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PhatheadWRX
04-09-2009, 11:38 AM
This post is going to be a compilation of information that should help people trying out off camera lighting. This stuff will be coming from Strobist 101 (http://strobist.blogspot.com/2006/03/lighting-101.html), Light: Science and Magic (http://www.amazon.com/Light-Science-Introduction-Photographic-Lighting/dp/0240808193), and my brain (http://www.worldofstock.com/slides/PFO7051.jpg) FWIW.

What is "Strobist"?
Strobist is generally a technique of using small speedlights to add light to your photos.

What do I need?
Strobist 101 goes into great depth about, this but there are two necessary components: 1) flash that has manual mode the more you can dial down (1/32, 1/64) the power the more control, 2) a way to trigger said flash. This can range from a off camera shoe cord, PC sync cord, optical triggers, ebay "poverty" wizards, cybersyncs, to the new flex pocketwizards that are $400 a pair (1 on camera, 1 on flash).

Some other things that are used often are stands (http://strobist.blogspot.com/2006/03/lighting-101-light-stands.html), clamps (http://strobist.blogspot.com/2006/03/lighting-101-super-clamps.html), umbrellas (http://strobist.blogspot.com/2006/03/lighting-101-umbrellas.html), softboxes, gels, (http://strobist.blogspot.com/2006/03/lighting-101-using-gels-to-correct.html) backgrounds, snoots, gobos (http://strobist.blogspot.com/2006/03/lighting-101-cereal-box-snoots-and.html). This part of the hobby can get expensive quickly.

There are a number of key things to know about flash before you ever start using flash:
1) Flash happens in an extraordinarily brief amount of time. Typically, one ten thousandth of a second depending on the power.
2) Light generally travels in a straight line. Light also reflects and refracts off objects at the same angle as they hit the object (think of billiard balls).
3) Light "falls off" (gets dimmer) the further the source is from the subject.
4) Light is hard if the perceived source is small. Hard light casts a harsh line where the lit area goes to shadow. Generally a bare speedlight is a hard source. Perceived size is key, even though the sun is a huge ball of gas, on a clear day it is a small perceived source because it is so far away.
5) Light is soft if the perceived source is large. Soft light has a feathered line where the light goes to shadow. You increase the size of a strobe by bouncing it off a large object (wall, ceiling, reflective umbrella) or shooting it through a large translucent object (umbrella, softbox, sheet). Remember that if you are bouncing or shooting through something with color, the light will retain some of that color.
6) Because of #1 above, your shutter speed has NO affect on your flash exposure (make sure you see 7 below). On the camera only ISO and aperture control the flash exposure (flash power and distance also come into play, see #3 above).

What mode do I need to shoot at?
If you shoot with an off camera shoe cord or the new PW Flex, then your camera will know there is a flash attached. But if you trigger your flash via one of the other methods ("poverty" wizard) then your camera has no idea that you're trying to add flash to the scene.

Therefore, your camera will not be able to correctly meter the scene in the auto modes or even Tv or Av. That's why I shoot Manual* when using off camera flash. (* I sometimes use Av mode to determine what manual settings I need to use to balance the exposure of the ambient light, more on that later).

How do you expose correctly when adding manual flash?
7) Determine what your cameras sync speed is. For most cameras it is 1/200 - 1/250 sec. The sync speed is the max amount of time that your whole sensor will be exposed in a fraction of a second. Its very easy to test your sync speed. Put any lens on your camera, set M mode with ISO whatever, aperture whatever, and shutter 1/100 sec. Put your flash on full (1/1) power and point it at the wall. Connect the flash to camera using whatever method you have for triggering. Point camera at wall and take a picture. If the whole wall is illuminated then you can sync at that speed. Up your shutter speed to 1/150, 1/200, 1/250, 1/500 and take pictures. If any black is seen in the final image (normally at the bottom when shot in landscape mode), then the shutter speed is faster than your sync speed. Also remember that sync speeds can be "cheated" (http://strobist.blogspot.com/2008/10/great-video-on-overclocking-your-sync.html) in certain situations. Also the sync speed can change for wireless triggers if the batteries are getting low.

8) Determine if you want to use ambient light, or nuke it. If you only want the light from your flash (black back ground) to expose the subject, then set the shutter to your sync speed and set the flash power & distance to an appropriate camera ISO and aperture.

However, if you want to use ambient (normally a good thing), then shutter speed will come into play. Your still set your flash power & distance to an appropriate camera ISO and aperture as above, but you want to set your shutter so that enough ambient light gets in at the ISO and aperture to expose it how you want.

