How do you meter for TTL flash & ambient light?
In taking these kinds of candid images, I set the camera so that there is enough light recorded on the test shots without flash. No real metering technique, but I judge by the LCD to see that there will be enough detail in the background. It is kinda the dragging the shutter technique, but not as specific perhaps. I just want some ambient light to register.
Then I simply use TTL flash to expose correctly for any subject which is turned away from the main source of ambient light – the window. Without flash, these kids’ features would be in deep shade relative to the rest. But the TTL flash lifts the exposure to where I want it to be … with everything well exposed.
It really is that simple, and this technique allows me to shoot fast, and get great candid shots by concentrating on the photography and not the specific settings all the time.
I used the Black Foamie Thing ™ to flag my flash and not hit people behind me in the face with a strong burst of flash. The back-ground is quite well-lit, because in bouncing flash behind me, the background inevitably opens up a bit. Again, this is the inverse square law helping us out with bounce flash photography.
camera settings: 1/125th @ f4 @ 1250 ISO (FEC not recorded.)
So back to the question, how did I meter for the ambient light here? I didn’t. And I certainly did not meter for the white tones via the histogram method. The reason is – I don’t want to expose correctly for my ambient light. The light levels are too low – ie, I won’t get enough depth-of-field, at a good shutter speed, at a useful ISO … with good quality light on my subject. So I purposely want to under-expose for the ambient light. And then I add TTL flash. The TTL flash here is a dominant light source, and not mere fill-flash. Hence, carefully metering for the ambient light here isn’t all that useful.
All of this discussion was triggered by a question posted elsewhere …
Hi Neil. I love your books and have I think learned a lot. I finished Off-Camera Flash and am now on On-Camera Flash. There was one technique you emphasize that has me confused in terms of interpretation.
If you indicate that when you must use TTL flash, one should meter for ambient light first and then use the TTL flash. Are you implying that I should set the camera on M and then meter for the ambient light but then leave the flas on TTL ?
This was my assumption but I just wanted to know if that assumption is correct. I would appreciate clarification as this seems to be an important part of your TTL technique.
So there you have it. I don’t meter. But my camera settings aren’t entirely random, yet there is a lot of flexibility.
I need to juggle these three things:
– enough depth-of-field
– a shutter speed where I don’t risk too much subject movement
– an ISO setting that I am comfortable with, for the size that the images will be used.
With all that in mind, *I* choose my settings – and then the bounce flash gives me great quality light. I rely on TTL flash to get me correct exposure. And if I decide I can do better, I ride my flash exposure compensation.
It is all within my control now, and I can concentrate on the moments, and on my composition. The most important aspects of photography.
Related articles
- Ambient exposure metering & TTL flash
- Bouncing flash
- Tutorial: Bounce flash photography
- More articles on wedding photography
Hello Neil,
as usual you have been fantastic.
I follow you every day ….
If I understand correctly … the exposure to the environment is not so important.
With the environment underexposed put in the device’s convenient TTL flash (no BL) Front-curtain and let the flash can find the correct exposure for the subject.
How do when (indoors at a party .. children .. at a wedding) the lighting conditions are such as not to get underexposure.
That is, I’ll explain, are aperture priority and the lighting conditions of my surroundings make to get the correct exposure without underexposure general.
At this point I turn the flash TTL bounce against a wall of the room ….
But this way I add flash light to TTL correct exposure setting ….. and this is not right!
What to do?
I move the FEC flash down measures 2.0 by 1.5 in the negative? And ‘right?
Or, should I work with the flash maybe OFF-CAMERA MANUAL and adjust the light to bounce through the diaphragm.
Thanks Neil and thanks for all the other resposte you have given me on other occasions.
Have a nice day
Edy Trigona
Italy Genova
Let me take this step by step:
1.) “If I understand correctly … the exposure to the environment is not so important.”
For *this* specific scenario – indoor bounce flash where the ambient light levels are comparatively low.
2.) “With the environment underexposed put in the device’s convenient TTL flash (no BL) Front-curtain and let the flash can find the correct exposure for the subject.”
Yup. Do keep in mind that Front-Curtain flash sync doesn’t affect the exposure of the flash (or ambient.) It’s a timing thing.
3.) “How do when (indoors at a party .. children .. at a wedding) the lighting conditions are such as not to get underexposure.
