Flash | Time and Time Photographer

Oct24 3

The Photography Tip of the Week #084

Posted by Philip in Photo Technique, Podcast

Far Flung Flash
084 Photography Tip of the Week (audio)

One thing I always find amazing at nighttime events in large stadiums is the flash of hundreds or thousands of cameras. Even though the light from the flash travels a tremendous distance, the effect it has on your subject from the nosebleed section of the stands is so minuscule that it’s basically zero. So asking the question, “How far does the flash travel?” is a misnomer. The light from your flash can easily travel an extreme distance. The real question is, “How far can your flash effective light your subject.” The inverse square law describes this quite well mathematically. But I promised several weeks ago I wasn’t going to explain things using math, so I’ll use a set of photos.

Brick is great for doing test photos. You have a regular pattern to see the effect of your test. In this case you can easily see the pattern of the flash, and how much light the subject would have hitting them based on how many bricks away they are from the source. Up close there is a lot of light, but as you get further away, the amount drops off very quickly.

Let’s say you have your subject at position 1 but you want to double the amount of light. The reason to double the amount of light is to increase your aperture by one stop. In order to double the amount of light you would have to bring them to position 2 which is half way closer to the light. If that wasn’t enough you would have to bring them in half way again to position 3 to further double the effect. That is the basics of the inverse square law for the light from your flash. If you want to double the amount of light either take the light half as close to your subject or move your subject half as close to the light.

The same holds true no matter the size of your light source. In this case I’m using a shoot through umbrella to make the light bigger. This creates a softer, more diffuse light. But there are several things you should notice:

Even though the light is bigger it’s not as strong as the bare flash and doesn’t effectively light the brick at distance.
Since I’m using an umbrella, there is a lot of light that bounces back.
The same inverse square law holds true. Even though the subject at position 3 isn’t being illuminated nearly as strong as the previous image, if you want to double the amount of light, you have to move them to position 2 which is half in as close.

I hope that this visually explained the inverse square law and how it pertained to the flash of your camera.

Oct17 1

The Photography Tip of the Week #083

Posted by Philip in Photo Technique, Podcast

Fill Flash

083 Photography Tip of the Week (audio)

Do you need a flash on a bright sunny day? Many people will say, “No, a flash is completely unnecessary on a sunny day.” That is absolutely wrong, and I’ll show you why. The initial reaction is to think that if you have a large and powerful light source such as the Sun, that a flash wouldn’t have any affect on your image. But like many things in photography it’s not the capability of the tool, but how you use it. My little flash can’t overpower the sun, or can it? For this image I’m going to put my subject looking away from the Sun. With the Sun behind them you don’t have to worry about them squinting or strong shadows on the face. You also get their hair to light up and glow depending on the angle of the light. But if you take a photo without a flash you get something like the following image.

Even though the image is sharp, it’s washed out and has a yellow-orange glow about it. There is also a noticeable lens flare, which isn’t a bad thing, but in conjunction with the other problems it adds to the overall blandness. But wait we can fix it in post, can’t we? Camera RAW and Photoshop can fix anything! But this isn’t a quick fix. Generally I don’t like spending more than 2-3 minutes on a single image unless it’s a wedding, fashion, or a final image for publication. Just to get the photo to a reasonable level took me about 15 minutes of selective adjustments and it’s still washed out. Granted it’s easily 10 times better even if the coloring of the skin is still a bit odd.

Now let’s look at an image made just a few seconds after the first using the same settings for ISO, Aperture and Shutter Speed but with a flash pointed directly at our subject. Both the original and this image are uncorrected so there is no post processing trickery here. The flash brings a richness to colors in her dress that are hidden in the original image. Her skin isn’t washed out and the sunlight making her hair glow is much more noticeable and doesn’t get lost. The lens flare still exists, but now becomes part of the image especially with the way she is gesturing.

So you can see there is a definite advantage to using a flash on a bright sunny day. It immediately brings balance and makes the scene look more like what you remember seeing and not what settle on capturing. I hope that this has shown you why you need to use your flash in the daylight. You will make a better photo instead of taking what you can. It can also save you an incredible amount of time in post processing and gives you more keepers.

Oct10 1

The Photography Tip of the Week #082

Posted by Philip in Photo Technique, Podcast

Flash Freeze
082 Photography Tip of the Week (audio)

When you are using a constant light source, be it room lights or the sun, the faster the shutter speed the more you freeze the action and the less light you bring into the sensor. However when you are using a flash, shutter speed no longer follows the same role as when you are using a constant light source. As soon as you put a flash on your subject, the flash is what controls freezing of the action. The main role for shutter speed is in how much ambient light hits your sensor.

There is a rule of thumb that when you are photographing hand held in available light, that your shutter speed should be 1/60 sec or faster to achieve a sharp image. In the right conditions you can possibly get to 1/30 sec, but to be safe 1/60 sec is best. This is to help ensure that your image does not pickup any motion blur from the movement of your camera. In the above image I had the shutter speed too slow at 1/20 sec. You can easily see the streaking from the motion of the subject and most likely my camera. All-in-all hand held photos taken at slow shutter speeds without flash will be blurry.

Model Nikki Craven looks nice and sharp with the motion frozen by the flash even though the shutter speed is slow.

Now lets look at an image with similar settings. In this case the model is indoors with less available light, however since I’m using a flash the image is sharp and there is no motion blur. This is the one thing that confuses many photographers especially when they get a handle on how shutter speed, aperture and ISO all work together. As soon as you add a flash it seems like all the rules completely change and you no longer have control. When I hear someone say that they only photograph in available (or natural) light, I know they haven’t figured out this aspect of using a flash.

