Auto FP in Nikon D90 with manual Ikelite Strobes

Hi All,

I have been trying to use auto FP in my Nikon D90 and using Ikelite ds161 strobes in manual. I have the FP turn on but it wont let me go faster than 1/200th. I am shooting in M mode.

I tried using the same camera with my SB600 speedlite and it allows me to use FP. Is it an issue with Ikelite strobes in manual??

Any help appreciated

Regards Mark

Hi Mark

It is a restriction of the Nikon D90. Max sync speed is 1/200 unless you are using the Nikon Creative Lighting System (CLS) features: By enabling an option called Auto FP, found on the Flash/Bracketing submenu of the Custom Setting menu (see Figure 5-33), you can use a shutter speed faster than the 1/200-second limit of the built-in flash. In fact, you can use shutter speeds as high as 1/4000 second!

look at your manual page 195

Hi All,

 

I have been trying to use auto FP in my Nikon D90 and using Ikelite ds161 strobes in manual. I have the FP turn on but it wont let me go faster than 1/200th. I am shooting in M mode.

 

I tried using the same camera with my SB600 speedlite and it allows me to use FP. Is it an issue with Ikelite strobes in manual??

 

Any help appreciated

 

Regards Mark

The Auto FP function only works with Nikon speedlights. In Auto FP mode the strobe fires a VERY RAPID series of flashes as the shutter curtains scan across the camera's sensor. This allows proper flash exposure at speeds beyond the normal flash sync speed. There are no UW strobes that have this function built into them. So unfortunately you can not do Auto FP underwater unless you can house your Nikon strobe.

Randall

I remember that I have tried the FP out on an Ikelite housing as the Ikelite TTL mimics the Nikon TTL. If I purchased the Ikelite TTL converter would this allow me to use the auto FP mode?

Can someone confirm this?

Regards Mark

I remember that I have tried the FP out on an Ikelite housing as the Ikelite TTL mimics the Nikon TTL. If I purchased the Ikelite TTL converter would this allow me to use the auto FP mode?

 

Can someone confirm this?

 

Regards Mark

Unfortunately the Auto FP function is something built into the flash, and only the latest Nikon speedlights have it. In my previous post in this thread I incorrectly described it as a series of very rapid flashes, but actually the speedlight's flash duration is long enough for the shutter curtain slit to scan the entire image area. Usually a flash has a duration of about 1/1,000 sec or shorter. But in Auto FP mode, and at shutter speeds above normal sync speed, the camera signals the flash to illuminate for about 1/250sec. It is a function one step beyond TTL automation, so even though many UW strobes can mimic the TTL magic, they are not built to stretch their flash duration to 1/250. Even the built-in flash on Nikon DSLRs won't do this. I hope this explanation helps.

Randall

There was a post on here, from Mike Veitch, describing how to use a bit of sticky tape to mask one of the pins on a D90, allowing 1/250 and 1/320, although at 1/320 you start to get a black band at the bottom of the frame.

I was stuck at 1/200 with IKE strobes in an IKE housing, but I have since switched to S&S strobes. I can set 1/250 and higher with the S&S strobes, although anyhing faster brings in that banding.

Maybe I might just wait a few weeks and use my D7000 with its 1/320th sync speed.

Thanks Randall, Bill, and Sean for your reply.

Regards Mark