ISO & studio strobes

I need some help. I use 2-3 adorama 320m studio strobes and I have very inconsistant results. I use my L-358 seconic meter and measure each light individually but that doesn't really get me anywhere. Just frustrated. I have been setting my shutter speed to 250 bc that is the fastest the 7d will sync with my setup. I set my ISO to 100 bc I have always heard the slower the better. So I set up and test fire and get a reading from the main light. say it is f5.6. I then adjust my fill light to something less like f8 or so. The problem I have is even if I'm just using 1 light, the exposure settings given by the meter make the image too dark. Is this a common problem and I am just inexperienced enough to not be aware? I normally jack around with f-stops and light power until I get the main light right. Most of the time I finish nowhere near where the meter started me at. I will sometimes take a reading after I am satisfied with my image and it is way off. Would shooting a higher ISO help this problem? I need some suggestions on basic defile and metering I guess because setting up and doing 20 min worth of test shots just kills me. Any help would be great.

Thanks so much

With a modern DSLR 400 will perform almost as well as 100 so there is no reason to stick at 100. Shutter speed is pretty much irrelevant as your flash all dumps as once so you wont see much difference if any between 1/100 and 1/250 in the studio, As for the problems you are having metering, I'm not entirely clear as to what you are doing. The way you are describing your technique your fill is brighter than your main?

That was a typo. Sorry. Reverse that. Like in had said though, even with a single light, the meter seems to under expose or I am just screwing it up somehow.

Something isnt right because if you start at f8, and you add a second light, you should end up with a higher exposure value. Have you viewed any of the Youtube videos showing how to use that meter? I have heard there are several useful ones.

First things' first......
You MUST calibrate your meter to your camera!
A quick and simple way to do this is to get a calbration target that has "White, Balck & Grey" on it..... If you don't have that readily available, then a white sheet of paper will have to do for now. Put you camera's ISO on 100, then put your meter on 100. Do a meter reading with you lights at least 6-8 feet from the subject. Place both lights at a 45 degree angle to the white card and make sure that they are both set to the same power (let's say 100ws for instance). Take a meter reading and adjust the power until you get an (exact even f-stop) something like EXACTLY f/5.6 or f/8.0 (personally, I just like using the "main" f/stops) Anyway, let's use f/5.6 for example. Now, open up 1 f-stop from f/5.6 which would be f/4.0 and do an exposure with your camera in 1/3 stop increments all the way to f/8.0. Now take all of those images and open them up in photoshop and measure the white using the eye dropper tool until you get an average of 245 across the board (I doubt that the reading will be even due to color consistancy) , but you want an average of about 245. Now, let's say that when you do this reading, the exposure that gave you that reading just so happens to be the image that you shot at f/5.0..... then you know that whenever you get ready to shoot something, you really need to set your meter to ISO 80, but your camera will still be on ISO 100. So, in layman's terms, your meter compared to your camera's "TRUE" ISO is off by 1/3 of a stop. So, no mater what ISO you set you camera at, you will always need to set your meter 1/3 of a stop brighter. Now there are more detailed and more proper ways to TRUELY calaibrate your Camera and Meter, but this is the Fast Low Down Dirty Quick way to do it. BTW, the reason you want to use a a white card or even the white portion of a calibration card is to see the what is the brightest or "whitest" white that you can get while still retaining detail in the white...... which just so happens to be 245, some may even say 235 or 240, I have found it to be 245 for my needs.

Now, regarding your lighting technique, if your main light is set to f/5.6 and your fill light is set to f/8..... then you are going about this TOTALLY wrong! If we go by your standards, then your fill light will now actually become your main and your main is now actually your fill. Anyway, regardless, after your meter your lights indivdually and get your "Ratios" (meaning one at f/5.6 then the other at f/8) you will still need to do a meter reading of them together, because then you will find that both flashes combined will up your exposure by 1/2 stop. So instead of setting your camera to f/8 (your main light reading) you actually need to set your camera to f/9 or f/10 (because there are no half stops any longer with digital cameras) so you'll have to settle for 1/3 stop under or 1/3 stop over.