Having the shutter too fast is like having a censored section of your image.

So when you are using a flash, your shutter speed can typically be between 1/200sec and 1/4sec hand held. The flash will freeze the subject and you won’t have to worry about motion blur. With a shutter speed faster than 1/250sec your camera can’t sync with most flash units and you get a black bar at the bottom of your image. This black bar is the shutter of your camera caught in action. In order to fix this you need to slow down the shutter. If you want to go slower than 1/4sec you will start to pick up some motion blur again, mainly from light sources, so you’ll have to mount your camera on a tripod.

When I use a flash with my camera I set my aperture to f5.6, shutter speed to 1/10 sec and ISO 100 as a starting point. I’ll change aperture first then adjust the shutter speed to give me a good exposure. I hope this will help you when using a flash.

Oct03 0

The Photography Tip of the Week #081

Posted by Philip in Photo Technique, Podcast

Why O Red Eye

081 Photography Tip of the Week (audio)

For the next few episodes we’ll be doing some Flash Basics. I know you may have learned some of these from a teacher, mentor or some homeless guy on the side of the road. But I’ve always been a proponent for understanding why something works instead of just how it works. So I hope to give you a more in-depth understanding of using a Flash, without the math. So why o why is there red eye in so many photos? You know it’s because of the flash, but what’s actually going on that brings out the demonic look in all of us?

Simply put the red eye you see is the light reflecting off the blood vessels on someone’s retina in the back of their eye. It may sound gross, but you are making a photo with blood in it. Here’s a photo of the retina of an eye… one of my eyes to be exact. You can see the blood vessels going through the retina. The over all red-orange color is the color you would see if you shined a light directly into someone’s eye.

Why a flash makes red-eye. (Image not to scale)

So now you know where the red comes from, why do you get red-eye in your photos? When your major light source, in this case the flash is in line with the lens of your camera, anyone looking directly at the lens and flash will allow you the opportunity to capture the red of their retina in your image. This greatly depends on the angle between the flash, the eye and the lens. But for the sake of argument, any flash that is on the camera and pointed at your subject has an extremely good chance to create red-eye in your image. There is no exact number to the angle, so creating a math equation is pointless.

Ways to remove red eye:

Increase the angle between your lens,the flash and your subject’s eye. In some cases this may be a difficult notion. If you are using a built-in flash either on a DSLR or a point and shoot camera, you may not be able increase this angle easily. You will have to turn off the built-in flash and use an external light source. If you hear photographers saying to get the flash off the camera, this is one reason to do so.
Point the flash another direction. You can’t always do this but many high-end flash units will allow you to rotate the flash around and point it in a different direction to bounce the flash off a wall or ceiling. Alternately you can put something over the flash to diffuse the light a bit like a paper towel or napkin which can reduce the effect.
Red-eye reduction mode. This is a feature on many point and shoot cameras. The idea is to blast your subject with lots of annoying flashes so their pupils close and create a natural shield to the final big flash. Hopefully this won’t get you punched for annoying your subjects too much.
Red eye removal in post production. Almost every image manipulation program has a red-eye removal. All this does is paint the red section black. This most often looks unnatural, but if you are in a bind, it’s quick and easy.

Of course the best way is to not have the red-eye in the first place. Now that you know where it comes from you can either move your light or position your subject to eliminate this problem. In some cases I just tell them to look at my shoulder or instead of having them face me directly I’ll have them at an angle and look to the lens of the camera, which in many cases is all that you need to do.

Even though it doesn't look like it, Abigael is not looking directly at the lens.

Aug08 0

The Photography Tip of the Week #073

Posted by Philip in Photo Technique, Podcast

More than just focus

073 Photography Tip of the Week (audio)

What are the things that are most appealing about portraits? I have my short list, and an image to illustrate.

1) Off center lighting. The light shouldn’t be coming from the flash mounted on your camera or a flash on the camera.

2) Blurry background. This helps you to focus on the subject and not notice that squirrel in the tree.

3) Eyes that are sharply in focus.

In this image of Lauren, I have those 3 requirements covered quite nicely. The first two are easily achieved. If you have your flash off camera, you get number one. And as long as you know how to dial down your aperture, getting a blurred background is easy. But getting the eyes in sharp focus takes a bit more than just focusing on the eyes. You see one thing many people don’t realize is that there is more to focus than just focusing.

There are more factors involved in getting a sharp image out of the camera than just focus.

You need to have plenty of light on your subject to get the sensor to distinguish between the pixels. You need to have your pixel sensitivity or ISO turned down, 100 if you can but most cameras work quite well at 200. Your lens isn’t at it’s sharpest wide open. In this case I could have set it at f3.5, but the lens is actually sharper between f5.6 and f8. The smaller aperture means that the light goes through less surface of you lens and thus makes more of the image in focus. Since I wanted to blur out the background I chose the more open end of that, f5.6. And finally your shutter speed needs to match. This is a hard concept for many people. When you think of a shutter speed of 1/10 of a second you think you will have a blurry image and difficult to focus. But that’s not the case since we are using a flash to illuminate the subject. The flash will freeze the action, so you just need the shutter to match your other settings for the environment.

1:1 of the original image out of the camera

Don’t believe me? Lets take a look closeup. This is part of the unmodified image out of the camera. There’s nothing done to this image other than the standard color correction. As you can see, the eyes are sharp. They have that classy glassy look to them that comes from being in sharp focus and having the flash (with a big umbrella) supplying enough light for the sensor easily capture the color of each pixel through a small portion of your lens. That can almost be consider an equation, but we’ll call it a recipe for a sharp portrait.