The Science Behind TTL
This is about a synergy is we want to get today but I think you need to do it if you've never heard of speak we talk about this every time but I kind of want to read what tl actually is because I know a lot of people out there going how do you know what detail is? Well tt ellis is through the lands is what t t l actually is and the top paragraph was right here is basically your natural light shooter when you push the shutter button halfway down in your camera and you get the f stop shutter speed that's the t t l that that's the light meter in your camera reading when you activate it reads the amount of light and life it's out there and it's going to give you with the proper it thinks is the proper exposure and that's the key is what the camera thanks because we want you as the artist to still have a final say so but to have the final say so you have to understand what's going on behind the scenes and so this first definition again as I put the official nerdy definition tl is a photogra...
phic term describing a feature of cameras capable of measuring light levels in a scene through their lens this information condemn be used to select the proper exposure and or controlled amount of light emitted from a flash connected to the camera so basically, if your natural light shooter or in your case you put the flash and top your camera and you let it go, that definition can't explains the tt l aspect so we have t t l through the lands with t t l that's controlling how much light is there now we're talking about flash photography today basically and also off camera lighting for the next two days and so this paragraph really plays more of a role and what we're going to be talking about and don't worry, we're going to break all this down to where it's very simple, so don't lock your brain up right now and say, I'm never going to learn this because I promise you by the end of these two days you're going to get this by the end of today you're going to understand so much more about gtl so just bear with us so again so keeping the above definition or the one that was on the previous screen in mind t this is the process of calculating the correct amount of light coming from your flash using through the lens meeting, which takes in several the conditions of the environment in which a portrait is being taken this meeting is significantly different than through the lands the non flash meeting, and we're going to explain why when you have a flash on top, your camera and you're going tohave communicating the master slave master wireless communication? Why it's so different? It is exact. It happens every time you push the button. And so once you understand this process that we're going to go through it's really going to help you understand what tl is and how it communicates and why probably you've had some of your failures. All right, so this is just kind of a real quick little little demonstration, but just to kind of let you know, you have the camera down here at the bottom with your master flash on, and we're going to get into how, what master and slave and all that stuff is in just a second, and then you have your winds flash up on the top and then course your part. I mean, on the on the right side, in your person, on the top to do this. Obviously, you need the the flash on top of the camera set into master mode, and if you have a cannon, the canon and nikon, the nikon, sony, this only a pin text up in tax, several of the brands, they all do this, you don't understand how to do it will show you in the brakes are on class, but if you don't the people that are watching just really quickly look at your manual will tell you exactly how to get your your flashes to master slaves if you have a question will be happy to answer it as well, but to get you have to have the master slave and then they will communicate wirelessly. The beauty of this concept is week control. The output of our wireless flashes are slave flashes from our master flash or match our camera. So as a event photographer, wedding, even children running around in the field, I can take a photograph look at the light in the back of the lcd, a beautiful, beautiful function of of digital, and if it's too bright or not bright enough, I literally can change that power from my camera or my master flash without having to move anywhere. That is a huge freedom, especially if you're solo shooting and so we're going to go over how that communication happens and really breaks down, and this is really the big failure. I would say that most people find they don't understand how communicates they don't understand what is communicating where it's coming out, where it's receiving they don't understand the functionalities of the flash, and so we want to explain every detail about how these flashes communicate, and so to begin with, we're going to talk about literally the science behind it. Throw out all the technical geeky stuff and then we're going to break it down into very easy to understand terms the rest of the workshop makes sense let's reiterate basically what the slide says what mike's been talking about what exactly the tl is ok so for for a single flash photography u t t l is as you click the shutter as I did the show halfway down the camera focuses and says oh there's my there's my subject as I click the shutter the flash emits a pre flash a one thirty second power pre flesh that pre flash has admitted it's my subject bounces back tl through the lens camera says hey I saw that one thirty second pre flash now I need plus or minus like it used its equation says ok that's my constant is the one thirty seconds to explain all this how it happened so it's saul that pre flashes okay now I need