Do determine if the flash portion of the scene is exposed correctly, be sure to check those histograms!!! Learn how to control the light (http://strobist.blogspot.com/2007/06/l102-light-controls-overview.html) like a tool.

Example: If I'm shooting a person in front of a sunset, its nice to have the person exposed correctly (by the flash) and the sunset underexposed to really bring out the colors and make the person "pop." I'd put my camera in Av mode and dial in -1 to -2 exposure compensation. Then meter the scene (half press), and the camera will tell me what shutter speed I need for the ambient exposure. As long as its slower than my sync, I'm good to go. I'll then set my camera to M with the same aperture, ISO, and shutter the camera told me (you can use Av, but M gives more control), and dial in the flash to correctly expose the person (or you can do the flash work first).

When working with ambient you'll also likely need to learn about gels (http://strobist.blogspot.com/2006/03/lighting-101-using-gels-to-correct.html), because ambient light isn't always 5500 color temp like your flash. Thankfully Sam already wrote a killer tutorial on gels (http://www.newschoolofphotography.com/forum/showthread.php?t=13512)

Last but not least, the only way to know how to light with strobes is to practice. Once you get proficient, you'll be able to see how the flash will look (http://strobist.blogspot.com/2006/04/lighting-101-see-flash.html) before you fire the shutter.


I'm sure I missed a ton, but this should be a good start for some of you new people wanting to go off camera. There are a lot of strobe shooters on the forum (Shawn, Sam, Jeremiah, and others) so feel free to ask questions.

jacobsen1
04-09-2009, 12:07 PM
nice dude, subscribed... :lol:

marcus.raw
04-09-2009, 01:22 PM
subscribed, what a teaser ;)

PhatheadWRX
04-09-2009, 01:45 PM
bump for it being pretty much done. would love to hear if this actually helps anyone. would also like to get others thoughts and opinions.

thomps6s
04-09-2009, 02:30 PM
I am going to throw this out there, French PM'd looking for additions to this thread.

6 Step Setup

1. Put your flash on a stand and connect it to the camera via wireless or PC cable
2. Set the flash power to 1/4 power as a starting point.
3. Set the camera to Manual - Aperture around F/5.6 - IS0100 - Shutter @ fastest (i.e 1/200) Sync Speed.
4. Grab the stand with your left or right hand, hold it off to your side about Two feet from your subject and position it approximately at 45 degree angle to them. Add a light modifier such as an umbrella if you want, not necessary. However, the larger the light source (relative to subject) (closer) makes for softer light...

Take the sun for example, it is a very bright light source but is so far away that it creates a small, hard light source.

Put the flash at a height that is above the subject and aimed down at them.
5. Take a test shot.

http://shawnthompsonphotography.com/ForumImages/LightingSetup.jpg

Was the shot over exposed? If so, If so you can do one of three things
1. Decrease the flash power
2. Decrease your ISO
3. Stop down the aperture (higher F/stop number)

Was the shot under exposed? If so you can do one of three things
1. Increase the flash power
2. Increase your ISO
3. Open your aperture (smaller F/stop number)

The closer the light is to your subject, the softer the light

The farther the light is from your subject, the harder the light

Remember these
1. Aperture controls the Flash Exposure - Wider Apertures allow more of the flash's light in
Narrow Apertures allow less of the flash's light in

2. Shutter Speed controls the AMBIENT exposure
The slower the shutter speed the brighter the Ambient Light will be.
The faster the shutter speed the darker the Light will be.

Sure there may be duplicate info in this short write up that french already discussed and I know there are more ways to achieve what I wrote, but the above will get you dialed in pretty quick.

PhatheadWRX
04-09-2009, 02:34 PM
great points and thought process shawn, should really help people get started quickly.

marcus.raw
04-09-2009, 02:36 PM
Was the shot over exposed? If so, If so you can do one of two things
a. Decrease the flash power
c. Decrease your ISO
b. Stop down the aperture (higher F/stop number)


:lol:

thomps6s
04-09-2009, 02:37 PM
:lol:

:lol: Fixed

danm
04-09-2009, 02:40 PM
great info, there is alot of info that i think i will find useful for my on camera external flash stuff.

exposure control with flash is what i am going to be using from this.

jacobsen1
04-09-2009, 02:42 PM
word!

and shawn, where's that setup .psd? I remember posting it a while ago around here somewhere.......................


