• Party Person •
Reflections on eyeglasses can be controlled. Check the angle of light sources.
Flash creates irritating reflections on eyeglasses.
Flash can be difficult to work with. Especially pop-up flash.
In particular, reflections on eyeglasses make ugly highlights. On-camera flash is directly parallel to the optical path of the camera. The light from the flash travels right down the line, hits the glasses and reflects right back into the lens. This can cause ugly bright reflections, highlights in the eye space of the glasses. Picture ruined.
Get off the optical path
The use of flash should always be off the optical path if you want to avoid red-eye or reflections on eyeglasses. Ensure that you do one of two things. Use an off-camera flash where the flash is off-set to the side on a stand or convenient surface. Alternatively you can redirect the on-camera pop-up flash using a diffuser or some type of reflector. You can find out more about the latter in this post: “Does Pop-Up Flash Ruin Your Shots?”. Both these help to reduce the highlight problem. The light will be on the subject from bouncing off other surfaces. This reduces the direct effect of the light reducing the reflections on eyeglasses from direct rays.
Controlling reflections on eyeglasses
If you use off-camera flash, or any other type of light to illuminate your subject you can get highlights on the glasses. The key to overcoming highlights and reflections on eyeglasses is knowing the simple “Law of the angle of incidence”. The law states…
• The angle of reflection = the angle of incidence •
Basically, light hits a surface and reflects off again at the same angle. Simple!
The “Law of the angle of incidence” teaches us not to stand so your camera is on the same angle as the light reflecting off the glasses. This applies to any light, not just flash. Remember, that when you line up your camera you should look carefully at your subjects eyeglasses to see if there are any highlights you can avoid. If there are lights reflecting off the eyeglasses then move so the “Law of the angle of incidence” does not apply.
Remember to keep the catchlights
Of course the way that eyes look alive is that wonderful bright spot called a catchlight. As in the image above that feature of a reflection brings vitality to an image. To help preserve that, use a tiny bright point directly in the line of the optical path. If you have an off-camera flash you probably have a white pop-up card on it. You can use that card for making a catchlight. Point the flash beam to bounce off a nearby surface. When the card is up, it reflects a gentle light at the subject. At the same time the main beam of the flash is heading off for the ceiling or walls nearby. That little card on the flash reflects just the right amount of light directly to the eyes of the subject. The small size of the card is critical. It is not bright enough to cause bad reflections on eyeglasses. But it is enough to create that lovely bright spot. The eyes suddenly become alive. They are not blotted out with massive back-reflections.
Avoiding flash reflections on eyeglasses:
In the video Mark Wallace explains the Law with a simple diagram then sets up the ways you can avoid the highlights. Remember, his advice applies to any light, not just off-camera flash or studio lights.
Ep 214: Digital Photography 1 on 1
More about off-camera flash
Off-camera flash is a much more controllable way to light with flash than pop-up flash. If you would like to know more about off-camera flash, including how you can buy effective equipment at affordable prices see this post: Off-camera flash. It provides more information about the flash units and how to use them. There is Also advice on purchasing.
Damon Guy (Netkonnexion)
Damon is a writer-photographer and editor of this site. He has run some major websites, a computing department and a digital image library. He started out as a trained teacher and now runs training for digital photogs.
See also: Editors ‘Bio’
By Damon Guy see his profile on Google+.
Posted in Camera control, Equipment, How to..., Light and Lighting, Shooting specific subjects, Starters School, Things to try, Tips Tutorials & Techniques, Video included
Tagged Angle of incidence, Angle of reflection, Eye glasses, Highlights, How it works, How to Shoot, Light, light and lighting, Light sources, Lighting subjects, People Shots, Portraits, Portraiture, Reflections, Video
A new angle on the London Eye. Be careful with long exposures, the urban environment can create strong colour casts. Click to view large.
Planning your night shoots are essential. Working in the dark can be dangerous and is more difficult. Make sure you plan ahead – read this first: Planning and Preparing for a Night Shoot
Night-time and low light composition is similar to daytime – the rules of composition don’t change. However, expect to account for the following:
- Highlights and shadows have different impacts at night compared to daytime. Practice in the garden at home before your shoot. Then you will be able to see the different quality of light that creates shadows and how much more powerful highlights can be.
- Low light and night leads to longer exposures. Be aware of any bright lights you will have in your field of view. You may need to think about the direction or angle of the shot to compensate.
- Be aware of very strong colour casts, especially in urban areas. Neon lights can make some strong orange or green effects. Be prepared with a knowledge of how to compensate using white balance settings.
