Confused about custom white balance

[SCraig]

3. Assume the strobes are triggered and the flash meter says f8 for example.
Then what? How do i tell the strobes I need f8?
I only have full power or reduced power on the strobes...how do I set f8?

You set the CAMERA to f/8.

 

[Quovadis]

It's actually very logical because f8 is an absolute value and is f8 is f8 is f8 no matter what camera you're using. "Dim" or "Bright" are relative terms and will not tell you what you need to know.

Okay... baby steps.

First decide what aperture you want. This will be determined by the depth of field necessary to have the amount of the scene in sharp focus that you want in sharp focus. The DoF is determined by the focal length of the lens, the aperture and the distance from the subject. You know the focal length and distance because you've figured out where you need the camera to frame the image the way you want. Now, take those two parameters and consult your DoF table of smartphone "app". It will tell you what aperture you need. For the sake of example, you need f8.

Now, set up your strobes the way you want, and make a WAG about the power settings; failing all else, go for the middle on all of them to start. Now, take the trigger off of your camera and place the meter against the subject, and using the test button on the trigger, trip the strobe FOR YOU KEY LIGHT ONLY (turn the others off for now). Let's say that the meter now shows f11. Reduce the strobe output power by a bit and test again, repeat until you have f8.

Next turn off the key light and turn on the fill light. You've decided that you want 1 stop of dynamic range between highlights and shadows in the shot, so that means you will need to set your strobe to f11. Repeat the 'test-adjust-test-adjust' process with your fill until you get f11.

Once the fill is done, turn it off and turn on both background lights and meter the background AT THE BACKGROUND; you want f8 (same as your key) or slightly above, say f8 +1/3; just enough to render the background pure white. Once you've done that, turn on all the lights, place your trigger back on the camera's hot shoe and shoot the scene with the camera at f8 and maximum sync speed (usually 1/200 - /250) and look at the image you get. Start adding flags and reflectors as necessary to increase or decrease light to a specific area.

THANK YOU!! got it!!!

 

[tirediron]

...Let's assume it reads f14.
I need f11 because i'm shooting at f11.
We have a discrepancy of 3. So the lights have to be increased or dimmed by 3? Not sure. I think dimmed.
So i have to dim the all 4 strobes by three points/stops/intensity ?
Is this correct?

No... you have a discrepancy of 2/3. Full f-stops: 2.8, 4, 5.6, 8, 11, 16, 32. Don't worry about WHY the numbers are the numbers they, just accept them.

 

[Quovadis]

ummm...to make matters worse I will not be able to use the exposure meter on the camera, that I have been using to date with continuous lightning.
So basically key light at f11
Fill light at f14
Background lights at f11.

So the fill light has to be slightly less bright than the other 3 lights?

 

[tirediron]

...So the fill light has to be slightly less bright than the other 3 lights?

Generally, BUT... you may not want any shadows; you may want an even or high-key look, in which case all lights will be the same. It really depends on what you want for your end result. Bear in mind that this is a very simplified approach. Don't think that getting the first set-up down is going to be easy; it will take some time. When you do get it nailed, diagram it, measure all of the distances and annotate with the power settings on the strobes so that the next time you need to, you can set it up in 5 minutes, do a confirmation shot and get shooting.

Remember too that you will have to move things and adjust slightly for different shapes, textures and colours.

 

[Quovadis]

Sorry but I have another stupid question.
I realize that the purpose of this exercise is to adjust the strobe light intensity with relation to the aperture number on the camera you want to use.
Let's say the strobes are too bright (all four),
Can't you simply increase shutter speed? I mean to dim the photo?
or is this cheating?

 

[Quovadis]

Here are the instructions on that website, it clearly assumes the source of light is continuous :

Using a Hand-held Meter
First, let's go through the basic steps for using a handheld meter:

• Set your camera to manual mode, and select your preferred ISO and Aperture.
• Turn the knob around the white dome of your light meter to make it protrude.
• Set the ISO on the meter to the same value you set on the camera.
• Set the aperture to the value you set on the camera.
• Hold the meter in front of your subject with the white dome facing the camera.
• Press the measure button.