edit: found it!
http://www.newschoolofphotography.com/forum/showthread.php?t=8599

we should all start filling those out, or at least those of us that want to help others learn this ****.... ;)

marcus.raw
04-09-2009, 02:50 PM
:lol: Fixed
is it really fixed???:wave: :lol:

thomps6s
04-09-2009, 02:51 PM
is it really fixed???:wave: :lol:

Yup! ;)

marcus.raw
04-09-2009, 02:55 PM
Yup! ;)
ABC's man!! a..b..c..!! lol just givin you a hard time! great info though, about the umbrella, ive seen them pointed open side toward subject, and the other way as pictured, is there pros/cons to such positioning?

thomps6s
04-09-2009, 02:57 PM
ABC's man!! a..b..c..!! lol just givin you a hard time! great info though, about the umbrella, ive seen them pointed open side toward subject, and the other way as pictured, is there pros/cons to such positioning?

Open side toward the subject is for a reflective umbrella, the flash fires into the umbrella and bounces back toward the subject.

Closed side toward the subject is for Shoot through (translucent white) umbrellas.

PhatheadWRX
04-09-2009, 02:58 PM
we should all start filling those out, or at least those of us that want to help others learn this ****.... ;)
OR just take a UWA shot of your setup like I did for marisa in the link at the bottom of post 1 - http://www.newschoolofphotography.com/forum/showthread.php?t=14531

:keke:

PhatheadWRX
04-09-2009, 03:01 PM
marcus, reflective and shoot through umbrellas both have their pros and cons.

I prefer shoot through because with a reflective umbrella your flash travels out to the umbrella then back past the flash and to the subject. That distance to travel back is wasted, and can matter when you're dealing with strobes (less power then studio lights).

Also a shoot through umbrella can get much closer to your subject, without getting the umbrella in the frame.

That being said, both my umbrellas are shoot through with a black backing that can be attached so they can be used similar to a reflective umbrella.

marcus.raw
04-09-2009, 03:07 PM
marcus, reflective and shoot through umbrellas both have their pros and cons.

I prefer shoot through because with a reflective umbrella your flash travels out to the umbrella then back past the flash and to the subject. That distance to travel back is wasted, and can matter when you're dealing with strobes (less power then studio lights).

Also a shoot through umbrella can get much closer to your subject, without getting the umbrella in the frame.

That being said, both my umbrellas are shoot through with a black backing that can be attached so they can be used similar to a reflective umbrella.
wow the light just turned on in my head, its so simple and makes so much sense, but i didnt think about the loss in distance or how close you can get etc, thanks!

jacobsen1
04-09-2009, 03:24 PM
link to cheap shoot throughs?

(I have 2 reflective umbrellas).

thomps6s
04-09-2009, 03:26 PM
link to cheap shoot throughs?

(I have 2 reflective umbrellas).


Just use them, they are efficient too. You don't need shoot throughs to make good portraits.

PhatheadWRX
04-09-2009, 03:49 PM
very true. a true reflective (silver) can be more efficient than my shoot through with a black backing. In my reflecting mode, some of the light still goes through the umbrella and is lost on the black. In shoot through mode, you also lose light that is reflected back (about a stop or so)

That's why softboxes are really nice. less loss of light, and great control over where it goes (like a big snoot).

thomps6s
04-09-2009, 04:10 PM
Just saw these lighting Setup helpers on another site.
Pretty cool.

http://www.lowel.com/edu/foundations_of_lighting.html#2

http://www.photoworkshop.com/static/lightcage/index.html

PhatheadWRX
04-09-2009, 04:16 PM
that rocks Shawn. great addition to the thread. shows me I need to play with lowering my stand height

ride5000
04-09-2009, 04:18 PM
i like this thread.

one thing though: there's a lot of light lost in a softbox. ;)

PhatheadWRX
04-09-2009, 04:19 PM
not if you build a softbox and the inside is all mirror reflective ;)

thomps6s
04-09-2009, 09:57 PM
not if you build a softbox and the inside is all mirror reflective ;)

My Westcott Apollo 28'' softbox is very efficient. The inside is reflective, the flash shoots to the back so all the light is reflected back out the front. No light loss except what the diffusion panel eats.

Mr.Krinkle
04-10-2009, 05:13 AM
Holy Carp!!! This was exactly what I needed. Thanks man!

nuklehead
07-02-2009, 04:38 PM
this really helped me ... thanks guys! :)