Strobes & DOF for Bar Mitzvah Dancing

[michael_scharf]

<p>A few months ago I posted the following:<br>

<a href="http://www.photo.net/wedding-photography-forum/00TI6C">http://www.photo.net/wedding-photography-forum/00TI6C</a><br>

I’ve always shot Bar & Bat Mitzvahs using only one flash. Recently I purchased a strobe kit for my portraits and I was wondering how I could possible use my strobes as background light for the room. My dancing shots always seem dark in the background and I would imagine I could get more DOF with more light. When I shoot my portraits I shoot in manual and use a light meter. For the rest of the affair, I’ve always shot in S mode in order to stop motion. In order to use the strobes for dancing would I have to keep the camera on manual? I understand that I can setup my lights and meter before guests arrive but how can I insure that my light will be equal throughout the room? Should I keep my camera on S mode and let me flash gauge the output independent of the strobes? I guess I am just nervous to shoot in manual. What aperture do you guys use for dancing? Do you use max sync shutter speed? How about ISO? Thanks for all your help.</p>

<p>Equipment relevant to my question: Nikon D300, 18-200mm Lens, Nikon SB 600, Pocket Wizard, Dynalite M1000wi with 2 strobes<br>

Most replies back were to use Dragging the shutter. So here are my new questions:<br>

1. Dragging the shutter seems to be great when you want to blur your background and keep your subject sharp in the center. In my situation I want my main subject as well as the people dancing in the background to be in focus. Is that possible with dragging the shutter?<br>

2. One reply stated that I would need a 2.8 lens to to allow more light into my camera but wouldn't using 2.8 during a dance set blur the subjects a few feet? I would think I would need more depth of field so adding more light would be the only way.<br>

Your help is greatly appreciated.<br>

Michael</p>

 

[picturesque]

<p>You're confusing DOF with dragging the shutter (motion blur). The rules that govern DOF are just that--they aren't affected by shutter drag, just as they aren't affected by subject motion. So first, figure out what DOF you want for this kind of dancing. I actually like a bit of DOF for dancing, since there is usually more than one person dancing--people still usually dance in twos--or more. You would be going to your DOF tables (dofmaster.com) and figuring this out. Luckily, if you add flash like the Dynalites, you don't have power issues, which is why people recommend f2.8 and wider--to maximize your on camera flash's power/recycling.</p>

<p>1. Manual camera mode is always best for indoor flash situations, to control shutter drag and balance with off camera flashes. I don't meter my off camera flashes. I've always used my cheat sheet derived from the guide number. I estimate what I need and then fine tune. I usually have the off camera flashes about a stop less than my camera EV at the middle of the general area I want lighted. I adjust f stop or ISO if my subject happens to be nearer to one of the off camera lights.</p>

<p>I don't know what S mode is on your Nikon, but I gather that is TTL? I use my on camera flash in ETTL. In theory it isn't supposed to work--in practice, it does.</p>

<p>2. I actually use f4-5.6 for dancing. I don't use max sync shutter speed. I use the shutter speed that gives me the shutter drag effect I want. I like to use ISO 800, but sometimes I go to 1250 or 1600.</p>

<p>3. If you have off camera flashes lighting up people behind your subjects, shutter drag is not going to give you blurred backgrounds.</p>

<p>4. Yes, using f2.8 will give you the DOF that one would get at f2.8 for the subject distance and focal length in use. Adding more light isn't the only way. Change your f-stop, subject distance or focal length for DOF. Then add flash to the background areas you want sharp (unblurred).</p>

[William Michael]

<p ><strong ><em >“I was wondering how I could possible use my strobes as background light for the room.”</em></strong></p>

<p ><strong ><em > </em></strong></p>

<p >Most reception places have light coloured ceilings. </p>

<p > </p>

<p >A simple “I begin here plan” is to have two of your Flashes on triggers about 15ft out from the back corners and bounced across at 45 degrees, inward and into the ceilings. that will give you light <em>on your background</em> of the room. . . </p>

<p > </p>

<p >But I am not sure that is what you actually want. </p>

<p > </p>

<p >Be careful in the way you ask . . . better images might be got by the triggered flashes giving <em>directional light across the PEOPLE in the background</em> . . . such as a fill side-light, hair-light, kicker or a side & scrimmed light . . . so this case about 12ft high and with a diffuser coming in from either (or both) sides.</p>

