Flash metering questions.

[Lightworks Imaging]

What am I missing? I shot some "Strobist-style" images of my sisters children and got decent results. But, I have some questions regarding the settings of camera and flash. I'm not understanding metering for flash. I'm using a 50D and a Tamron 28-75mm f/2.8 lens.

My lighting gear consists of a single 430EX, off camera, with a shoot through 42" Wescott umbrella. My subject is about 4' from my background and I'm shooting from about 5'-6' away. The images are acceptable.

Here's my quandary. I'm not understanding the concepts of metering for flash. I'm setting my camera for f/5.6, 1/160th sec. and ISO 400. My lens is zoomed out to 75mm. I'm using the flash "off camera" and shooting thru the umbrella, from approximately 4' to my subject. I'm also using a reflector for a secondary light source. The room I'm shooting in is my living room, and the ambient is dampened, through use of "blackout drapery". The 430EX is operating in manual mode and set at 1/4 power. My cameras meter is indicating a >2 stop underexposure.

My question(s) are these: (1) is there any way to set the exposure without a light meter? (2) am I mistaken in my observation that there is no really consistent method of determining proper exposure without having light meter?

I'm reading everything I can find about metering, and I am comfortable metering to blend ambient light with flash, and "dragging the shutter". This seems to be a less than scientific process, in the absence of a light meter.

Am I the only one having this gap in my understanding? I'm not feeling like I'm terribly smart. Thanks for any insight. I've included two examples of the photos I took.

[Wilt]

My question(s) are these: (1) is there any way to set the exposure without a light meter? (2) am I mistaken in my observation that there is no really consistent method of determining proper exposure without having light meter?

With flash you use a flashmeter, or you can use the slow trial and error method of shooting and peeping at the histogram until it is right.

I'm reading everything I can find about metering, and I am comfortable metering to blend ambient light with flash, and "dragging the shutter". This seems to be a less than scientific process, in the absence of a light meter.

Am I the only one having this gap in my understanding? I'm not feeling like I'm terribly smart. Thanks for any insight. I've included two examples of the photos I took.

A number of things about flash is not intuitive obvious, but comes about via education and experience. For example, if you wanted the intensity of light from front to rear to fall off more slowly, would you move the light closer or farther away? A: Farther away

Furthermore, using a speedlight hinders the process even more, because you HAVE TO shoot and look at the result, in order to know what your light positions will result in. With a studio flash, the modelling allows your eye to directly SEE the result without shooting.

[GenuineRolla]

Chimping is not a slow trial & error. Once you get the hang of it, you'll get the settings down within a couple frames.

Remember, f/stop controls the flash exposure so you'll want to shoot in M. More often than not, when doing strobist shots, you don't really need to keep an eye on the exposure meter, that is unless you see that the shot is going to be over exposed by the ambient itself.

[Wilt]

Chimping is not a slow trial & error. Once you get the hang of it, you'll get the settings down within a couple frames.

Remember, f/stop controls the flash exposure so you'll want to shoot in M. More often than not, when doing strobist shots, you don't really need to keep an eye on the exposure meter, that is unless you see that the shot is going to be over exposed by the ambient itself.

This works for a hobbyist. Don't thing many pro shooters or their clients can afford wasted time, though.

[vadim_c]

With one light a lightmeter is optional (stll makes your life more pleasant).
With multiple lights you still can leave without it but prepare to see your model go while you are spending all that valuable time on setting/chimping/setting again/...

[Lightworks Imaging]

Thanks guys. I understand, I guess that I'll be needing to pry open the wallet and front for a flashmeter. Thanks again.

[Damian75]

I agree with Wilt that it is less intuitive and more and education also I have always considered a light meter a very valuable part of my camera bag I use it even for natural light portraits when using reflector to make sure I am getting the right light ratios and I just find it more accurate and on a paid shoot more professional than the shoot chimp approach.

[matonanjin]

Just a quick couple questions:
1) Why ISO 400? You always want to use the lowest ISO you can for best quality. Although depending on camera there shouldn't be a lot of degradation at 400.
2) Why shutter speed of 160? You didn't mention what camera but at 5D will sync at 200 and most the amateur camera's at 250.
3) Why F 5.6? By lowering ISO you can open up to F/4 and get better blurred bg. Although with these particular set-ups the bg is black. The real "sweet spot" on the Tammy 28-75 is F4. You can up output on your strobe to 1/2 if necessary or move it closer.

Just a couple alternative starting points for thought.

[Gatorboy]

This works for a hobbyist. Don't thing many pro shooters or their clients can afford wasted time, though.

