Tuesday, April 22, 2008

Strobist: Lighting 102: 3.3 - Balancing Flash/Ambient Indoors

Strobist: Lighting 102: 3.3 - Balancing Flash/Ambient Indoors

This was an interesting exercise for me as I had never understood the relation between the flash and the camera settings. This is mainly due to being an "Av Mode" addict. The most I had gone into controlling the flash was using the camera flash compensation, which I would dial down for fill in flash.

Learning that the light from a flash is only affected by the aperture and ambient light was affected by both aperture and speed made me scratch my head for a while to understand the concept. I couldn't quite understand (or maybe it was believe) that the flash was also not affected by speed.

But as I could see from the results after this set of exercises I was convinced and have been putting this fact into use for some other experiments I have been doing (see the last photo).

The set of images below were all black when no flash was added. All shots were taken at 1/250, through a shoot through umbrella about 3 feet away.

The light seen in the images 1/250 to 1/100 is mostly fall off from the umbrella. All the walls in my house are white and bounce light like crazy. This is taken with no Gel on it hence the mixture of orange light from the ambient and white light from the flash.



The next set of images is taken with a Lee Filter CTO -Full, which as you can see also stops down the light between 1-2 Stops. Whereas in the previous image light was seen from the flash fall out from 1/250 to 1/100 here they are almost pitch black, and light doesn't start to show up until 1/60 to 1/40.


The next set of images is taken with a Lee Filter CTO -Full, which as you can see also stops down the light between 1-2 Stops. I also added tracing paper onto the umbrella to remove the obvious signs of umbrella light. To compensate for the loss of light I increased the light power by 1 stop.

The image below I took a few days ago to prove the above theory to myself and combine it with an experiment I had wanted to test out taking a photo with a Tungsten White Balance and gelled with a Full CTO.

I set the camera to 1/250 and then measured the sky and stopped down two stops using the aperture. I then set the flash to around 1/4 and placed it around 3 feet from the person camera right.


This was taken at mid afternoon and I really liked the affect. As it's only my first time attempting this you need to forgive the quality. You can be sure I'll be messing around with this affect a lot more. You can see all the attempts from the shoot here.

Please feel free to leave comments or questions about this article and I will endeavor to answer them as soon as possible.

Previous lessons from Lighting102:

Saturday, April 12, 2008

Strobist: Lighting 102: 3.2 - Balance | Flash/Sun Crosslighting

Strobist: Lighting 102: 3.2 - Balance | Flash/Sun Crosslighting

I completed the exercise for this lesson the following day after shooting the exercises for the previous lesson "Balancing Light: Twilight". I went back to the same beach but this time in full daylight, but found that this time round was not as intimidating as I thought it may be.

Previously, photos I have taken during the day time have typically been of people looking like panda bears or if they were wearing a hat then they usually ended up looking like "people with no faces". This may sound like a good name for the rock band but is definitely not good for photography.

I had attempted to use fill-in flash for some images, but as David points out, the images in the camera manuals were nothing like I was creating!

I was pretty happy with the results from this exercise, but ran across the problem of trying to convince my wife to stay in the blazing sun for long periods of time. April & May are considered 'summer' months here in the Philippines and the sun was almost at 12 o'clock and was scorching hot even though these shots were taken around 9-10am! Next time I will go out either earlier of slightly later in the afternoon or just wait till later in the year.

Anyway, below are some of the photos I shot that morning.

This is my favourite of the bunch and not just because it's my wife. The flash is probably a bit too bright and if had a bit more time I would have lowered the flash a bit. Another problem with the sun so bright it is really hard to see the images clearly on the screen.
Flash used at roughly 1/16. Backlight from the sun.
Exposure Time: 0.004s (1/250)
Aperture: f/8
ISO: 100
Focal Length: 55mm (EF-S lens)

This close up of the above shot came in as my second choice. It is too bright due to the closer crop which was done by moving closer to the subject. Lesson learned - stop down the closer you get to the subject.
Flash used at roughly 1/16. Backlight from the sun.
Exposure Time: 0.004s (1/250)
Aperture: f/8
ISO: 100
Focal Length: 55mm (88mm in 35mm)

The next two photos were really experiments to see the difference between the flash and non-flash. The first shot was to taken with no flash and I adjusted my settings to get the correct exposure for ambient light. There is an obvious shadow on the face making it too dark.
No Flash used
Exposure Time: 0.004s (1/250)
Aperture: f/8
ISO: 100
Focal Length: 28mm (EF-S lens)

The second shot of the two shows the flash switched on coming from camera right. This is straight flash with no diffusion, which you can see from the hard shadows on the right (left?) leg. I did actually bring a Stofen filter and an umbrella but I was too short of time to get them out to try. Using some kind of diffused light would have softened the shows somewhat. The flash is probably still too bright
Flash used at roughly 1/16. Backlight from the sun.
Exposure Time: 0.004s (1/250)
Aperture: f/8
ISO: 100
Focal Length: 28mm (EF-S lens)

The next four photographs were still balancing the sun and flash - but not cross lighting. They were all taken under some kind of shaded area and my aim was to try and light the people nicely whilst keeping the background correctly exposed.

