Question on canon flash high speed sync

[johndow]

I have a 350D and recently took delivery of the new 270EX speedlight. I understand that i cannot set the shutter speed higher than 1/200 in AV mode with the flash turned on, but i was trying to see if i could use the flash for fill on sunny days, so as i could control the depth of view.

Both the speedlite and 350D's instructions say the flash can be used for high speed sync (obviously the power would decrease considerably), but i am struggling to see how i can do this.

When i use the AV mode, shutter speed is restricted to 1/200 as expected, but when i switch to manual, i cannot seem to set the shutter speed above 1/200 here either

Any suggestions, or is it a lost cause.

JD

[Gordon @ Convergent AV]

not familier with that flash but on the 430/580 I think you need to actually turn on the high speed sync custom function..you may have to do it on the camera as well...it'll be in the manual if it's possible

[Spod]

Is it related to custom function #3 thats sets the flash sync speed in aperture priority auto mode to a fixed 1/200 second or leaves the sync speed on auto/slow sync?

[tdodd]

I don't have a 270EX but according to what I've read you can only enable high speed sync through the camera menu. Ther are no controls on the flash unit itself to adjust this setting. I know Canon released new firmware for some cameras for full compatibility with the 270EX but I don't know whether the 350D was one of them but I doubt it.

If your 350D has no such flash control menu then maybe you can borrow a 450D, 1000D, 50D or higher/later and enable the feature from one of those cameras. Whether it would continue to work on the 350D I do not know.

[Martin.D]

EDIT:

There is no option for high speed sync on a Canon 350D..

[ksten]

I can't answer the original question as I have no experience with the 270EX or the 350D.

However, if you can't select HSS mode on the 270EX or via the camera then another option would be to add ND filters to bring your shutter speed back down below within the sync speed. This obviously will reduce the effective flash power, but that would have been reduced is HSS mode anyway.

I must have a play some time and work out which method gives you the best effective range of the flash (ND filters with flash at full power or HSS).

Cheers.

[johndow]

Originally Posted by tdodd

I don't have a 270EX but according to what I've read you can only enable high speed sync through the camera menu. Ther are no controls on the flash unit itself to adjust this setting. I know Canon released new firmware for some cameras for full compatibility with the 270EX but I don't know whether the 350D was one of them but I doubt it.

If your 350D has no such flash control menu then maybe you can borrow a 450D, 1000D, 50D or higher/later and enable the feature from one of those cameras. Whether it would continue to work on the 350D I do not know.

That is very interesting, as i have just read review which now states that only the 40D/ 1000D onwards have the ability to control certain functions of the flash through the camera. And as you rightly say, some other models require a firmware upgrade. I am just well p$$$ed off that both manuals led me to believe it was possible.

Your suggestion of setting the function on another camera is a good one. I have a colleague who owns a 1000D. I will ask him to try it out for me and adjust the settings to see if it will hold.

As an aside, it was a close call between the 270 and 430, but i went for the 270 because it also had bounce, was cheaper, smaller and would probably suit my limited needs. If the 430 can be set to HSS from the flash, i may reconsider and just upgrade.

Thanks
JD

[ksten]

Yes, the 430EX has a button to select HSS.

Cheers.

[tdodd]

Not much comfort (none at all in fact) but if you ever shoot in portrait orientation then the bounce (but non-swivel) head of the 270EX will not serve you very well, unless you have a rotating flash bracket. The 430EX, on the other hand, does swivel as well as tilting, which gives it more flexibility.

If you don't know what I'm talking about then take a look at these examples....

Landscape orientation (flash is swiveled and tilted) - http://www.abetterbouncecard.com/0643.jpg
Portrait orientation (flash swiveled only) - http://www.abetterbouncecard.com/0634.jpg

Personally I use a 580EX and 580EX II and find tilt/swivel to be extremely useful for bouncing flash at weddings, or wherever else I need to bounce. Sometimes you may want to bounce from a wall beside you, rather than the ceiling above, so tilt/swivel covers all the options.

[ksten]

Going back to my thoughts above on using an ND filter instead of HSS and its affect on the effective power/range of the flash, I've just had a little play.

This is based on a 580EXII and the range readout on the back of the flash so isn't particularly accurate but gives a feel for what's happening. I used ISO100 and set the flash to full power for this simple test:

HSS: 1/8000 @ f/2.8 - effective range indicated as 1.5m

Not-HSS: 1/250 @ f/16 (I.e. equivalent exposure) - effective range indicated as 4m

So adding a 5 stops of ND filters would bring you back from f/16 to f/2.8, for your shallow DOF, but keeping your 1/250 (I.e. non-HSS) sync speed and leaving you with more than twice the effective power of the speedlight.

Of course, Joe McNally would just throw more flashes at it and avoid the faff with filters!

Sorry if I've gone slightly off topic but it was a useful test for me as I've been struggling with HSS reducing the power of my flash recently, so thought the info may be of use to others (And to the OP if he can't select HSS mode anyway).

Cheers.

[ksten]

Originally Posted by ksten

... thought the info may be of use to others ...

Haha, I guess not then.