Need flash with high sync speed - suggestions?

[amolitor]

Yup, that's meters.

The deal with Guide Number is:

(distance to subject) times (aperture) = (guide number)

will give you the correct exposure, at the specified ISO. So, adjust aperture to match distance, or vice versa, or both. That's where the meters and feet comes in. The ISO is always 100 (but you'll know someone is being a crook if they say 'Guide Number of 1200 in inches at ISO 800' -- which means a thing, but it means a pretty wimpy flash, and it's obviously an attempt to befuddle the buyer!)

The Vivitar is GN 50 in meters, so, about 1 stop more power. So you could put a 1 stop neutral density filter on the camera, and this flash would be just like your old flash, but with 1 stop less ambient light.

 

[Derrel]

How about just buying a flash that supports Nikon's high-speed flash synch mode, and then being able to shoot fill-flash shots outdoors in bright light at high speeds like 1/4000 second?

The thing is, shooting flash along with very fast shutter speeds switches the flash to a series of very rapidly-paced,tiny repeating flashes, and that reduces effective flash power...buuuuuuut, the mitigating factor is that when shooting Fill-in flash, you want the flash to be around 2.5 to 2.7 f/stops LESS than the ambient light exposure, so....a loss of flash power is really not that big of a deal.

How about buying a "good" flash unit, like one made by Metz or Nikon? Here is a web page that shows how this is done:

Set up your Nikon for high-speed sync | N-Photo

 

[Rebekah5280]

So what is a good high-powered flash number? Like, can I get a GN of 100 or is that not possible? lol I need parameters for when I go and scout out flashes.

Like, is 33 vs 54 a significant difference? Its a little less than double the power right?

 

[amolitor]

Relative power of flashes is something I have a hard time visualizing. "double"?

If the GN goes up by 1.4, that's 1 stop more light, which is arguably twice the power. It means you can close down the aperture by a stop, OR move the subject 1.4x as far away (light drops off as a square of the distance, which is the tricky bit).

Listen to Derrel, though. Derrel is good. Derrel is wise.

 

[ronlane]

You should learn more about flash; new equipment won't necessarily solve this problem. People have been dealing with bright outdoor light and flash for decades. The answer is generally not to boost shutter speed. If bright light is your problem, you typically use the lowest ISO possible and raise the f-number until you get a shutter speed that falls within sync. You can also scrim and diffuse. Otherwise you run into sync speed problems if you go above 1/200. Remember aperture can control ambient and flash; just realize that it controls both at the same time. Raising the f-number may cut out ambient light, but it also means you need more flash power or a closer distance. The only way to shoot at high speeds is to use high-speed sync. This is a function set in the camera, not the flash. The limitation is you need to be closer to the subject. You can also cheat the sync at 1/400 with the understanding that you'll get a black bar in some part of the frame. If you know this and compose correctly, you can just crop that out.

Shutter speed doesn't affect flash output so using an ND to cut light means only that you can use a lower aperture. Cutting the light doesn't mean you can go from 1/200 to 1/400; that makes no sense. You would go from 1/200 to 1/400 with more light, not less. A faster shutter speed lets in less light, not more. I understand that using an ND means you'd need more light, thus would be able to go from 1/400 to 1/200 to get back into sync, but the OP is asking to get a sync above 1/200.

The op is asking about hi sync because they are "blowing out the background every time". That is why I was suggesting the nd, which would help with that. But you would need the light to fill in on the subject to get proper exposure.

 

[Rebekah5280]

How about just buying a flash that supports Nikon's high-speed flash synch mode, and then being able to shoot fill-flash shots outdoors in bright light at high speeds like 1/4000 second?

The thing is, shooting flash along with very fast shutter speeds switches the flash to a series of very rapidly-paced,tiny repeating flashes, and that reduces effective flash power...buuuuuuut, the mitigating factor is that when shooting Fill-in flash, you want the flash to be around 2.5 to 2.7 f/stops LESS than the ambient light exposure, so....a loss of flash power is really not that big of a deal.