David Hobby doesn't use a lightmeter. I wouldn't call him a hobbyist (no pun intended)

[Lightworks Imaging]

I suspect that some clarification is necessary. I chose ISO 400 in a vain attempt to get a decent shutter speed. My lack of understanding of the nature of "off camera flash" in concert with the triangle of Tv, Av, and ISO, led me to try to crank things up to get a reasonable shutter speed. I realize that ISO 100 would be a better choice. I see now that when using strobe as the primary light source, with little to no ambient, EVERYTHING is dependant upon flash power settings. I need to set the light first. Then, after I get that, go to synch speed, and the aperture settings for my lens, which I didn't realize were still "sweet" at f/4. I suspect that my next effort will involve the same environment, and I'll make my modifications accordingly. Same distances, and shoot at 1/2 strobe power, ISO 100, 1/250th, and f/4. Starting there, seeing what happens, and chimp and adjust accordingly. Next up on the list; Sekonic L-358! (And some more strobe(s))

[Wilt]

Professionals who have a studio set up that is 'dialed in' and seldom changes from established lighting setups, will not need to bring out a meter. This is very different than trying to set up lighting from scratch.

If one does a lot of location portraiture, it is fairly simple to set up lights at pre-established distances and power settings, and get very good lighting results. This is similar to using a 'dialed in' studio, since effectively you are copying your studio setup on location.

For example, I could rapidly set up lights at known positions of the clock, around the subject, and I could get 3:1 lighting simply by using a ratio of distances to my main vs to my fill light. So, yes, you don't "have to have" a meter, if you know what you are doing, and have a pair of lights whose output differences are well understood. I would not tell a beginner with a mixed bag of lighting gear to learn to set up this way, however. Nor would I do this with flash equipment that I was not well familiar with using (having set it up before with a meter).

[bobbyz]

Tinner18,

In the shot syou posted, since they are taken indoors, at the settings used, the majority of light is from the flash. You can check this by turning off the flash and taking a shot at your chosen setting. I fyou get black or almost balck frame then flash in the only one providing the light for your shot.

So in this case, shutter doesn't matter. You can set to 1/60 or 1/250. So that is out of the way. Now you want lower ISO, if it is ISO100 on your camera use it. Some Nikons only go to ISO200, that is fine. Now pick some power setting on your flash, say 1/2. Adjust your camera to say f8, take a shot of some white cloth. If it is underexposed, open your aperture. If overexposed, make aperture smaller. Adjust so tha white cloth is exposed properly without any blinkys. Now you ready to shoot. You can also use one of those Ed Peirce target things. Check out Chuck Gardner's website. He explain all this in his tutorials.

Now if you were outside, you have to worry about ambient. Even at say ISO100, f8, 1/250 you will more ambient light than what you typically need. So you need to stop down (as you can't increase your shutter due to flash sync speed limitations). This will lower ambient. Then you adjust flash exposure just like you do for indoors.

This is just simpel explanations. I would read here and other forums and try things to see how it all works.

[Brett]

Bobby covers the way I do it. I do not own a flash meter, and one isn't in the cards since I just bought my first house and have to furnish it.

Everyone seems to advocate ETTR. As I understand it, ETTR is fine as long as the highlights aren't blown. Exposing any one shot just below the highlights being blown seems to work very well for strobist photography, and that's the way I've learned it. I've read "use a flash meter and meter the chin". Is it so different to ETTR so that the chin highlight isn't blown?

I'm honestly curious. :)

[TMR Design]

Let's also not forget about lighting or rendering backgrounds as black or white. It's easy to be fooled by the histogram as well as the LCD display on the back of the camera. The light meter comes in to play not only for subject and subject area lighting but is an incredibly useful tool and timesaver for rendering those backgrounds pure white or pure black. No guesswork, no chimping. Meter the subject area, set your strobes accordingly for the background, meter and shoot. No test shots needed. Simple, painless and spot on every time.

[matonanjin]

Bobby covers the way I do it. I do not own a flash meter, and one isn't in the cards since I just bought my first house and have to furnish it.



A light meter is way more important than furniture ;)

[Brett]

A light meter is way more important than furniture ;)

Hehe, yeah, what was I thinking? :p

[Wilt]

And for anyone wanting a real bargain in a meter...just listed on POTN by another member is a Kenko meter, which is the same as the Minolta meter which sold for about $270 at B&H about 15 years ago. Cost is not a reason NOT to buy and use a flashmeter for flash setup!

[Brett]

And for anyone wanting a real bargain in a meter...just listed on POTN by another member is a Kenko meter, which is the same as the Minolta meter which sold for about $270 at B&H about 15 years ago. Cost is not a reason NOT to buy and use a flashmeter for flash setup!

I missed out on it. That's the kind of price I'd be willing to spend.

[Lightworks Imaging]

Thanks again guys. This kind of feedback is precisely why I love POTN! I learn every day and this is were I get fed. Now, off to shoot more. Saving for that flashmeter!