Overpowering Sun with ND Filters & Bokeh

[mgvishal]

you really cant explain yourself or ur going off topic n simply misleading users

Let me google that for you

I don't have the luxury of typing a lengthy explanation while at work so you will have to forgive me.

you could have simply mentioned HSS ..

 

[Mach0]

you could have simply mentioned HSS ..

What I'm talking about is not HSS or auto FP. The flashes aren't pulsing.

You could have simply googled it vs saying that I am misleading or can't explain myself. In this day and age, you'd be surprised what a simple bing or google search will yield.

 

[tirediron]

1. Mount the 5 stop ND filter.
2. Meter the background for desired exposure (for the sake of argument, ISO 100, 1/250, f2.8)
3. Set up light(s), and using flash-meter, GN exposure calculation, or s**t-house luck, adjust lights to 1 - 1.5 stops over background (ISO 100, 1/250, f4 - 5) + the 5 stops of the ND, so your flash meter should read ~f22.

 

[Gavjenks]

Okay first of all, I'm a little confused by what the OP wants to do. You don't overpower the sun "to get nice blue skies." You overpower the sun if you want the background blacked out, basically, in mid day. Or at least significantly dark compared to the subject.

If you want bright faces and also bright blue skies, you simply want to use the flash as supplementary lighting. This is pretty easy. Basically you just shoot a normal exposure or a little bit underexposed (maybe by 1 stop or so), and then highlight your subject with a bit of bonus flash. And make sure your normal exposure is fast enough to not blur too much (if it's a still person then you're fine at sync speed. If it's an action shot, you might need a flash with HSS capabilities).

If you want to overpower the sun, though, and black out the background, then what you do is you figure out how much exposure you get at your minimum acceptable parameters for that situation, without flash. Let's say you need f/2.8 for desired blur, and your sync speed is 1/250th, and lowest ISO is 100. So set those in manual, and see what you get. Look at the histogram and determine how much darker it would need to be to make it as black as you want. Let's say at 1/250, ISO 100, f/2.8, it's still 3 stops too bright for what you want the background to be. If so, use a 3 stop ND filter. Then crank up your flash so that it produces enough light to fully light your subject with that filter on, and you'll get a subject lit entirely by flash with a blacked out background during the day.

I personally wouldn't bother trying to calculate any of that, versus just trial and error (using the histo or a spot meter). Calculating it would be very difficult, involving equations with distance and guide number and focal length of the flash, blah blah. And lord help you if you're bouncing or using reflectors. Easier just to try it out on yourself when you get your strobes, and see if they're strong enough for a sunny day. Then once you're confident that they are, just trial and error it in the field during a shoot. If they aren't strong enough, then only attempt this on a cloudy day, or get better strobes.

 

[tirediron]

I think there's some translation issues Gav, as I understand it, the OP wants to produce an image in very bright sunlight which has a large aperture for shallow DoF, but at the same time renders some detail into the sky.

 

[Derrel]

If you want the flash to truly be "fill light", that is light to lighten shadows, you want the flash to be about two and one-half f/stops "LESS THAN" the exposure for sunlight, so instead of flash that requires f/16, you would want to reduce the flash power so the flash exposure would be more along the lines of between f/5.6 and f/8.

 

[hirejn]

The sunny 16 rule says that the correct exposure is 1/ISO @ f/16. Therefore in your example the correct shutter speed would be 1/100, not 1/250. The sunny 16 rule, BTW, is 100 percent accurate and can be tested with an incident meter. If you need clarification on using sunny 16, read this.

Let's say the exposure for ambient is 1/250 at f/16 at ISO 250, but you want to shoot at f/2.8 without changing the shutter speed or ISO. You need to gain five stops with aperture and cut five stops somewhere else to balance the exposure, but you can't cut it with shutter or ISO. If you simply drop the aperture, the shutter speed goes up to 1/8,000.

To solve this, you could add a five-stop ND. So you drop the aperture to 2.8, and instead of needing to raise the shutter to 1,8000 or change the ISO, the ND itself balances the exposure by cutting the five stops gained from the aperture. This enables you to keep the 1/250 shutter speed and same ISO. Light is light, and the ND also reduces the flash by five stops, which is why you keep it at f/16 and not 2.8 or f/90. That's if you want flash to be equal to ambient. Remember the ND is reducing the ambient from f/16 to f/2.8. Think of flash as only an f-number. If the flash is balanced with ambient, the flash also goes from f/16 to f/2.8; you don't need to raise it another five stops. If you want the subject to stand out even more, you need to reduce the ambient by another one to two stops, leave the flash at ambient, and expose for the flash. Once you understand how to balance flash and ambient exposures, you can create the exact look you want.

