question re: shutter speed when using SB900

[bluewaterjon]

Hi folks, here is my question. Why is it that when I am using my SB900 flash on top of my D300, it doesn't use a higher shutter speed than 1/250? Unless I am mistaken, it won't lemme shoot any quicker than that when the flash fires, even in shutter priority. As it is I often shoot in P mode when I am underwater because I am doing so many different things and I can't access my controls much so I need something versatile. This is a problem for me- the 1/250 being the fastest shutter speed- because I am using the camera and flash in an underwater housing, shooting moving fish, and I need more than 1/250 to get really sharp pics. Some come out but others would benefit greatly from a higher shutter speed.
Tx in advance,
Jon

 

[Steph]

1/250th is the maximum sync speed of your camera, so theoretically you cannot use a faster shutter speed wit flash. At any higher speed the shutter is never fully opened at any time during the exposure so you would get a black band from the shutter curtains when the flash is fired. However, modern flashes such as the SB900 offer a mode, which let you use any shutter speed you want. Read your flash manual.

 

[andrew99]

Turn on high speed FP sync in the camera's menu, and then you can use any shutter speed.

 

[JerryPH]

Andrew hit the nail on the head. Set your camera to use a maximum sync speed 1/320th FP and if you are in manual, shutter or aperture priority mode, your flash will sync up to 1/8000th.

Be aware that above 1/250th, even if the flash is in sync, it will not be as strong and your flashable distance will be reduced at higher shutter speeds above 1/250th.

I would also suggest that you spend some time with the D300 manual... all this stuff is in there.

 

[Garbz]

Here's a question for you. If you are using flash then why do you need a fast shutter to get sharp pics? There may be another reason for your problem.

A typical flash duration is 1/40000th of a second to about 1/5000th of a second. The only thing that is important for a sharp shot then is that the flash is the primary light source. I can't imagine you would need more than 1/250th at a reasonable aperture underwater to eliminate the natural light. Can you explain what you are doing at the moment and what you are trying to accomplish?

 

[andrew99]

He's shooting fish under water.. I've never done it, but it brings up an interesting point. If he's shooting with a very high shutter speed and using the flash as the primary light source, the light won't travel far and the background will be completely dark, which might not be the effect he is looking for.

Bluewaterjon - can you post some samples of what you are doing? I'd be interested to see! Also what housing do you have that can fit a D300 and SB900?

 

[JerryPH]

Well, ideally the reason we use FP is to be able to use wide open apertures in bright conditions and still properly expose a subject. However, if a person thinks that they can get full power/distance from a flash at 1/8000th shutter speeds, they need to do a little reading to understand what is happening.

High speed FP limits you to about 6 feet maximum distance (flash to subject) for a clean 1/2 body shot at maximum power.

 

[LarryD]

High speed sync is handy, but as has been said it is limiting.. It is mainly beneficial for fill flash where you have enough ambient light for the higher shutter speeds but want to brighten up the shadows...

A full power flash at 1/250 sync should stop most movement...........so maybe your problem is P mode...

Why not try 1/60 Shutter Priority with full flash and let the camera choose the f-stop for greatest DOF.

 

[JerryPH]

A full power flash at 1/250 sync should stop most movement...........so maybe your problem is P mode...

Why not try 1/60 Shutter Priority with full flash and let the camera choose the f-stop for greatest DOF.

As mentioned, it may not be about movement at all, but about wide aperture on a bright day. In that case, there is nothing but high speed focal plane that will work.

P-mode... I have my opinions of that... they mostly point to the person using the camera and me telling them to get off their butt and learning how to control their own equipment... lol.

 

[Flash Harry]

Been through all this before, I reckon its a piss take, flash freezes movement, period. H

 

[Winterson]

People shot for years with Nikonos underwater cameras, myself included, and the max shutter speed for strobe sync is 1/90. Underwater if you are deeper than 20 feet most of the light is coming from the strobe and the most powerful UW strobes have guide numbers of 36 or less. So at ISO 200 the camera settings would be f4 at 8 feet and one does not use a strobe to light a subject at a distance greater than 8 feet underwater. At greater distances the strobe is ineffective and the resulting backscatter degrades the image. With an aperture of f4 a shutter speed of 1/250 is hardly a handicap. Even in clear tropical waters exposures run around f8 at 1/90 or f5.6 at 1/180 for the ambient and in most situations one is setting the shutter speed for the ambient and the aperture based on the expected subject distance and the GN for the strobe. I use faster shutter speeds and FP sync in bright sun above the water but there is not need for this capability underwater and the proof is in the millions of spectacular underwater images taken over the past 45 years with cameras with maximum flash sync speeds of 1/90 or less.

 

[Flash Harry]

YAY, can't argue with that, now we just have to convince the f1.4 boys you dont need to shoot wide open in all situations to put the background OOF and we'll be getting somewhere. H

 

[sabbath999]

This is a problem for me- the 1/250 being the fastest shutter speed- because I am using the camera and flash in an underwater housing, shooting moving fish, and I need more than 1/250 to get really sharp pics. Some come out but others would benefit greatly from a higher shutter speed.
Tx in advance,
Jon

Here are a few thoughts from a fellow underwater shooter.

1) The Best Underwater Photography Forum

2) Know your photo equipment backwards and forwards before you get into the water with it.

3) Asking non-divers about underwater photography isn't always helpful, since they don't realize just how tricky it is to shoot while maintaining buoyancy, in surge or current, watching your air, watching your depth, watching your buddy, not damaging the reef, etc. That's why you have to do #2 and know your camera backwards and forwards, left and right.

4) FP is cool, it will allow you to bump up your shutter speed but will reduce the flashes power. Above water shooters will tell you "yeah, but not by that much" but underwater shooters realize that water is 600 times more dense than air so a flash that shoots 100 feet on the surface will struggle illuminating 10 feet underwater.

What kind of housing are you using for your SB900 and your camera? Would love to hear about your setup.

 

[Andyp]

Hi folks, here is my question. Why is it that when I am using my SB900 flash on top of my D300, it doesn't use a higher shutter speed than 1/250? Unless I am mistaken, it won't lemme shoot any quicker than that when the flash fires, even in shutter priority. As it is I often shoot in P mode when I am underwater because I am doing so many different things and I can't access my controls much so I need something versatile. This is a problem for me- the 1/250 being the fastest shutter speed- because I am using the camera and flash in an underwater housing, shooting moving fish, and I need more than 1/250 to get really sharp pics. Some come out but others would benefit greatly from a higher shutter speed.
Tx in advance,
Jon

Hi,

I just sent a thread about the same camera and flashgun and subject.

I'm having the same issues but my flash shutter speed only seems to go upto 1/60th? I' m using Aperture mode in both.

Any idea's where im going wrong?

thanks

 

[Garbz]

Opposite situation man, I replied with a full explanation in the other thread.