SB-30 or SU-4?

[angel_o.]

Hi all, <br><br>I'm interested in getting an additional, flexible and

cordless light-source to match my F80/SB-28/SC-17 combo. Therefore, I

thought of mounting the SB-28 on a SU-4 and trigger it with the built-

in flash of the F80. <br><br>

Now I saw that a SB-30 Speedlight costs in Europe the same as an SU-4

and also offers remote slave capabilities. So, the "inner conflict"

started:<br><br>

 

Since the different natures of the SU-4 and SB-30 offer a completely

different approach to the solution of what I initially wanted, what

is, from your personal experience, the most convenient option?<br><br>

(a) SB-28 mounted on a SU-4 and triggered by the built-in flash of

the F80 <br>

(b) SB-30 triggered either by the built-in flash, by the SB-28

mounted on the hot-shoe of the camera or by the SB-28 attached to the

SC-17 cord<br>

<small><br>[© Worst case: forget completely about the SU-4 or SB-

30, rob the piggy bank, sell house, car, dog, ... and buy an SB-80dx]

</small><br><br>

 

Thank you very much for your kind advice and opinions helping me in

making up my mind!

[david_h._hartman]

Compare the price of an SB-28 & SU-4 with an SB-80DX then decide. Oh heck just buy the SB-80DX.

[angel_o.]

Thanks for your reply, David. <br><br>

Maybe I didn't express right myself in the first post. My intention was not to buy an additional SB-28 and mount it on a SU-4. My primarily intention was to use my available flashes (the built-in flash of the F80 and my SB-28) in a more flexible way. Nevertheless, what causes the inner conflict is that the SB-30 costs the same as the SU-4 and therefore, I don't know what is more useful due to my lack of experiencce with multiple flashes.<br><br>

Therefore, my question was aiming on what is more convenient: to use the built-in flash of the camera for triggering the SB-28 (wich I already own) over a SU-4

or to use a SB-30 as remote slave, beeing the built-in flash of the camera or my SB-28 the master. <br><br>The background is that I don't have the experience to judge if it is more important to use a powerful flash to backlit the background (e.g. my SB-28 mounted on a SU-4) and a small one for the foreground (e.g. built-in flash) or is it more useful to use as master flash a powerful Speedlight that is capable of lightning the foreground and part of the background (SB-28 mounted on the SC-17) and therefore, to use a small remote flash to fill the left shadows - or should both flashes be in any case similar in power to avoid trouble (e.g master flash SB-28 with slave SB-80)? <br><br>I know that the ideal lightning solution is to buy an additional SB-80 but its cost is less than optimal for the survival of the piggybank. ;-)

[joseph_wisniewski]

Personally, I'd go for the SU-4. The SB-28 has about 15 times the power (four full stops) of the SB-30. At their wide angle settings, which you need when using umbrellas, soft boxes, or just about any off-camera flash work, it's 32 feet (10 meters) versus 125 feet (38 meters). Point an SB-30 into an umbrella or soft box (an extra 1.5 stop loss) and you have to be at f2.8 to take a portrait with the light 6 feet from the subject. An SB-28 on the same setup can let you stop down to f8 or f11, and get a reasonably sharp portrait.

 

Later you can add a second SB-28 or SB-80 and have two powerful flashes with a variety of manual or automatic control options.

 

Hope this helps.

 

Ciao!

 

Joe

[jim_gifford]

Joseph, I think you're understating the guide number of the SB-30 somewhat. By my calculations the SB-28 is not 15 times as powerful, it is something like 6 times as powerful. Maybe I'm wrong -- that has happened once or twice before* -- but my guess is your range figures are not using the same f/stop and ISO. Just use guide numbers, the math is simpler.

 

In any case, you're right that the SB-28 throws much more light than an SB-30 unit.

 

Angel: The SB-30 is lovely and I just got a pair of them to go with my SB-28. But you should bear in mind that the SB-30 as a wireless slave flash works only in Auto mode or in full-power manual mode. The TTL and fractional power settings don't apply when it is used as a wireless slave unit. By contrast, the SU-4 is designed to offer wireless TTL control.