That is, I’ll explain, are aperture priority and the lighting conditions of my surroundings make to get the correct exposure without underexposure general.”
This technique works very well when there are bounce-able surfaces … and you have the aperture / ISO combination that is in your favor, and your flash has the power.
If there isn’t enough power, ie, you can’t reach the aperture / ISO combination you like, then you improvise your technique.
– What if your bounce flash isn’t powerful enough?
4.) “At this point I turn the flash TTL bounce against a wall of the room ….
But this way I add flash light to TTL correct exposure setting ….. and this is not right!”
I’ve lost you here. What went wrong? One of us skipped a beat here.
5.) “I move the FEC flash down measures 2.0 by 1.5 in the negative? And ‘right?”
If your flash is meant to be the dominant light source (to give you correct exposure), then you shouldn’t be dialing your FEC down – unless your subject has a lot of dark tones. But for average scenes / subjects, your FEC should be around zero.
6.) “Or, should I work with the flash maybe OFF-CAMERA MANUAL and adjust the light to bounce through the diaphragm.”
That would work too.
Hi Neil, ok…question: Are you pre-flashing in this photo above or are you just taking the shot as is with the TTL?
The pre-flash is part of the TTL flash metering system. The camera and flash does that automatically in TTL mode.
If you’re referring to Flash Exposure Value Lock, then the answer is nope. I don’t use it. It’s not easily applied to candid photography of people. If you lock your TTL flash exposure this way, then often people think you’ve already taken the photo, and they move on.
That makes total sense and it’s easy enough to do! Once you set the manual values on your camera, I presume you don’t change them until you change scenes. If you do need to use FEC, do you find you’re usually dialling it up or dialling it down?
That’s it!
(Keeping in mind that the scenario here is specific – indoor bounce flash.)
ciao neil ti faccio i miei complimenti per le belle immagini che scatti. ogni tanto se possibile mostraci le foto scattate con la luce ambiente e poi le stesse foto con l’aggiunta del flasc sarebbero piu’ interessanti
But I already do. Often.
If there are comparison photos, and they make sense, I do post them.
Neil if you bounce your flag flash behind you, how do you avoid hitting them with a burst of light?
The infamous Black Foamie Thing will most often block the light from directly hitting people in the face.
Keep in mind that I don’t usually bounce my flash directly behind me. It’s usually over my shoulder when I say “bounce flash behind me”.
My thanks for that answer. Can you advice how to angle my strobe when doing portraits please.
Follow the links in the article to the related material. It’s all in there.
This article is like a confirmation that what I have learned from you, Neil, I learned right. What you’re describing here is similar to what I did yesterday. Tried the available light, and when it wasn’t good enough, I kept only small portion of it, and used flash and that was it. I was with my wife in our friends’ flat, with a 9-months-old baby. Small living room, white ceiling, orange walls. Outside it was late afternoon, cloudy, raining – not much light. Inside, a single central tungsten source of light hanging from the ceiling. I tried a test shot to see if available light would be enough. ISO 1250 – I didn’t want to go much higher, that’s what I was comfortable with (I have a Pentax k5). I tried f3.5, to keep at least some depth of field. With those values set, I tried 1/50th sec. The picture was still underexposed by about a stop, and with a fast-moving baby, there was already motion blur. So I knew right away that I’d need more light. I mounted a Metz 58 on the camera and I knew I had all the power I might need. Suddenly there were no worries, no need to compromise. I set the shutter speed to between 1/100th-1/160th to stop any motion blur, increased the DOF with f4.0-5.6, and kept the ISO at 1250. Gelled my flash with 1/2 CTS gel (I didn’t know if that would be necessary, since the walls were orange, but it worked very nicely, so I left the gel there), set my white balance to tungsten and didn’t change it any more, flash in P-TTL mode, shot in RAW, and THAT WAS IT! It really IS that simple. For most shots, I just bounced the flash behind me to the left, up somewhere between the ceiling and the walls, without the BFT. The pictures were awesome – bright enough, sharp enough, and CONSISTENT. There were lots of “Aaaah, wow, beautiful!” moments. I ROCKED! :-) And it really looked like daylight, there’s no flash light visible. Friends of mine were shooting with Sony NEX 5 and 7, but without flash, and, well, their pictures were… Some of them were OK, but they couldn’t match the look of mine, because of the QUALITY and DIRECTION of light! I can’t thank you enough, Neil. You are such a generous person, sharing all your knowledge with us. Before knowing your blog, I was lost in the dark, but with your explanations, it all clicks, it all makes sense! Thank you, thank you, thank you!
