Flash Power & Distance Explained: How to Balance Outdoor Strobes for Natural Portrait Lighting

Hey everyone it's Eli Infante and in today's video I'm going to show you how flash power and distance affect your exposure and more importantly how to balance out your strobe for natural looking results. Let's get into it. For today's shoot I'm going to be using the Westcott FJ400 but keep in mind you can get the same results with a speed light, a 200 watt strobe or a 600 watt strobe. Now when it comes to strobes, when it comes to power they're usually measured in either integers or fractions. So fractions meaning 1 to 1 being full power and 1 25th, 250th of a second being the lowest or if you're using integers power 9 being the highest and power 1 being the lowest. For today's shoot I'm going to be using high speed sync and high speed sync allows me to go above my flash sync speed which is usually 1 200th of a second or 1 250th of a second. Now using high speed sync gives me that ability to use faster shutter speeds like 8000, 5000 and more importantly it gives me those shallow depth of field that I love in my portraits. One of the first steps when you're about to take your photograph when you're using strobes is to get your ambient exposure and more importantly to lock in your settings. When I'm shooting outdoors I always go to the lowest ISO I can get to or the base ISO which in my camera is ISO 100 and I'm not going to mess with that unless I get into blue hour or I get into some nighttime photography. With the ISO set up at 100 now I'm going to be focused on my aperture. Now this answer can vary depends on the depth of field that you want in your portraits. In my case I'm going to be using 1.8 to start off and I'm going to lock in that parameter. Once I have those two settings the main one you're going to adjust is the shutter speed. By increasing your shutter speed the faster I make it the darker the background is going to be and the slower I make my shutter speed the more ambient I'm going to let in and that is going to make it feel a little bit more natural depending on your ambient exposure but one of the key things to keep in mind as I'm out here in the sun the clouds are coming in sometimes the sun's out the ambient is constantly changing. So as you can see here I've set up my ISO to 100 that's my base ISO. I'm shooting outdoors I don't need it to be any higher than that and my aperture I've adjusted it to 1.8 because I love those shallow depth of field portraits you can get. Now at 1 200th of a second let's say that I was not using high speed sync this would be my exposure but because I'm using high speed sync I'm able to increase my shutter speed and as you're noticing I'm increasing it and the background ambient is getting darker. So the first step like I was mentioning earlier is to figure out how dark or bright do I want my background to be. So if I went all the way to 8 000 this is too dark this is too moody unless that's something you're going for this would be great for like sports or if I'm photographing a male and I want that moody look this would be great but in our case this is not going to look good. So I want something to look natural so what I'm doing is right now I'm not worried about my subject I'm just thinking about how dark or bright I want my background and for right now I'm going to try between 1600 and 2000 and see what I get from there. Now that I have my ambient locked in I'm going to show you what that looks like so I'm going to go ahead and get my camera and I'm going to go ahead and take a test shot here so that you guys can see exactly what I'm going for. So I'm going to go one two three and there's the ambient exposure we still get the beautiful brightness of the background not too dark and my settings right now are at one two thousandth of a second. Now this is where people freak out right so they're so focused on the background getting the ambience but now the scary part is then adding in the flash. So my general rule when I'm adding the flash and my strobe is I like to have it about six feet away from the subject. Now I'm not there measuring it with a measuring tape but just kind of eyeballing it. I usually have it about 45 degrees to the subject and the bottom of the modifier is usually about maybe elbow level maybe shoulder level and I always have it tilted down. Now one rule that I always do when I'm shooting outdoors doesn't matter what strobe I'm using I always start off at power seven or one fourth. This is the biggest mistake people make they get their strobe they turn it on and they set it to power one or two and they notice they're not getting enough power on the subject and they don't see results or it's way too bright and then they freak out. That way I can start off at power one fourth or seven and I can make adjustments up and down to get the right balance. All right Miss Ashley we're going to go ahead and get a photograph right here and then we're going to go one two and three. Okay exposure looks fantastic on her. I'm going to go ahead and show you power nine and see what it looks like when you have too much power. So I'm going to go one two three. That's way too bright as you guys can see there. After this first series one of the big takeaways is that the ambient is constantly going to change. So during this photo shoot we're in the shade here the clouds are coming in. Keep in mind and I'm going to show you some photos here the background wasn't as bright because the clouds came in it got darkened so I had to lower my shutter speed to compensate because if I left it like that what happened is the background ambient got too dark. It made it more moody. Now that might be something that you want but in my case that's not what I wanted. So when the clouds came into play remember work with that shutter speed adjust it and as you're adjusting the shutter speed you're going to have to go to that power on your trigger. So I had to adjust it there were times where I was at power seven then I had to go to power six and I'm constantly changing it throughout even just these five minutes that we were shooting I was changing the power back and forth and adjusting settings. For this next spot I found this beautiful fence and it's all in shade which can be a good thing because what that basically means is that my ambience not going to be changing so much. So let me show you my screen so you can see the ambient exposure that I'm getting first. Remember we always get the ambient exposure first. My settings in my camera is 1.4 on my aperture and ISO 100 and right now my shutter speed is 8000 shutter speed and as you can see it's very dark. So I'm going to lower down my shutter speed to let in more ambient and at 1600 this looks pretty good. This is the natural results that I want. If I lower it down