- Cloud levels can affect light levels, especially in urban areas. Clouds reflect light back down – you can lose the blackness of sky in heavy cloud cover. Wilderness shots can be ruined by nearby light sources like cities. Plan for this by pre-visits. Colour casts may be intensified by cloud cover.
- Night reflections are brighter than day reflections – be aware of the difference with your settings. Night reflections will still need a longer exposure, but you may need to experiment with the settings or take a range of shots to get it right. It is easy to over-expose a night shot with bright reflections.
- Consider the shot angle relative to bright lights. They may produce great flare – fun to shoot and it looks good (see the bright multipoint street light in the photo above). It can also mean colour banding and bright reflection spots inside the lens. This leaves orbs of light all over your shot. Consider excluding very bright lights, especially if they are coming in from the side. A lens hood is always worthwhile at night.
- If you are doing light painting or catching light trails from something moving, watch the background. Some light trails are ruined by the colour or brightness of say, a shop front. Compose for different angles or heights to avoid it.
- The light/dark contrasts are much stronger at night. So you might consider black and white instead of colour – especially when there are strong neon colour casts.
- Preparing your shot is important. Advanced practice helps, but often the actual settings are done on the spot. Do lots of shots. Try different settings and lengths of exposure. You will certainly mess up some shots – we all do. The more you experiment (especially in your first few night shoots) the better you will get at estimating what works.
- Be logical in your experiments. Start using the light meter in your camera to get a good exposure setting. Then go up one third of a stop and shoot again. Then one third more… until you are certain you have it all covered. Do the same going down a third from your ideal, then another… and so on.
Light Battles Dark
Digital cameras cannot see the same wide range of contrasts as the human eye. The range of contrasts at night is far too wide for even top-of-the-line cameras. Try and find a happy medium, avoiding very bright lights in particular. Make sure you have your histogram turned on and set to ‘blink’ if the white detail is lost. Than you will be able to spot very bright lights in the screen after each shot. You can then change your shot.
Weather Conditions – night effects
In wilderness areas, away from light pollution, ‘dark’ is very dark! It sounds odd to say that. However, most urban dwellers do not really know how intense ‘dark’ can be. They have always been used to street lights. With no cloud the darkness can be very intense on moonless nights. So you really need a torch (flash-light). Wilderness long exposures will be much longer than if you took a night shot in an urban environment.
Cloud may lighten the environment a little in the wilderness, and quite a lot more in an urban environment. They reflect the light back. So it may increase any colour casts from local light sources like neon street lights. Fog can create some odd colours at night too. Sometimes orange neon colours turn greenish. Darkness under trees may look black, but may come out bluish in post processing – depending on light levels and background colours.
Strong local light sources and reflected light may mean that the sky is very dark and the ground level is comparatively light. This is especially true when photographing light trails from cars. The light from a busy road can light up the local area. Our eyes see a constant level of light. But over a long exposure the light levels get very high in the shot. Try shooting to exclude the sky so that there is less contrast against bright lights near the ground. Alternatively you might shoot upwards to get the sky – shooting above the light at ground level.
The Moon and stars
The moon is a strong light source. Be careful with it in the frame if you want to include other things. It can be too bright causing highlights or flare on your lens. Check your screen after each shot (Chimping). If you are shooting at ground level the moon can help by lighting the sky. This lessens the sky ‘darkness’ making light levels at ground level manageable.
The Earth rotates and as it does so the moon and stars change position relative to us on the ground. To the eye the movement is not apparent. However, to a stationary camera they both move. If your exposure is too long then they will leave a track. Short exposures will not be too noticeable. If you are exposing for more than 15 seconds the stars will start to have an elongation noticeable to the eye in a high resolution image. This is an approximation as the atmospheric conditions and your position on the Earth’s surface will both change this time. However, it is worth considering how long your exposure will be when you can see stars in the frame.
On the other hand, very long exposures can create exciting star-tracks. These are where the movement of the Earth cause the stars to create long arcs of light during a long exposure. Look up “star tracks” in Google Images .
Night shooting is great fun. With practice and awareness of the above you can get great results. Fortunately you don’t need to go far to practice. Your garden or the street outside is a great place to start. Try out some of the ideas in your local area before planning a more complex shoot on location. You will benefit from what you learn.
Have fun with your night shots!
Posted in Background Info., Camera control, Composition, How to..., Light and Lighting, Things to try, Tips Tutorials & Techniques
Tagged Approach, Blinkies, Camera, equipment, exposure, Light, Low light, Moon, Night, Planning, Reflections, Tripod