Canon 420EX Flash not syncing with 40D - help!!

Canon EF 70-200mm f/2.8L IS USM II

10/19/2007 09:19:22 AM · #1

Has anyone else experienced this and found a solution? It's driving me nuts! Perhaps 1 in 5 shots now, the flash either doesn't fire or doesn't fire synchronised with the camera. I've tried new batteries. I've tried turning the camera on-and-off and the flash on-and-off.

Can anyone help?!

Edit: still an issue, and still investigating. Sent an email to canon today. Reading online it seems like this issue has been around a while.

Message edited by author 2008-02-29 15:08:37.

PhotoDave

Canon EOS-5D Mark II

10/19/2007 09:29:09 AM · #2

sounds kinda odd, I used my 430ex quite a bit with my 40D and didnt notice it acting strange at all. are you giving it enough time to recharge?

-dave

Spork99

OM System OM-1

Canon EF 100mm f/2.8 USM Macro

10/19/2007 09:33:54 AM · #3

You may not have good contact between the flash and the shoe. Try cleaning the contacts with a pencil eraser.

Prof_Fate

10/19/2007 09:51:54 AM · #4

AFAIK it should work.
Have you fresh batts in the flash?
What is the shutter speed on the camera?
What ISO - 800 works best with eTTL indoors, or at leat 400
Are you set for rear curtain sync? (you don't want to be)

What mode is the camera in? I use only M, Av and rarely Tv. I have no idea the workings on other modes other than Sports mode and Landscape mode I believe disable the flash completely. Check your camera manual on this.

10/19/2007 03:08:22 PM · #5

I'll try cleaning the contacts.

New batteries - check!
Shutter Speed - have been setting it to P.
Have been shooting in ISO 100 with eTTL.
I need to check the rear curtain sync setting.

The weirdest thing is that it sometimes goes off and sometimes not in time and sometimes not at all. There doesn't seem to be any logic. Anyway, I try later tonight and report back.

Thanks.

dwterry

Canon EOS-1D Mark III

10/19/2007 03:25:17 PM · #6

Can the slave see the master?

The sensor (for the slave) is on the front of the body. It needs to see the flash from the master. So if the master is pointing at your subject, then you either need walls that will bounce the light around so that the slave can see it, or you need to point the body of the slave towards the master. I do that a lot! I point the head of the slave into the umbrella (which is pointing at the subject). But I turn the body of the slave towards the camera so that the sensor can see the light coming from the master.

dwterry

Canon EOS-1D Mark III

10/19/2007 03:27:02 PM · #7

On other thought...

I thought my 550 or 420 were broken one time .. because I was holding the 550 in my hand and pressing the button on the back of it to make it fire. Shortly after it fired, the slave fired. But it was NEVER "in sync". It scared me ... I wondered what I could have done to it to cause it to no longer sync with the master.

Put it back on the camera and it worked fine. It was only when I was pressing the TEST button that the slave would fire out of sync.

Any chance you're doing that instead of firing from the camera?

violinist123

Canon EOS-6D

Canon EF 17-40mm f/4.0L USM

10/19/2007 03:46:56 PM · #8

Now he has two flashes? Heheh.

soup

Canon EOS-30D

10/19/2007 06:09:57 PM · #9

well there is one on the camera - built in no...

Tamron SP AF 28-75mm f/2.8 XR Di for Canon

10/19/2007 08:37:12 PM · #10

I guess I should clarify. The 420ex is mounted on the camera body. I have made sure that the switch is flicked so that it is NOT a slave. Also I have the E-TTL set to high-speed sync mode.

SamDoe1

Canon EOS-350D Rebel XT

10/19/2007 09:36:35 PM · #11

Originally posted by samchad:

I guess I should clarify. The 420ex is mounted on the camera body. I have made sure that the switch is flicked so that it is NOT a slave. Also I have the E-TTL set to high-speed sync mode.

If you're shooting in P mode, try setting the flash to normal mode not high speed sync. It should automatically balance out the shutter speed, aperture, and flash exposure on it's own.

Bear_Music

Samsung Galaxy S24 Ultra

Sony 24-70mm F4 Vario-Tessar T* FE OSS

10/19/2007 09:44:08 PM · #12

Originally posted by samchad:

I guess I should clarify. The 420ex is mounted on the camera body. I have made sure that the switch is flicked so that it is NOT a slave. Also I have the E-TTL set to high-speed sync mode.

Try it in normal synch mode and see how it works. Hi-speed synch can be squirrelly with lower-powered strobes.

R.

jmsetzler

Sony Alpha a6000

Sony 16-50mm f/3.5-5.6 E-mount

10/20/2007 01:39:21 AM · #13

Originally posted by Bear_Music:

Originally posted by samchad:
I guess I should clarify. The 420ex is mounted on the camera body. I have made sure that the switch is flicked so that it is NOT a slave. Also I have the E-TTL set to high-speed sync mode.

Try it in normal synch mode and see how it works. Hi-speed synch can be squirrelly with lower-powered strobes.

R.

I have never had any issues with high speed sync on any of my flashes. This problem is either a defective flash unit or an intermittant contact issue. Would it be out of the question to ask if the flash is properly tightened onto the hot shoe with the little wheel? I know it sounds stupid but sometimes the obvious things are overlooked.

10/21/2007 03:53:25 PM · #14

Yes the wheel was tight. I shall try on the normal mode (rather than hi-peed sync). I was at the PDN Expo yesterday and took the camera and flash combo to the Canon desk and asked them to look at it. Obviously, after I gave it to they guy, he tried it and it worked perfectly. Hmmmm. So he just looked at me and said there was nothing he could do. I'll try cleaning the contacts. I have an important shoot on Wednesday, and the client will be pretty annoyed if it's not working properly by then!

10/22/2007 10:50:42 AM · #15

So, I tried the flash on another camera. It's the flash. :(