even more it starts to get a little bit too bright but that could be a good thing. You got to think about the client that you're photographing. If I'm doing a high school senior or a birthday session I tend to go a little bit brighter for those type of scenarios. So you have to think about it. It's an artistic choice on how dark or bright you want your background but now that I have this locked in I'm going to start off at 1250th. I'll see if I need to make any more adjustments and then we'll talk about the inverse square law about using the strobe bringing it in closer or further back to also adjust the power. When it comes to the inverse square law I want to keep it simple and I don't want to over complicate it. This topic could be its own separate video but basically the inverse square law when it comes to shooting outdoors means the further you get your light source from the subject the faster the light fall off. So what does that mean when we're shooting outdoors in simple terms? Well let's say I have the light about five feet away from the subject like we've been doing in this video so far. Well if I move it further back it's going to lose power output and I need to compensate. So if let's say the correct exposure was at power six it's probably gonna have to go to 6.5 or 7. Now the opposite if I have the light five feet away and I bring it in closer now that light is going to be brighter. So now I'm going to have to lower the power output so instead of power five it might be 4.5 or 4. So I'm going to start off at power seven that's usually my starting point. Let's see what power seven looks like. So we're going to go one two and three that is way too bright. Okay so I'm going to go down remember we don't panic here okay don't get all scared now. I'm going to power five let's see what that looks like so two stops down. All righty one two and three and power five looks fantastic. So we're just going to keep shooting here and rock and roll right here. Now one thing I want to reiterate about the inverse square law remember what I mentioned if I bring the light in closer and if I leave the power output at power five it's going to be brighter. I just brought it in closer light's going to be brighter that means the subject's going to be brighter. If I notice that she's too bright I have a choice I can go to my trigger I can bring the power down if I want to or if I have an assistant I can have the assistant simply just move it further back that will compensate and that will get the correct exposure. So just keep that in mind. Right now I'm getting an awesome shot but one of the things I'm noticing is that the light even though I like to get it close because I get that nice beautiful soft light I am going to move it further back. Remember I'm going to quiz you guys by moving it back what am I going to have to do with my power let me know in the comments the answer. So I'm moving it back my power is going to either have to go up or down if you were paying attention you know that the power is going to go up so I was at power 5.5 I'm going to go up power six because I moved it back. So Ashley we're going to keep doing that pose there I'm going to be looking over your shoulder that looks amazing yes good the ambient exposure looks great too I'm at 1000 shutter speed okay now one thing I want to show you guys is what it looks like when your ambient is too dark. So I'm going to purposely show you what it looks like when it's too dark so I'm going to go ahead and change my ambient on purpose so you can see the difference. Now as you can see in the final photograph there's a huge difference between the first photo I got where the ambient was balanced out really well in the second shot where I purposely made it darker. Now I know some of you might say hey Lai but I like the darkness I like the moodiness go for it it's all up to you it's an artistic choice but once again think about what you're doing is it a birthday session is it a senior session what is your concept and that will dictate your ambient exposure. Alright guys for this last series we got beautiful golden hour we left the last location now we have the beautiful bright sun we don't have any trees or anything blocking the sun. Now I don't want to shoot directly into the sun for this shot now this shot this is a good example where I am going to go moody here okay I'm going to go a little bit darker just because when I expose for that background the sky because as the sun's basically coming down what's happening is that everything down here is going to go silhouette but I want to expose for that beautiful clouds back there it's really really beautiful. Now when I expose for that it's going to create a silhouette so let me show you what the ambient looks like so I'm going to go ahead and get an ambient exposure actually we're going to go ahead and get a photo right here it's ambient one two and three now the angle that I'm shooting at I'm choosing it very selectively I'm using the sun off to the right so that we get that nice little rim light edge light right here I don't want to shoot directly into it because then the sky is just going to be overexposed and I want that texture of those clouds right so that's why I'm shooting at this angle so you saw the ambient exposure now I'm going to turn on my trigger as always starting off at power seven so I'm going to get a photo at power seven all right miss Ashley we're going to go here one two and three now as I look at that photograph I noticed that it could probably be a little bit brighter I have two choices I can bring up the power on my trigger or I can move in the light now I don't want to move in the light in this specific scenario because then the softbox is going to show up in the shot so I'm going to go instead and do 7.5 so let's see what 7.5 looks like all right miss Ashley one two and three there we go and that is looking fantastic so I already love this shot so we're going to just keep shooting here so what I'm going to do is I'm going to move the light in the same direction as the sun if you want your photos to look more natural keeping the light in the same direction is going to help achieve that right now I was doing a technique called cross lighting it's going to look a little bit more artificial so I'm going to go ahead and move the light so I'm going to get this light I'm going to move it camera right and let's see what that looks like that way we can compare both of them it's not that one's better than the other it's just the look you're trying to achieve there you go and let's see what we get here one two three mastering flash is an important skill to add to your portrait photography I hope this video helped you out and if you love this content don't forget to like comment and subscribe for more behind the scenes content