# Canon Flash Question - Please Help



## Jane (Jun 19, 2013)

Hi everyone, 

Hoping this is the right area to ask a question that is not necessarily LR related.

I have a canon 600 EX RT flash which I put on ETTL and a 5d mark III - it will go on M (manual flash exposure) no problem with me being able to dial in my focal length of the lens.

I want to use it in A (auto flash exposure) but when I try and take it off M - it just has *zoom-----mm *on the LCD and just won't dial onto Auto for me.

Has anyone else had this problem? I've looked at a couple of other photography forms and I saw that a couple of people said to wipe the pin areas with a dry cloth and reconnect the flash to the camera. I've done this several times but nothing. I'm in manual mode on the camera.

Any ideas??
Thank you
Jane


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## Bryan Conner (Jun 19, 2013)

Lots of possibilities come to mind.  What lens are you using?  Have you tried different lenses?  Some lenses are manual lenses and do not give any information such as focal length to the camera.
Pages 29 and 31 of your owner's manual describe how to set up the two different manual settings: Manual zoom and manual flash.  Is it possible that you are not setting both of these parameters correctly?


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## Jane (Jun 21, 2013)

Thank you Bryan for your reply. OK, I have tried a couple of different lenses but they are all primes. Same thing happens and it won't let me dial in 85mm, it will only go to 80, then 135 and lastly 200mm.

I called canon and what they said was that if I point the flash head directly towards the subject, the flash will then go to A Zoom MM (which it did when I did this - all very strange) but as soon as you move the flash head towards the ceiling or left or right to bounce, it ove-rides it and goes back to M. I rarely point the flash facing my subject so that is possibly why I couldn't see that when trying to work it out. This manual flash and manual zoom you mention has me intrigued though as I didn't realise there were 2 different things (zoom and flash). Should I just keep the flash in manual zoom and dial in the focal length and that will be fine most of the time? I will definately look up pages 29 and 31 as this may help. Are the differences purely that with zoom I can dial in the focal length and with manual flash I don't...? thanks so much. Sorry to be vague - I am still very frightened of my flash!
Jane


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## Bryan Conner (Jun 21, 2013)

Your flash is operating normally.  When you have your flash pointed directly at the subject, with an 85mm lens mounted, the camera adjusts the flash zoom setting to allow for complete coverage of the subject based on the distance to the subject.  If you are bouncing the flash off of a wall, or off of the ceiling, the camera has no way of knowing the total distance from the flash to the ceiling and then to the subject.  It only knows the distance from the lens/camera to your subject.  It has no way of knowing that the ceiling is 6 meters higher than the height of the flash while you are holding it to your eye while sitting in a chair and then to calculate the angle that the light is striking the ceiling and then reflecting to the subject whose head is 5.7 meters lower from the ceiling...etc.

If the wall is close to you or if the ceiling is low, then I would set the flash to its widest focal length setting.  This is because the whole point of using the wall/ceiling is to have a larger/softer light source instead of a small/harsh source from the flash head.  So, use the widest focal length setting on the flash to spread the light out as much as possible.  Now, if you are in a room with a very high ceiling, it may be useful to set your flash zoom setting to its highest focal length setting to compensate for the distance.  I say that it may be useful, but I have never tested this.  I would be surprised if it made a significant difference. Usually, I raise the iso setting of the camera if the ceiling is high and the flash is wimping out.

The flash having only the 80, 135 and 200mm setting does not seem odd to me.  This is not anything to be concerned with.  Every flash, Canon and Metz, that I have owned has always only had zoom settings that were in steps, not continuously adjustable.


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## Tony Jay (Jun 21, 2013)

That's a good explanation Bryan.

Tony Jay


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## Jane (Jun 23, 2013)

Thank you very very much Bryan - I get it now!!! really appreciate your time to reply


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## Bryan Conner (Jun 23, 2013)

Jane said:


> Thank you very very much Bryan - I get it now!!! really appreciate your time to reply


  I am glad that I was able to help.


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