An easier way to do this is simply use TTL flash, which enables flash syncing at any shutter speed, so you can go to 2.8 without an ND and avoid focusing and quality issues that come with most NDs. Speedlights will struggle in TTL at 1/8,000 and will need to be on top of the subject, unless you double or triple them. The Profoto B1's handle this with ease as they put out 500 watt seconds of light (about 10 times the amount of one Speedlight) and are capable of TTL without wires, but you pay exquisitely for the convenience.

 

[480sparky]

Once you get the flash to equal the sun, adding an ND to the lens will cut both light sources equally.

If the shot is properly exposed at f/16, a 5-stop ND will get you to f/2.8.

background will be underexposed at f16
and subject correcly lit.
so now add 5 stops of nd
and dial now aperture to f 2.8 and i will get the same shot ???

Yep. If your sun and flash exposure are good at f/16, adding a 5-stop ND and opening the lens to 2.8 is all that's left to do.

 

[Gavjenks]

The sunny 16 rule, BTW, is 100 percent accurate and can be tested with an incident meter

It's quite a good rule, but nothing that consists of "yup, it's pretty darn sunny out" as a metric seems appropriate to label "100% accurate" ...

In particular, a no-clouds, sunny day at noon will yield significantly different exposures in winter vs. summer, in Barcelona versus Toronto, etc.

A meter is always more accurate, if you can justify the expense and space in your bag. And more so if you're messing around with flash.

 

[mgvishal]

The sunny 16 rule, BTW, is 100 percent accurate and can be tested with an incident meter

It's quite a good rule, but nothing that consists of "yup, it's pretty darn sunny out" as a metric seems appropriate to label "100% accurate" ...

In particular, a no-clouds, sunny day at noon will yield significantly different exposures in winter vs. summer, in Barcelona versus Toronto, etc.

A meter is always more accurate, if you can justify the expense and space in your bag. And more so if you're messing around with flash.

Have a sekonic in my bag .. it saves lot of trail & error & headache part and lets me concentrate on the shot

 

[mgvishal]

Once you get the flash to equal the sun, adding an ND to the lens will cut both light sources equally.

If the shot is properly exposed at f/16, a 5-stop ND will get you to f/2.8.

background will be underexposed at f16
and subject correcly lit.
so now add 5 stops of nd
and dial now aperture to f 2.8 and i will get the same shot ???

Yep. If your sun and flash exposure are good at f/16, adding a 5-stop ND and opening the lens to 2.8 is all that's left to do.

Clear with the theory now !

 

[mgvishal]

The sunny 16 rule says that the correct exposure is 1/ISO @ f/16. Therefore in your example the correct shutter speed would be 1/100, not 1/250. The sunny 16 rule, BTW, is 100 percent accurate and can be tested with an incident meter. If you need clarification on using sunny 16, read this.

Let's say the exposure for ambient is 1/250 at f/16 at ISO 250, but you want to shoot at f/2.8 without changing the shutter speed or ISO. You need to gain five stops with aperture and cut five stops somewhere else to balance the exposure, but you can't cut it with shutter or ISO. If you simply drop the aperture, the shutter speed goes up to 1/8,000.

To solve this, you could add a five-stop ND. So you drop the aperture to 2.8, and instead of needing to raise the shutter to 1,8000 or change the ISO, the ND itself balances the exposure by cutting the five stops gained from the aperture. This enables you to keep the 1/250 shutter speed and same ISO. Light is light, and the ND also reduces the flash by five stops, which is why you keep it at f/16 and not 2.8 or f/90. That's if you want flash to be equal to ambient. Remember the ND is reducing the ambient from f/16 to f/2.8. Think of flash as only an f-number. If the flash is balanced with ambient, the flash also goes from f/16 to f/2.8; you don't need to raise it another five stops. If you want the subject to stand out even more, you need to reduce the ambient by another one to two stops, leave the flash at ambient, and expose for the flash. Once you understand how to balance flash and ambient exposures, you can create the exact look you want.

An easier way to do this is simply use TTL flash, which enables flash syncing at any shutter speed, so you can go to 2.8 without an ND and avoid focusing and quality issues that come with most NDs. Speedlights will struggle in TTL at 1/8,000 and will need to be on top of the subject, unless you double or triple them. The Profoto B1's handle this with ease as they put out 500 watt seconds of light (about 10 times the amount of one Speedlight) and are capable of TTL without wires, but you pay exquisitely for the convenience.

