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Nikon SB-600 FP Sync

PostPosted: Sat Jan 27, 2007 11:29 am
by terminator
Just wondering if anyone knows if the SB-800 is better than the SB-600 on a D200 when using FP Sync.

When using the SB600 as soon as you exceed the 1/250 flash sync speed there is a really big drop in exposure. I thought the FP mode was supposed to allow for faster effective flash syncing.

I`m pretty sure I have the camera set to FP sync (FP is visible on the flash LCD).

Does anyone else have problems in this regard with the 600?

Would buying an 800 improve fast flash syncing?

My D70 was so much better when using flash than the D200 :twisted:

PostPosted: Sat Jan 27, 2007 12:14 pm
by Yi-P
When I was trying the D200 with FP on the SB800, didnt find any problem with the exposures, they were all well exposed, not very sure why the SB600 is underexposing, they both should expose the same way.

Re: Nikon SB-600 FP Sync

PostPosted: Sat Jan 27, 2007 9:46 pm
by Steffen
terminator wrote:When using the SB600 as soon as you exceed the 1/250 flash sync speed there is a really big drop in exposure. I thought the FP mode was supposed to allow for faster effective flash syncing.


It is. The problem with flash at speeds faster than the flash sync speed is that at no time the shutter is fully open, but rather a slit travels down the format. In FP sync mode the flash is kept burning during the whole time the slit takes to travel, which is much much longer than the normal flash burn time. Also, much of the light is wasted as it hits the shutter blades instead of the sensor.

Therefore, FP sync mode is very much less efficient than normal sync, and your flash reach is greatly reduced. A more powerful flash helps a lot with this mode.

Cheers
Steffen.

PostPosted: Sun Jan 28, 2007 2:10 am
by lukeo
Pretty much what Steffen says. From memory the SB800 is almost identical to the SB600 except the 800 is 1 stop more powerful.

How I've had the FP high speed sync described to me is thus:

Image for every stop above the maximum normal sync speed (1/500th on a D70) you lose half the power of the flash.

The flash cannot physically fire any faster, so when the shutter speed gets doubled, the maximum light burst is captured for only half the amount of time. Half the time is half the light or there abouts.

The higher sync speed you use the less of the actual flash you capture.

My take on your problem, and my opinion is if the sync speed is so high your photo's are underexposed I don't think an SB800 would help.

Can you boost the ISO, open the lense a stop or two and use a slower shutter speed?

PostPosted: Sun Jan 28, 2007 8:48 am
by terminator
Thanks for the info guys,

I guess the best would be to try the 800 to see what happens in this regard before splashing out any cash.

I`ve had some say the 800 would help and others say it won`t help.

Have also been told an extender(eg: better beamer) would help also.

Regards,

PostPosted: Sun Jan 28, 2007 9:01 am
by gstark
Termy,

Let's get back to basics for a moment: what is the problem that you're trying to solve?

For now we're only dealing with the symptoms. What is it that you're trying to photograph, and specifically, how?

Let's understand that part of the equation, and let's see if we can find the best way to deal with the situation.

PostPosted: Sun Jan 28, 2007 10:33 pm
by terminator
Gary,

The problem is the drop in flash effectivness once the 1/250 flash sync speed is reached.

My main problem with regards to this is when shooting portraits/candids of my son outdoors in bright sunlight and wanting to fill in shadows with my SB-600.

From what I understand the FP mode just doesn`t cut it for any sort of range when shooting in these types of situations.

Regards,

PostPosted: Sun Jan 28, 2007 11:58 pm
by Steffen
terminator wrote:From what I understand the FP mode just doesn`t cut it for any sort of range when shooting in these types of situations.


It does cut it as long as you're aware of the inherent limitations. You cannot expect a leaf shutter and flash combination to perform miracles outside of physical limitations.

The only common situation where you'd need flash at high shutter speeds is fill flash in broad daylight, AFAICT. FP sync gives you a bit more freedom on those situations. If that's not enough you need either a more powerful flash, or multiple flashes.

Cheers
teffen.

PostPosted: Mon Jan 29, 2007 1:05 am
by lukeo
"My main problem with regards to this is when shooting portraits/candids of my son outdoors in bright sunlight and wanting to fill in shadows with my SB-600."


Ultimately I think your asking the flash to be "the sun", if your shooting in broad daylight, with dark shade in the shots as well... I don't think anything short of flood lights would fill the shadows.

Fill flash takes the dark circles out from peoples eyes, the shadows away from cheeks, hair and lips. It can remove the darkness underneath leaves etc, but I don't think it will fill in large portions of any shot that's in shade when your subject is in the sun.

my 2 cents!

PostPosted: Mon Jan 29, 2007 7:51 am
by gstark
terminator wrote:Gary,

The problem is the drop in flash effectivness once the 1/250 flash sync speed is reached.


No, that's a symptom. :)

The question is why are you wanting to shoot with a shutter speed faster than 1/250?

