# Flash at more than ISO 400 with the 1Dx Help Please



## Skulker (Nov 21, 2013)

Can anyone help please, I'm missing something obvious and can't find how to use flash at more than ISO 400 with my 1Dx.

I know its possible and have a work round, but I don't know why its working. I've read the manual and know I must be missing something Blimming Obviouse. :-[ Be gentle with me. :-[

I don't use flash often as I'm mainly a wildlife photographer but some times I need a bit of extra light. Today I was photographing Kingfishers. When the sun set I was using ISO12800. It was nice to get the sunset reflected in its eye. But I would have liked to have been able to use a bit of fill in flash. I was using a 300 f2.8 with 2x converter. So I'm out of zoom on the flash, a canon 580, by a long way.

If I just slap the flash on top of the camera, it defaults to ISO400. And I can't alter it. Of course it works fine, but I can't use it as fill flash.

If I use my custom settings (C1, C2 or C3) I can use any ISO. 

Clearly its a case of incompetence on my part, but could someone point out what settings I'm getting wrong.

These are what I'm getting. A bird at ISO12800, a stick at ISO400 and a stick at ISO4000.


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## neuroanatomist (Nov 21, 2013)

It defaults to ISO 400 in Auto ISO, but that can be changed. Depending on mode, it may have been limiting your ISO since with default flash settings you're limited to a 1/250 s shutter speed (max Xsync). You need to enable high speed sync (HSS) on the flash (directly or via camera menus) to allow shutter speeds faster than 1/250 s. 

Regarding the focal length vs. flash head zoom, you need a Better Beamer. It also helps to get the flash off camera, to reduce/avoid 'steel eye' (avian equivalent of red eye). With my 600 II, I use a RRS B91-QR flash bracket with an FA-QREX2 extension to get the 600EX-RT off axis. I started with an OC-E3 cord, now I use an ST-E3-RT to trigger it wirelessly (and with no cord, I might get a second extension to get the flash even further off axis.


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## Skulker (Nov 21, 2013)

neuroanatomist said:


> It defaults to ISO 400 in Auto ISO, but that can be changed. Depending on mode, it may have been limiting your ISO since with default flash settings you're limited to a 1/250 s shutter speed (max Xsync). You need to enable high speed sync (HSS) on the flash (directly or via camera menus) to allow shutter speeds faster than 1/250 s.
> 
> Regarding the focal length vs. flash head zoom, you need a Better Beamer. It also helps to get the flash off camera, to reduce/avoid 'steel eye' (avian equivalent of red eye). With my 600 II, I use a RRS B91-QR flash bracket with an FA-QREX2 extension to get the 600EX-RT off axis. I started with an OC-E3 cord, now I use an ST-E3-RT to trigger it wirelessly (and with no cord, I might get a second extension to get the flash even further off axis.



Thanks Nero, I'll try that out.

I do have a 3 Meter lead for my flash. So for things like the kingfisher I can set it up near the perch. That's fine when the wild life goes where I want it, and I anticipate properly. 

When I had the 7D I used the wireless flash and I miss it. I have a bit of crumpled cooking foil and a couple of rubber bands in the flash case. I often use that when trying to push the flash. The crumpled foil gives a soft light.


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