<p > </p>

<p >Lighting is a 500,000 word essay in itself . . . so as to exact F/stops etc there are no exacts . . . you have to experience it but have a beginning point – I have given you two: just practice beforehand, not at the Wedding. </p>

<p > </p>

<p >*** </p>

<p > </p>

<p ><strong ><em >1. Dragging the shutter seems to be great when you want to blur your background and keep your subject sharp in the center. In my situation I want my main subject as well as the people dancing in the background to be in focus. Is that possible with dragging the shutter?</em></strong></p>

<p ><strong ><em > </em></strong></p>

<p >Yes. But it depends upon: the speed of the dancing; the Tv you use; Flash Power on the particular subjects</p>

<p > </p>

<p >I have not read the thread you linked. But irrespective (and with no disrespect) of what was written there, I suggest you clear you mind of it for one small moment and think of dragging the shutter in these simple terms . . . <strong ><em ><br /><br /></em></strong></p>

<p >You have TWO exposures to consider: </p>

<p >a) The first is the Flash exposure. (Decided by: FLASH power / Aperture / iso)</p>

<p >b) The second is the ambient exposure. (Decided by: SHUTTER SPEED/ Aperture /iso)</p>

<p > </p>

<p >Now the Aperture and the ISO must be the same for BOTH exposures so the ONLY variables you have are FLASH POWER and SHUTTER SPEED. </p>

<p > </p>

<p >Next remember that FLASH POWER (on any subject) is also controlled by DISTANCE (of the FLASH to the SUBJECT) and well as the output power of the flash. </p>

<p > </p>

<p >This is important to understand because you can use your secondary Flash units to illuminate the people dancing in the background, and your on camera Flash to illuminate the main couple <em >and still drag the shutter to get some ambient exposure.</em></p>

<p ><em > </em></p>

<p >***<em > </em></p>

<p ><br />“<strong ><em >2. One reply stated that I would need a 2.8 lens to to allow more light into my camera but wouldn't using 2.8 during a dance set blur the subjects a few feet? I would think I would need more depth of field so adding more light would be the only way.”</em></strong></p>

<p ><strong ><em > </em></strong></p>

<p >I think you need to understand the <strong ><em >practicalities of DoF for any particular shot or sequence.</em></strong> </p>

<p > </p>

<p >Note <em >most</em> dance shots <em >which want the dancers in the background to be in shot, </em>would necessarily have to be shot at the wide, and in landscape format.</p>

<p > </p>

<p >So for one example - taking your APS-C format D300, you would want about a 17mm to 20mm lens and be about 12 ft from the subjects to get a FoV about 10ft high and 20 ft wide . . . for that shot at F/2.8 you will have about 25ft DoF and thus it should extend to most of the people in the background dancing.</p>

<p > </p>

<p >WW</p>

 

[picturesque]

<p>It occurs to me--were you asking about the horas? Slightly different story with the horas and someone up in a chair.</p>

[William Michael]

<p >Yes . . . I was writing as Nadine was writing - - - she makes a very important point: - larger apertures (and usually wide FL) are popular for dancing sequences <em >to conserve Flash power and maximize recycling time.</em></p>

<p > </p>

<p > </p>

<p >That's why it is important to think about the "shot or sequence" and then apply the technical bit like dragging the shutter.</p>

<p > </p>

<p >Thinking about the technical bit (like dragging the shutter) with no practical application doesn’t gain all that much. </p>

<p > </p>

<p >For example, dragging the shutter whilst the B&G are kneeling at the Altar is a different shot or sequence to dragging the shutter whilst dancing. At the Altar we want the ambient of the Church so it is most likely the FL, Tv, Av, ISO and Flash Power will be entirely different from the dancing shot . . . </p>

<p > </p>

<p >Firstly we would likely not be at the wide, rather more telephoto and secondly we need maybe F/8 for adequate DoF on a half shot and thirdly we would not usually need a super fast flash recycle because if we were allowed to use Flash during the Service, we would not want machine-gun Flash, because we would want to impress the Priest / Rabbi / whomever with our skills, not get him/her off side.</p>