Thanks for the clear reply ...!
Now after your post m looking at 2 options.
1. normal strobe + ND filters at slow sync speed
2. profoto b1 strobe + TTL trigger at any shutter speed ( can do slow shutter also HSS )

 

[Mach0]

Thanks for the clear reply ...! Now after your post m looking at 2 options. 1. normal strobe + ND filters at slow sync speed 2. profoto b1 strobe + TTL trigger at any shutter speed ( can do slow shutter also HSS )

According the profoto site, it doesn't do HSS. The amount of money you would spend on that light, you can buy a lot of CLS compatible flashes and use Auto FP or you can look into a set up like I mentioned earlier. I'm waiting on a yn622 tx that comes with software to delay the flash timing. For the price I couldn't turn it down. If I don't like it, I will buy a Pocket wizard set up. Another member on here (2wheelphoto) uses a flex tt1 or tt5 ( can't remember ) and uses vivitar 285's outdoors( although I do believe he has used other strobes but you can ask him.) The trick is having a duration that 1/1000 of a second or longer so that the duration is long enough to cover the frame. Auto FP and HSS are basically firing the flash multiple times across the maximum normal sync speed. The hack that I mentioned earlier will Involve using a flash that is hss capable and either plugging a PC cable into it that is plugged into a trigger to fire receiver or using the hss capable flash to optically trigger another flash or slave of some sort to fire a flash. It's all possible but it will require you to go out and try it. I've done the hack and was able to get up to 1/2500 of a second at 2.8 ( or 3.2- can't recall ) and anything faster the flash wasn't effective ( flash was a sb28 at full power shooting through a shoot through umbrella about 5-6 feet away. However, the times I did that, the exposure was balanced fine. I would start with a decent trigger set up and see where that takes you first unless you get bored and would like to try the hack. Just make sure if you try the hack to make sure your monolight is at full power. See how it does. It might just work.

 

[mgvishal]

Thanks for the clear reply ...! Now after your post m looking at 2 options. 1. normal strobe + ND filters at slow sync speed 2. profoto b1 strobe + TTL trigger at any shutter speed ( can do slow shutter also HSS )

According the profoto site, it doesn't do HSS. The amount of money you would spend on that light, you can buy a lot of CLS compatible flashes and use Auto FP or you can look into a set up like I mentioned earlier. I'm waiting on a yn622 tx that comes with software to delay the flash timing. For the price I couldn't turn it down. If I don't like it, I will buy a Pocket wizard set up. Another member on here (2wheelphoto) uses a flex tt1 or tt5 ( can't remember ) and uses vivitar 285's outdoors( although I do believe he has used other strobes but you can ask him.) The trick is having a duration that 1/1000 of a second or longer so that the duration is long enough to cover the frame. Auto FP and HSS are basically firing the flash multiple times across the maximum normal sync speed. The hack that I mentioned earlier will Involve using a flash that is hss capable and either plugging a PC cable into it that is plugged into a trigger to fire receiver or using the hss capable flash to optically trigger another flash or slave of some sort to fire a flash. It's all possible but it will require you to go out and try it. I've done the hack and was able to get up to 1/2500 of a second at 2.8 ( or 3.2- can't recall ) and anything faster the flash wasn't effective ( flash was a sb28 at full power shooting through a shoot through umbrella about 5-6 feet away. However, the times I did that, the exposure was balanced fine. I would start with a decent trigger set up and see where that takes you first unless you get bored and would like to try the hack. Just make sure if you try the hack to make sure your monolight is at full power. See how it does. It might just work.

Hey i read about articles of what your talking about.
Its Hypersync Feature offered by pocketwizards.
Yeah its a cool feature to extract as much flash as possible at higher shutter speeds.
But there are very in consistent results. Not much you would what. Its depends on the DSLR you use combined with flash you use and plus the settings.
If your lucky you might go even upto 1/8000.
In future, if they refine it much more then it might be useful.
But now its useful when light is at full power, On Some High End FX Cameras when they are used in DX mode.
Might stick to ND filter solution for more consistent results.
Hypersync is good for sports photography, I'm not into that so i don't see any advantages.
Also if i get client for sport work, i will 5-10 TTL speedlights to use HSS/AutoFP.

 

[NancyMoranG]

Can we SEe the shot ??
and what settings etc?
Nancy