Yongnuo YN14EX Ring Flash Will Not Work Properly on Canon 90D

[Chris_N]

My Yongnuo YN14EX Ring Flash worked perfectly on my Canon 550D (Rebel T2i) and on my Canon 760D (T6s). I got perfect exposure with ETTL. However, On my Canon 90D it gives me about 3-4 stops of underexposure at iso 100. The other problem is that the ETTL will not automatically compensate for the changing iso. So using iso 200 increases exposure 1 stop, iso 400 - 2 stops etc. In theory, setting the iso to 800/1600 would compensate for the 3 or 4 stops of underexposure but that would give me a lot of grain. I prefer to shoot macro shots at iso 100.

All I can do is run a test exposure and dial in 3 stops of exposure compensation on my camera or on the flash which is very annoying. By that time, the subject may have disappeared.
I know the short answer may be that this flash is just not compatible with the 90D. I have no idea what the difference is in the firmware that makes the 90D handle flash differently compared to earlier Canon models.

I would appreciate any thoughts and suggestions to find a solution to this problem. Maybe, I have the wrong camera flash settings. I have firmware 1.1.1 which appears to be the latest one. Your thoughts would be appreciated.

Kind regards
Chris

[Ray-uk]

What exposure mode are you using this in, you really need to be in manual to stop it acting as a fill light.

[Chris_N]

Thank you for your reply. Good point. I did all my tests with the camera in manual mode. Generally 1/200 sec, F8, iso 100 using my 60mm macro lens. But I still get the problem of 3-4 stops of underexposure.

Kind regards

Chris. 

[RobertTheFat]

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@Chris_N wrote:

Thank you for your reply. Good point. I did all my tests with the camera in manual mode. Generally 1/200 sec, F8, iso 100 using my 60mm macro lens. But I still get the problem of 3-4 stops of underexposure.

Kind regards

Chris. 

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I think Ray's point was that the flash has to be in manual mode. An ETTL flash unit will invariably see itself as a fill flash and shut down as soon as it thinks the image's highlights are properly exposed. That effect is largely drowned out if you're using bounce flash, but a ring flash doesn't give you that option.

[Waddizzle]

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@RobertTheFat wrote:

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@Chris_N wrote:

Thank you for your reply. Good point. I did all my tests with the camera in manual mode. Generally 1/200 sec, F8, iso 100 using my 60mm macro lens. But I still get the problem of 3-4 stops of underexposure.

Kind regards

Chris. 

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I think Ray's point was that the flash has to be in manual mode. An ETTL flash unit will invariably see itself as a fill flash and shut down as soon as it thinks the image's highlights are properly exposed. That effect is largely drowned out if you're using bounce flash, but a ring flash doesn't give you that option.

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I do not use flash much, but I thought it was the other way around.  Use M mode for fill flash.  Use Av mode when the flash/strobes will be the primary light sources.

[Chris_N]

Thank you all for your comments. I understand Ray's point more clearly now. If the flash is in manual mode, it works fine. But then getting the right exposure is still a matter or trial and error. The problem is that the flash will not work properly in ETTL mode which I prefer to use. That is the main problem I wish to solve.  It will give good exposures on my 550D and 760D but underexposes 3-4 stops on my 90D. In the 90D's external flash settings exposure mode there are 3 options. ETTL face priority, ETTL and average. I have tried all 3 and they all produce about 3-4 stops of underexposure. 

I generally use the camera in manual mode at 1/200 sec with apertures of F8-F22. Most close ups are in the shade. So my main exposure will still be from the flash even if the camera is set to Manual mode with the flash in ETTL mode.

I did try setting the camera menu to TTL (instead of ETTL) to see if that will make a difference but with the flash attached and switched on it will not give me that option. 

I rather suspect that there may me no solution to this problem and I will have to live with it*. It's unlikely that Canon will make a firmware revision to address a problem with a non Canon product.The Yongnuo flash firmware cannot be updated by the end user. 

In the meantime, I will just have to dial in 3 stops of extra exposure compensation on the flash or the camera settings. If I need 4 stops then I will need to change from iso 100 to iso 200.

