How to meter lights

[spcalan]

I am learning how to set up my light set.
I have 2-300 watt JTL lights

What is the trick?

Meter background? meter subject?

I know I need to be in manual mode.
I do have a light meter. but lost on what is the correct way to use them together

[ghms421]

What kind of meter? You should use incident metering at the spot where your subject will stand. Depending on the tone of their skin you may need to adjust exposure accordingly.

[c71clark]

There are lots of places to go for info, including the stickies here. Try these and browse around...
http://www.studiolighting.net/
http://strobist.blogspot.com/

[staffer]

(assuming you're doing portraits)...I meter my fill light first and set it (typically) at 5.6 for single portraits. I then control the ratio with my main light. Make sure you meter only the main; some incident meters have a flat diffuser that when pointed at the main will not take into account the fill (you can also turn off the fill or use your body to block the light). Once you've set your main, take another reading with all lights on (the fill adds to the main reading).
I usually use a spot meter to measure the background but some incident meters have reflection caps as options. As you have only two lights, controlling background illumination will mean moving the subject closer or further from the background . You could use one light on the subject, one on the background and reflectors for fill ,rim and hair, but I would still use a reflective meter for the background.
This will all require practice of course. I would suggest rattling off a bunch of exposures of your backdrop(s) and identify the densities you prefer, that way you could use your incident meter for everything.
Make sure your fill is softer than your main.

[Titus213]

Assuming you get your subject metered properly, and without a separate background light, the only way you can impact the light on the background is by adjusting it's distance from the lights.

[staffer]

Moving the subject with respect to the background (that would mean lights as well) is usually easier than moving the backdrop because the lighting should be in place before the subject sits down. This differs of course when you're lighting the background with fall off from the main and you want somewhat even illumination; then you would angle the backdrop. It should still be in place before the subject shows up.

[spcalan]

Thank you for your help.

I will mostly be doing church photos ( not weddings ).

I use a Polaris light meter and I have 2 -JTL Mobil Light 300's.


1. So I should always shoot in manual
2. So 5.6 is what portraits should be? why? Why not 6-7? I am trying to learn.
3. Adjust lights until background is 5.6?
4. Adjust lights until subjectis 5.6?

Then shoot?

[staffer]

I assume you'll want to expose some of the church interior so...
1. Establish an exposure for the church interior; this is based on your taste.
2. Use the aperture from that exposure to set your lights. The shutter speed will control the church exposure. Always start with the light you can't control. Once you've established your base exposure you can bring in your controlled lights.
3.Start with the main, you may not need a fill if the ambient light does the trick.
4.You may need to filter your lights to match them with the colour temperature of the ambient light if you're going for a faithful rendering. A lot of photographers let the ambient go and balance on the artificial light - personal preference.
If you want a quick and dirty way of getting started:
A. Use your camera meter to measure the church interior and adjust until you like the exposure.
B. Position your main light where you want it and with an appropriate light modifier.
C. Make an exposure with the main and ambient
D. Adjust the power on the main light until you get the result you need.
E. Note the position of the main and it's power level...take a reading at the subject position with the meter's diffuser pointed at the main light.
F. Make note of the reading and compare with the ambient exposure.
G. If you need the fill light, set it up in the same manner as the main
H. Take a reading when it's power level is to your satisfaction (turn the main off for this) and compare the apertures for the main and fill.
This will get you started understanding about light ratios. You'll have the experience in your head when you sit down to figure it all out.
While your fill is set up change the power level only and take a shot. Record a meter reading and change te power again (up and down a couple of stops). You'll get an idea of how the fill relates to the main and what it means for the underlit side.
I just reread your post; Are you doing portraits inside a church or just church interiors?
If it's church interiors, you are into interior architecture (actually, the area I started in) and that is something different.

[spcalan]

These tips are great and I appeciate them.

I have a couple who wants to "recreate" their wedding.
That is the reason for the church.

I am very new to lights.

1. So I should meter the background ( choir pit ) and depending on exposure taste ( dark or light ), then I should set my camera to those settings?

2. Then meter the couple? and adjust my lights to meter the same so they will have the same shutter speed?

3. Again, I am looking for the "lighting for dummies" approach, and exactly the process to use lights.

Again thank you all for helping me

[staffer]

To answer your questions:
1. I always shoot in manual for interiors and portraits (actually, most things)
2. 5.6 is where I set my fill light (usually). It's a personal preference because I typically will shoot head and shoulders at 8 or 11. This changes of course with subject, skin tone, assignment and style; 5.6 was just an example. The important thing is the ratio of main light to fill light. The highlight side of the face is affected by the main and fill lights; the shadow side is controlled by the fill light or ambient light. By setting my fill at 5.6 I establish a base density for my image. I can then add my main light and adjust the power and position until I get the lighter side of the subject and modelling that I want.
3. Forget about 5.6, it was just an example. You'll have to find a formula that works for your style of shooting. Try my earlier suggestion of shooting the background at different exposures. Set your camera up in front of your backdrop for a fixed exposure of say, 1/60 @ f/8. Move your lights closer to and further from the background taking an image at each position and take a reading from the backdrop position. You'll establish a relationship between the position and power of the Main and fill lights and the background.
4. Here's a starting point for a studio portrait (find a willing model) set your fill for 5.6 and your main for 8. Take a reading with both lights on and shoot a frame. Set your main for a half stop less and shoot a frame. Notice the tonal relationship between the two sides af the face. Now set your main for f/11, meter with both lights on, shoot a frame and compare again. This is just an excercise, you should establish your own preferred settings. Remeber though that the light ratio should change depending on skin tone. Practice for this as well.