But anyway, try these exercises and see what you come up with..... And last but not least, I believe that the 7D flash sync is 1/200, but it's probably best to use 1/125 and make sure that you are pointing the "DOME" of your meter towards the camera when doing meter readings.
Good Luck!

No but I will check it out now. I know when I finally figure this out, it will be a big palm to forehead moment

@loft. Great advise. I know what my tomorrow afternoon will be full of. Would it be better to set my meter to the camera? This model will let me adjust it that way also. I stated in another reply that I had typoed the above settings. The f8 was the main and 5.6 was the fill. Sometimes I get so frustrated with these lights. They don't give power in watts, only hash marks with the markings also for 1/8 1/4 1/2 & 1.

momoe wrote in post #12147014
@loft. Great advise. I know what my tomorrow afternoon will be full of. Would it be better to set my meter to the camera? This model will let me adjust it that way also. I stated in another reply that I had typoed the above settings. The f8 was the main and 5.6 was the fill. Sometimes I get so frustrated with these lights. They don't give power in watts, only hash marks with the markings also for 1/8 1/4 1/2 & 1.

This is normal.. 1/8, 1/4, 1/2 & 1 is the power output of the flash.. 1 is full power, 1/2 is half power etc..

BTW,, I have never calibrated my L-358. I find it deadly accurate straight out of the box..

Just a thought, are you using the incident dome on the L-358 and are you measuring each flash with the dome pointed at the flash from subject distance??

As far as the dome, yes. Each from the subject with dome out and facing the light

Have you set the ISO on the L-358 to correspond with the ISO on your camera? Do you have your L-358 set to flash meter mode? Is the ISO on your camera set to manual and not auto? Is your camera in full manual mode?

I don't want to ask the obvious, just trying to elliminate any user error..

Do you have a specific reason for shooting at 1/250? I'm assuming you're firing your second and third units via the slave eyes. Often when using remote triggers to trip flash you need to shoot at a slightly lower shutter speed as there is a slight delay. Try shooting at 1/125, 1/160 or 1/200 and compare results.

Yes. I shoot in full m on the camera and I try and shoot the max sync speed. I will do some test shots this afternoon with the above advise and see what happens

Its possible to get reasonably close using the technique Mark described with the LCD on the back of your camera to save going to Lightroom.

Set your camera so the highlight blinkies work. Then find the power setting and F-stop that causes the blinkies to show in white that is fully lit. 1/3 stop below that should get rid of the blinkies and is your exposure. This is fast and easy if you have a color checker, PassPort or similar.

Crumbled white paper towel also works.

Most meters have a means to adjust the reading to match the camera.

If you are reading the lights with dome facing light (proper technique) for individual readings and setting ratio, then have the dome facing the camera at subject position for the exposure reading, you should get a good exposure. I always fine tune using a Passport. It also gives me a white balance reference if necessary during post.

Bottom line; remember the meter reading is not the proper exposure, just a light quantity reading for you to use as a basis for getting proper exposure in the camera.

Ok so I meter each light by it's self and get everything ready. When I meter this, I have the dome out and it is pointed at the light I am measuring. Ok. Now when I have everything set, I place the meter in the subjects face and do I still have the dome out or on? Also, just for my clarification, when all lights fire, is the number that displays on the meter my f stop for proper exposure or do I have to drop it by 1/3 stop. I just want to make sure I get this so I am not wasting an entire day

momoe wrote in post #12148486
Ok so I meter each light by it's self and get everything ready. When I meter this, I have the dome out and it is pointed at the light I am measuring. Ok. Now when I have everything set, I place the meter in the subjects face and do I still have the dome out or on? Also, just for my clarification, when all lights fire, is the number that displays on the meter my f stop for proper exposure or do I have to drop it by 1/3 stop. I just want to make sure I get this so I am not wasting an entire day

Dome Out - Facing Camera - Exactly what meter says.....