Any further thoughts or suggestions will be appreciated.

Kind regards

Chris

* I saw a note on B&H photo that this flash is not compatible with the Canon 5D Mk IV. I suppose the 90D should be added to the list. 

[Ray-uk]

Lot's of confusion going on here.

I meant the camera in manual mode with the flash set to ETTL.

In all camera exposure modes except manual the ambient lighting will be taken into account and give a fill in effect.

In camera manual exposure mode you have set the shutter speed and aperture and the camera then adjusts the power output of the flash according to the light read from the preflash and totally ignoring the ambient light.

I think your problem is more a case of compatibility. FWIW I have a similar ringflash (K&F Concept KF-150) which I occasionally use with my 7D2 and this suffers with a similar problem, I just dial in -2 EV and it gets it right every time.

The annoying thing is if I set the flash compensation on the camera it shows on the camera but not the flash and doesn't adjust the exposure but if I set it on the flash then it shows on both the flash and the camera and then gets the exposure correct.

[Chris_N]

Thanks Ray for your further comments. With my setup, if I set the camera Flash exposure compensation (+3) it actually works. Using the Camera exposure compensation disables it on the flash which makes sense. But its a lot simpler just to dial it in with the flash. If I change the camera aperture the ETTL adjusts accordingly. But if I change the iso, ETTL does not compensate.  

Kind regards

Chris

[RobertTheFat]

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@Chris_N wrote:

Thank you all for your comments. I understand Ray's point more clearly now. If the flash is in manual mode, it works fine. But then getting the right exposure is still a matter or trial and error. The problem is that the flash will not work properly in ETTL mode which I prefer to use. That is the main problem I wish to solve.  It will give good exposures on my 550D and 760D but underexposes 3-4 stops on my 90D. In the 90D's external flash settings exposure mode there are 3 options. ETTL face priority, ETTL and average. I have tried all 3 and they all produce about 3-4 stops of underexposure. 

I generally use the camera in manual mode at 1/200 sec with apertures of F8-F22. Most close ups are in the shade. So my main exposure will still be from the flash even if the camera is set to Manual mode with the flash in ETTL mode.

I did try setting the camera menu to TTL (instead of ETTL) to see if that will make a difference but with the flash attached and switched on it will not give me that option. 

I rather suspect that there may me no solution to this problem and I will have to live with it*. It's unlikely that Canon will make a firmware revision to address a problem with a non Canon product.The Yongnuo flash firmware cannot be updated by the end user. 

In the meantime, I will just have to dial in 3 stops of extra exposure compensation on the flash or the camera settings. If I need 4 stops then I will need to change from iso 100 to iso 200.

Any further thoughts or suggestions will be appreciated.

Kind regards

Chris

* I saw a note on B&H photo that this flash is not compatible with the Canon 5D Mk IV. I suppose the 90D should be added to the list. 

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The way that ETTL works (and I don't think Canon explains it very well) is to assume that "all flash is fill flash". If you don't believe it, try using an ETTL flash outdoors on a dark night. Absolutely nothing will be lit except the brightest highlight of the nearest object. That feature (or misfeature, depending on your point of view) works very nicely if you actually want fill flash. And indeed most serious photographers find fill flash useful. And if you're indoors, you're likely to be using bounce flash, whose lack of directionality greatly mitigates the effect.

But in cases where you do want the flash to illuminate the scene, setting it to manual may not be your only option. At least some Canon flashes have a mode where you can let the flash decide how much light you need (like we used to do back in the film days). Whether your 3rd-party ring flash has that capability, I wouldn't know.

It is never correct to set the flash to TTL mode if you're using it with an ETTL camera. The usual effect of doing so is that the flash fires at full power, resulting in massive overexposure. But it sounds as though either your camera or your flash is smart enough not to let you try that.

[mikemathmiller]

I had the same problem. I got 5 stops of underexposure when using external flash. I changed my metering to average and I changed flash control in the camera's menu to average (not evaluative) and the problem went away. Perhaps setting metering to average and flash control to evaluative created a conflict. Try different combinations of average and evaluative for camera metering and flash control metering and see what works for you.