exposure w/o a light meter?

[steve_andrews]

well i think i will not purchase a light meter at this time. But i just want to make sure i cant this straight...I know that

most experiences event photographers can walk into a room, church, recetional hall etc.. and have a pretty good

idea of what seeting they should use in manual mode.

 

But for people who don't have that experience, i assume the only way is to punch in an aperture you want, a shutter

speed that you can hold w/o getting camera shake and fast enough tofreeze motion ( 1/60 to max synch speed

1/250) and then adjust your ISO until your histogram looks right?

 

If there is a better way, i'd like to know.

 

Thanks again, I know i have been asking a lot of Qs, but i love learning about this stuff, and have my first wedding

ina few months!

[laronge photographie coutu]

Most cameras have a light meter built in. If your camera has one, check the owners manual or ask someone familiar with the camera to show you how it works. It's a good place to start.

[steve_andrews]

JOsh, yes mine does... i do understand how to use it but i guess what throws me off is when i am in a dark room with i set the aperture, and SS based in the in camera light meter, so that the line is "in the middle" the settings ( SS) are way to slow even with iso bumped up.

 

I gess what im trying to ficure out is using the in camera light meter with my 580 ex on camera. This really confuses me. The flash fires and lights the scene, but the S. speed is too long. So if i increase the shutter speed, then the in camera light meter show that it is underexposed. Here if i take a pick the flash still exposes the scene giving me a decent shot. It just makes me feel like i wont know if i get a good expose by looking at the light meter.

 

Does this make sense? Good thing Im a second shooter at this wedding, but i really want to understand these concepts. The more i read the more confused i get.

[laronge photographie coutu]

If your aperture is wide open and your shutter speed is too slow, your options are to increase iso or add light to the scene. There's no right or wrong reading, as long as you're using the meter properly, the reading is what it is.

 

I'm suspecting from your second paragraph that you are using Av mode. What's happening is that by using Av mode, you're telling the camera that aperture is the most important thing to you in the shot you're taking. The camera is making a decision based on what the flash is capable of to lower the shutter speed in order to not under expose the entire scene. In cases like this, you'll have to either add more light or accept the background underexposure. If you decide to accept the background underexposure, try putting your camera on M with your aperture wide open, the iso cranked up as much as you can stand the noise, your shutter speed at 1/focal length of the lens and your 580 on e-ttl.

[steve_andrews]

ok... i guess i was thinking that there was a "right " reading on the in camera light meter. I was talking about Manual Mode. So let me see if i understand what you are saying to me, sorry, im slow sometimes.....

 

If im in a dark room, and in Manual Mode with my 580 ex on, i dial in the aperture that i want and the shutter speed fast enough to aviod shake and blur. Lets say the in camera meter reading is saying that the scene is uderexposed. So its telling me to add flash or ISO. Lets say my ISO is as high as i want it to go and i dont change it..... I need to add flash. Hopefully in ETTL mode the flash will send the right amount of light to balance the scene. Thats it?

 

See I was thinking that if the scene described above showed that the reading was wrong b/c it was showing to be underexposed, instead of me looking at it as, the camera telling me to up the ISO or add flash.

 

Do i have it right?

[geoffcauble]

Steve,

 

You are correct, once you've set the aperture and ISO you want the flash, using ETTL, will put out the right amount of light to expose the scene (as best the flash can). Your in camera meter will read underexposed because it is underexposed based on the ambient light. The meter doesn't take into account the light the flash will add.

 

Set desired ISO and desired aperture, set your shutter as slow as you can (without causing blurring, hand shake) to pick up the ambient light and take the shot. The main subject will be illuminated by the flash and the background will be illuminated by the ambient light.

 

Shutter speeds aren't relevant to the flash exposure as long as the shutter speed is below the camera's flash sync speed (the speed at which the first shutter curtain is fully open before the second curtain begins to close).

[picturesque]

The first thing you should do is to understand that the ambient and flash metering systems are separate but related. If you meter a scene with your in camera meter, you are metering the ambient light. The camera does not tell you that you need flash, it just tells you that you are underexposed or overexposed, but only according to it's brain (or meter) for the ambient light.

