# EOS M and Flash X-Sync Question



## Cb33 (Mar 15, 2013)

The original 1D and the G1X are two Canon cameras that I know of that have an electronic shutter which can be exploited to get much faster maximum flash sync speeds (flash x-sync) than their specs indicate. If you use a non ttl pc cable or speedlight or tape over all but the center contact point on a ttl flash (essentially disabling the ttl metering) you can use any shutter speed longer than the flash duration. I have considered buying a 1D for this feature.

Canon's spec sheet says the EOS M has a "vertical-travel, mechanical, focal-plane shutter with all speeds electronically-controlled". DPReviews preview states that "the EOS M uses an electronic first curtain to activate the exposure, and the physical shutter is only used to end it". It seems it is at least in part an electronic shutter, which gives me hope that this exploit might be possible with the M. 

I would love to know if this works, but have no way to test it. Are there any EOS M owners out there that have tried this trick or that are willing to experiment?


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## Wildfire (Mar 21, 2013)

I would be interested in this as well. Any EOS M owners out there want to try it for us? I'd definitely consider buying one if high sync speeds are possible!


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## wickidwombat (Mar 21, 2013)

phottix odin on it lets me fire up to 1/8000 sec on my elinchrom lights if that helps


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## Wildfire (Mar 22, 2013)

wickidwombat said:


> phottix odin on it lets me fire up to 1/8000 sec on my elinchrom lights if that helps



That's just an old trick that works with any camera -- turn your strobes up to full power so the flash duration is longer and set your shutter speed to the fastest it will go and chances are the flash will be lit the entire time the shutter is open.

At less than full power flash or with a slower shutter speed this doesn't work anymore. Try it with 1/1000s and strobe at half power.


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## RLPhoto (Mar 22, 2013)

I use my G15 @ 1/1000 sync speeds with slow el cheapo cowboy trigger's. I could do 1/2000th with faster triggers.
This is at 1/1 power on 580II's.

If EOS-M was completely electronic, I'd own one just for its sync speed but I haven't heard anything about higher speeds than its rating.


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## jerryrock (Mar 22, 2013)

First of all, the maximum shutter speed on the EOS-M is one four thousanth of a second. With a Canon 580EXII flash and the EOS-M set to high speed sync, you can use the fastest shutter speed available. There is no PC terminal on the EOS-M so a triggering device would have to be fitted to the hot shoe for strobes.


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## Wildfire (Mar 22, 2013)

jerryrock said:


> First of all, the maximum shutter speed on the EOS-M is one four thousanth of a second. With a Canon 580EXII flash and the EOS-M set to high speed sync, you can use the fastest shutter speed available. There is no PC terminal on the EOS-M so a triggering device would have to be fitted to the hot shoe for strobes.



PC terminal doesn't work with HSS anyway, as the camera must communicate to the flash to let it know when the shutter is going to open.

Anyways, the question has nothing to do with HSS. We just want to know the normal flash sync speed of this camera.


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## botw (Mar 23, 2013)

Sync speed is 1/200. HSS works for all. 

If you want to use a manual powered speedlight or strobe, you can use any speed where the flash duration is longer than the shutter travel.


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## jerryrock (Mar 27, 2013)

Wildfire said:


> I'd definitely consider buying one if *high sync speeds* are possible!


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## Wildfire (Apr 9, 2013)

jerryrock said:


> Wildfire said:
> 
> 
> > I'd definitely consider buying one if *high sync speeds* are possible!



_*High sync speed*_ is different from _*high speed sync*_ (commonly abbreviated HSS).

A high sync speed is a feature of the camera body, regardless of which flash is used . High speed sync (HSS) is a feature only available on certain flashes.

I don't care about high speed sync (HSS) because I want to use AlienBees, which do not have HSS as a feature. However, I do care about the EOS M's sync speed, because if it has a high sync speed then I can use it to cut more ambient light out of an exposure in which I use my AlienBees to light the subject.


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## paul13walnut5 (Apr 13, 2013)

> First of all, the maximum shutter speed on the EOS-M is one four thousanth of a second. With a Canon 580EXII flash and the EOS-M set to high speed sync, you can use the fastest shutter speed available. There is no PC terminal on the EOS-M so a triggering device would have to be fitted to the hot shoe for strobes.



Yes, but at vastly reduced range and output.

The question was is it a truely electronic shutter. Yes in video mode, it's sensor read off, and I'm not sure in photo mode. Canon have rated the max synch speed at 1/200th, the only physical limitation to this a mechanical shutter, therefore in photo mode it seems likely to be a mechanical shutter. 

It's a shame canon couldn't implement a leaf shutter type solution, but then you would still need a conventional shutter for the legacy lenses.

Damned if they do, damned if they don't.


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## Cb33 (Jul 4, 2013)

Well, I bought an EOS-M and answered my own question. I taped over all but the center contact point on the hotshoe and put on a 430EX II. I was able to take pictured at any flash power at shutter speeds up to 1/250 with no black banding. 1/320 gave just the slightest hint of banding at the bottom of the frame. 

So, sadly, the answer is no. I was able to eke out just slightly more than the official 1/200 max sync speed, but nothing like I was hoping. 

It's still a pretty remarkable little camera and I'm happy to own one.


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## curtisnull (Jul 4, 2013)

Good to know. There will probably be lots more EOS-M owners after this week. I just ordered mine from B&H on the incredible $299 deal.


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## xeqtr_mkd (Jul 6, 2013)

Here on this video, eos-m can sync up to 1/4000s. Is is possible to do with cheap triggers or it needs to have some of this expencive triggers ? 

ste3


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## neuroanatomist (Jul 6, 2013)

xeqtr_mkd said:


> Here on this video, eos-m can sync up to 1/4000s. Is is possible to do with cheap triggers or it needs to have some of this expencive triggers ?



