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Author Topic: Canon ST-E2 use as a Focus Assist only?  (Read 9893 times)

danski0224

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Canon ST-E2 use as a Focus Assist only?
« on: December 07, 2011, 06:25:27 AM »
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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Canon ST-E2 use as a Focus Assist only?
« on: December 07, 2011, 06:25:27 AM »

outsider

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Re: Canon ST-E2 use as a Focus Assist only?
« Reply #1 on: December 07, 2011, 07:31:56 AM »
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.

bycostello

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Re: Canon ST-E2 use as a Focus Assist only?
« Reply #2 on: December 07, 2011, 07:41:27 AM »
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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Re: Canon ST-E2 use as a Focus Assist only?
« Reply #3 on: December 07, 2011, 07:57:50 AM »
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.

JR

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Re: Canon ST-E2 use as a Focus Assist only?
« Reply #4 on: December 07, 2011, 08:30:25 AM »
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

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Re: Canon ST-E2 use as a Focus Assist only?
« Reply #5 on: December 07, 2011, 06:32:14 PM »
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...

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?

Jettatore

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Re: Canon ST-E2 use as a Focus Assist only?
« Reply #6 on: December 07, 2011, 07:04:05 PM »
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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Re: Canon ST-E2 use as a Focus Assist only?
« Reply #6 on: December 07, 2011, 07:04:05 PM »

neuroanatomist

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Re: Canon ST-E2 use as a Focus Assist only?
« Reply #7 on: December 07, 2011, 07:24:56 PM »
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

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Re: Canon ST-E2 use as a Focus Assist only?
« Reply #8 on: December 07, 2011, 07:33:24 PM »
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...

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?

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

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Re: Canon ST-E2 use as a Focus Assist only?
« Reply #9 on: December 08, 2011, 05:52:08 AM »
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.

Jettatore

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Re: Canon ST-E2 use as a Focus Assist only?
« Reply #10 on: December 08, 2011, 07:42:25 AM »
yup I agree, on the 7D, I use it when toying around in the dark to help me find focus though.

Flake

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Re: Canon ST-E2 use as a Focus Assist only?
« Reply #11 on: December 08, 2011, 11:32:33 AM »
"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.

wickidwombat

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Re: Canon ST-E2 use as a Focus Assist only?
« Reply #12 on: December 08, 2011, 06:45:09 PM »
"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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Re: Canon ST-E2 use as a Focus Assist only?
« Reply #12 on: December 08, 2011, 06:45:09 PM »

JR

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Re: Canon ST-E2 use as a Focus Assist only?
« Reply #13 on: December 08, 2011, 07:41:39 PM »
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

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Re: Canon ST-E2 use as a Focus Assist only?
« Reply #14 on: December 09, 2011, 12:04:05 AM »
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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Re: Canon ST-E2 use as a Focus Assist only?
« Reply #14 on: December 09, 2011, 12:04:05 AM »