Bear in mind that a large part of my pro photography involved shooting with film, with fill flash, with a Nikon FE, which had a sync speed of just 1/125. There were no electronic tricks that permitted fudging a faster sync speed, and if I was using a Canon A1, my sync was further curtailed to just 1/60.

My main problem with regards to this is when shooting portraits/candids of my son outdoors in bright sunlight and wanting to fill in shadows with my SB-600.


Let's forget FP mode for a moment, and let's just look at what you're shooting, and how.

Without flash, what are the camera settings in place? Shutter, aperture, ISO?

How are your subjects positioned with respect to the sun? Facing it? Back towards it?

What is the typical camera to subject distance? With a camera mounted flash unit, is also the flash to subject distance of course, and it's that which is a relevant factor here.

From what I understand the FP mode just doesn`t cut it for any sort of range when shooting in these types of situations.


That's probably true, but I doubt it's the problem. :)

We need to return to some basics for the moment, and reevaluate the shooting scenario. Let's fully understand that, and see if we can find the best solution to the problem.

PostPosted: Mon Jan 29, 2007 7:55 am
by gstark
Steffen,

Steffen wrote:
terminator wrote:From what I understand the FP mode just doesn`t cut it for any sort of range when shooting in these types of situations.


It does cut it as long as you're aware of the inherent limitations. You cannot expect a leaf shutter and flash combination to perform miracles outside of physical limitations.


Surely you meant to say "focal plane" shutter here? Nikon DSLRs don't have leaf shutters. :)

Were a leaf shutter in flace, such as in my Bronica, then sync speeds all the way to 1/500 are avaialable.

But your point about expecting preformace beyond physical limitations is, of course, correct.

PostPosted: Mon Jan 29, 2007 8:18 am
by gstark
lukeo wrote:
"My main problem with regards to this is when shooting portraits/candids of my son outdoors in bright sunlight and wanting to fill in shadows with my SB-600."


Ultimately I think your asking the flash to be "the sun", if your shooting in broad daylight, with dark shade in the shots as well... I don't think anything short of flood lights would fill the shadows.


The trick is that you don't really want your flash to be the primary light source. You use it as a secondary source, to fill the shadows. Hence it's called "fill flash" :)

The goal is to reduce the contrast between the sunlit and shadowed areas in your image by adding more light. Careful posing can often, but not always, help: stand your <strike>victims</strike>subjects with their backs to the sun, for instance. Set your exposure for the available light shot, and let your flash unit, on A, provide an appropriate amount of light to correctly illuminate your subject.

Here's Glen's wife, Terri, at last Sunday week's Bradley's Head picnic. She was about 10 feet away, shot with the 80-400, no flash, exposed for the background.



Image

Same subject. Same location. Same lens. Same date. Just add flash and a bit more zoom.

Image

This was using the on-camera flash (not even an SB-whatever) on a D70. Although there are obvious areas of shadow and sunlight, in the second, the contrast range between the extremes has been seriously reduced, which is where fill flash comes into its own.

PostPosted: Mon Jan 29, 2007 8:30 am
by Yi-P
From what Gary said above, the exposure and the scene with and without a flash.

What exposure program are you using? A,S,M? How are you metering the scene? Are you setting the flash to read correct exposure of the scene?

At some difficult points of tricky lighting in outdoor situations, it is better to manually meter the scene and expose manually using FV Lock. Not sure if the SB600 has a TTL-BL mode, but that might help a little bit, too.

PostPosted: Mon Jan 29, 2007 8:34 am
by Reschsmooth
gstark wrote:Were a leaf shutter in flace, such as in my Bronica, then sync speeds all the way to 1/500 are avaialable.


And that's only because that is the fastest shutter speed on the Bronica (if it's like ours). By their design, leaf shutters can sync at any speeds.

P

PostPosted: Mon Jan 29, 2007 8:37 am
by Reschsmooth
One other option, if camera/subject distance is an issue (ie. too far), use the SB in remote mode off camera, and closer to the subject than the camera. This will effectively increase the amount of light hitting the subject from the flash.

P

PostPosted: Mon Jan 29, 2007 9:08 am
by gstark
Patrick,

Correct on both points.

PostPosted: Mon Jan 29, 2007 12:20 pm
by lukeo
Not sure if the SB600 has a TTL-BL mode


It does.

PostPosted: Mon Jan 29, 2007 12:48 pm
by Steffen
gstark wrote:Surely you meant to say "focal plane" shutter here? Nikon DSLRs don't have leaf shutters. :)


Of course not :roll: :lol:

Cheers
Steffen.

PostPosted: Mon Jan 29, 2007 1:46 pm
by terminator
Yi-P wrote:What exposure program are you using? A,S,M? How are you metering the scene? Are you setting the flash to read correct exposure of the scene?

At some difficult points of tricky lighting in outdoor situations, it is better to manually meter the scene and expose manually using FV Lock. Not sure if the SB600 has a TTL-BL mode, but that might help a little bit, too.


Yip,
I think you may have something here with the metering.
Something definatley to try might be spot meter or use the FV lock as you suggested.
Thanks to everyone for your input.
Regards,