 

Your "worst case" of buying an SB-80DX and using its built-in wireless option is not a bad idea... just more money. The SB-30 can act as an infrared trigger for that SB-80DX unit, by the way. A cool little shade slides up to block the visible light from the SB-30 flash, and what's left is an IR pulse to trigger wireless units. So you get to play with off-camera flash without having to add any on-camera flash to your shot.

 

Heck, Angel, buy four SB-30 units AND a new SB-80DX. More fun than a barrel of monkeys.

 

-Jim

 

* once or twice before lunch, most days.

[david_h._hartman]

The SU-4 has a 1/4 x 20 thread in the bottom that is convenient to use with a micro ball head such as those made by Stroboframe. This combination is quite easy to use with macro flash brackets such as those by Kirkphoto.com and others. Some of the umbrella brackets I have also use 1/4 x 20.

 

If you have a flash with a built in SU-4 function you still need a safe, non-metallic or non-shorting, ISO shoe with a 1/4 x 20 thread in the bottom so figure that into the cost. I�d much rather have the use of the more powerful SB-28 for both macro and umbrellas.

 

Also if you want to use the SB-28 as the only light and use it off camera the SU-4 comes with a little SG-1 diffusion panel that fits the hot shoe of your camera and cover the built in flash. The SG-1 and built in flash will trigger the SU-4 while putting an insignificant amount of light on the subject. I under stand that the SG-1 is not available as a separate part.

 

Hope this helps,

[angel_o.]

Hi all,<br><br>

thank you very much for pointing out the streghts of either systems. <br><br>I must admit that I didn't think at all about the light-loss due to bouncing or using possible umbrellas with the flash. So I'll go in a first step for a SU-4. Nevertheless, the SB-30 is still very interesting and I really liked the suggestion to <i>"buy four SB-30 units AND a new SB-80DX. More fun than a barrel of monkeys."</i><br><br>

Err, but for latter suggestion I'll need a many very big bouquets of red roses for my wife to explain how the "monkeys" came home... ;-))<br><br>

Have fun!

[joseph_wisniewski]

Jim,

 

You're sure right about how much fun a handful of small flashes can be.

 

My power calculations were a bit off, but they do tell the right story. The SB-28 does have 10 times the power of the SB-30. For my earlier calculation, I used the SB-30 with its wide angle diffuser in place vs. the SB-28 at its widest zoom setting, but no wide angle diffuser. I've corrected that, here. You always use the flash's widest angle setting when using umbrellas and even then, it's usually note wide enough (see the end note).

 

With its wide angle diffuser on, the SB-30 has a GN of 32 feet (10 meters), and can cover the field of view of a 17mm lens, which is just barely wide enough to cover a standard umbrella.

 

http://www.nikon-image.com/eng/speedlights/

 

The SB-28, with its wide diffuser, has a guide number of 105 feet (30 meters), for the same coverage. Since Guide numbers are proportional to the square of power (inverse square law on distance) and the square of 105/32 is, indeed 10.7, 3 and a half stops more light.

 

Note on umbrella coverage:

 

A "normal" umbrella needs a 120 degree coverage, with the flash at the very end of the umbrella shaft (which is an awkward and dangerous way to use one). This means you have to set the flash for 20mm lens coverage to get the full width (but some vertical vignetting) or 14mm coverage to illuminate the entire umbrella and use all the umbrella you pay for. (With studio strobes, I use a "spill plate", a 160 degree reflector, which lets me set the umbrella at about 2/3 shaft, making it much more stable on the light stand.

 

If you don't set the flash as wide as possible, it only illuminates the center portion of the umbrella, and you might as well be using one of those little "lumaquest" diffusers. Last year, I was watching a supposed "pro" Nikon rep with a 48 inch "shoot through" style umbrella, an SB-28DX, and a couple of SC-17 sync cords. He was shooting an 85mm f1.4, and the flash set itself to cover 85mm, illuminating about a 12 inch portion of his 48 inch umbrella. He was amazed I showed him the difference.

 

From what I hear, the SB-80, with that little dome thingy, does very well on an umbrella, you can be at the comfortable "2/3 shaft" position, with full, even illumination of the umbrella.

 

Ciao!

 

Joe

[joseph_wisniewski]

Feeding the hungry SB-30

 

One other point to keep in mind. The SB-28 and SB-80 are quite happy running rechargable AA NiMH batteries. The SB-30 feeds on disposable Lithium CR123A batteries.

 

Ciao!

 

Joe