The meter will instantly read out the correct shutter speed for the shot you want. Ensure that your camera is set to manual mode or shutter priority mode and then set the shutter speed to the reading given.

You won’t have to get a new reading until the light changes, so you can keep shooting from there without worrying about your exposure. Instead, you can concentrate on composition and your subject itself.

So, what do you think? Worth trying one out?

So i have to press 2 buttons simultaneously? The one on the flash meter and the one on the wireless trigger?
Other wise the light meter will have no light to measure apart from ambient light coming from the balcony.
Is this correct?

 

[tirediron]

Shutter speed doesn't enter into the flash exposure equation (much). Every focal plane shutter has what is called a 'sync' or 'max sync' speed. This is the fastest speed at which both halves of the shutter are completely open at the same time. At any speed above that* if you use a flash you will see a black bar appear on the image, which is the second shutter curtain closing. This is usually 1/200 - 1/250. You can use almost any speed below that, with NO affect on the image until (a) it become so slow that ambient light begins to affect the exposure or (b) it's so slow that vibration and motion affect it. Try it... you will see NO difference in exposure shooting with flash only if you shoot at 1/60 or 1/200.

Also, don't get into the habit of thinking of the strobes as "all four". In the examples I've used, you have four individual lights lighting in three separate ways. The two background lights should be the same intensity and adjusted the same up or down. The key light and fill light should be adjusted to preserve the exposure difference between them.

With respect to your 'Using a hand-held meter', that's pretty much exactly it. The only detail relates to the button pressing. Press the meter button and then the trip the strobes. Flash meters all have a 'waiting' period after the measurement button is pressed, in other words they will all continue to "look" for flash (ambient light will be ignored) for anywhere from 15 to 60 seconds, so you don't have to press the buttons at exactly the same time.

*High-speed sync or HSS is an exception, but the strobes you've ordered don't support it.

 

[tirediron]

Moved thread to a more appropriate location.

 

[Designer]

Gosh
I know nothing about light ..

FIFY

 

[Quovadis]

Thank you for explaining that both buttons do not have to be pressed at exactly the same time. I was already getting very anxious about that.

I tried something with my cfl lights I have never ever tried before. I pointed all 4 soft boxes to the white ceiling. It was more an act of desperation than anything else.
Low and behold, this is what I got. hardly any reflections on the bag. I do notice on the left side of the bag is considerable ambient light coming from the garden, and there were green reflections from the grass, which of course will not be there tonight when i take more shots.
This shot proves, that I need to bounce light as much as possible on shiny bags, as opposed to point a light at the bag. I am surprised the picture is not dark either.
What I just did, goes against all logic of having a key light fill light etc...they were just all randomly aimed at the ceiling. It has taught me that nothing is written in stone.
The front of the bag obviously needs more light, I have to figure out how to give it more bounced light, maybe put the softboxes as high as possible near the ceiling.

 

[tirediron]

What this proves is that you need to diffuse the light more. All that bouncing the light does is provide additional diffusion by creating in effect, a single, large light source. When I look at that I see shiny areas all over it, which to me, would not be acceptable.

Bear in mind too, that the first few shots with the strobes will probably look like crap, but if you read LSM, and follow the advice yu've been given, it should come together very quickly. The biggest issue with using this sort of lighting technique is that it's almost impossible to control a small area using flags or scrims.

 

[Quovadis]

Which lighting technique are you speaking of? Cfl or strobes?
Do you mean a small area on the bag?
Or do you mean my photography area is small?

 

[tirediron]

Which lighting technique are you speaking of? Cfl or strobes?
Do you mean a small area on the bag?
Or do you mean my photography area is small?

Bouncing all the lights off of the ceiling - you have no idea what lights are doing what and which are contributing and how much and which aren't.

 

[Dave442]

I was looking for a Distribution box after seeing a nice one at a recent concert. Anyway, one site that came up in my search just made me think of this thread and how the OP must be feeling (and for anyone not in the movie business that has sat around with friends in LA)...

What Are You, New?