I have PW's, canon 5d, and Profoto monoheads - and my actual max sync speed is 125th. It says all over the place that I should be able to sync higher.

I have an old dinosaur Metz unit that syncs at a 200th. This tells me its not the camera, its the light. Seems odd that new profoto heads would be so slow!

Meow?


Thanks


(ps, not a newb, just not a technophile )

Yeah my 5D says I can sync at 1/200, but I don't try anything much more than 1/160.

Strange... from what I have heard PW's give full sync.

Do you mean the Compact 300/600/1200 line? If so, the flash durations on those are _terrible_, but I don't as bad as 1/125 (t.1). It's possible that the electronics introduce a 1-2ms delay, which would cause a disparity like that. Do they have built-in PWs, or are you attaching one with a cable? Have you tried using the optical sensor instead to see if that has a shorter delay? You should also try with a PC cable straight to your 5D and see what happens.

The 5D is a big sensor in a consumer body. That means slow components that have to cover a large distance (slow components compared to the 1-Series, large distance compared to the cropped-frame consumer cameras).

Where the other cameras actually have a bit of sync speed cushion and can stand the inevitable sync lag created by any radio trigger, the 5D has no cushion whatsover. If the 5D sync is delayed by even a slight degree--which even PW does--it shows.

The 5D 1/200 sync speed stands with its toes right on the edge of the cliff. By contrast, the 1/250 advertised speed of the 1-Series is well back from the precipice--its actual sync speed is about 1/350.

I get 1/200th with PWs and Profoto Compacts or Acutes, on 5D or 5D2.

sboerup wrote:
I get 1/200th with PWs and Profoto Compacts or Acutes, on 5D or 5D2.

How much you can fudge depends much on what you're actually shooting--specifically what the ambient light intensity is toward the bottom edge of the frame. If the ambient intensity is bright enough or the subject tones don't lend themselves to revealing a bit of underexposure, you might be able to fudge the sync speed quite a bit.

Your sync problems are a result of latency: the delay between the time the camera closes the switch to fire the flash and when the flash reacts to it. PWs don't have much latency, but it does take some time for the transmitter to react to the camera and the receiver to react to the transmitter, and the flash to react to the receiver.

The rated x-sync limit for Canon cameras is for Canon flashes in the hot shoe. The manuals state that sync speeds with studio lights may be lower.

To determine whether the latency is caused by the flash or PW try connecting the flash to camera with a PC cord.

Chuck

sboerup wrote:
I get 1/200th with PWs and Profoto Compacts or Acutes, on 5D or 5D2.

When shooting with backdrops in the studio, I get dark edges if I use anything faster than 1/160. I am using a 5DII, Pocketwizard II's and 580EX II speedlites. By comparison, I can use my 1DMkIII or D3 at 1/250 with the same setup and do not get dark edges.

Daan B wrote:
Strange... from what I have heard PW's give full sync.

They do. I can sync at 1/500th using pocket wizards on a Copal shutter using Metz 60's, Nikon SB-28 or 580EX. Pocket wizards are not the problem.

I don't know why but many 'large/studio) strobes sync at lower speeds on some Canon bodies. It actually says so in the Canon 1dsmk2 manual, it probably says the same in the 5d2 book.

JJ

I can get an almost completely clean 1/340th with my 40D on radio triggers (just a hint of a shadow on the bottom edge). My 1Ds hits the rated 1/250th and is fine...anything past that is asking for a shadow. I've seen this topic come up a few times here...there just seems to be some variation between bodies as to just how fast they will sync on a radio trigger....

Yeah, I max out at 160, as well. I shoot almost exclusively at 1/125 with the 5D II when shooting with Profoto.