this much light so then the flash fires again shut her opens closes you get your image that in a nutshell is tl through the lands meeting now when we start talking about using the wireless functions of these flash master and slaving it's a little it's a little more complex now so now we're going introduce an external flash and this is set into slave mode this is sitting to master mode and so and mike is my subject so now instead of just that initial pre flash there's there's a lot more going on in my equation so now as like click the shutter this flash says hey I'm in master mode so hopefully there's a slave somewhere out there in space it doesn't know where that but it knows hey I'm in master mode so there should be a slave I should be telling something what to do but it doesn't know I mean this doesn't have eyes it's not the never brain and don't know where that flash that so as looks like the shutter this flash says marco who's out there it sends out this flashes hey if they just laid out there where you at this slave sees that first flash and says oh polo here I am now this slave flash gives me that one thirty second pre flesh one thirty second power is admitted it's my subject bounces back tl through the lens canvases ok I saw that pre flash from my slave out there now I like that a man a light I need more or less so than this flashes ok give me this amount of power basically talking to the slave flash this flash gives another fire signal there's a flash telling this one of fire at the given rate flash fires shudder opens and closes I get my image ok that's a lot of communication back and forth that's one of the major um, obstacles that people encounter when they start using this technique because there's a lot of communication happening, and if you don't understand how it's communicating, where it's communicating and why it's communicating, you can run into problems. The first foremost and most important thing is this flash is communicating with the flash to the math. The master flag communicates through the flash to it doesn't communicate through this black window on this little red window he communicates with this flash to so as I click the shutter this flash says marco who's out there okay, this slave flash listens with this little black window right here can for night gone, it will be the little inset on the batteries out of your flash. We're not perfect put your finger over if you're holding it up for someone, everyone notices that this some flashes blinking this little red or amber window ok, that has nothing to do with the communication. The only communication that has to do is communicating with me, the photographer tell me, hey, I'm enslaved mowed my betters air charged my capacitors charged, and I'm ready to fire, so if I'm at a reception, our event or venue, I can have this flash posted up in a corner somewhere, and at a glance I could look over and say, oh, it's blinking batters iran its enslavement it's ready to go did you see the walk over and turn that flash in just a while ago? The reason why I knew was off that red light was not blinking at me that either the batteries were dead and it wasn't charged which we just put new batteries in or wouldn't turn on and that's why when we walked over just turned it on that's just a visual learners this blinking red light is essentially no different in this red light on the back your flash which is hey I'm charged I'm ready to go ok so when we talk about good communication between master and slave most of the time not up to the time I leave my master flash turned off so it means it will not appear in my image on we're going to go over all this as well guys so it is going to train it is still going to fire because it's transmitting that information it's saying hey who's out there marco who's out there polo here I am so it's still going to fire two still talking and like I said, we are going to show you slide shows you had to turn this master flash off toe only transmit a signal and not show up in your image basically he's turning that master flash into a wireless transmitter which you can purchase a wireless transmitter on its own you know you're the s t to the s three for canada the issue not nine hundred four nikon what your flashes, which a lot of people don't know can also be just a wireless transmitter, which is how we try those normally shoot most the time we're going to explain that as well later on. So when I talk about good communication most of time, I leave my master flash pointing directly at my subject, so if I'm not using any sort of radio converter like radio poppers, are there any others? Then I'll leave my flash head pointed directly at my subject because what's going to happen is the splash and say, hey, marco who's out there this flash signals going to hit him, I may get some spill on my flash when I worked at or it'll see him and bounce back through this window they say, hey, I see you, I'm talking, okay, I get good communication, so this is good communication talking to him. This is best communication because now I'm communicating directly with my slave flesh and you got remember, this is the speed of light, so our human eyes simply cannot pick up the foul fastest is communicating so to us it looks like one big giant flash burst, but if you could actually video it and slow it down, you would actually a bunch a tiny little flash burst going off and it's almost like a morse code of life so as he said that communication when it says master and it sends out the command, if there's any slaves out there give me that pre flash of one thirty second that's one little flash burst or maybe a couple in a pattern that actually is a communication that these guys could talk