How about buying a "good" flash unit, like one made by Metz or Nikon? Here is a web page that shows how this is done:

Set up your Nikon for high-speed sync | N-Photo

Yes, this is what I was thinking originally. I am upgrading most of my equipment and I'd rather work with a flash that can synch at higher shutter speeds, than using a filter, but I will do anything to eliminate my post-processing time spent on darkening the backgrounds.

I have a couple outdoor weddings coming up and I shudder at the post processing time without better lighting.

 

[Rebekah5280]

OK, so now I need to know which flashes support High-speed sync. I've googled trying to find lists, but I haven't found any sights that give me a clear answer about sync speed as I'm assuming my starter flashes won't cut it...

 

[Derrel]

Here is a good article on the topic of flash sync speed. It has plenty of information and descriptions to help demystify flash synch. http://www.kenrockwell.com/tech/syncspeed.htm

A list of flashes that support high-speed sync...ummm...not sure if there is a list per se, but "most" of the higher-priced flashes that say they are "dedicated" (that is the term, dedicated) for Nikon d-slr will offer this feature. Nikon's SB 600,700,800,900,and 910 are all capable of high speed synch with Nikon bodies that offer the feature.

Metz makes superbly-made,reliable flash units. Sunpak makes decent units. Sigma makes so-so to decent units, and usually has a couple of models which appear similar, but are in actuality, usually pretty different in terms of capabilities. A good tip is to check the Technical Specifications of ANY flash unit you are considering the purchase of, and verifying that is supports high speed flash synchronization.

 

[Derrel]

Here is a scan I made of an old flashbulb gun's rotating calculator dial. The index is set for a flash with a Guide Number of 110 in Feet at ISO 100. Guide Number is the USA is usually specified in FEET, and also at ISO 100. Obviously, as ISO doubles, GN increases by a factor of 1.41x for one-stop; a two-stop ISO increase increases the GN by 2x. Three stops would be 2.83x. FOur stops would be 4x, and five stops more would require the GN at ISO 100 to be multiplied by 5.6.

This old-fashioned, mechanical calculator is all I saved from this 1960's flashgun...I threw the rest away, and kept this nifty little mechanical wonder. If you'd like, PRINT this out, and glue the outside part of the dial to a paper plate, and then cut out the inner circle and rivet it to the bottom paper plate to make your very OWN rotating calculator. Perhaps seeing this will help you? Sometimes seeing things like this helps understanding and flips on that nifty mental lightbulb.

Keep in mind...for filling in shadows, you want the flash exposure to be 2.5 to 2.7 EV LESS than the exposure that the shutter and f/stop and ISO are making using the natural or existing "ambient" light on the scene.

 

[Robin_Usagani]

Just make your aperture smaller so you can shoot it at a shutter slower or as fast as your sync speed. You should really be asking this question if you want one of these 2 scenarios:
1. You want to use large aperture during a sunny day with flash
2. You are shooting a moving subject during the day that requires pretty fast shutter.

 

[amolitor]

Obviously, as ISO doubles, GN also doubles!!!

This one always makes my head hurt, but I *think* that as the ISO doubles, the GN goes up by 1.4 times, doesn't it?

 

[Derrel]

DOAH! Yes! My bad. x1.41 FOR ONE-STOP. I will make the correction to the post!

 

[amolitor]

The biggest leap forward with digital, for me, is that I can pop off a couple tests and chimp my way to correct exposure approximately 129819829x faster than I can calculate the right value, because I am forever dividing by 1.41 when I should by multiplying by 2, and vice versa

 

[Rebekah5280]

The biggest leap forward with digital, for me, is that I can pop off a couple tests and chimp my way to correct exposure approximately 129819829x faster than I can calculate the right value, because I am forever dividing by 1.41 when I should by multiplying by 2, and vice versa

I do not do any math when I shoot. lol I do trial and error with test shots. I have a good feel of my typical settings, so my test shots are usually right on.

 

[Buckster]

Just F.Y.I.; Yongnuo has a flash (and triggers) that utilize Nikon's High Speed Sync. The flash model is the YN-568EX and it's about $200, which is less than half what you'd pay for the genuine Nikon. You've already experienced working with Yongnuo flashes, so I don't need to tell you if they're "good" or not.