Best metering mode for strobist work? and best one for night landscapes.

[ecphoto]

I am starting to work with strobes on light stands with some umbrellas. My question though is how would I use the in camera meter for this? Should I spot meter(if so on which portion) or should I use a different mode.

I will be travelling to Vegas next month and will be doing a lot of night landscape shots of the casinos and other sights. How should I meter for this?


Thanks in advance for the help!

 

[amolitor]

Your camera's meter has no idea what the light is going to be in the future, all it knows about is now. So it's pretty much useless when you're using strobes. You CAN use it to measure the ambient light, if you're trying to balance ambient and artificial light. In this case, spot metering aperture priority is probably a good choice, since you'll be setting the aperture to manage your strobe lighting.

You can also use a TTL system, if your strobes will integrate with your camera's TTL system ("dedicated speedlites" is, I think, the term of art here for that kind of strobe). Monolights, you're on your own.

You can also acquire a flash meter for measuring the actual light from the strobes.

I just fire off tests and peer at the results and the histograms on the camera.

--

For night shots it's another case of testing a lot. The dynamic range of these scenes is typically quite high, so spot metering can help you expose correctly for specific elements of the scene. If you want the facade of the hotel to be correctly exposed, then spot meter that and let the rest of the scene fall where it may.

Bracket and test, though. The histogram may be mostly useless here, since the whole point is to make a picture with a whole bunch of black in it.

 

[David444]

.

 

[Robin_Usagani]

If you afe shooting Vegas at night, then you dont need flash? You just need a tripod.

 

[cynicaster]

For shooting with lights on stands and all that, you probably want to ditch the camera's meter and dial the settings in manually, and leave the settings alone for the session once you get the right exposure. That will ensure consistency, whereas your camera's meter will be apt to set different exposures from frame to frame.

I'm assuming the Vegas question is separate, as the flash will be pretty much useless for taking cityscapes and the like. There you need a steady tripod and some trial and error, as the camera's meter won't have a clue. If you don't have a remote shutter release, use the camera's shutter timer so that you don't shake the camera when taking the shot.

 

[ecphoto]

If you afe shooting Vegas at night, then you dont need flash? You just need a tripod.

They were two different projects lol. I just got lazy and tried saving a post. I always use a tripod and release cable for night shots. I'm just wondering is spot or matrix would be best for this kind of shot? With all the bright lights from every direction.

Sent from my C5155 using Tapatalk 2

 

[TCampbell]

Your profile says you have a Canon 550D (and an AE-1 but I'll ignore that for the moment.) The 550D can only "meter" flash if it's shooting in E-TTL mode. In that mode the flash technically fires twice and the camera meters twice.

Here's a simplified version of how it works:

1) The camera fires a pre-flash at a substantially reduced power level (I think the default is 1/16th power but you can usually change it.)
2) The camera "meters" the scene in "evaluative" metering mode with no flash at all.
3) The camera compares the metering zones between #1 and #2. If it finds a zone with a bright point in #1 but is dark in #2 that this indicates a reflection (a shiny surface). If it finds a zone with very little change between #1 and #2 this indicates a light source within a room (e.g. a table lamp). It basically tries to ignore those zones (because they don't accurately indicate how the flash is illuminating the scene) and then compares the differences for the remaining evaluative metering zones (between #1 and #2) to detect how much of a difference the flash made (at 1/16th power).
4) Depending on the lens, it may be able to get focused subject distance information. Based on the guide number of the flash, the aperture of the lens, and the ISO of the camera, it can calculate the amount of flash power which *should* be needed to illuminate the subject. But even without that info, it can use the differences between the metering sample from #1 and #2 to determine how much of a difference was made at just 1/16th power, and then adjust to determine how much REAL power should be used to take the shot.
5) The camera then sets an appropriate power level for the flash and takes the shot (firing the flash again, but this time and the prescribed power level.)

ALL of this happens so fast, that if you didn't know it was happening, you'd swear your flash only fired once.

Canon calls this "E-TTL" or "E-TTL II". Nikon calls it i-TTL. Just about every camera maker has this or some variation on it.

That's the ONLY way the built-in metering on your camera can meter "flash"... and it only works for dedicated Canon E-TTL compatible flash units (or Nikon i-TTL compatible units for Nikon owners, etc.) If you take the flash out of that TTL mode and use it manually then your camera cannot "meter" the flash at all.