back and forth to each other and they understand but that's also why when you're using this method on lee can into cannon will work with each other only nikon the night common working the each other only son of disowning because each one has a different pulse pattern of life that's why you can't mix a sony in a cannon or canon and icon when you're using this method because they speak two different languages it's the same basic concept of communication it's just completely different patterns, so I just want to explain that really quick. So again, like on the communication issues on the slave, the slave listens in this little black window above the amber window so you want that window pointed directly towards your master flash to get good communication if you're fortunate enough to have a light stand are an assistant, you don't want your system to hold your flash like this because all of a sudden it's and it's interfering with your communication that's bad this is good. This is best pointed directly back tortures and again, that is I would say the failure knight can cause nightgown makes a great flash, but cannons is right in the front nine kinds is on the side and if you are, if you're shooting is a partners, we have a couple of guys and you're holding this up. I had this you think it's just don't you so you have it up on your finger is literally right over the part that receives the signal and you're like wise it's not communicating I'm five feet from each other and not communicating, so you have to be aware of that because it won't pick it up. That makes sense. That's awesome there's a lot of questions coming in from the internet. Okay. Absolutely. Ok, cool. A couple similar questions. One from j t b and one from j c three photo can you use your camera? Pop up flash as the master? Or do you need an additional flash on your great question? The answer is yes for nikon. Yes, it's across the board for the most part, it's that all the modern cameras the papa flash can be a master now there's some issues exactly what kind of cody was talking about I can't turn that pop up flash to face my slave flash and if you're outside and bright light, the more powerful your master flashes, the better off you are because it's going to overpower the sauce. So if the sun is really bright, which hey, we're in seattle, we have bright light, bright sun today, it's awesome! You have to have this flash to be able or this last to be able to see your master flash your slave has seen so pop up flash has his drawbacks because you want you can't turn it towards the slave like I can hear the master and two it's not as powerful, safe forever think enclosed area I can't get back ready for I have only a pop up flash, which is pointed directly at my subjects and now for the communication I'm relying on this bounce to see this slave flash, but if I have a master flash or say this is after having behind me for some reason there's an obstacle in the way shooting details on a cake in a wedding or something of that nature, whereas your papa flash can only face forward and talk, I can now turn this flesh thank you to communicate with my slave flash behind me something with a wireless transmitter has the same I wouldn't say failures, but but hindrances puerto pop up the on ly pop up right now in the cannon line is seventy and it could be a master we can. Users were all happy, happy, happy because they were finally catching up tonight counter that area, but there's still one major failure, and we're going to get into that yet it has no high speed sink in the cannon pop up system. So what are some of those could be a master flash? It can't be a high speed scene there's no high species function. So good question in colorado, I was hoping he was in colorado not that would be a weird name. Thank you for that geo geographic, uh, settlement let's take in the tt el pre flash cause subjects to react or is the time between the pre flashing full flush so short that it won't matter? Typically it's not an issue, but there are some people who are very susceptible to blinking and that's. All they need is that that little initial communication and they'll blink every time. I don't have many clients to do that, but occasion we do rent and some people that I say, man, you have very fast blinker, you'll have the mauricio you'll have, and we're going to get into this second day when you really get to advance off in line if you have a stroke, a studio strobe that has an optical slave the pre flash will set that strobe all too soon and won't show up in your image. That's, mme or the issue you're gonna have to answer that question. So what good is that? Some people will be really but such a small minority? We really have never had too much of an issue with that literally. I'm sure the difference literally, this is the communication flash. I don't know if you don't see this at all on campus, but little this a communication flash. This is a non communication flash there's not much difference, but some people are very sensitive flash and they can they do pick up on that, and if you really get into t t l, you'll be able to photography will be able to see the pre flush you. You'll start to be able to separate the pre flash from the main flash and lots of times when your flashes start to die and battery power, which will also get into that pre flash starts going going away. That happened all the time because it's just it's zwei of screaming for help because it needs more battery power didn't have enough strength to keep going. You know, the questions were good for now, I think we're great for now, okay, all right, so again, let's just kind of talk about what cody and I have talked about the let's do it in a I