Question about using flash in Manual setting mode

[kindred_fp]

I shot a bday party this weekend and was a bit struggling with my nikon 5200. Using the exposure indicator I was able to correctly get the right amount of Shutter and aperture setting.

however, if I put the flash on and I have it set to TTL, how do you guys compensate for this as the exposure indicator does not predict how much flash should fire?

Especially if I'm limited with my lens aperture opening if its going to the extreme open and I know that the flash would be enough to not even go to the extreme end. Does my question make sense?

Thanks for the help.

 

[MOREGONE]

Just to make sure I understand,

How do you use TTL flash while in Manual mode on the camera?


TTL means through the lens and is the Auto mode of flash. So to answer your question, you just use it. The flash will send out pre-flashes and the camera will detect and determine the proper flash power based on what it is seeing Through The Lens.

Not sure I am understanding you last question about being extreme open to extreme end.

 

[MOREGONE]

For indoor shoots with poor lighting I will usually set my aperture based on how I want the photos to look, say f4 for a little DOF but not too much and I will set my shutter somewhere around a little faster than I can steadily hand hold, say 1/40 - 1/60. Then I let the TTL work its magic. I will adjust based on the outcome by first raising my ISO because I have the f/stop and Shutter I am looking for.

I really wish the flashpower was part of the metadata so you could see what it popped at and then set it to manual for more consistency.

 

[cynicaster]

I shot a bday party this weekend and was a bit struggling with my nikon 5200. Using the exposure indicator I was able to correctly get the right amount of Shutter and aperture setting.

however, if I put the flash on and I have it set to TTL, how do you guys compensate for this as the exposure indicator does not predict how much flash should fire?

Especially if I'm limited with my lens aperture opening if its going to the extreme open and I know that the flash would be enough to not even go to the extreme end. Does my question make sense?

Thanks for the help.

If I'm understanding your question, you're wanting to know how you should adjust the reading on the exposure meter to "compensate" for the presence of flash.

The answer is, you don't.. at least, not in the way you're thinking.

In perhaps slightly over-simplified terms, you can think of it like this. When using flash, the result will consist of 2 separate exposures. The "background" or "ambient" exposure, which is set by ISO/shutter/aperture, and is indicated on the meter as you said. Then, there is the "flash" exposure, which is only for the foreground subject(s). When in E-TTL mode, the flash exposure is set automatically based on some fancy calculations the camera does by first firing a quick "pre-flash" before the "main flash". Based on the info gleaned from the pre-flash and calculations, the camera will make an assumption on what the intended subject is, and then set the flash power in an attempt to properly expose that subject.

 

[kindred_fp]

Thanks for the response, I was playing with Program mode and Shutter mode when taking shots of my son. I guess what I need to do is set the aperture and shutter on manual and see how it looks. When I'm trying to use manual since I have a prime lens i get sufficient light. But noticed at this indoor place my aperture was maxed at 1.8.

 

[TCampbell]

I shot a bday party this weekend and was a bit struggling with my nikon 5200. Using the exposure indicator I was able to correctly get the right amount of Shutter and aperture setting.

however, if I put the flash on and I have it set to TTL, how do you guys compensate for this as the exposure indicator does not predict how much flash should fire?

Especially if I'm limited with my lens aperture opening if its going to the extreme open and I know that the flash would be enough to not even go to the extreme end. Does my question make sense?

Thanks for the help.

When using TTL, you meter and set the exposure based on ambient light... but then add the flash.

That's the short answer. But if you want to understand "why" this is true... keep reading.

Lighting has a light "fall off" property whereby the concentration of light falling on any given square inch (or any fixed unit of area) will be reduced by half each time the distance to the light increases by a factor of 1.4 (the actual value is the square root of 2... but 1.4 is close enough). This also works backwards... each time something is closer by a factor of 1.4 (in other words divide the original distance by 1.4) the amount of light at that distance will be doubled.

This means... for example... that if your intended subject is 10' away, then anything which is 14' away (10 x 1.4 = 14) will get exactly half as much light. Anything which is 20' away (14 x 1.4 = 20) will get half as much again (1/4 of the light) and anything 28' away (20 x 1.4 = 28) gets half as much again (1/8th the original light). incidentally anything 7' away would get double the light and anything 5' away would get 4x the amount of light.

