is a "External Speedlite control" menu where you just have to set "Flash firing" to "disable" - with this the AF assist will still fire on an ST-E2 but metering will be unaffected. I should have thought to look in my manual first...


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