guess, a printed way that kind of help you understand exactly what happens behind the scenes. So when the photographer presses the button halfway, the ambient light of the scene is evaluated through the lens of meeting. So again, when you push that shutter button halfway and you get your f stop your shutter, speed your camera reading that's the initial reading through the lens meeting the photographer present the shutter release all the way, which begins the communication pre flash and the main flash process of capture the image again, we're talking the speed of light, so this happened so fast you really can't tell the human I just didn't advance enough to see it all the master flag shoot, it sends a wireless signal toe all slave units using a very fast coded light signal, which commands each slave flash to issue a low power pre flash. We're going to kind of get into mme or why that pre flash is, it says here any slave units that see that command from the master flash will fire a pre flash at one thirty second power that one thirty second power is important. Because when you're trying to solve an equation in math, you gotta have at least two knowns there's three, three issues you gotta have at least two to solve that one third that third one and our two known in this case is proper exposure is the solution, and we're going to get into that in a second what it thinks proper exposure is, and then the one thirty second power. So if it knows what proper exposure is for whatever we're focused photographing whenever we focus on and a pretty flash of one thirty second comes back and we know the camera knows that that one thirty second that much light is what originated. If it comes back to little after, does the calculation for proper exposure is going to tell you to put out more like if it comes back? Not too much it's going to do the calculations to say it's too much light, so it's going to command the master the slave flash to put out less light so that one thirty second is extremely important, and again, we're going to go over this in layman's terms a little bit later, our promise, and then the camera calculates the correct amount of life that should be admitted from each slave flash during the actual exposure. The main flag based on the amount of light observed in the pre flash like I said it knows how much like started off at one thirty second and it knows how much comes back and it does his calculations for you so basically again is a photographer you don't have to worry about all this mathematics it's done every time you click the button the camera may adjust the calculated values the doctor has said any exposure compensations or ratio settings in the master flash basically it's saying this is what I think is proper exposure but you're the human you're the person behind it you're the artist so you're allowed to make adjustments because I don't really know what you're photographing I'm just going over a general this is what I do every time and you're the artist so if you want to raise the power or lower the power you're able to do that and like I said earlier, the beauty of this system is you can do it all from your camera or your master flash so you don't have to go over to the slave flashes if you have two three, four, five it doesn't matter you can adjust each and everyone from your camera the final calculated value is sent to each slave flashes in the second coded light signal the camera mirror flips up and the shutter opens that's the clunky here when you take the photograph and then the master flash sends a final short command, which causes all slave flashes to fire the same time. This is the main flash that illuminates the actual captured image also a flash fires at whatever level the master unit tells him to the camera mirror flips down, closes the shatter completing image process so every time you click the button and urine master slave function this happens every single time that's a lot of information that's a ton of information at the speed of life that happens every time you click the button and that's one reason why you can get some bad readings if your batteries fail you're focusing on different things and we're going to get into all this but I've seen there's a lot that goes on behind the scenes so let's talk about the battery issue so as as mike said as you click the shutter this flash says, hey marco who's out there since that a flash this flash says follow miriam gives the one thirty second power light comes back through here camera says ok, I saw that amanda light I need this much more like so it's talking to the slaves and ok, I saw that talking with multiple flashes if I used a high speed camera and were filmed this I would see this flash to talking, giving multiple flashes and it basically like said coded light so if during that communication and again, this happens within milliseconds between that first flash, the marco on the polo and all that this slave flash knows that it has to receive basically a packet of information so money flashes long, and it also knows that it has to receive it in a very short amount of time because it knows that this shutter is about to open and close very quickly so if during that communication your batteries start to get week, you've been on a shoot for a while maybe it's hot outside, who knows but some some how that battery power drops down so it doesn't deliver all that information that flash this flash says basically say marco who's out there polo, hear I am okay, so light now give me this as it's talking I need to see this because it doesn't get all the information out there I need this man and this class you go, what would you say? You need what? Hurry up, tell me I got a lot and finally