Can you use speedlite with ND filter?

Say you are using a 3-stop ND filter outside to combat the bright day

At that point, aren't you restricted in being unable to use the speedlite? Wouldn't it need to produce 3-stops stronger brightness to still light up the subject? Speedlites have enough trouble with bright sun... it is impossible if you add a ND into the mix, isn't it?

You will open up the aperture by three stops to accommodate the ND filter. The issue is whether the speed light has enough power to overcome the sun for the lighting scenario you're you're shooting in without the ND filter.

windpig wrote in post #16003611
You will open up the aperture by three stops to accommodate the ND filter. The issue is whether the speed light has enough power to overcome the sun for the lighting scenario you're you're shooting in without the ND filter.

This is the reason that using a ND is usually a better option than HSS, with a 3 stop filter, you lose 3 stops of light, but you can open up your aperture by 3 stops, and basically come out even. With HSS, you lose a lot more power.

Oh... maybe I'm mistunderstanding then

Adding the ND filter - I don't actually have to adjust flash power AT ALL?

Example:

Flash set to full power at 5 feet =f/16 can camera at f/16 you get proper exposure.
Nd filter will drop the camera down to f/5.6 your flash will stay the same at f/16

kaitlyn2004 wrote in post #16003643
Oh... maybe I'm mistunderstanding then

Adding the ND filter - I don't actually have to adjust flash power AT ALL?

So if you are using a 3 stop filter, there are a few different scenarios here...

If you leave your camera settings the same, and the flash power the same, then everything will be three stops underexposed.

If you leave the camera settings the same, but bump up the flash by three stops, the ambient/background will drop by 3 stops, and your subject, or anything else lit by the speedlite will be back up to the original exposure.

If you open up your aperture 3 stops, say from f8 to f2.8, but leave the shutter speed and flash power at their original values, you will get the same exposure as not using the ND filter at all, but have the advantage of a thinner DOF.

I am confusing myself even as I write this haha...does that make sense??

davidmtml wrote in post #16003692
So if you are using a 3 stop filter, there are a few different scenarios here...

If you leave your camera settings the same, and the flash power the same, then everything will be three stops underexposed.

If you leave the camera settings the same, but bump up the flash by three stops, the ambient/background will drop by 3 stops, and your subject, or anything else lit by the speedlite will be back up to the original exposure.

If you open up your aperture 3 stops, say from f8 to f2.8, but leave the shutter speed and flash power at their original values, you will get the same exposure as not using the ND filter at all, but have the advantage of a thinner DOF.

I am confusing myself even as I write this haha...does that make sense??

Perfect sense. When I originally played it in my head I naturally thought that the flash needed to adjust as well, but of course adjusting of the aperture takes care of that

Thanks for explaining it in terms of three scenarios, David...

ND filter doesn't help kill ambient, period. It only helps you use wider apertures using strobe/flashes in bright ambient when you limited by your max sync speed. It lowers flash as well as ambient so your flash has to have more power than ambient light at the moment.

I have hard time bringing in ambient down with my 640ws Einstein. This when using Kacey BD in full sun at noon. Not sure how measly 60-80ws speedlite will help.

Using flash at max power without any modifier will provide the best bang. Use ND filter to use wider aperture that is all.

Old shots. Without ND filter, strobe matched to ambient meant I had to use something like f9 which makes for ugly bg.

bobbyz wrote in post #16004313
ND filter doesn't help kill ambient, period. It only helps you use wider apertures using strobe/flashes in bright ambient when you limited by your max sync speed. It lowers flash as well as ambient so your flash has to have more power than ambient light at the moment.

I have hard time bringing in ambient down with my 640ws Einstein. This when using Kacey BD in full sun at noon. Not sure how measly 60-80ws speedlite will help.

Using flash at max power without any modifier will provide the best bang. Use ND filter to use wider aperture that is all.

Old shots. Without ND filter, strobe matched to ambient meant I had to use something like f9 which makes for ugly bg.

Add 3 stop ND filter and shoot at f3.2 with better bg. No change in flash settings etc. Only aperture change on the camera.

I understand what you are saying, but saying that "ND filter doesn't help kill ambient, period" is incorrect.

All a ND filter is sunglasses for your lens, so you can work at sync speed when using flash / use more open aperture / Shoot longer exposures in sunlight

davidmtml wrote in post #16004346
I understand what you are saying, but saying that "ND filter doesn't help kill ambient, period" is incorrect.

Well then it kills ambient as much as stopping down or increasing shutter speed does. In the context of the original question though, nd filters do not effect ambient.

Of course an ND filter will affect the ambient light. That's what it was designed to do. After all, it's not like it's a piece of clear glass so it will inhibit some light from passing through it. But it will affect the flash light passing through it equally as well.

Regarding the question of whether an ND filter can be used with a hotshoe flash or not, the answer, of course, will depend on what the OP intends to do with the ND filter, as was pointed out by David in post #6, and the power range the flash was working at prior to the filter being used.

PacAce wrote in post #16004985
as was pointed out by David in post #6, and the power range the flash was working at prior to the filter being used.

Uh, Leo, that was pointed out by the brainiac in post #2

davidmtml wrote in post #16004346
I understand what you are saying, but saying that "ND filter doesn't help kill ambient, period" is incorrect.

Let us say my flash gives me f16 at distance I am shooting, ISO100, Max power on flash. Sunny 16 gives ambient at f16, 1/100, ISO100. So tell how ND filter helps.

Power of the flash helps you kill ambient. ND filter just lets you shoot at wider aperture that is all. I can shoot at f32 if I got power to burn. And if I had camera which could sync at any shutter speed then ND filter will be worthless for portrait shooters using strobes.