A question for the flash gurus - Auto FP related

ImagenEstilo

Hi there,

I have been trying to simulate the black banding you get when above max sync speed but not in HSS (Auto FP) but cannot seem to do it. I have the Pocket Wizard Flex TT5 and Mini TT1 and have tried everything to simulate what happens when Auto FP is deactivated but cannot get the black bands. I have set up the Mini TT1 in Basic Trigger Mode but this doesn't work either. All in all, I am stumped. Any ideas how I could simulate it? I am using a D800 and an SB910. I've a few SB910's so could try using one of them as a master mounted on the camera but I would have thought the Pocket Wizards could be turned into simple triggers like the older Plus II's. Any ideas would be greatly appreciated. Obviously if I had a plus II the problems would be solved but it is strange that I cannot do such as simple thing as this.

Thanks

pixbyjohn

If you set the flash to manual and then set the shutter speed on your camera above the flash sync speed you should get the result you wish for

ImagenEstilo

I wish it was as easy as that but it aint, setting it to Manual sets the SB910 to M FP mode, in other words manual HSS mode, so even if in manual it will see it as a HSS. What I might try and do is see will commander mode or master/slave allow this. I cannot imagine camera setting info being transferred in this mode. I will give it a try.

pixbyjohn

ImagenEstilo wrote: »

I wish it was as easy as that but it aint, setting it to Manual sets the SB910 to M FP mode, in other words manual HSS mode, so even if in manual it will see it as a HSS. What I might try and do is see will commander mode or master/slave allow this. I cannot imagine camera setting info being transferred in this mode. I will give it a try.

Yes you are correct. How about trying it off camera with non ttl triggers. I am trying this now to check. Will post results

pixbyjohn

Flash sync speed demo by pixbyjohn, on Flickr

Exposure0.003 sec (1/400)
Aperture f/4.0
Off camera flash with non ttl trigger

ImagenEstilo

Yep, that is exactly what I am after, but I don't have non-ttl triggers. I've only got the mini TT1 and Flex's. I've tried to convert the Mini into a Basic Trigger using the PW Utility but it doesn't work as that function is for non Canon/Nikon cameras.

I don't want to go out and buy a set of cheap triggers as this test is only for a blog article I am writing. I'll never use them again!

John, if you do manage to get the same results using master/slave or a pop up flash as a commander it would be great to hear.

I'll try the master/slave idea later and see how that goes. It's hard to believe, a problem that is a nightmare for a vast amount of flash photographers, I cannot replicate, bananas altogether!

Thanks for the input John, I appreciate it.
Dave

Cameraman

If it's only for a demo - why do you need to use using triggers in the first place ?

Can't you just take the shot with on-camera flash.

ImagenEstilo

Absolutely, but the problem is, once I have HSS (Auto FP) enabled on the camera itself, the flash will not accept any other option. You must use TTL FP or M FP. HSS and FP are the same thing just Nikon and Canon versions.

So all in all, using on camera or off camera with Flex/Mini triggers, the TTL data is transmitted so it knows that it must use HSS. A cheap SB-400 would work, or cheap triggers, but I have not got these.

If you turn of HSS on the camera then your shutter speed is restricted to whatever you set it at in the menu.

It is hard to believe I cannot simulate such a simple thing with the gear I have. Genuinely cannot believe it.

ImagenEstilo

As a follow up. I have tried commander mode and master/slave but again to no avail. TTL/HSS information is transmitted in both cases so the slave flash knows whether or not to use standard flash sync or HSS.

Honestly, Nikon have bullet proofed this one!

ImagenEstilo

OK, I am stumped here (and replying idiotically to my post repeatedly).

Would anyone, John in particular, mind doing me a favour. In return I will link from my blog to your Flickr Feed or whatever pages you like to be honest.