That's high speed sync (HSS) in action. The ST-E3 and 600EX-RT support that (with recent bodies), not sure if cheaper triggers support HSS (although expensive ones like PocketWizard TTL triggers have something similar).


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## Cb33 (Jul 6, 2013)

xeqtr_mkd said:


> Here on this video, eos-m can sync up to 1/4000s. Is is possible to do with cheap triggers or it needs to have some of this expencive triggers ?



Yep, that is definitely just High Speed Sync. HSS is somewhat useful but different than what I was hoping the M could do. 

I do know that a few of the less expensive radio triggers support HSS as long as the flash and camera both support it also. I have Pixel Kings which are around $125 for a transmitter and receiver set. They do HSS and it works pretty well with my 60D and 430EX II.
I see no reason why they wouldn't also work with the EOS-M. 

I'd be happy to test it on Wednesday or Thursday when I get my lent out M back. 

Note though that I don't necessarily recommend these triggers. I've had some issues with them. I'll still test for proof of concept, though.


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## spturtle (Jul 6, 2013)

xeqtr_mkd said:


> Here on this video, eos-m can sync up to 1/4000s. Is is possible to do with cheap triggers or it needs to have some of this expencive triggers ?



Yongnuo YN-622C


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## Cb33 (Jul 6, 2013)

spturtle said:


> xeqtr_mkd said:
> 
> 
> > Here on this video, eos-m can sync up to 1/4000s. Is is possible to do with cheap triggers or it needs to have some of this expencive triggers ?
> ...



From reading online, those look better than Pixel Kings. Too, bad I didn't find those when I bought the pixel kings; maybe they weren't out yet.


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## Zv (Jul 8, 2013)

Cb33 said:


> spturtle said:
> 
> 
> > xeqtr_mkd said:
> ...



Pixel kings do HSS. Yeah the YN-622C came out afterwards and even look suspiciously similar to the Kings! The Yongies seem better built though. 

Update - did a quick test with the following outcomes

EOS M + Pixel Kings + YN560II manual flash = max sync speed is 1/200. The camera limits you to a max of 1/200 no matter what. Even in manual mode with HSS switched off. (Same with 430exII though I had a strange malfunction and had to reboot all gear, after that it was fine).

EOS M + YN603 manual trigger and YN560II manual flash was same result though you can change shutter speed. Black band present at 1/250.

EOS M + YN560II on hotshoe = max sync speed of 1/320. Black band presents at 1/400, though could be cleverly cropped out. (Note to self, try with 7D).

Don't know why you would want to plonk a YN560II on top of the EOS M but good to know you can squeeze out 1/320!

I wonder if I had better manual triggers maybe I could get off camera flash with 1/320 sync?


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## Cb33 (Jul 8, 2013)

Zv said:


> Cb33 said:
> 
> 
> > spturtle said:
> ...



Thanks for all the testing. I was really hoping way faster x-sync, but it is not to be. 

I bet you could squeeze a little more out of your 7D with on-camera manual flash. With triggers it is pretty unlikely you will get more than the rated max sync of either camera. The delay of even the best triggers probably won't give you more than a third of a stop faster, if that.


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## Mellonhead (Jul 8, 2013)

I'm a bit confused the difference between High Speed Sync and Sync Speed. I'm a rank beginner at flash photography, but recently decided to try off-camera flash, so I have ordered a (very) cheap flash, Yongnuo YN460 Speedlight and a pair of RF603 Flash Triggers. I am hoping to be able to do some outdoor portrait shots with the EOS-M, in manual mode, using large apetures and really fast shutter speeds. Is this not possible with the EOS-M?


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## Zv (Jul 9, 2013)

Mellonhead said:


> I'm a bit confused the difference between High Speed Sync and Sync Speed. I'm a rank beginner at flash photography, but recently decided to try off-camera flash, so I have ordered a (very) cheap flash, Yongnuo YN460 Speedlight and a pair of RF603 Flash Triggers. I am hoping to be able to do some outdoor portrait shots with the EOS-M, in manual mode, using large apetures and really fast shutter speeds. Is this not possible with the EOS-M?



In the simplest terms X-sync or "sync speed" is the cameras ability to "keep up" with the flash. The mechanical shutter is the limitation here. At slow speeds it doesn't matter as the shutter is open way longer than the flash pulse. At above a certain speed however the shutter starts to get in the way and blocks some of the light from the flash and looks like a black band across the bottom of the image. You only see this with manual flash because usually the camera overides your shutter speed. This means you are limited to using lets say 1/200 shutter speed. Now imagine a bright sunny day or a nice sunset that you wanna underexpose but then use fill flash for a environmental portrait. At 1/200 the sky will be too bright and the only real way around this issue is to use a ND filter. (If you look on you tube you can find slow motion videos of mechanical shutter curtains in action. They act as a pair.)

HSS is a feature on some Canon speedlites. What it does is fire a series of high speed pulses to mimic continous light so the light will still get in as now the flash duration is longer than the shutter movements. The only downside here is that HSS uses up a lot more power so the power of the flash will be very weak. It is ok for fill flash but outdoors in midday can be lacking. 

This is why strobists like a faster sync speed in camera so they have more power and more control. Sadly only the high end cameras like 1DX have 1/500 sync speed. Though with the invention of mirrorless tech some manufacturers are taking advantage of something called a leaf shutter which is located in the lens and is circular. These can sync at whatever speed you like. I think the Fuji X100s has this.


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## Mellonhead (Jul 9, 2013)

Thanks, Zv, that was helpful. I will go the ND filter route.


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