Does your 30d / 580ex work in Tv mode?

[tom l]

I was shooting an event the other day with my 30d & 580ex. I had the camera in

Tv mode with shutter at 1/125 and the 580ex in eTTL mode. At one point due to

difficult lighting I decided it would be better to control the flash power

manually so I changed the flash from eTTL to Manual. As soon as I did that and

pressed the shutter button half way down, I noticed the aperture was flashing

22. I'd put the flash back in eTTL mode and the problem went away. I put it

in manual and the problem would reappear. I found leaving the flash in manual

and setting the camera to Av mode or manual mode also worked properly.

 

Is this normal behavior?

 

I see nothing in the flash or camera manual to indicate Tv mode is not allowed

when the flash is in manual. Although my local camera dealer says this is

mentioned in one of the lower numbered flash (430ex?) manuals.

 

Thanks.

[rainer_t]

Read ...

 

http://photonotes.org/articles/eos-flash/

 

... Section: "Tv (shutter priority) mode flash."

 

Rainer

[tom l]

Thanks, Rainer. That agrees with what my local camera dealer told me. But I submitted the same question to Canon's tech support via e-mail and they are telling me to send the camera in for repair. I wish this was documented in the 580ex's manual.

[kin_lau]

Tom,

 

Is High-speed sync on? I've noticed that funny things happen with my 20D & 580EX in both Tv & Av modes if the flash has HSS on and is in manual mode.

[tom l]

Thanks, Kin, no high-speed sync is turned off on the flash.

[john_schwaller]

By coincidence, Chuck Westfall answered a similar question on how Canon cameras react when flash is in manual mode....http://digitaljournalist.org/issue0703/tech-tips.html

 

"...

Q-I was playing around with my wireless flash setup just now in preparation for my wedding tomorrow and then I remembered that I can control the 550EX slave flash in Manual mode via the master 580EX (i.e., I can set the 580EX to Manual and to not fire and the 550EX will fire at the specified Manual power setting). However, when I set the Master to Manual (i.e., 1/32), my 5D locks the shutter speed at 1/200 in Av mode, even though I've set the custom function to "Auto." If I set the Master back to E-TTL, the shutter speed goes back to Auto. Does anyone know of a way to get this setup to work with an auto shutter speed?

 

A-When an EX Speedlite flash is set to its manual mode, wireless or not, the only way to set the shutter speed to something other than maximum X-sync is by setting the camera to its manual mode.

 

Q-Is there a technical reason for that? I assume maybe it's because the camera can't meter the scene not knowing how much light the flash is going to output, and therefore, what's the point of a slower shutter?

 

A-Actually, that behavior extends all the way back to Canon's first TTL flash system in 1986, the T90 camera and 300TL Speedlite. As I recall, the explanation at the time was that setting up Av mode to default to maximum X-sync when the flash was set to manual mode was to make it more intuitive for photographers to set apertures using the main dial and LCD data panel. Fixing the shutter speed at maximum X-sync was (and still can be) appropriate for handheld flash photography indoors, in situations where the ambient light is contributing nothing significant to the overall exposure. Manual mode on the camera combined with manual mode on the flash makes it possible to control shutter speed and aperture freely and independently, which becomes useful when you want to drop the shutter speed to pick up more of the ambient lighting in indoor scenes.

 

Q-I guess there's no way to use High-Speed Sync with Manual flash, eh?

 

A-FP flash mode (high-speed sync) is still supported when manual flash is combined with manual exposure mode on the camera, but if you set high-speed sync with manual flash when the camera is set to Av mode, the shutter speed defaults to the camera's maximum shutter speed, such as 1/8000 for most current EOS digital SLRs..."