I was on Manual-probably 1/16 power and no HSS.

I posted this issue in the EOS Magazine Forum run over here in the UK and a reply has suggested that as the light was used as fill only, it is not affected by the second curtain, whereas it would have been had the subject ben lit principally by the flash, as per Neil’s results above in the studio set up which is ambient free.

I don’t know if this clears it up-i’m not convinced, but like any keen photographer/pro, when I don’t understand something about the technical side, I worry it will undermine my creative side because whilst it went well for me on my recent shoot, on the next one….

Neil, anyone, is there any chance we can get to the bottom of this issue-it’s like defying the laws of gravity to say a flash can properly illuminate a subject when fired with shutter speeds beyond the camera’s theoretical synch speed! And it’s driving me nuts now…

Excellent, thanks. I have just finished reading a lot of your posts on your site less than 2 minutes ago. :)

Trev

The cheat sheet is Pocket Wizard specific and was based on my results, so yours might be a little different.

There’s very little discernable difference between the X5d-R and T5d-R results. Using a speedlight on your hotshoe will just trick the camera into advancing the sync point and you just plug a transmitter into the speedlight or into your camera’s PC sync. On Nikon, both are advanced for FP mode sync when higher shutterspeeds are used. With the Quantum D adapter the camera just ‘thinks’ it has a FP mode flash fitted and advances the sync point accordingly. Canon might be different.

Rather than taking up Neil’s message board, if you post your question on my blog I’ll show how I fit the FW9T and various flashes all at the same time. Managing all the equipment and cables and be adaptable at the same time can be a right chore.

I’m glad you found it useful.

Great write-up on that link provided. I must explore the use of my Quantum with *HSS*.

I have the QFlash T5D-R, and the Quantum FW9T FreeXwire using the Quantum FW7Q FreeXwire Wireless Digital TTL Receiver on the T5D-R QFlash.

Now, although I have the FW9T mounted under the Nikon D3, but using the Sync Cord from my camera’s sync socket into the ‘Sync In’ on the FW9T instead of the D22wR QTTL adapter, can I still be able to utilise the HSS say at 1/2000th with QFlash set in Manual Mode at Full Power?

In the write up you stated: “This was with a D3x, 24-70 f2.8 @100ISO using a FreeXwire transmitter and D22-wr adapter on camera, nothing else. The same can be achieved without the D adapter but using a speedlight in it’s place instead.”

What do you mean by that exactly and how do you use a speedlite in conjunction with the QFlash. Using a sync cord from speedlite to FW9T?

I do have the D adapter but for a Canon, which I could use, but wanted to use this HSS theory on a Nikon D3s and QFlash.

Judging by the sample shots you showed I am verrry impressed with the 1/1000th f6.3 up to the 1/4000th f2.8 range.

The exposure table you provided is a great little cheat card, printed out and shall keep in bag. :)

I presume you were manual full power on the Quantum X5d-R you were using.

If I can get something similar with the 160Ws QF T5D-Rs then I would be happy.

Great explanation once again.

Trev.

I posted some samples and a write up here: FP mode and HSS – exceeding flash sync with no loss in output. I think that the reason why the faster end shutter speeds benefit more over the 1/320s+ shutter speeds is that at this lower end the shutter duration is almost double that of the faster 1/8000s shutter speed end with the second shutter curtain being so far behind the first. Essentially, this means the 1/8000s shutter is using more of the peak output/greater brightness and tail than the 1/320s is and there is less of the decaying tail being used. Although 1/150s to 1/180s might be the ideal flash duration to match shutter duration in this respect, the 1/250s and 1/300s of the Quantums turn in pretty decent results, and afford this little bit extra at the top end as well.

Chuck Arlund posted an interesting article on his blog about using studio strobes at higher than max sync speed.

Neil vN

Regards
Brian Carey

Thanks Neil