The first image of my wife on the beach is almost correctly exposed for the sea, sand and sky, but she is obviously too dark. I accidentally knocked my exposure (overexposing the ambient slightly) from 1/250 to 1/200 - which is something I tend to do on a far too frequent basis. This is mainly because I am still getting used to using the camera on manual mode and somewhat due to me being someone who is slightly heavy handed and fumbles around a bit :-)
No Flash used
Exposure Time: 0.005s (1/200)
Aperture: f/9
ISO: 100
Focal Length: 20mm (EF-S lens)

The next image of my wife shows her lit with a flash. The balance is OK, but maybe a little on the dark side. The ambient is now correctly exposed at 1/250, as I had spotted my error mentioned earlier. I would really like to try this kind of shot with some kind of diffuser and see the results.
Flash used at roughly 1/16.
Exposure Time: 0.005s (1/250)
Aperture: f/9
ISO: 100
Focal Length: 24mm (EF-S lens)

The last two images of my youngest daughter (in the hat) and one of her friends was taken at breakfast time - yes I know that's junk food on the table - we were on holiday :-) Again I started by getting the correct exposure for the ambient light however after taking the shot I realized that I would have to change the aperture as the speed was too high.
No Flash used
Exposure Time: 0.005s (1/800)
Aperture: f/5.6
ISO: 100
Focal Length: 55mm (EF-S lens)

I stopped down the aperture and changed the speed to 1/250 then took of few shots to get the flash right. The flash for this shot was on-camera due to the location. Although the ambient is slightly over exposed the balance still kind of works for me - although next time I must remember to hide the evidence of our bad eating habits!.
Flash used at roughly 1/16.
Exposure Time: 0.005s (1/250)
Aperture: f/7.1
ISO: 100
Focal Length: 40mm (EF-S lens)

So what did I learn? A number of things:
  1. I need to spend more time practicing this lighting technique (that goes for all the lessons so far).
  2. that if I move closer to the subject the light reaching my camera will increase and I have to adjust accordingly - either in camera or the flash.
  3. that the sun during summer here is hot and very bright and I need to take this into account when planning a shoot.
  4. It's not so bad taking your equipment out into the public. No ambulances turned up with straight jackets to take me away.
  5. I need to continually learn from other people, what they are doing and how they are doing it.
You can see all the shots from this exercise at my web site. I'm now looking forward to reading, learning and doing more lighting like this. Now, on to the next lesson!

Please feel free to leave comments or questions about this article and I will endeavor to answer them as soon as possible.

Previous lessons from Lighting102:

Strobist: Lighting 102 - 3.1 Balancing Light: Twilight

Strobist: Lighting 102 - 3.1 Balancing Light: Twilight

The exercise for this lesson took me outside and I felt some trepidation about take my equipment outside to do this stuff in front of others - thankfully this first lesson was towards the end of the day and it soon got dark :-) The next lesson however takes me outside in the day time!

Although I have taken photos at sunset and tried to use my flash before, but this time with the great guidance from David Hobby I enjoyed the results from the exercises and am looking to get out at sunset more often to practice getting more comfortable controlling my flash in manual mode whilst trying to balance flash and twilight.

These first of the two shots below were taken to try and get the right aperture for the background with the speed at 1/250. At first I thought the aperture 5.6 was OK but after reviewing the photo a bit more I decided to drop it down to 6.3 for the second shot.

The second shot was taken with the flash on camera. I wasn't comfortable working off camera on a beach at sunset for the first time so I kept it on camera for this time.

No flash used - trying to get the background balanced.
Exposure Time: 0.004s (1/250)
Aperture: f/5.6
ISO: 100
Focal Length: 70mm (112mm in 35mm)


On camera 580EX II on manual at around 1/16
Exposure Time: 0.004s (1/250)
Aperture: f/6.3
ISO: 100
Focal Length: 70mm (112mm in 35mm)


The second set of shots were taken a bit later as the sun continued to go down - which it does really quickly! The first shot was taken at f4.0 and the second was taken at f5.6. Something I struggled with was working in manual trying to get the light correctly balanced at 1/250. The reason for this is that I normally use Av mode on my Canon which means I don't think about speed much.


On camera 580EX II on manual at around 1/8
Exposure Time: 0.004s (1/250)
Aperture: f/4.0
ISO: 100
Focal Length: 70mm (112mm in 35mm)


On camera 580EX II on manual at around 1/8
Exposure Time: 0.004s (1/250)
Aperture: f/5.6
ISO: 100
Focal Length: 70mm (112mm in 35mm)

Just had a thought - I could leave my camera in Tv mode and let the camera worry about the aperture. But if I am trying to learn to take complete control of the shot taking process, I still feel that I should learn to control the whole process without relying on the camera. Once I have learned to control the process I may then choose to use semi auto modes based on circumstance rather than habit.

The last set of shots were taken after the sun has disappeared below the horizon. I like these two shots the most, not because it's my wife and youngest daughter (although I am biased like that), but because of the sun light playing on the clouds in the background.

On camera 580EX II on manual at around 1/8
Exposure Time: 0.0125s (1/80)
Aperture: f/6.3
ISO: 100
Focal Length: 70mm (112mm in 35mm)


On camera 580EX II on manual at around 1/8
Exposure Time: 0.0125s (1/80)
Aperture: f/6.3
ISO: 100
Focal Length: 127mm (203.2mm in 35mm)

I'm now looking forward to doing this again but with the flash off camera, and maybe even with two lights, to see what I can come up with.

Please feel free to leave comments or questions about this article and I will endeavor to answer them as soon as possible.

Previous lessons from Lighting102: