This article was written by Andrew S Gibson, the author of understanding lenses: part I, and is the third in a series of lessons on camera lenses. Links to the others are at the bottom of the article.
If direct sunlight (or light from another source, such as a street lamp) hits the front element of your lens, you’ll almost certainly get flare.
There are two types of flare. Is a specular flare; circular spots or streaks of light across the frame. You can see specular flare in the photo below.
On the other hand, is auctioning flare, where light in the shadow areas of your photo creeps, reduction of contrast in the darker tones and decreasing sharpness and definition. This is more subtle and not always noticeable if specular flare. An example where you might See auction flare is lit by the Sun in a portrait. Open the photo to this article contains veiling flare.
Quick tip: use of the auto-levels or Auto contrast features in Photoshop that helps compensate for caused by lack of contrast by veiling flare.
Flare is caused by direct light hitting the front of the lens (this is ‘ not image forms of light ‘). This can happen with any lens, but wide angle lenses are more prone to this than long focal points because of their wider angle-of-view. The easiest way to prevent flare is to ensure that there is no direct light shines on the lens. There are several ways to do this:
A lens hood is an essential accessory for any lens. Some lenses, usually the more expensive models in the range, be supplied with hoods. For any other lens you must separately. The manual of your lens hood will tell you what to buy.
It is best to buy that particular lens hood as you can, or an alternative to third-party products that matches the shape and size of the recommended lens hood. These are often less expensive, although they are not quite as good can be created. But for a lens hood build quality not really important, as its main task is to exclude light your lens.
The above picture shows a Canon EF 17-40 mm zoom lens with the lens hood, that it comes with. This is called a lens hood petal shaped hood and is common with wide angle lenses. The cut away corners are designed to avoid vignetting.
This picture shows a metal lens hood third parties that I bought for my first lens of 85 mm. The field-of-view of this lens is much narrower than the 17-40 mm zoom, the lens hood can so longer without vignetting. Longer lenses are better protected by hoods than shorter ones.
Lens hoods work by cast a shadow on the front element of the lens. Once you have purchased a lens hood, which you should keep on the lens when you take pictures. Even if you think your images are flare free that, there may be a small amount of flair that you don’t notice until you view the photo on your monitor.
Lens hoods also have the advantage of helping to protect your lens from accidental bumps and scratches-another reason to keep them on your lenses while using your camera.
If the lens hood is not enough that the Sun from your lens, there are other techniques that you can use:
If the camera is tripod mounted, you can shade the front element with your hand or a piece of card during the exposure. Make sure that your hand does not appear in the photo.
In the shade when you take a picture, if possible. This prevents the light from the Sun hitting the front element of your lens. If you have a picture of someone with illuminated by the Sun, and there is too much flare, try to place them instead in the shadow. If you also in the shade when you take the photo, you will not flare.
Use prime lenses. Prime lenses (if you have one) are less prone to flare than zooms. One reason for this is that they contain less internal lens elements. Flare is a cause of light into the lens is distributed as it passes the lens elements. The fewer elements in the lens, how are less likely to flare.
The lens to keep clean. If your lens is dirty or dusty, greasy will be more prone to flare. Anyone who has looked at the sun while wearing glasses or sunglasses will appreciate. Your vision is clearer if the lenses are clean. It is the same for camera lenses.
Cleaning is easy. I use a blower brush to remove dust and dirt, then tissues lens with a lens cleaning solution for cleaning of the element. Check your lens (and filters) regularly to ensure that they are clean. Shining a torch on the front element is a good way to see if there is dust or fat otherwise invisible to the naked eye.
The debate about filters seems divided about whether hang and advice they adversely affect the quality of the image or not. I don’t think it makes much difference and use ultraviolet (UV) filters to all my lenses. I feel more comfortable to know that the filter is there to protect the front element of the lens against shocks or scratches.
I buy coated filters that help reduce flare. They cost a bit more, but for me it is worth it. I keep it in my camera bag filter cases, so that if I am in a situation where flare is an issue (if I’m shooting in the Sun, for example) I can temporarily remove the UV filter and save. I can also remove the UV filter if I a polarizing filter, used to prevent more than one filter connected to the lens at a time.
Finally, don’t forget you can than creative flare. Sometimes it is added to the atmosphere of the picture. There is even a Photoshop filter for those situations where you would like to add it afterwards. Thats how I created the flare in the picture above.
These are the previous articles in the series. My next article will be about flare; the causes, exploring how to avoid flare and also how to use it creatively.
Why your Kit Lens is better than you think
7 ways to get more from a wide-angle lens
Why lens quality doesn’t matter Quite as much as you think it does
If you found this article then take a look at my latest eBook, understanding lenses: part I-A guide to Canon wide angle and Kit lenses. I have a special discount code for Digital Photography School readers. Dps2 at checkout type to receive a