Speedlight in manual mode... Question about my camera's light meter

virginie

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Hello all,

I've said it before, I am experimenting with speedlight and now that I feel comfortable understanding the TTL mode I'd like to learn to use it with Manual mode. I'm shooting with a NIKON d600 and my speedlight is a Yongnuo 468ii.

Here's my question, I hope it doesn't make me sound completely dumb :wink: So when I shoot (in manual mode on my camera) in TTL mode (on my speedlight), my camera's light meter changes and lets me know if I'm over or underexposed as I'm playing with ISO, shutter speed, and apperture (I mean it works as it normally would without a speedlight). When I shoot in Manual mode (on my speedlight, as well as on my camera), the light meter on my camera doesn't seem to be affected by my speedlight (I mean it's as if the light meter wasn't considering that I'm using a speedlight). For example, in my dark living room to have a correct exposure on my camera using a speedlight on manual mode, I'd have to be at ISO 600ish at half-power on my speedlight... it doesn't make sense right?

I've read the manual, tried to check online for answers to my question. No luck.

Should I not take the light meter on my camera in consideration? Is it supposed to be like this...? Or is it because there is a setting on my camera I haven't understood/set properly?

Your help is very appreciated. Thanks a lot
Virginie
 
The light meter in your camera reads the reflected light from the scene. It has no way of knowing what the flash will do to the scene. In TTL the cameras meter isn't changing to compensate for TTL either. Instead, the camera is using the flash as a way to compensate for any underexposure caused by the current settings. The camera pops off a pre flash; then it reads the exposure created by the preflash to determine how much flash power will be needed. This all happens very fast when you hit the shutter. The cameras meter however isn't "compensating" for flash while you're adjusting settings.
 
The camera meter relies upon reflected ambient light in the scent itself. It can't take into account the power of the flash light because that light isn't present in the scene until the flash actually fires.

When you use the flash in TTL mode the flash fires a preflash (so fast you can't actually see it) just before it fires its main beam; this preflash hits the subject, is reflected back through the lens and the information on the exposure is sent to the flash - thus telling the flash how its light has affected the exposure - the flash then adjusts its output based upon that information (although its not always perfect).

In a fully manual setup you've a few options;
1) Take the shot and review on the LCD (using hte histogram display).

2) Experience - if you've shot in the same/similar conditions before chances are that you can set the camera and flash settings roughly to what you think they'll need to be; the more experience of course, the more accurate you'll be.

3) External light meter - these can be used to measure light from the source, rather than light reflected off a subject (which is what the camera meter relies upon). So you can aim the external light meter at your light and hold it in the place of the subject and then measure the lights effect. Of course this takes time and requires you to be at the location of the subject - so many times this is a more studio setup where you've control over the scene and the lighting.


Essentially you're either thinking for the camera (you know the flash is there and experience has taught you what will roughly work) or you're using support items to aid the camera (external light meter).
 
As far as what to do when shooting with the flash in manual mode there are two schools of thought on it. One, you can just adjust the flash power and shoot a test to see where you are, then keep shooting and adjusting until you get the light where you want it. The other is to use a handheld lightmeter and meter the light to where you want it to be.
 
Thank you both, your explanations are very clear!

One more question: in a situation where the shot looks too dark, would you prefer to boost your ISO instead or change your flash intensity? What is the difference? I've been looking at tutorials on youtube and there was one of B&H ("One speedlight, multiple looks") where the guy said he never changes his speedlight flash intensity, he always leaves it at one half. Thoughts on that?

Thanks
Virginie
 
It depends somewhat.

The ISO will increase the sensitivity of the sensor across the whole of the sensor. Increase it by one stop and you'll get one stop more exposure on your shot (assuming all other settings remain the same). The cost is noise, although a photo taken at a higher ISO, but with a correct exposure will show far less noise than one taken at a lower ISO and underexposing the photo.