Suppose you're taking a close shot of subjects at the party who are only 5' away. When the flash provides correct light for 5', then anything 7' away gets half (5 x 1.4 = 7), at 10' away (7 x 1.4 = 10) you get 1/4 of the light. You get 1/8th of the light at 14'. You get 1/16th of the light at 20'. And at 28' you get 1/32nd as much light.

In other words... the closer your intended subject is to the flash, the faster the light fall-off problem will seem to occur. If you're intended subject was closer... say 3-1/2 feet away... the fall off would be even more noticeable.

If you were to exposure just for the flash (and you could) what you would get is a properly illuminated subject and a very dark background that looks very unnatural.

To correct for that "dark background" you use a technique called "drag the shutter" -- which simply means you leave the aperture and ISO alone... but you extend the amount of time that the shutter is open. This allows the camera to collect more light long after the flash has finished firing. This fills in the background with the ambient light from the room -- but since the flash will seem significantly more powerful than the ambient light, the extra shutter time collecting more ambient light will add almost nothing to your intended subject... so little that you don't actually need to adjust the flash exposure at all.

Suppose you do everything manually... manual exposure and manual flash... you'd configure the flash power and aperture, and ISO correctly to illuminate your subject when using flash (ignoring shutter)... but you'd simply extend the shutter time to collect more ambient light. (remember... the flash is only a momentary burst of light... so you won't get any more light from the "flash" by leaving the shutter open longer... you'll only get more light from ambient sources.)

But since you're shooting using TTL (Nikon iTTL)... and part of the point of TTL is to remove the complexity... the camera and flash just do this automatically for you. They do this by metering and setting the exposure for the ambient light... and then adding the flash to ensure your intended subject is nicely exposed.

One last thing... while shooting with slow-ish shutter speeds might normally seem like a good way to end up with blurry subjects due to movement, when you use flash, the flash has a tendency to freeze the subject anyway. When the camera needs a long-ish shutter exposure, it's because there's hardly any ambient light. MEANING... once the flash finishes firing, there isn't much ambient light on the scene and that means that even if the subject moves it probably won't show up in the resulting image.

If you want to understand the properties of light fall-off a bit better in order to be more confident in your flash photography, here's a good video on the topic by Mark Wallace (Adorama TV):

 

[Derrel]

"How much flash" depends on the specific flash unit being used. The more-advanced Nikon speedlights have two TTL modes, the second which is TTL-BL, which stands for balanced lighting.

There are different ways to shoot flash; there is flash as main light source or "full flash"; there is also shadow fill-in flash or "fill-flash"; and there is "balanced flash and ambient".

In darker environments, and at lower light levels, there is a crossover point where TTL-BL will cut the amount of flash power down, as the shutter speed drops into the slow-speed zone, which is I think basically designed to allow the MANY people who like to drag the shutter, to get just what is called a tiny little squirt of flash, and to pick up ambient light by slowing the shutter down to the 1/20 to 1/8 second zone, which is typical of the "dragging the shutter" shooting style.

How you go about shooting Nikon TTL-metered flash depends in a large part on whether or not you have a flash that can do regular TTL flash and also TTL-BL. The "economy" flashes default to TTL-BL as I understand it. Each specific Nikon-made speedlight has its own feature set. I would suggest reading the (somewhat awful) manual, and jotting down some notes on things that appear there, and also trying some experiments to see how YOUR flash interacts with your preferred shooting methods.

There is flash exposure compensation (aka +/-) available in most instances, one way or another.

 

[Scatterbrained]

I shot a bday party this weekend and was a bit struggling with my nikon 5200. Using the exposure indicator I was able to correctly get the right amount of Shutter and aperture setting.

however, if I put the flash on and I have it set to TTL, how do you guys compensate for this as the exposure indicator does not predict how much flash should fire?

Especially if I'm limited with my lens aperture opening if its going to the extreme open and I know that the flash would be enough to not even go to the extreme end. Does my question make sense?

Thanks for the help.

Check out Neil Van Neikerks "Tangents" blog. Also, his book "On Camera Flash Techniques" will teach you everything you need to know about using on camera flash in a way that is very easy to follow and understand.

As to my personal technique, I meter the background, then set the camera to underexpose the background by a stop or so, letting the flash handle the subject exposure.

 

[kindred_fp]

Thanks a lot guys

 

[WayneF]

Thanks for the response, I was playing with Program mode and Shutter mode when taking shots of my son. I guess what I need to do is set the aperture and shutter on manual and see how it looks. When I'm trying to use manual since I have a prime lens i get sufficient light. But noticed at this indoor place my aperture was maxed at 1.8.

I think the best answer to your question is that you surely want to use camera A or camera M mode with flash indoors.

Modes S or P are the worst choices for flash indoors. These can work, but mode S indoors in dim light will simply always be forced to use the maximum widest aperture, every time.
Camera P mode has some quirks with indoor flash (ISO and maximum aperture).

However, camera P mode is very good with fill flash outdoors in bright sun, because it understands needs of both bright ambient and of flash.

But indoors with flash, surely you want to use camera A mode or camera M mode (with flash). Flash power is about aperture, and both of these modes allow you to directly set the aperture for flash, like to f/5 or whatever you deem best.

Indoors, the ambient is dim (which is why we need flash) and the insignificant ambient exposure is typically "don't care". So camera M mode works as well as camera A mode then (flash indoors, when ambient is dim and don't care).


Some flash rules which may not be automatically obvious at first.

All flash pictures are affected by both flash exposure and by ambient exposure. Ambient might be weak or strong, but always should be considered.

The camera exposure meter only reads and shows and sets the ambient exposure. Flash metering has its own metering system, which invisible to us. The flash power level simply has to use whatever ambient settings it discovers are in effect, regardless of why those settings were chosen. When ambient level is insignificant, we can use settings better suited for the flash instead (specifically aperture in camera A or M modes).

Shutter speed does not affect flash exposure, shutter speed only affects ambient exposure. Camera A mode (with flash indoors) likely always will be 1/60 second shutter speed, which is a Minimum shutter speed. But we can set any value of shutter speed with camera M mode. Otherwise, A and M modes can set same aperture for flash power.

TTL flash is fully automatic in any camera mode, including camera mode M. The way we control automatic TTL flash exposure is Flash Compensation.

 

[snerd]

Thanks for the response, I was playing with Program mode and Shutter mode when taking shots of my son. I guess what I need to do is set the aperture and shutter on manual and see how it looks. When I'm trying to use manual since I have a prime lens i get sufficient light. But noticed at this indoor place my aperture was maxed at 1.8.

I think the best answer to your question is that you surely want to use camera A or camera M mode with flash indoors.

Modes S or P are the worst choices for flash indoors. These can work, but mode S indoors in dim light will simply always be forced to use the maximum widest aperture, every time.
Camera P mode has some quirks with indoor flash (ISO and maximum aperture).

However, camera P mode is very good with fill flash outdoors in bright sun, because it understands needs of both bright ambient and of flash.

But indoors with flash, surely you want to use camera A mode or camera M mode (with flash). Flash power is about aperture, and both of these modes allow you to directly set the aperture for flash, like to f/5 or whatever you deem best.

Indoors, the ambient is dim (which is why we need flash) and the insignificant ambient exposure is typically "don't care". So camera M mode works as well as camera A mode then (flash indoors, when ambient is dim and don't care).


Some flash rules which may not be automatically obvious at first.

All flash pictures are affected by both flash exposure and by ambient exposure. Ambient might be weak or strong, but always should be considered.

The camera exposure meter only reads and shows and sets the ambient exposure. Flash metering has its own metering system, which invisible to us. The flash power level simply has to use whatever ambient settings it discovers are in effect, regardless of why those settings were chosen. When ambient level is insignificant, we can use settings better suited for the flash instead (specifically aperture in camera A or M modes).

Shutter speed does not affect flash exposure, shutter speed only affects ambient exposure. Camera A mode (with flash indoors) likely always will be 1/60 second shutter speed, which is a Minimum shutter speed. But we can set any value of shutter speed with camera M mode. Otherwise, A and M modes can set same aperture for flash power.

TTL flash is fully automatic in any camera mode, including camera mode M. The way we control automatic TTL flash exposure is Flash Compensation.

When you say A mode, are you meaning Av, Aperture Priority? Or are you talking about Auto mode?

 

[WayneF]

When you say A mode, are you meaning Av, Aperture Priority? Or are you talking about Auto mode?

I mean Aperture Preferred mode. Canon calls it Av mode, and Nikon calls it A mode.

Auto mode is generally bad news for flash, since automation meters the ambient like P mode (controls aperture strictly for ambient, not for flash), and it enables auto ISO.

 

[snerd]

Ah, that's what I thought, just wanted to make sure.


Sent from my iPhone 6 using Tapatalk 2 Pro

 

[rambler]

Wow. Lots of great info above in this thread.

So, the power of the flash is not effected by shutter speed, but the amount of ambient light is! A faster shutter speed means less ambient light, less light fill means more contrast, more contrast means less detail in the shadows. Hmmm.

Translation: Teddy bear indoors in front of a window. Correct exposure f/4 1/250 ISO 100 Teddy Bear backlit, face and front in shadow = poor photo of Teddy. Add flash: same exposure, front and face filled-in by flash, now clear = nice shot.

Increase shutter speed to 1/500, same flash. Increased shutter speed = less ambient light. Teddy now completely dark (too much contrast).

Decrease shutter speed to 1/50. More ambient light and too much ambient light = Teddy now clear but background totally washed out.

The camera was set to Manual, so increasing the shutter speed was done by lowering (negative) exposure compensation and lower shutter speed meant over (plus) exposure compensation.

BTW: Shutter speed effects ambient light, and aperture controls the flash exposure.

Next Step: Understanding the difference between in-camera exposure compensation and flash exposure compensation!!

I think there are learning advantages to using manual flash rather than TTL to help get a better understanding of how the flash works. Then go to TTL.

Note: Mark says it this way: " Flash power is about aperture" and "Shutter speed only effects ambient exposure"

The flash happens so fast, it really does not matter what the shutter speed is, the flash is faster. But, think about the aperture that is influencing the amount of light from the flash that reaches the sensor. The shutter speed is acting just like it does with natural light. The longer the shutter is open, the more light comes in, but that is natural light or light AFTER the flash, ambient light.

TCambell calls it "Dragging the Shutter" the amount of time the shutter is open after the flash. Drag it and the shutter stays open longer, letting in more ambient light.

Try this on the Teddy. Using the camera flash. Manual setting. Shoot at f/4 then at f/16. Get the correct exposure for each aperture, do not look at the shutter speed. F/4 looks great. F/16 the Teddy is too dark. Why? The aperture was effecting the "power" of the flash, or how much light of the flash was reaching Teddy. The smaller aperture meant not enough light from the flash was getting to Teddy, so he was too dark. But, it might be more accurate to say "darker" rather than "too" dark. The point is try to see the different look depending on the aperture.

 

[Derrel]

So, the power of the flash is not effected by shutter speed, but the amount of ambient light is! A faster shutter speed means less ambient light, less light fill means more contrast, more contrast means less detail in the shadows. Hmmm.

Note: Mark says it this way: " Flash power is about aperture" and "Shutter speed only effects ambient exposure"

The flash happens so fast, it really does not matter what the shutter speed is, the flash is faster. But, think about the aperture that is influencing the amount of light from the flash that reaches the sensor. The shutter speed is acting just like it does with natural light. The longer the shutter is open, the more light comes in, but that is natural light or light AFTER the flash, ambient light.

YES!!!!!! The above principle is really important in understanding how flash + daylight exposures, or flash + ambient light exposures actually work. The power of the flash is NOT affected by the shutter. The "power" or "influence" of the flash comes from the aperture setting, as it relates to the power of the flash burst.

The shutter's duration controls the brightness or the dimness of the backgrounds, in areas where the flash does not reach. Indoors, it is possible to shoot a flash photo at say f/4, and use a shutter speed of say 1/250 second with a modern Nikon d-slr, and make the background 10 feet behind the subject look almost totally black; OR, we could slow the shutter time wayyyyyyyy down, to say 1/6 second, which is called "dragging the shutter", and we would then "pick up ambient light", and allow the room lighting to start forming an image in the background areas, well beyond the distance where the flash's light even reaches.