 

I suggest you get the book by Petersen called "Understanding Exposure". You are getting confused because you think there is one correct exposure which the camera can tell you, and that it can incorporate flash exposure into it's 'correct' exposure. After reading the above book, I'd then read and re-read the photonotes.org/eosflash article.

[songtsen]

Would centre-weighted metering be less likely to show under-exposure on the in-camera meter in this situation (as compared to evaluative metering)?

[geoffcauble]

Songtsen,

 

Center-weighted would give you a more restricted ambient light reading. The flash is going to illuminate the subject, the meter will help you expose for the background. I don't think center-weighted is going to help. If the object in the center is better illuminated a center weighting would help your flash to put out the right amount of light for the subject regardless of the background. I don't think that is what Steve is looking for. I think Steve is trying to figure out how to balance ambient and flash in the same photo.

[picturesque]

Geoff--I use center weighted ambient metering all the time because I can predict it better than matrix or evaluative. I find evaluative puzzling and unpredictable at times. The times that I do use automated metering (AV or TV) with flash, I don't find evaluative better than center weighted, necessarily. The way ETTL is supposed to function, it supposedly does it's own evaluation of the background using the same metering segments but not necessarily the ambient metering mode before settling on an EV for the flash. However, since ETTL always was and still is, somewhat of a mystery, I can't say that is the way it actually works. Just how I think it works.

[geoffcauble]

Nadine,

 

I use center weighted and spot metering (or as close to it as the camera has) most of the time. Not so much because I don't like evaluative or matrix but more because I've never taken the time to learn to appreicate those other modes. I'm used to metering and locking focus and exposure then re-composing, I like being able to decide which light the meter weights and I have no idea how evaluative and matrix modes make those exposure determinations.

 

I probably spoke when I shouldn't have above. My point was more that the type of metering Steve uses isn't the primary issue. If he understands how to use his flash the metering mode will be a secondary or tertiary concern.

[steve_c.5]

As a general rule, I treat Program mode and automatic settings with caution. Whenever I get into a difficult lighting situation, I usually go Manual, rather than letting the camera's computer tell me what it should be. It's often off or wrong altogether. Those TTL modes are great for certain situations, but you can rely on them too heavily. The camera's meter (keeping it in the center) is a very good starting point and indicator to rely on, but what you see on your LCD, what the histogram tells you, and what you learn from much experience is really the better indicator. Now, of course, when you're on the run in varying lighting conditions, those auto settings can be a lifesaver. But when you're in a stable environment shooting portraits or in a church shooting the ceremony, you're almost always better off tweaking in a Manual setting and varying it as needed, and as your eye and the histogram tells you.

 

Steve, understand that the ISO controls how sensitive the sensor is. As you increase it, you make it more sensitive, and increase grain at the same time. Increasing the ISO lets you shoot in lower light conditions, while keeping your shutter speed high enough to prevent or reduce motion blur. If ISO 400 still results in some blur because you have to bring the shutter speed down to 1/30 to get a decent picture, then you need to increase ISO (or augment the lighting with flash) to get your shutter speed up high enough. The downside is increased grain. I'm assuming here that your aperture is already f2.8 or better, so your lens is letting in all the light it can. The latest DSLRs in the pro realm have cleaner high ISO performance to improve your low light results, but you sure pay for those bodies.

 

Sometimes, motion blur is cool, though. We've all seen cool magazine ads where one person is standing still while folks are all blurred, moving around them. Or, you can use longer shutter speeds and lower ISO to blur backgrounds or streak the lights for special effects. It's all in the effect you want to achieve.

[wedding-photography-denver]

If you are setting up to use flash its not the same as w/out.

 

W/out flash, you will need a higher SS to "feeze" action.

 

For aisle walking, 1/80th+ is ok depending on your lens. W/flash, you can shoot from 1/40th ok. I prefer to get somewhere in the 1/100th region. Add this to your aperture (select that based on the DOF you will need), which for aisle shots I like to keep at least f4.5 or narrower. Now you have the starting point to decide where your ISO should be. Test and retest. Check your histogram and push it a little to the right side. If shooting RAW, you can afford to push it a little too far (about a stop max) and still be in the zone.

 

Hope that helps. D.