Going back to your AE-1... that technology was quite a bit different. Notice on the AE-1 there are only 3 contacts on the hot-shote (rather than 5). Technically the metal foot plate is actually the "ground" pin... so really your AE-1 has 4 electrical contacts (3 plus ground) and your 550D has 6 contacts (5 plus ground). The AE-1 doesn't have any form of TTL flash. It used a Thyristor-based flash system. In that system you'd set the Canon speedlight to either the high or low power mode. The speedlight would notify the camera that it was "on" and the camera would automatically set an aperture based on whether the flash was in the low or high power mode). The thyristor has a sensor on the flash gun which senses the return from the flash and then cuts off the power to the flash when it detects that enough light has returned. While this seems straight-forward and sensible... the PROBLEM with that system is that was easily fooled by highly reflective surfaces and or scenes in which there was a light-emitting source in the scene (such as a lamp). The current modern TTL technologies (such as E-TTL and i-TTL) are very difficult to fool because the advanced multi-zone metering systems in the camera and pre-flash are used to "test" the scene for reflections or light sources within the scene (and ignore them) so the exposure will be set based on what the "rest" of the metering zones showed.

So that's all great for TTL systems... what about for manual flash.

There are hand-held light meters which can tell you what exposure you need to set when shooting with flash on manual control. These meters measure "incident" light. You place the meter where you expect your subject to be and the meter "collects" the amount of light landing at the subject's location. This is basically the most accurate way to meter a shot (the built-in meter on your camera can only measure "reflected" light which bounces off your subject... that's less accurate because some subjects are either more or less reflective than others.)

Not all hand-held incident light meters can meter "flash". My first meter was a Sekonic L-308s... that's probably one of the most basic incident meters (costs a little over $200) which is also capable of metering for "flash" photography (you put it in a mode where it's expecting a flash and it continuously monitors the light looking for a huge spike in the light value... it locks onto that "spike" in light levels and then tells you what the meter reading would be. It's simple and fairly straight-forward. The Sekonic L-358 is more advanced and one of it's features is the ability to show you "flash contribution"... the percentage of light that came from flash vs. the percentage which came from ambient. This is VERY handy when shooting in mixed lighting situations.

If you're doing flash photography, it's nice to own a light meter which can meter flash. A light meter is one of those tools which I think just about every serious photographer (whether pro or enthusiast) should probably own -- even though you wont use it very often.

 

[ecphoto]

Your profile says you have a Canon 550D (and an AE-1 but I'll ignore that for the moment.) The 550D can only "meter" flash if it's shooting in E-TTL mode. In that mode the flash technically fires twice and the camera meters twice.

Here's a simplified version of how it works:

1) The camera fires a pre-flash at a substantially reduced power level (I think the default is 1/16th power but you can usually change it.)
2) The camera "meters" the scene in "evaluative" metering mode with no flash at all.
3) The camera compares the metering zones between #1 and #2. If it finds a zone with a bright point in #1 but is dark in #2 that this indicates a reflection (a shiny surface). If it finds a zone with very little change between #1 and #2 this indicates a light source within a room (e.g. a table lamp). It basically tries to ignore those zones (because they don't accurately indicate how the flash is illuminating the scene) and then compares the differences for the remaining evaluative metering zones (between #1 and #2) to detect how much of a difference the flash made (at 1/16th power).
4) Depending on the lens, it may be able to get focused subject distance information. Based on the guide number of the flash, the aperture of the lens, and the ISO of the camera, it can calculate the amount of flash power which *should* be needed to illuminate the subject. But even without that info, it can use the differences between the metering sample from #1 and #2 to determine how much of a difference was made at just 1/16th power, and then adjust to determine how much REAL power should be used to take the shot.
5) The camera then sets an appropriately power level to the flash and takes the shot (firing the flash again, but this time and the prescribed power level.)

ALL of this happens so fast, that if you didn't know it was happening, you'd swear your flash only fired once.

Canon calls this "E-TTL" or "E-TTL II". Nikon calls it i-TTL. Just about every camera maker has this or some variation on it.

That's the ONLY way the built-in metering on your camera can meter "flash"... and it only works for dedicated Canon E-TTL compatible flash units (or Nikon i-TTL compatible units for Nikon owners, etc.) If you take the flash out of that TTL mode and use it manually then your camera cannot "meter" the flash at all.

Going back to your AE-1... that technology was quite a bit different. Notice on the AE-1 there are only 3 contacts on the hot-shote (rather than 5). Technically the metal foot plate is actually the "ground" pin... so really your AE-1 has 4 electrical contacts (3 plus ground) and your 550D has 6 contacts (5 plus ground). The AE-1 doesn't have any form of TTL flash. It used a Thyristor-based flash system. In that system you'd set the Canon speedlight to either the high or low power mode. The speedlight would notify the camera that it was "on" and the camera would automatically set an aperture based on whether the flash was in the low or high power mode). The thyristor has a sensor on the flash gun which senses the return from the flash and then cuts off the power to the flash when it detects that enough light has returned. While this seems straight-forward and sensible... the PROBLEM with that system is that was easily fooled by highly reflective surfaces and or scenes in which there was a light-emitting source in the scene (such as a lamp). The current modern TTL technologies (such as E-TTL and i-TTL) are very difficult to fool because the advanced multi-zone metering systems in the camera and pre-flash are used to "test" the scene for reflections or light sources within the scene (and ignore them) so the exposure will be set based on what the "rest" of the metering zones showed.