is just gonna go I'll forget it and it's going to power it's going to give a full dump it's getting up everything in these capacitors, which is way more than beautiful power flash so you're going to go on a shooting a bit all man's looks great, yeah, that picture a little bit powell and and bound then you could get one and it's just going to just totally blown out this flash because it didn't get all information blaspheme I'm in that that's horrible let's do another one so you click another one and then it's black it's tilly dark because after it just gave that full dump this capacitors they take three to five seconds toe fill back up again so you're going to say even with an external battery charger she could say, well, this this methods it's horrible mike and cody you're dumb, I'm not doing this anymore you could take this flash off you could put in a way you could like natural, so be aware lecter or whatever else like you, so really be aware any time that you start getting strange results erratic results was old that you don't normally get and you know you have good land aside good communication first thing I always do is change the batteries and I don't care if you just put, brennan said, and change or batter before you freak out. I can't tell you how many times especially use offline or use rechargeable you didn't recharge him or you think you retarded, but maybe it was the other four that you recharge always change your batteries out before you freak out on anything when you're using tio, sometimes you could have one cell that's just not as strong as the others, the three year helping it to catch up, and after a while maybe work good for twenty, thirty, forty shots and then after a while, it's just going gets weak and weaken weaker, and you can start to have bad results. So any time, any time you get a hint of something going wrong, switch about herself and for the for the flashes, a lot of them will give you a little warning. You don't go back to your flash right now, it says ttcl which, again is we talked about earlier is the third generation of tl was the battery power starts to fail on these flashes that he's going to disappear? Because the third generation of tl has a lot more of mathematics? We just went over how much more mathematics that the first generation of detail has, and so it's saying, ok, I don't have enough power to do all this mathematics. I'm tired, I could only do this much so it's going to tell you on the back of your flashes? I'm in tomo, not tomo, because your battery died and then the next step it's going to go straight to manual because it says, I have no more energy to look to do any this mathematics, I'm just gonna fire that's all I can do so I can't tell you how many times teaching workshops of the year people go out of network in this details useless I don't know what's going on you look in the back of their flash and the red light's not on because their batteries can't recharge flash and it's in manual mode and supposed to be in t tl mode on state t l can our nikon will say so we say well, you got to replace the batteries and so even though we go over this every single time, I can't stress you how important fresh batteries are when you have any issues with detail whatsoever another tell tale is your little red light on back your flash again it says, hey, I'm ready everything's charging me to go if you'll notice after a bunch of suits brainy but he's a great body but after a while you may see I got no idea forget it normally this light will go off and these rechargeable you can see they're really good this is the best place I've ever had typically typically how'd I get more were secretly feeling a feeling that I get it oh, I know this is going to do it because I'm blind I just getting to this point oh this is it right here that's the one that the winner now it's still doing and I got one to one you're doing full power that yeah, so typically, this light will go off for a while and how long it stays up for going back on? You'll notice like you were taking a shot and he goes off one one thousand two one thousand you need to change it. If it didn't come back on almost immediately, then you need new batters e I think we've had some problems with linus site and I'm kind of curious on the communication between slave in the master. Is it that the sensor on the masters at the actual flash itself? And is that the sensor on the slave again? Let's reiterate exactly how they communicate slave communicates with this flash to that's the only thing it does, it doesn't, it doesn't send any signals back to the master. The master communicates with the flash tube, so if you're my subject, this says hey who's out there. Marco who's out there is communicating with this. The slave hears it in this black window for canada again for nikon the slave will receive so is that what needs to be pointed to that's? What? I think we just really seriously. If I were shooting you, I would turn this towards me that towards you, this is the best. Communication and get well so for an icon you put that little indention towards them after flash and then roll this torch mine. So when that's near you're at right there. If that was a nikon flash your sensors on the other side, that doesn't matter. No, not for the master. We're doing master on. Lee talks with the flash too. Okay that's a slight listens and the little round window there. So for your master, you wanna point the flash to towards this part on your slave or for candidates, the partners right in front. So where we going to later? How that all happens with multiple it actually it's all with multiple flashes. It all works the exact same. We're going to get into that a little bit later how you