The flash will add light to the scene; but it will also affect;

1) The colour temperature of the shot - because now as well as the ambient light you've got the flash light as a source too

2) The direction of the light - using the flash as a major component to the lighting will mean that it will start to create things like its own shadows. This can be a complex area if you've multiple light sources (esp if they are all flashes you control).

3) The effect won't be even over the whole shot; light falls off inversely so even a small distance can result in a big change. So the flash might light the main subject easily; but because the light falls off so fast the background/surroundings might well end up still under-exposed because the light that reached them was that much darker
 
I've been looking at tutorials on youtube and there was one of B&H ("One speedlight, multiple looks") where the guy said he never changes his speedlight flash intensity, he always leaves it at one half. Thoughts on that?

I fry everything in a cast iron pan on Medium High heat. Steaks, eggs, crepes, pancakes, onions, chicken. My pancakes are like rubber, my crepes resemble cardboard, and my eggs bounce when they hit the plate.

I drive everywhere in third gear at 3,500 RPM...I get stopped for speeding in town, and get passed on the freeway 100 times per hour, often with a friendly middle finger salute and a horn blast...

I watch ALL my TV shows with the volume set to halfway up...I cannot hear anything unless the room is very quiet. But I AM CONSISTENT!!!! I always have the volume set to ONE-HALF!


With the Nikon SB-800, 1/2 power manual flash setting is often wayyyyyyyyyyyyyy too much flash in many lower-light scenarios where the flash is being used for fill against low-light backlighting; in those cases, 1/32 power flash is often about right from close distances. While half-power flash can be useful, I would reallllly not recommend it in any sort of a blanket way, unless a person shoots in a very rigid, inflexible, repetitive manner. Full, half, quarter, one-eighth, and one-sixteenth power flash ALL have a big place in my book.
 
Hello all,

I've said it before, I am experimenting with speedlight and now that I feel comfortable understanding the TTL mode I'd like to learn to use it with Manual mode. I'm shooting with a NIKON d600 and my speedlight is a Yongnuo 468ii.

Here's my question, I hope it doesn't make me sound completely dumb :wink: So when I shoot (in manual mode on my camera) in TTL mode (on my speedlight), my camera's light meter changes and lets me know if I'm over or underexposed as I'm playing with ISO, shutter speed, and apperture (I mean it works as it normally would without a speedlight). When I shoot in Manual mode (on my speedlight, as well as on my camera), the light meter on my camera doesn't seem to be affected by my speedlight (I mean it's as if the light meter wasn't considering that I'm using a speedlight). For example, in my dark living room to have a correct exposure on my camera using a speedlight on manual mode, I'd have to be at ISO 600ish at half-power on my speedlight... it doesn't make sense right?

I've read the manual, tried to check online for answers to my question. No luck.

Should I not take the light meter on my camera in consideration? Is it supposed to be like this...? Or is it because there is a setting on my camera I haven't understood/set properly?

Your help is very appreciated. Thanks a lot
Virginie

One thought occurred to me, mainly because the question is not very clear in my mind. I am wondering if the flash unit is FULLY communicating with your Nikon camera's metering system. There are situations in which the flash unit's presence and mode will electronically communicate to the camera, and limit the shutter speed to a top speed of say, 1/250 second, and thus constrain the metering system. Nikon cameras can also be programmed in the custom function menu to a SET flash speed, so when the camera detects the presence of a flash turned on and in the hotshoe, it sets the speed to the pre-determined speed.

Also, I am wondering if the flash is 100% compatible with your camera. Modern "dedicated flash units" as they are called must be in 100 percent accordance with the camera; some flash units allow high-speed flash synchronization at speeds above the X-synch speed [which is usually 1/250 in many Nikons, 1/200 or 1/180 in other cameras, as slow as 1/125 in some older cameras, and as slow as 1/50 second in some Leicas], but if the camera is set to a speed faster than the X-synch speed, and the flash is NOT 100% compatible, it might not work the way you expect.