I am looking for a series of photos going from say 1/60th all the way to 1/1000th using flash just like the one above. The photos from 1/60th to 1/250th (or the max sync speed) I can handle myself as they will all look the same once using TTL, but as soon as you go over max sync speed of your particular camera, then you should notice (if you use basic triggers) the shutter starting to appear in the photos. So John, if you wouldn't mind, would you be able to take photos at 1/3 stop increments above your max sync speed. Ultimately the goal is to show that the further you go above your max sync speed, the more apparent the shutter will be in your flash photos.

I want to take into account propagation delay as well but I reckon I can test this using 1/320 sync on the D800, you just about get a glimpse of the shutter at the edge of the frame.

I know this is an off the wall request but if anyone could help here I would really appreciate it. I find with photos it is easier to explain certain concepts. Usually I can do them myself but hard to believe I can't do it in this instance.

Cameraman

Once again - if it's just to produce demo photos - turn off HSS or Auto FP or whatever it's called on Nikon (I use Canon !).

As you move to faster shutter speeds you should get the banding - and produce your demo photos. No one need ever know you didn't use triggers

ImagenEstilo

But what I was trying to say was, when I turn off HSS, I have to set a maximum flash speed and then my shutter speed is limited to that in camera, I cannot go over it, impossible. I can only go over it when I enable one of the 1/250 HSS or 1/320 HSS options in camera.

The camera will not allow me do it.

Cameraman

OK - it's obviously a Nikon-specific thing then.

Using manual mode, I can set any speed I like with flash (however silly) on Canon. There is a default maximum, but I can override it.

Sometimes the apparently simple things can be really awkward.

ImagenEstilo

Yep, it seems to be Nikon specific alright. If I set a non HSS max speed then the camera limits the shutter speed to that when I have a flash attached or pop up active. Then if I use a HSS setting it uses HSS no matter what you do. No way to mix and match!

Thanks for the suggestions Cameraman

pixbyjohn

I will take a set of photos as you suggest later tonight and email them to you if you wish.
Cheers,
John

pixbyjohn

1/320" by pixbyjohn, on Flickr


1/400" by pixbyjohn, on Flickr

pixbyjohn

1/500" by pixbyjohn, on Flickr


1/640" by pixbyjohn, on Flickr

pixbyjohn

1/800" by pixbyjohn, on Flickr


1/1000" by pixbyjohn, on Flickr

ImagenEstilo

John, I would very much appreciate that and thanks a lot for this.

I will send you a PM with my email details.
Thanks again.

paulusdu

I have the same flash and camera, and the only way i can simulate that banding is to use it off camera with a remote trigger and set the shutter speed 1/320 or greater. Could it be an inbuilt safety mechanism to stop getting this banding accidentally ?

ImagenEstilo

A big thanks to John for providing the photos. Very much appreciated. I will stick the article up when I get it completed if people want to have a look.

Paul, the only way I can get a hint of a band is by setting the flash sync speed to 1/320 Auto FP in the camera and then shooting off camera at 1/320 shutter speed. But this only occurs because of propagation delay, nothing else. As soon as I go to 1/400 I enter HSS and bands disappear. If I had cheap Chinese triggers or Plus II'2 I could replicate what John has done above no problem but for some reason the pocket wizards will not allow me turn them in to basic triggers. They are an ingenious little device and transmit the standard basic signal on one channel and the TTL information on another channel. I tried to turn the TTL info channel off (and you can) but for some reason then the flash simply does not fire.

Anyway, I can safely say it is not something I want to replicate in the field, it is really only for a blog article I am putting together. Equipment not allowing you make mistakes is always good I find!

Another thing I discovered with the Flex and Mini pocket wizards is this thing called hypersync. It will let you sync normally up to 1/1250s without going into HSS territory. This to me is incredible. This is 2 and 1/3 stops over the cameras recommended max sync speed, allowing 2 and 1/3 stops of extra aperture on your flash. More aperture = more distance or less flash power. Phenomenal little gadgets.