Btw, those phrases you use (“It really IS that simple”, or “I ROCK!”) do get under one’s skin :-)
Juraj,
Slovakia
Hi Neil, with Nikons, the FEC and on the camera EC are additive. That is, +1 on the flash and +1 on the camera results in an overall +2 exposure compensation, correct?. So, do you prefer to adjust the exposure all on the camera or all on the flash? I was thinking, that if I were in aperture priority mode and I wanted to underexpose the ambient by say -2, I would set that on camera and then adjust the FEC on the flash for the flash/foreground exposure?
Bill,
Yes, cumulative with Exposure Compensation and Flash Exposure Compensation but only in manual mode.
Once in any mode other than manual on the camera, the Camera Compensation will only work on the ambient and not flash.
So, if in AV mode, yep, you expose for ambient and dial in -2 on body for under-exposure of ambient, you then adjust flash to suit the subject until correct.
Hello Neil,
When you wrote the flash was in TTL (not BL) can I take it that the exposure metering mode set on the camera was spot (not weighted or matrix) correct?
I didn’t use spot-metering here. I rarely use anything other than Matrix / Evaluative metering, and selectively metering for my subject.
This topic “how do you meter for TTL flash & ambient light” arrived with perfect timing. I was at a 21st birthday party on Saturday and set my camera (manual) the way I wanted it F5.6, ISO around 2000 and let the TTL flash do its thing.
I go the white balance wrong but that was easily corrected and the photos just looked so natural. There were some avid photographers amongst the guests and they want to know why I wasn’t pointing the flash at my subjects. So I showed them (as they say a picture is worth a thousand words) and it was quite wonderful to see that they got it.
Thanks Neil
HI Neil
Thank you for posting the answer for me…
I incorporated the technique at a resent wedding…..
Fantastic results…..
My exposures were bag on in 90% of the shots it not going to take me very long to edit this wedding.
Lou
very informative and helpful article. I must say that I learn a heck of a lot from you Neil. Thank you so much
Hi Neil
Can you clear up a little confusion..?
In this present article you say that you do not meter in low light, instead the flash is the dominant source of light. But in a previous article you say that you do meter and underexpose slightly (or use fill flash).
Am I right in thinking that with the example in the present article the light was much much lower? Thanks!
Stacey .. with this article I wanted to push the idea that you don’t need to carefully and precisely meter. You need to under-expose the ambient light a bit. A stop. Maybe two stops. Somewhere there. It doesn’t really matter indoors. But you do want some ambient light to register usually. So you under-expose a bit.
But stating it like that – that you need to under-expose a bit, sounds like you have to be precise about the metering process, and then dial down a specific amount on your exposure. With this article, I wanted to make it clear that it isn’t such a specific sequence. You under-expose to an extent … and then let the TTL flash take care of the exposure.
The idea there is that you take a general reading – no need to be specific and evaluate the tonal range, etc. You just under-expose somewhat.
The “metering” there is just to give you ball-park exposure settings.
So even though the linked article mentions that you should check your camera’s exposure meter … these two articles aren’t contradictory. It’s still the same idea – to not get too wrapped up in the specifics of the exposure metering process.
I hope this helps clear the confusion.
Neil vN
Right. Got it. So, when the flash is dominant: chose your exposure settings (Aperture/ISO/Shutter combo) and as long as you are not underexposed to the point where – 1) no ambient registers and 2) your flash is not capable of ‘bringing up the slack’ you are good to go…?
“I used the Black Foamie Thing ™ to flag my flash and not hit people behind me in the face with a strong burst of flash.”
Everytime I see you write this, I wonder the way you have you BFT set up. If you angle you flash behind you and flag the light from the subject. It will blind the people behind you. I may look like a complete idiot here, but I thought the idea was to keep it off the subject and behind you.
I think I answered my own question with this photo.
https://neilvn.com/tangents/images/flash/bft/NV1_2125-900.jpg
Follow this link to the video clip on how I use the black foamie thing.
Neil vN