Canon 430Ex on 7D not working in TTL

Canon EF 24-105mm f/4.0L IS

05/10/2011 01:07:55 PM · #1

I have the flash set to ETTL.

I have the camera set to aperture priority f4.

The camera does not adjust shutter speed to compensate for the flash though. It's reading 1/8th of a second, which results in a blurry photo.

I've never used TTL before, but I'm pretty sure this isn't working right...

robs

Canon EOS R6 Mk II

05/10/2011 01:17:53 PM · #2

It's working as intended (ass opposed to expected :-) )....

AV mode has a set of rules that basically tries to include some ambient and chances are f4 that is going to be a real slow shutter speed (depends how much light)... There is a custom option to force AV mode to a fixed something (1/250 maybe).

Edit: I had the camera sitting here.... cf1#7... You have 3 options :-
0 - Auto
1 - 1/250 - 1/60 Auto (limited auto is what I use so AV does not drop too low)
2 - 1/250 always

Message edited by author 2011-05-10 13:24:00.

Panasonic LUMIX DMC-LX100

05/10/2011 01:25:27 PM · #3

Originally posted by robs:

Interesting. Thanks.

spiritualspatula

Nikon AF-S NIKKOR 24-70mm f/2.8G ED

05/10/2011 04:07:07 PM · #4

Just shoot in full manual with flash. It'll make your life twenty times easier. Seriously. I use aperture priority almost exclusively under normal conditions, but anytime I throw a flash into the mix... manual it is. Makes your headaches go away and it's much much much easier to pin down issues, as a whole.
ETA: This is particularly true if your flashes support hypersync. Sometimes you won't catch that you're getting into hypersync territory and your power suddenly disappears or your batteries get eaten. Of course, you can disable this on flashes, but having it ready on the fly is better, IMO.

Message edited by author 2011-05-10 16:08:47.

Simms

Canon EF 24-70mm f/2.8L USM

05/10/2011 07:00:08 PM · #5

Remember AV will try to expose the scene as it sees it, that is, before any flash is introduced - so in a dark room, you will get wide aperture and slow shutter speed - the flash will then fill in with enough power to correctly fill in the scene. As Spirtualspatula says, shoot in manual - expose for the scene as required and let the flash handle the rest.

05/10/2011 07:35:53 PM · #6

Originally posted by Simms:

Why? AV should use the aperture I tell it to use and the proper flash exposure/shutter speed combination for that aperture...

Message edited by author 2011-05-10 19:36:03.

Nikon AF-S Nikkor 70-200mm f/2.8G ED VR II

05/10/2011 07:36:49 PM · #7

Originally posted by spiritualspatula:

I shoot in full manual when it's off the camera. When I'm doing simple stuff with flash on camera I just want the camera to do it's job with ETTL...

MattO

Nikon D4

05/10/2011 08:15:08 PM · #8

Originally posted by kgeary:

Originally posted by Simms:
Remember AV will try to expose the scene as it sees it, that is, before any flash is introduced - so in a dark room, you will get wide aperture and slow shutter speed - the flash will then fill in with enough power to correctly fill in the scene. As Spirtualspatula says, shoot in manual - expose for the scene as required and let the flash handle the rest.

Why? AV should use the aperture I tell it to use and the proper flash exposure/shutter speed combination for that aperture...

It will use the appropriate shutter speed for the aperture and and use flash as fill. Meaning if your ISO and Aperture combination requires 1/8 shutter speed that is what you are going to get, with a pop of flash to fill.

Nikon AF-S NIKKOR 24-70mm f/2.8G ED

05/10/2011 09:02:44 PM · #9

Originally posted by MattO:

Originally posted by kgeary:

Originally posted by Simms:
Remember AV will try to expose the scene as it sees it, that is, before any flash is introduced - so in a dark room, you will get wide aperture and slow shutter speed - the flash will then fill in with enough power to correctly fill in the scene. As Spirtualspatula says, shoot in manual - expose for the scene as required and let the flash handle the rest.

Why? AV should use the aperture I tell it to use and the proper flash exposure/shutter speed combination for that aperture...

It will use the appropriate shutter speed for the aperture and and use flash as fill. Meaning if your ISO and Aperture combination requires 1/8 shutter speed that is what you are going to get, with a pop of flash to fill.

That's retarded. And when I watch Joe McNally videos, that doesn't seem to be the case.

chromeydome

Nikon D7000

05/10/2011 09:08:59 PM · #10

Joe McNally is using Nikon gear. Nikon speedlights can be set to auto fill or to be the "sole" source of light in TTL modes, so the camera/flash calculation loop will account for the fact that you want the flash to be the main light, or just for fill.

I don't know whether or not Canon speedlights will do this.

robs

Canon EOS R6 Mk II

Canon EF 24-105mm f/4.0L IS

05/10/2011 09:18:11 PM · #11

Just different....
Set custom switch#1 to be limited auto (basically) = Nikon fill flash
Set custom switch #2 to forced 1/250 (basically) = Nikon main light

spiritualspatula

Panasonic LUMIX DMC-LX100

Nikon AF-S NIKKOR 24-70mm f/2.8G ED

05/10/2011 09:22:01 PM · #12

Another reason I only use manual with the flash (even on camera) is that, at least with Nikon, if you shoot in aperture priority with a flash, your shutter is limited to a ceiling of 1/60. Not sure if this exists for Canon, but it does for Nikon.