This is part 2 --> part one here!
Studio lights (monolights)
If you are financially ready to go with studio monolights, please don’t overdo it. For a home studio space like mine at 3m X 4m something like the Profoto 250WS D1 light is more than enough. (I eventually got 400WS monolights and have ample power to spare, so no need to go for more watt seconds monolights, that will only drain your wallet… save that money for some nice softboxes instead.
How much is enough? How do I decide?
Well this question had me stomped a little too. No doubt this will vary to some extent based on the room you have. And one thing to know before getting monolights, (besides the “T5” or “T1” flash duration speed, mounting systems, and triggering options, color temperature stability etc etc(more on this later), is that to make matters more complicated, not all monolights are created equal.
I.e. a 300WS (Watt Seconds) “brand A” monolight might NOT deliver the same power light-output as the 300WS “brand B light”. sigh
2014-04-19 | UPDATE!
I just got a Sekonic L478D lightmeter.
I here are a few output numbers for the MSN400 Jinbei mono lights.
With a standard 55degree reflector
Distance 4m :
shutter 1/180 ISO100 power 1/1 = F16
shutter 1/180 ISO100 power 1/4 = F8
shutter 1/180 ISO100 power 1/8 = F5.6
Distance: 3m :
shutter 1/180 ISO100 power 1/1 = F22
shutter 1/180 ISO100 power 1/4 = F11
shutter 1/180 ISO100 power 1/8 = F6.7
Have a look at Mark Wallace’s video for Adorama that explains some of the differences on this subject to better understand the issues involved.
The way I approached it was, when setting up my monolight at one end of the a blacked out room, I checked at which settings on my Canon 6D would I still be able to overexpose the furthest wall in my home studio.
For me, the Profoto D1 250WS Air monolight would overexpose the furthest wall at f9, ISO100. This means I will have plenty of power for properly exposing anything in between the wall and the light. And remember even though f9 may not sound like a high number, because of the inverse square law covered in part 1, I have 4 times as much power times spaces between the light and the wall, so more than enough.
Disclaimer: One more important thing to keep in mind is that the Profoto D1 and B1 lights have a build in recessed 70 degree reflector and therefor do have more punch than most non-Profoto monolights in the same power range, but if you get 300WS lights for a room like 4m X 4m, or 4-500WS for a room 5m X 5m I would expect that it will be enough.
Monolights have the power supply built in and require a power socket to work, however there are also portable solutions like the battery powered Profoto B1”s, Elinchroms quatra Ranger series where you have a separate studio head, and a portable power supply/battery/control unit which both are the obvious choice for location shoots where a normal speed light is not powerful enough, if you want to overpower the sun, or if you want to use your existing big light shapers. Alternatively there are also actual mainpower battery solutions like the Profoto BatPac delivering 120-240v battery solution in a backpack. For comparison the standard Yongnuo 560 speed lights is only approx. 1/10~1/5 light output of studio strobes.
Freezing motion with flashes
Traditionally speedlights have the advantage in terms of shortest flash duration, and the lower the setting (1/128th power) the shorter the flash duration. Typically this will be around 1/800sec @ 1/1 power ~ 1/10000 sec @ 1/128 power. And if you are killing ambient light with low iso, >1/200 sec shutter and F6< aperture, you will know that what ever if in the frame when you fire the flash will be there because the flash lit it.
This also means that it does not matter if your camera shutter is open for 1/30 sec or 1/200 sec (or more depending on your flash sync speed of your camera) the effectively turning the flash into you camera shutter speed.
- Turn your ISO down as far as it will go. (ISO 50~200)
- Turn you camera shutter speed up as far as its flash sync capability will go. (For my Canon 6D it is 1/180sec, yours will vary depending on brand and model)
- Turn your aperture up until, when you take a photo, you only get a black frame.
Congratulations, you now have the speed light or studio strobes flash duration as your “effective shutter speed” as the sensor can only see anything for the duration of your flash use. And thats how you can create the cool photos like freezing the motion of water droplets in air etc.
T5? T1? values of studio strobes!! whats that all about!?
Okay, so this is where things get a little technical, because when measuring the flash duration of a strobe, you have to decide when the cutoff point for when you are still reading the light.
Basically there are 2 widely accepted standards in use for measuring the flash duration, and depending on which the manufacturer is using in the specification sheet of your desired mono light, there will be a big difference.
our eyes can’t really catch this but, the strobe or flash goes off, it reaches the power output we define VERY fast, but will then “fade” out. And the longer it takes for the light to fade, the harder it is to freeze action in a photo.
The “T5” flash duration is really the time it takes the flash or strobe from desired power output until the light have faded to half the value. (“T5” is actually “T0.5” = Time to reach 50%) and you guessed it!, the “T1” value is the flash duration from desired power output faded to 10%. And here is the kicker, usually T1 value is 3 times higher than the T5 value.
So imagine you see a nice studio strobe with a flash duration of 1/1000 sec.
But once you get it, it turns out that was the T5 value, and really you should divide by 3 to get the T1 value… 1/333 sec. flash duration (please note that one is not “more real” than the other, it is just two ways to measure the flash duration.) If you want to learn more about this in technical terms, have a look at the below link:
Light shapers - Shoot through umbrellas, softboxes, octo-boxes, beauty dishes etc etc.
Although you can get small softboxes for use with speed lights, I would argue that if you take the next step and get studio strobes, you should also get softboxes as they can not only help you control the light-spill as discussed in part 1, but also because they in my opinion give a softer and more even spread of light due to the fact that most softboxes have a double front diffuser material versus an umbrellas one layer of material. Softboxes also have the light bouncing on the internally reflective materials before reaching the from diffuser, where as the speed light will often not hit the umbrella evenly and create a hotspot in the middle, causing you to sometimes get a specular highlight in the middle that is blown out before you get a proper exposure on the surrounding areas.
A soft box or octobox will have a flat front that gives an even light from that surface. A reflective umbrella will for the most part be without hotspots, but usually do not have a diffuser material, and cannot be placed as close to the subject or model due to the light being in the front of the umbrella as per below diagram.
With light shapers you can take your photography (and your wallet) to a whole new level. And many expensive brands have light shapers as expensive or more than the prize of the monolights. Many adapters are available on the market to use for different brand light shapers with different brands monolights mounting systems, but keep in mind that once you get into buying light shapers you will also be loosing space in the studio, but gaining "space" in your wallet. So have a look at what type of mounting system your desired lights are using, and have a look around if adapters exist for you to use different brands of softboxes with it, as the proprietary light shapers might be really expensive.
To mention a few of the mount systems are: Profoto, Bowens/Calumet and Elinchrom.
Some have a more or less elegant adaptor solution so have a look around the net before buying into a system that might be very expensive to expand later.
A note on light stands
The small and easy light stands are great for speed lights and umbrellas, but once you place your expensive and heavy monolights and softboxes you will want more stabile light stands, and sandbags to secure them. (I personally have a few dumbbells lying around, they work great too)
(more on good alternatives to expensive cloth backgrounds, tips and tricks coming soon in part 3 so stay tuned)