<p > </p>

<p >WW </p>

<p > </p>

 

[William Michael]

<p><em><strong>"were you asking about the horas . . . up inthe chair?"</strong></em><br>

<strong><em></em></strong></p>

<p >Then IMO do <em >not want lighting on the background of the room</em>: but rather on the mass of people in the centre of the room and milling around the two chairs - not that I have done many Jewish Weddings, but the ones I have done the “Up in the Chairs” stuff is quite congested and moved around quite a bit - slave Flash units from the side and more front on would be my first choice - the faces of the Congregation are nearly as important as the faces of the Bridal Couple.</p>

<p > </p>

<p >WW </p>

<p > </p>

 

[michael_scharf]

<p>Thanks for your replies. I will read them over and follow up if I still have questions. I appreciate all your help.</p>

[picturesque]

<p>I see now that by S mode, you must mean shutter priority? I would gently ask if you have read info on dragging the shutter, that covers how flash freezes motion if it is about/at least (this is not black and white) 2 stops over the ambient EV. If you have, then you know that using an automated camera mode when dragging the shutter isn't the best thing, since the camera's meter can easily be fooled and your exposures will go up and down based on each scene, meaning you will get blurring on some and not on others because the 2 stop margin is compromised.</p>

<p>Also, if you are doing this, the camera will most likely spend a lot of time at f2.8, with the flash taking up what slack there is, if any. So you lose control of one DOF factor.</p>

[aimee_pieters]

<p>With most Bar-Mitzvahs, you're working in an indoor location with most people dressed in black and most of them with dark hair. If you don't illuminate the background, in many photographs, you'll see nothing but the face. You'll see no separation between the hair and clothing from the background.<br>

This is the kind of situation that will separate you as the professional from the hobbyist. Make sure you're using a radio slave to trip the off-camera flash as opposed to something that another person's flash will trip and give them the same results.<br>

I always find it best to light the dance floor in diagonal corners. It seems to be easiest to work with and less chance of images with your own flash in the background....-Aimee</p>

[fotografz]

<p>Sorry, I don't agree that you need additional strobes in the background to shoot "professional" dance shots. It's nice to have them if you want, but not necessary to get good shots with more than a sea of faces in a sea of black. Personally, I rarely use aux. lights around a reception floor. Not that there is anything wrong with it ... and you can get some very cool stuff, but it isn't necessary. </p>

<p>Perhaps more importantly, if you don't understand how to get good action shots with on-camera flash, aux. lighting isn't going to help as much as one would think.</p>

<p>Simple rule of thumb for on-camera flash shooting more active subjects:</p>

<p>Flash controls the foreground exposure. Camera/lens controls the background exposure.</p>

<p>To open up the background you can use a combination of a slower shutter speed (aka, dragging the shutter), the widest aperture you can get away with for Depth-Of-Field needed (which is dependent on focal length and distance to subject), and a higher ISO selection. Any one or all three can be employed depending on how dark the room is.</p>

<p>Flash acts as a surrogate shutter for the foreground action. Flash power is ALWAYS the same ... it is the amount of time it is on that determines exposure. "Flash" is appropriately named because it is ON for a very brief amount of time and is usually always faster than the camera shutter speed is.</p>

<p>So with the right combination of shutter speed, aperture, ISO and flash you can freeze the foreground subject ... while seeing into the background.</p>

<p>Once this concept is mastered, you can vary each element of the combination for effect ... like an even slower shutter speed using flash set to second shutter so you get a little motion blur behind the moving subjects.</p>

<p>Then you can add off-camera lights for more creative effects and even better lighting scenarios.</p>

<p>A picture is worth a thousand words: Typical low light reception room with no windows ... Manual camera settings, Diffused TTL flash @ plus 2/3rds stop ... ISO 640, 18mm @ f/2.8 1/30th shutter speed.</p>

<p> </p><div></div>

[c._f.]