[staffer]

[quote=spcalan;3787751]3. Again, I am looking for the "lighting for dummies" approach, and exactly the process to use lights.


OK, here goes:

1. Choose the aperture you want to use (for depth of field sake)
2. Meter the choir pit using your chosen aperture (never mind the people yet). Keep your shutter speed reasonable, you don't want to make them "stay still" (you may have to adjust ISO but with the 5D-no problem)
3. If you have made an ISO adjustment, don't forget to change the meter as well.
4. Position your main light and adjust it's power to match the chosen aperture.
5. Take a shot with someone in the frame to make sure the light is correct and make adjustments if necessary. If the background is too light, choose a faster shutter speed; if it's too dark choose a slower shutter speed. Similarly with the subject exposure; too light? decrease power, too dark? increase power.
6. If the shadow side of the couple is too dark then add your fill light. Fill should be non-directional. You can bounce the light off the ceiling or pump it out of a large umbrella or softbox. It should be softer than the main light and positioned directly behind the camera or on the same side as the main near the camera. Do not create secondary shadows by placing the fill too far on the other side. Try setting your fill initially for a stop less than your main light.
7. Take a picture and check the results. Adjust if necessary and remember, your fill light has just added additional light to the bright side of the subject so you'll have to adjust again.

This should take you no more than 5-10 minutes once you're comfortable

Arrive at a balance you find pleasing and begin your shoot

[spcalan]

1. So 5.6 is usually used for portraits?
I do understand that the lower the number ( 2.8) that mean less will be in focus, but with a huge choir pit behind the subject, wouldnt I want to have the largest number ( F1000? ). Or maybe I want a smooth fade away from the people to the background. So maybe I need to play with it to decide if 5.6 is best for what background blur I want to achieve.

2. Then use meter to decide what shutter speed I need to use?
3. What is a reasonable shutter speed?
4. So set camera to background meter settings, and let lights light the subject.

I apologize for being a nag.

[staffer]

I apologize for being a nag.

No need, this is enjoyable.

Portraits are made using the gammut of apertures, one is no better in general than another, there are too many factors that enter that equation.
The lens you use will play a part in the aperture you settle on. Wide lenses exhibit greater depth of field at the same aperture than do longer lenses. What focal length will you use?
Are you photographing the couple full frame, 3/4 or head and shoulders?

Lets say you want the couple head to toe. You want the choir pit and some of the church in the shot to establish mood and location. You choose a 35mm lens on your 5D and place the couple 13 feet away. Focusing on the couple will give you an acceptably sharp range of approx. 7.5' - 60' at f/8. The hyperfocal distance is closer to 17' in this example but you wouldn't set focus for that when you should be focusing on the couple.
Using an 85mm lens under the same conditions would give you a sharpness range of 11.5'-15', surely not enough to get the choir pit and you've chopped the couple at the knees.
Don't stop down all the way if you don't have to. Smaller apertures introduce diffraction problems into the image.

Try not to get too slow a shutter speed, 1/2 second is pushing it. 1/30 and up would be ideal, you could even get them still enough for 1/15 or 1/8 but you need to remind them of the slower speed and the need to remain still. The problem with that is you lose spontenaiety of expression.

I think you 're getting it

Easy way:
select aperture
set background exposure with camera
use aperture value to set lights
adjust power on lights until subject looks good
adjust shutter speed until background looks good

[Titus213]

Alan,
The f5.6 mentioned above is the meter reading you should shoot for with just your fill light on the subject. I think what staffer is getting at is the ratio of the fill to the main. If you set the fill light to f5.6 you will then add a main at slightly higher f-stop. This will create a controlled shadow on the subjects face, not deep and dark but soft and pleasing shadow. The main light will ADD light to your image so you will shoot at something slightly over your fill + your main. Staffer indicates he uses f8.0 - f11.0 for head shots and it is a personal preference. If you want the background blurred with DOF you will probably want to start your fill at something lower. Just keep enough DOF to insure all the key people are in focus. I generally shoot for a shutter speed around 1/125 but will go down as necessary for ambient light.

As far as metering for ambient light, you do that first to create a mood for the background. Your lights will not light much of the church so the available/ambient light will need to be considered as much as possible. Obviously (or maybe not) if the ambient light is too high you will have issues adjusting your strobes higher. I've not yet encountered many churches with that problem.

[Titus213]

BTW - if the 18-55 you have is the kit, and you use it, make sure to keep your f-stop above at least 7.1. That's about where most of the kit lenses start getting sharp. It does tend to crimp DOF though.