What is the advantage of powerful lighting if it cannot be used?

<p>Hello Experts,</p>

<p> So I was not sure if this should go in the lighting forum or here. But since I do mostly portraits, I thought, let me put it here. Just a intro, I am a beginner, use a Nikon D90 and have two elinchrom D200 (200W/s) strobes with 1 meter size softbox. Basically, its the entry kit for amateurs. My question really is that, I know size of the light source make a lot of difference in the type of portraits and big light sources are preferred over small ones. Now, I have been enjoying my small strobes with some good results but I wanted to expand my knowledge and control of light.</p>

<p> My question really is, that, I have a 7* 18 feet room where I do portraits of people mostly half body or face sometimes full of 1 or 2 people. With my current Dlights, which are a maximum of 200ws. I literally have to dial them down all the way down and then also get a reading of about F8/11. Now, I like the light and the effect. But my question is, that all professional level lights are like 1200 W/s etc. What do they do with all that power. Is it purely for places where you have to light up a subject far away?</p>

<p>Or is it that the more the power, they can use that against a larger softbox/diffuser and get a bigger light source? As I mentioned, I am a beginner and have not tried anything bigger than my 1 meter softbox, so just wanted to ask all of you.</p>

<p>Also, for portraits, fashion etc, do you advice a much bigger lightsource? Woudnt the output still be the same if I were to buy a 1200W/s srobe and keep it close to the subject.I will still have to dial it down all the way right? to remain in the F8/11 range?</p>

<p>Basically, is a higher wattage strobes only to light distant objects or am I missing something.</p>

<p>thanks,<br>

Sun</p>

<p>Sun, One thing about pro lighting is you can dial down the power level a lot more than prosumer type lighting. For example, on Broncolor lighting that I often use, I can dial down even high output strobes to provide just enough light for near-macro work at close range, and even the duration of the flash itself.</p>

<p>Your light source depends entirely on the lighting effect you want to achieve. You could use a single large light source, or you could use multiple smaller light sources. A 1m soft box is relatively small, but if it works for you, then it's just the right size.<g></p>

<p>Don't confuse wattage with watt seconds. Generally, higher watt seconds provides more light. That could be a great distance, or smaller apertures. There is a tutorial or two on this site, and it would probably benefit you tremendously to go through it.</p>

<p>Sun,</p>

<p>You have asked some very relevant questions that deserve well thought out answers. </p>

<p>First of all, your selected f stop is a function of not only the power setting on the lights, but also of the ISO setting on your camera (whether film ISO or selected ISO on digital) and of the types of modifiers you may use on the lights. As you already know, it is also varied by the distance of the lights to the subject and by the size of the room and to some degree, the reflective qualities of the walls and ceiling.</p>

<p>With films, generally the best results are with low speed ISO products which usually give the smallest grain. That would mean less ability to record light and so a higher power electronic flash could boost you to whatever f stop you may target. By using a lower ISO setting on your digital camera, you increase your ability to select from the full range of your lights to also select whatever f stops you may wish for a given subject.</p>

<p>For right now, doing individuals, you may need only a limited f stop range, but if you switch to groups or still life; you will want more depth of field and therefore will need more lighting power.</p>

<p>Yes, more power is needed to burst through soft boxes and to get to the brightness level you may want.</p>

<p>As to the size of a soft box, I go by the rule that the bigger the better. The larger the light source, the softer and more delicate the quality of the light becomes and for portraits, that is quite important. Think of the difference in an outdoor portrait between shooting in direct sun (an incredibly small and harsh light source), or shooting with the open sky as your light source (an almost infinitely huge and delicate source of light. Also, a small soft box like you are using now may be good in very close (large relative to the subject due to distance) but will be quite small at a distance of six or eight feet and it will give a more specular (harsh) quality of light when farther away.</p>

<p>You must also take into account the distance at which you use your lights. In close the power level does not need to be high to get a lot of light on the subject, but get back only twice as far and reduce the output by the square of the distance. That is if you are at f8 at five feet and move the lights back to ten feet, you drop down to f4 instantly. If you then go from a one meter soft box to a larger one, say 4x6 feet, you spread the light over a much broader surface and reduce the power output even further without touching the controls. Therefore you need to be able to have power in reserve when the need arises.</p>

<p>Now, lets take on an assignment where you have to do a family group in a large living room or, God forbid, a sports team in a huge gymnasium or class reunion in a very large banquet hall. You may have to place your lights back twenty or thirty feet from the subjects in order to evenly light the large group. If those lights were set to output f16 at five feet, you would only be at about f2.8 at thirty feet, leaving you absolutely no depth of field to carry from front to back for the subjects in the group. You would actually need to have an output of about f11 at that distance to be remotely safe in keeping all the people in focus. Remember that is you have a deep group, that is four or more rows, you need to meter at the back row as well as the front. You will have at least a one f stop difference in exposure value between front and back so you have to be metering for everyone to have adequate exposure.</p>

<p>In short, reserve power is just that; power that you have waiting for the need to arise. When it does, you will be grateful for every extra watt second you can afford to buy.</p>

<p>Yes, watch your nomenclature - flash energy is measured in "watt seconds" (watts x seconds = joules) not watts/second (watts per second, watts divided by seconds) which would be a measure of something entirely different.</p>

Using larger format film effectively requires more light for similar depth of field. I regularly shoot 4x5 or 8x10 film at f22.

The camera's bellows extension loses a stop of light. To do this, I need to be reading f32@iso 100 at the subject.

I sometimes use a single big light from a long distance with small cameras to light backgrounds etc in order to minimise

the amount of light fall off over the lit area.

<p>An old proverb: It is always better to have horsepower you don't need, than to need horsepower you don't have. The same can be said for flash guide numbers.</p>

<p>With low powered units you can hit a wall one day. An example is a large group shot in a big room. Small wattage lights can't hit small apertures over much distance. Especially if certain modifiers are used. Large soft boxes for example, eat up large amounts of light.</p>

<p>Thanks a lot experts!!</p>

<p>Tim, that was beautifully explained! Apologies for the delay in the response. I was travelling. But that made sense! I think my brain was on a one dimesnsional track. Good to hear expert advice.</p>

<p>HAve a great weekend!!<br>

thanks,<br>

Sun</p>

<p>Thanks, Sun. Glad to be part of the help you are getting here. I can't begin to count the number of mentors I've had in the last few decades, so it's great to pass along what I've been taught.</p>

<p>If you are looking for more information about the precise and artistic control of lighting, I can not recommend anyone higher than the late Dean Collins. Lots of his tapes and the 'Fine Light' information series can still be found (ebay and elsewhere) and can teach you tremendous and clear insights into why and how different lighting techniques are used. The first time I saw Dean in person, I nearly fell out over how much I previously did not understand even though I had a successful studio. He was and remians the revelation.</p>

<p>Good luck.</p>

<p>Tim</p>

<p>Thanks Tim, just doing a google search on him!</p>

<p>Cheers!<br>

Sun</p>