Help? Canon 20D + 580EX High-speed Sync?

photobug

I have a 20D and 580EX flash. I turn on the 580EX and set it to (supposedly) enable High-speed Sync , by making the little "H" appear next to the flash "thunderbolt" symbol on the flash.

My understanding is that an "H" is then supposed to show up in the 20D viewfinder, next to the flash "thunderbolt". And the camera should then be able to use shutter speeds faster than 1/250 with the flash (albeit at some loss in flash power). However, the "H" never shows up in the 20D's viewfinder and I have not been able to get it to shoot any faster than 1/250 with the flash turned on.

Can anyone clue me in as to what "magical step" I'm missing here? There must be a simple cockpit error, but I haven't been able to figure this one out.

Thanks for any help!
= Dave

Eric&Susan

I tried it with my 300d and 430ex and the H does show up in the viewfinder.

The flash works fine other than this?

Eric

photobug

I tried it with my 300d and 430ex and the H does show up in the viewfinder.

The flash works fine other than this?

Yes, other than that, it seems to work just fine. I'm really hoping there's a cockpit error involved, and not a "bug" that I need get repaired in either the flash or the 20D...

Other suggestions, anyone?

ziggy53

Dave,

What mode is the camera set to?

ziggy53

Bob Bell

photobug wrote:

I have a 20D and 580EX flash. I turn on the 580EX and set it to (supposedly) enable High-speed Sync , by making the little "H" appear next to the flash "thunderbolt" symbol on the flash.

My understanding is that an "H" is then supposed to show up in the 20D viewfinder, next to the flash "thunderbolt". And the camera should then be able to use shutter speeds faster than 1/250 with the flash (albeit at some loss in flash power). However, the "H" never shows up in the 20D's viewfinder and I have not been able to get it to shoot any faster than 1/250 with the flash turned on.

Can anyone clue me in as to what "magical step" I'm missing here? There must be a simple cockpit error, but I haven't been able to figure this one out.

Thanks for any help!
= Dave

I'm pretty sure HSF only works in M or AV mode. I just checked my 20D and I was able to get it to work in AV mode up to 1/8000 and the H shows up next to the lightning bolt.

photobug

I'm pretty sure HSF only works in M or AV mode. I just checked my 20D and I was able to get it to work in AV mode up to 1/8000 and the H shows up next to the lightning bolt.

Ziggy53, Bob,

I usually shoot in Program mode, with forays into Av and Tv, as needed. I'll bet that's it -- I'll try that tomorrow when I get a chance to pull my camera bag out of the car.

(although I don't know why it shouldn't work in P mode)

Thanks!!
= Dave

photobug

Tried other modes -- still "no joy"
Refresher of setup: Canon 20D with 580EX flash.
Problem: Can't get high-speed sync to work.

Based the suggestions in this thread (thanks!), I've tried it with the camera set in each of the standard modes -- A-DEP, M, Tv, Av, and P. Even though the 580EX flash is set with "H" next to the thunderbolt symbol, the flash is "on", and the flash-ready thunderbolt shows up in the viewfinder, no "H" ever appears in the viewfinder so high-speed sync never seems to happen.

Any other suggestions? !

Mike Lane

Just reporting my findings. When I plug in my 580EX to my 20D and turn it to high speed synch I get an H indicator in the viewfinder but only in Av and Tv modes. No other mode has this indicator.

HTH
Mike

ziggy53

photobug wrote:

Refresher of setup: Canon 20D with 580EX flash.
Problem: Can't get high-speed sync to work.

Based the suggestions in this thread (thanks!), I've tried it with the camera set in each of the standard modes -- A-DEP, M, Tv, Av, and P. Even though the 580EX flash is set with "H" next to the thunderbolt symbol, the flash is "on", and the flash-ready thunderbolt shows up in the viewfinder, no "H" ever appears in the viewfinder so high-speed sync never seems to happen.

Any other suggestions? !

Turn off the flash, and try setting to "M" mode on the camera and set the shutter speed to 1/500th sec. (The aperture really shouldn't matter for a test.) Now turn on the flash, and see if you can get both to go into "FP" mode by setting that mode on the flash. FP mode won't engage at speeds slower than the x-sync, so you are just making absolutely sure the camera is beyond that for the test.

You should see the FP indicator in the "Viewfinder" of the camera. (I keep trying to see it in the data screen on the back of my XT, but it's not there (D'oh)). It also only appears when the shutter-button is half-depressed.

It's all so confusing, but ... I'm easily confused.:):

Good luck,

ziggy53

photobug

Mystery solved!
I finally got it to indicate in the viewfinder!

How? By reading the instructions very, very carefully. Here's the catch: the "H" will not show up in the viewfinder unless the shutter speed is set faster than 1/250. Just turning on the flash and setting it to HSS (a.k.a. FP) isn't enough. Pressing the shutter button halfway isn't enough. Putting the camera in the right mode (e.g. Av or Tv) isn't enough. It also has to be set such that if a shot is taken, the shutter speed will be faster than 1/250.

Who would have thought?

I would have thought that if the flash was set to go in HSS, then the viewfinder would indicate that the flash is "ready, willing, and able" to do so by posting the "H". But nope, the "H" on the back of the flash means that it's "ready, willing, and able", but that's not what the "H" in the viewfinder means. It means that the HSS function is not only available, but is actually going to be used if the shot is taken.

Whew.

Thanks everyone for all the help and pointers. They eventually got me to the right place ... but what a pain it was, getting there.

= Dave

juliejules

I just got a new 430EX to go with my 20D. Although I haven't tried this yet, I'm sure I would have run into the same problem. Thanks for the education.

photobug

I just got a new 430EX to go with my 20D. Although I haven't tried this yet, I'm sure I would have run into the same problem. Thanks for the education.

You're welcome -- glad that my "wrestling match" with HSS mode has been helpful to someone else!!

= Dave