I'm not fully conversant with any of the Yongnuo flash units, but there are some pretty common issues that have existed for decades when using NON-dedicated flash units in different exposure modes. I think that, re-reading the original question, you're a bit unclear about what exactly HOW MANUAL exposure on a Nikon is regulated, as far as speedlight and camera settings relate to one another in manual mode; provided that is that I understood what you meant when you wrote "on my camera using a speedlight in manual mode". Your comment about half-power and ISO 600 skips over 1) aperture in use and 2) distance. In MANUAL flash or manual exposure modes with manual flash, the flash-to-subject distance, and the lens aperture AND the ISO are all huge factors.
 
Thank you both, your explanations are very clear!

One more question: in a situation where the shot looks too dark, would you prefer to boost your ISO instead or change your flash intensity? What is the difference? I've been looking at tutorials on youtube and there was one of B&H ("One speedlight, multiple looks") where the guy said he never changes his speedlight flash intensity, he always leaves it at one half. Thoughts on that?

Thanks
Virginie
I would say that guy is stuck. Personally I prefer to alter my settings to get the shot I want in the given conditions. That may mean more or less iso to bring in more ambient light; it may mean a wider aperture for less DOF or more ambient light (or both), it may also mean a slower or faster shutterspeed to adjust to movement and ambient light. Don't get set on something like "only shooting half power". That's one of the dumbest things I've heard in a while. If someone is locking their flash at a given output it means they have to adjust flash contribution by actually moving the flash. This will change the quality of the light on the subject. Seems very counterproductive to me. Of course, it could be that they have a very formulaic shooting style where they always put the light in the same spot so they already know that 1/2 power is what will work with their setup. Then you have to ask yourself if you want to keep taking the same picture everyday, and what if you find yourself in a situation where you want to do something different?

As far as shooting on camera bounced flash I tend to prefer to get as much ambient as I can, while keeping it about a stop underexposed relative to the subject. Then I let the flash handle the subject. Indoors this can mean anything from iso 800 at f/5 to iso 3200 at f/2.8.
 
The first thing to know and understand is that every flash photo is actually two separate exposures, one from the flash and one from the ambient light.

There are essentially 5 things that affect the flash exposure; Aperture, ISO, Flash Power, Distance from flash to subject and any light modifier that may be blocking or diffusing the light.
(note that shutter speed does not affect flash exposure).

There are three things that affect the ambient exposure; Aperture, ISO & Shutter Speed.

So, with all that being said, we can see that adjusting either the Aperture or ISO, will affect both flash and ambient exposures. But changing the shutter speed only affects the ambient exposure and changing the flash power (or adding/removing a modifier) only affects the flash exposure.

If you can wrap your head around that, you can really start to work well with flash photography.

As others have mentioned already, the camera's meter does not take flash exposure into account...it is for metering the ambient light only. So you'll need to find another way to meter for flash. Using the built-in TTL (auto flash metering) is one way to do it. If you do, note that changing the ISO or Aperture won't necessarily change the flash exposure, because the TTL metering will account for that and use more or less flash power. If you use TTL, you have to use Flash Exposure Compensation (FEC) to change the flash exposure.

Another method of getting your flash exposure, is to use the flash in manual mode. Most modern flashes have a distance gauge/scale on the display that changes based on the Aperture, ISO & Flash Power settings. All you have to do is match the distance on the flash, to the actual distance from flash to subject.

And of course, using a flash meter is another way to do it.
 
So, with all that being said, we can see that adjusting either the Aperture or ISO, will affect both flash and ambient exposures. But changing the shutter speed only affects the ambient exposure and changing the flash power (or adding/removing a modifier) only affects the flash exposure.

If you can wrap your head around that, you can really start to work well with flash photography.
Very informative and easy to understand, thank you!

@Scatterbrained: I too think that limiting yourself to one way of working only is counterproductive. Good to have you guys advice on that

Thank you all for the infos, I think for now I'm going to stick to TTL mode in order to practice (using Flash compensation). Once that is mastered I'll give Manual mode a try
 

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