control the power from each one. We just know when you're doing a lot of sight. This is what receives the signal for cannes. For nikon, this little black, shiny part above the red plastic is what receives it on a cannon. And you have to have that part pointed towards your master. Flash the flash, too. So the flash to is what sends out the marco. This little part in this little part is what received it and receives the polo does that make sense, so multiple flashes this flag this flash doesn't know if there's one flash to flashes are two hundred flashes it doesn't know how many's out there it just sees the combined light that they produce when it says marco and they respond so it doesn't matter I could have a bank of seven hundred flashed over here and I could see this marco who's out there and they're all gonna go follow here we are and then that combined about a life one three seconds they send out comes back video camera sees it allots all that amount of light so give me this amount change that plus or minus minutes going again talk to e talk to it and then say ok, fire on my command and give one more fire command and they're all going to fire combined opens and closes and you get your shot the whole two three four flashes doesn't doesn't matter. The whole concept is you have to make sure that what is communicating what's receiving the signal you have that set up and then again at one thirty second power pre flash if I have to flash is it's going to be that pre flashes going come back twice as bright as one flash so the odds are when it makes that communicate that calculation for proper exposure it's going to actually tell two flashes to expose our output less life than it would with one because that makes it mike and cody could question I'm related to you shooting in bursts, mo, just now from boston. Jake here's. My question most of the time, when I used to tail off camera. If I take the same picture fighting five times, the light exposure is a little different each time. Is there any way to make it consistent every time, like manual again? Not moving or changing the shot in any way? Both way. Let me let me just say, sometimes you don't think it depends on your meeting mode because they were talking tpl, because as you click the shutter utility hey, I want this man light. It fires it, it looks at the entire scene, and then it gives it a final command, even though you may not change much if you changed your compositions just a little bit. If you change your focal length just a little bit, you know what? That flashes bouncing off of it's gonna give you different reading each time now, if you have it, theoretically, if it's on a tripod and you're not touching it not changed anything. You should get the same exposure each time. If you let your batteries charged up. Enough in the capacitors, too is another issue, but it's, not a speech eating but it doesn't take a large movement doesn't take much to get maybe a tree or two something else in that is reflective that's going to see that my light for it to change the exposure each time now with that said at the beginning of the program, I said there's time to use tl there's, tom, to use manual if you're in a controlled environment where you want everything looked the same every time tio is not the option you want to choose, you would rather go with men because nothing's going to change the environment change. I'm always going to be in this setting, so the light and change tio is wonderful when you have a vast range of lighting situations that's going to be thrown at you. So from a wedding scenario from an outdoor portrait session or even indoor light, we're going show later with natural light coming through windows, but it's still changes because right now, if we had clouds and one went over the sun, it would get darker here, and that would change your whole, said that's, where thiel comes into an advantage. So I don't know from this question, if it's the exact same shot every time, but for speed shooting again, the batter capacitors are big because it's got all this mathematics it's going through. So it takes a lot more battery power than just manual and it just says fire fire fire doesn't care what you have to set it and it's just telling you to fire hopefully that helps answer one more quick question after you couldn't drain your battery now everybody wants to know what batteries you use rechargeable system you have these are and I wish we get money from these data because we don't yeah these air vanna white energies we use those in power but those are our two main brain brands this one these we just bought so they were actually probably about a year old maybe not quite a year but we we use the maha chargers and um you weren't even in charge if you like it. Okay freak over this this is his favorite thing in the whole world I'm getting these it's just there was having um the battery charges we use we use the maha chargers some you are familiar with them. Some of you may not be its it's a little more expensive of a battery charger than most some most better charges. When we first started doing this we just catch a regular plane owned by the chargers got a red light green light you put four batters in there they stood on their from one hour two hours who knows? You get really hot red light turns green and make your way to go what I really like about the maha chargers it must have to pluck people I mean my god use my heart chargers they're really good what I like about him is it gives you the individual battery condition of each cell ok and it's it's a battery bank of eight batteries and each individual battery it gives me the status of that battery tells me when it's charged it is not charged if