<p>I'd say 99.9% of my clientèle are orthodox Jews.</p>

<blockquote>

<p>In order to use the strobes for dancing would I have to keep the camera on manual?</p>

</blockquote>

<p>No</p>

<blockquote>

<p>I understand that I can setup my lights and meter before guests arrive but how can I insure that my light will be equal throughout the room?</p>

</blockquote>

<p>If you can set up to heads, do so - set them up in the middle of the room, or behind the head table facing away from each other, maybe bounce up and since you're shooting digital, see what you get. If you have a light meter, use it and see what you get where - generally, your background will be, <strong></strong> nicely lit.</p>

<blockquote>

<p>Should I keep my camera on S mode and let me flash gauge the output independent of the strobes?</p>

</blockquote>

<p>I'm a manual shooter but will very the flash. Sometime will keep flash on manual and othertimes on ttl or A. If you don't know what your flash can do, yank a stofen with bounce card at 45-60*bounce, ttl+1 (or 1 2/3) iso 400 1/100sec f8. Start with that, and see what your foreground looks like.</p>

<blockquote>

<p>I guess I am just nervous to shoot in manual. What aperture do you guys use for dancing? Do you use max sync shutter speed? How about ISO? Thanks for all your help.</p>

</blockquote>

<p>Generally, I shoot at ISO400, 1/125sec, f/8. flash at 1/4power with stofen straight fwd OR if bounce then will set it to 1/4-1/2 power. I'll probably be going b/n f/5.6-11 to obtain correct exposure based on distance b/n me and the subjects. If my flash in TTL then it'll probably be +2/3ev if straight fwd center metering.</p>

 

<blockquote>

<p>1. Dragging the shutter seems to be great when you want to blur your background and keep your subject sharp in the center. In my situation I want my main subject as well as the people dancing in the background to be in focus. Is that possible with dragging the shutter?</p>

</blockquote>

<p>A lot of the time one of the guests will present with juggling fire or something to that degree. This is when I'll drag the shutter. I'll take few shots at my regular settings (above) and then will drag it by 2-3 stops while compensating with f/stops to maintain correct exposure.</p>

 

<blockquote>

<p>2. One reply stated that I would need a 2.8 lens to to allow more light into my camera but wouldn't using 2.8 during a dance set blur the subjects a few feet? I would think I would need more depth of field so adding more light would be the only way.</p>

</blockquote>

<p>I wouldn't shoot dancing at f/2.8. First of all, optimum sharpness of lenses is about 2-3 stops down from widest aperture & I like seeing reflection in the eyes (crispy images). #2 by shooting wide open UNLESS I'm far enough to actually get what I need to be in focus (face) I won't shoot at 2.8 PLUS during dancing, people are continuously moving. I'd shoot few portraits at such apertures, those rings shots, flowers, details but <strong>not</strong> dancing.</p>

<p>Good Luck<br>

Adam</p>

<p> </p>

[William Michael]

<p><strong><em>OK already! . . . a Technical Clarification . . . :)</em></strong><br>

<strong><em>"Flash power is ALWAYS the same"</em></strong><br>

Yes Marc. Agree. <br>

Also I was ever so slightly tempted <strong><em>not</em></strong> to write phrases such as: "<em>Flash Power</em> on the particular subjects" and "ONLY variables you have are <em>FLASH POWER</em> and SHUTTER SPEED".<br>

<br>

But I did write those in full knowledge that technically the phrase is not correct . . . <br>

<em>BUT</em> it is common parlance to speak of Flash in terms of 1/2 power and etc . . . <br>

and in that regard, conceptually it might be easier that way explained, for the sake of a simplicity . . . <br>

if one likes "the (resultant) Power (or effect of) of the Flash" <br>

<br>

Thanks,<br>

WW </p>

[michael_scharf]

<p>Thanks guys for all the great info. I've been shooting for a few years but never learned the technical aspects. I guess I 've been lucky that I've never had an unhappy customer. Now I'm looking to take control instead of relying on luck.<br>

So it seems clear from this post and others that I have read that dragging the shutter is great if you can hold steady at 1/15 or your background isn't moving. Doesn't seem to be great for fast dancing (hora dance) pictures at a Bar Mitzvah. Dragging the shutter might not be the solution to have better lighting for dancing but maybe a second flash or room lights will help. Does that sound right?<br>

Regarding using f2.8 for hora dancing - It would allow more light into the camera but the DOF on 2.8 would not be ideal and something like f4 or higher would be better.<br>

Am I on the right track?</p>

[c._f.]