So that's all great for TTL systems... what about for manual flash.

There are hand-held light meters which can tell you what exposure you need to set when shooting with flash on manual control. These meters measure "incident" light. You place the meter where you expect your subject to be and the meter "collects" the amount of light landing at the subject's location. This is basically the most accurate way to meter a shot (the built-in meter on your camera can only measure "reflected" light which bounces off your subject... that's less accurate because some subjects are either more or less reflective than others.)

Not all hand-held incident light meters can meter "flash". My first meter was a Sekonic L-308s... that's probably one of the most basic incident meters (costs a little over $200) which is also capable of metering for "flash" photography (you put it in a mode where it's expecting a flash and it continuously monitors the light looking for a huge spike in the light value... it locks onto that "spike" in light levels and then tells you what the meter reading would be. It's simple and fairly straight-forward. The Sekonic L-358 is more advanced and one of it's features is the ability to show you "flash contribution"... the percentage of light that came from flash vs. the percentage which came from ambient. This is VERY handy when shooting in mixed lighting situations.

If you're doing flash photography, it's nice to own a light meter which can meter flash. A light meter is one of those tools which I think just about every serious photographer (whether pro or enthusiast) should probably own -- even though you wont use it very often.

Thanks for the detailed response it really helped me understand the differences. I should invest in a meter. Does it work the same with studio strobes?

Sent from my C5155 using Tapatalk 2

 

[TCampbell]

All hand-held light meters will measure "incident" light but only _some_ of them can also meter "flash". If it meters flash, it can typically meter any type of flash -- but it only makes sense to meter flashes which are operated in manual mode (there'd be no point in metering a flash operating in TTL mode because the camera can change the power level of the flash on every exposure.) The meter doesn't care if it's a studio strobe or shoe-mounted flash.

Meters that deal with flash usually have a sync-cord socket so they can fire a "wired" flash, but they don't require that the flash is wired (they can be put into a mode where they meter the ambient light and wait for that big spike in the light level and then lock in the reading they got at the peak of the light.)

Also, some meters can trigger radio-based flash. I have a Sekonic L-758DR which includes a Pocket-Wizard compatible radio transmitter. That means if my strobes have Pocket-Wizard receivers then my light meter can trigger them. This is nice because the meter needs to be in the SUBJECT light (e.g. if you're going to shoot a model, then you'd hold the flash in front of the model and trigger the lights. If the lights are far away then it's hard for you to hold the meter and trigger the lights at the same time (sure, you could use the camera's self-timer or a remote release, etc.) but it's a convenience to allow the light meter to trigger the strobes.

When a flash is operating in manual mode (either a studio flash or a hot-shoe mounted flash configured to fire in manual mode) you can set the power output level. The levels are basically 1/1 (full power), 1/2, 1/4, 1/8, 1/16, etc. (notice that each successive level is half the power of the previous level.) That's one of the ways you control how much light is on your subject. The second way based on distance from the subject. Each time the distance from the light increases by another factor of 1.4 (technically it's the square root of 2 but it's simpler to just round that to 1.4 since it's very close) then the amount of light will be halved. e.g. if the light is about 5' away and you move the light to 7' feet away then you've roughly "halved" the light because 5 x 1.4 = 7. That seems like a huge difference for merely 2'... but the farther away the light, the farther (in real distance) you have to move the light to get a significant change. If the light was originally 20' away then you'd have to move it to 28' away to halve the power again.

I mentioned the Sekonic L-308s is a basic model that can read flash. The L-358 (and higher model numbers) can meter something called "flash contribution". Basically it tells you the percentage of light coming from ambient sources vs. the percentage coming from flash. This is REALLY nice for fill flash situations. If you shoot someone in bright sun then you get really harsh shadows. You want to soften those shadows but you don't want to over-power the sun by making the flash become the key light. By metering "contribution" you can set the power on your flash so that it comes in a little weaker than ambient (e.g. maybe adjust the flash until the flash contribution is, say, 30%) that way you get soft gentle shadows rather than harsh shadows but the subject is still primarily lit by the sun.

 

[Vautrin]

When I shoot flash I actually don't meter at all.

I set the camera to take photos in black and white, and shoot in raw.

The black and white images make it easy to see the exposure, and with a little fiddling, looking at the histograms, and some test shots I get the right "number" to dial in.

I find that's the most reliable way to get a well lit portrait. Flash meters won't be able to visualize in their head light and dark areas, they just tell you if it's properly exposed.

That's OK if you're looking for a run of the mill evenly lit portrait, but if you start playing with shadows (painters call it chiarusco) then the meter is crap...