it's a bad sale and I can tell that one away, whereas most the ones with the read the green light they just go for a while until he gets to a certain average level are keats and then it turns off with the ma ha's it's a fast charger so you can put all eight and and then to may be ready to pull those two output it too. And so if you're on the go are leading situation it's it's a lot faster to charge a bunch of batteries. Also, one of the biggest things is it'll tell you if you have a bad cell that's a huge, huge thing when you're buying a charger, make sure you get one that tells you the bad self we've had plenty of times when it comes to hold one look at this basically basically this is the maha charger scott and little led readout here what you'll tell me each individual batters better sale in the condition of each one it has a couple of cool functions also where you can reset the memory on him you can do we're totally drains them down and then rebuild them back up so you you don't get a column memory which some chargers will give which shortens about her life so in our slow time which it's different everywhere in the world right now is our sometime because so miserably hot back home will recharge all are rechargeable is and it takes about seven to three to four days to basically do that and so we'll put up a bank of eight and we'll do a recharge and basically just wipes out everything and then slowly recharges the batteries and we found by doing that we'll get another year out of our batteries and so it saves you not only a lot of money when you do that but as you can see they're really really powerful because for the most part when we're shooting the wedding I'll change out our batteries and we have an external battery pack which will go into a minute will change it out during the wedding reception but it'll last all day long for regular session for seniors or family or a baby one flash one battery pack and we're good to go the whole the whole time another important factors when you're buying your rechargeable cz go with a with a quality battery you can use it till you can tell how much power these betters hold. They have a an image, a on him that's like the million power rating. So these power exes are twenty six, twenty, seven hundred. I like to use at least twenty, five hundred or greater. So twenty five, twenty seven, twenty, nine hundred like that? I'm not sure what the blue ones are, but you can you can find some batteries that are more economical, they're less expensive, but they'll have a lower million power rating, so that means they don't hold us much power, and they don't release that powers fast. So if you have one, I've seen some before we had that we're on, like, six hundred million power and those take a very long time to recharge between flashes, and they just don't they don't last very long, so I like to use at least a twenty, five hundred or greater. These were twenty six is these air twenty seven? So somewhere in that range and that's a good quality battery. Now, one of the drawbacks to a fully rechargeable like we use isas soon is you basically take him off that charger. For the most part, we're going start draining the power that you just charged a pill, so if you have a bunch you really do have a big event you really charge him up and take him off put it in your gear and go you don't want to leave him in your flash on your camera back because it will lose the power without that know what that said there's some batteries out there that are hybrids in a sense that a kind of half alkaline half rechargeable cz that will hold their battery charge a lot longer and those could work for you we're so used to this obviously as you saw it's effective it doesn't so we go with we have for these chargers in our studio we have a little shelf and we literally just leave we have enough batteries the where we can have our flashes and our battery packs on a session and still and then have just enough that are on our battery packs I mean on our battery chargers charging so if they do die we can come back and pull off something we're good to go but as you said, we leave our batteries on here all the time it's a trickle charge is not going to hurt it's gonna charge him up and then if they drop it'll charge him back up that little trickle charge so they'll always be ready did you have a question? Yeah for someone that's never or or but rechargeable batteries how many would you recommend to buy pins on how many flashes you have or how much you want to use to be honest again I prefer to have five four flashes there's four in each one that sixteen batteries so I would buy like thirty two batteries or I would have tried to buy twice as much that I need that way there's something always charge and you might not need to do that much you maybe I would at least have like a next year you have four flashes that haven't at least eight extra so you could actually have two full flashes when you need to is a minimal and one more question how many would you recommend to take on if you're doing a wedding verses ah senior session because obviously you're not going to need this many senior session you're pretty much good to go um what you have the advantage of this and the battery packs which we'll get into the minute they all are double a's so worst case scenario you're rechargeable die you forget to charge whatever just go buy a convenience store and you can buy some double a's and get through it it won't be as powerful but again you won't look like an idiot in front of your clients so you'll be able to get through the session and that's what another is what we like flashes and like using tts because when we travel we can buy batteries anywhere in the world