<p>Michael,</p>

<blockquote>

<p>Dragging the shutter might not be the solution to have better lighting for dancing but maybe a second flash or room lights will help. Does that sound right?</p>

</blockquote>

<p>Yep, something like that :). 1/15 is nice for portrait with waterfall in the background :)</p>

<blockquote>

<p>Regarding using f2.8 for hora dancing - It would allow more light into the camera but the DOF on 2.8 would not be ideal and something like f4 or higher would be better.</p>

</blockquote>

<p>If you're too close to your subject you'll end up nice sharp point while everything else will be nice and blur. The <strong>problem</strong> is that the nice sharp point might be a nose while eyes will be out of focus or maybe it'll be the eye that is sharp, <strong>ONE EYE</strong> :)~<br>

HOWEVER, If you're far enough it'll work. Use this, if you'd like, to calculate dof <a href="http://www.dofmaster.com/dofjs.html/">http://www.dofmaster.com/dofjs.html/</a></p>

<p>good luck<br>

Adam</p>

<p> </p>

[picturesque]

<p>Perhaps re-read Marc's great explanation of how flash works when dragging the shutter. When dragging the shutter in these situations, you can indeed use 1/15th shutter speed and have the subjects 'frozen'. Very short flash duration acts like a 'second' shutter speed. However, if your ambient EV is less than about 2 stops from the flash EV (which is determined by f stop, not shutter speed), then you can get ghosting/blur. This is why moving subjects in the background receiving less flash are blurred. This is separate from DOF.</p>

<p>I've shot bat/bar mitzvah hora images dragging the shutter, and they are sharp. I also shoot them with off camera flashes. It depends what the room/environment is like, which method I use.</p>

<p>I'd suggest you research dragging the shutter. Look up the phrase using the search function on this forum and also look up Neil Van Niekirk's site and his articles on using on camera flash. Then just experiment one night (where you have time--not on the hora images) with off camera flashes. Then use your tried and true method for the important shots. You won't get the hang of things until you try it and experiment. You also will get maximum use of off camera flashes if you already have a very good idea wha dragging the shutter does.</p>

[picturesque]

<p>Here are a couple of examples. The first one has a shutter speed of 1/30th, which is too slow to stop motion, normally. The reason it works here is that the ambient light is more than 2 stops from the flash EV. The environment has a lot to do with using off camera lights. In this kind of environment, unless you light up what you want to see, you aren't going to see it. It is an open courtyard kind of place with a glass ceiling.</p>

<p>The second one is in a much different environment--smaller, with light walls and ceilings, so the flash bounces around a lot. Even 1/60th is normally too slow to stop motion by itself, but because the ambient is brighter than the other, I didn't want to go too slow. If the room was darker in value, I might have gone with more off camera lights. Here I only had one, providing weak accent light.</p>

<p>I generally use f5.6 for these shots because I normally zoom in and out--you have very little time--perhaps 2 minutes or less sometimes, to get these shots so you have to set and go. The first shot is at 75mm, the second at 33mm. Also, with these shots, the clearer the people's faces below, the better. Nobody wants selective focus on these shots. If the people in the background are exposed correctly (flash exposure), they aren't blurred from subject motion--DOF is another thing.</p><div></div>

[michael_scharf]

<p>Here are a samples of what my shots look like. What do you think? I don't have the camera settings on me since this is an old photos but I'll post some new ones from my job this past Sunday.</p>

[picturesque]

<p>I'm going to post your image, since a .bmp won't show up.</p>

<p>IMO, there is too much of that 'flashy', direct flash look, and the backgrounds can indeed be 'opened up' by shutter drag.</p><div></div>

[picturesque]

<p>I'll point you to the following thread. My long answer in the middle of it tells exactly how to determine shutter drag. But you need to understand the concept to truly be able to size up a room and figure out what is needed. Same for off camera lighting. But I'd master shutter drag first.</p>

<p><a href="http://www.photo.net/wedding-photography-forum/00PFGA">http://www.photo.net/wedding-photography-forum/00PFGA</a></p>