Lens flares and ways to eliminate them
What is flare?
Sometimes you look at your photos and notice there are flares. Flare is mainly caused by direct light hitting the front glass of the lens. The main sources of flares are sunlight, street lamp, or direct light from another source.
Flare could be circular or manifested in stripes of light across the photo. The later casts light creeps into the shadow areas of your photo, reducing contrast in the darkest tones and decreasing sharpness and definition. This is also called veiling flare and and an example of veiling flare is in a portrait backlit by the sun.
Using the levels or contrast functions in Photoshop or Lightroom helps improve photos with veiling flare. Circular flare however is trickier but can be reduced using Spot Healing brush and Cloning functions.
However, why introduce flare in the first place. Why not avoid flare by paying attention to the source of light and your composition angle.
This can happen with any lens. Wide-angle lenses however are more prone to this than zoom lenses because of their glass composition and their larger area of view. The easiest way to prevent flare is to make sure there is no direct light hitting your lens.
Get a lens hood
A lens hood is an essential accessory for any lens. This is why you see professionals always using lens hoods. For some lenses lens hoods are already included in the box when you buy them. Others are not; and you will need to know the lens diameter to buy one separately. Longer lenses are better protected by lens hoods than shorter ones.
Lens hoods comes in 2 main shapes:
Different types of lens hoods. Source: Wikipedia
- Petal lens hood (or tulip lens hood) and is common with wide-angle lenses. The cut away corners are designed to prevent vignetting.
- If the lens is a prime lens (fixed focal length, non-zooming) the hood looks like a tube, often wider at the other end .
Even if you think your photos are flare free, it may be that there is a small amount of flare that you don't notice until you view the photo on your computer.
A lens hood’s main purpose is to block light but they also help in protecting your lens from accidental knocks and scratches – another reason to keep them on your lenses at all times.
Change your angle of view
If the camera is mounted on the tripod use your hand or a card to shade the front of the lens. Make sure your hand doesn't appear in the photo. If possible, stand in the shade. This prevents the light from the sun hitting the front element of your lens. If you're taking a photo of someone back-lit by the sun, and there is too much flare, try placing them in the shade instead. Try moving around your subject but also try changing the height that you're shooting from. All these will change the angle at which light hits your lens.
Keep your lenses clean
If your lens is dusty it will be more prone to flare. Try wearing sun shades and look directly into the sun. You will notice that a cleaner sun shades are better. The same applies to your camera lenses.
Use a blower or a lens brush to remove dust and dirt. Check your lens (and filters) regularly to make sure they are clean before the shoot session.
Invest in filters
Consider using UV filters to protect your lenses and at the same time reduce flares. UV filters cost a little but for me it’s worth it. Keep the filter cases in your camera bag so that if you are in a 'flare' situation, you can use them. You can also make use of a polarizing filter. Polarizing filters are made to remove flares and reflections from waters and other identical sources plus they have a wonderful saturation effect on your photos. Filters and their use is a topic by itself. I will try to discuss them seperately in a future blog topic.
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