Do I really need a Lens Hood?

Lens Hoods have 2 main advantages:

1. Lens Hoods shield yours lens from direct sunlight or other bright lights that might fall directly on the lens and in turn, cause flare. By reducing the contrast and creating flare, your pictures will have much richer colors and deeper saturation. Flower shaped lens hoods are often used on zoom lenses as a normal lens hood will block the field of view on certain zoom settings.

2. Lens Hoods also protect your lens. As the hood does project from the lens, it does make the actual lens difficult to reach. This helps reduce the accidental fingerprint on the lens or even the accidental drop which could result in the need to replace the lens. And if you are a serious photographer, you know how expensive that is!

The only time you do NOT want to use a Lens Hood is when are you are shooting Macro or when are you are shooting using the on-camera flash. In these cases, the Lens Hood can obstruct your shot.

Check out the latest Canon Lens Hoods here and the latest Nikon Lens Hoods here.

Here is an interesting video on Lens Hoods by Jared Polin

Image by: nlewis039

How to use a Circular Polarizing Filter (CPF)

I was looking online on how to use a Circular Polarizing Filter (CPF) and I came across this good explanation:

For the level best polarization effect, the sun should be at a right angle to your subject. That means when you’re facing your subject ideally, either your left shoulder or your right shoulder will be pointing at the sun. The polarizer will still work if the sun is at less than 90′, but to a lesser degree. It also works well when the sun is directly overhead, though it won’t have much of an effect on the sky when the sun is that high.

Sometimes the polarizer effect will be subtle, and you won’t always notice a dramatic darkening of the sky, but if you look closely you may find bright reflections being reduced and/or eliminated on leaves, rocks, etc. If you’re not seeing any effect, then you can simply remove the polarizer and gain a stop or more in shutter speed if you need it.

The nice thing about a polarizer is that you see exactly what it going to do as you rotate it while looking through the viewfinder. It’s either doing something, or it isn’t. So you don’t really have to remember to have your subject 90′ off axis to the sun though you can use that knowledge to reposition yourself and/or the subject if you want to achieve the maximum polarization effect.

Image Credit: Beverly & Pack

Why are faster lenses sharper in the telephoto range?

Someone asked this question in a forum and here is a great answer that will be helpful to all of us!

“First off, lenses are designed for their specific maximum apertures. A 300mm f/4 is not a stopped down 300mm f/2.8. It was designed as a f/4 from its inception.

Virtually all lenses are sharpest at about two stops down from wide open. This is because lenses are designed for a range of apertures, and anything with any kind of range in its design must have compromises. The 300mm f/2.8, therefore, is sharpest at about f/5.6, and the 300mm f/4 at about f/8.

In theory, a lens could be designed with a single aperture and maximum sharpness at that aperture. Such a lens, however, would be severely limiting in its use. Mirror lenses have this drawback—this plus the fact that they are almost always use very poor glass to keep the price down.

Secondly, large aperture lenses require very primo front elements. These elements are the most critical elements in most lenses, and cannot tolerate aberations. After all, the light passes through these elements first, and, if distorted, remains distorted forever after. These elements are also the largest elements in the lenses. When grinding and polishing glass, the larger the diameter, the harder it is to prevent aberations from creeping in. Large aperture lenses means means super-precision grinding and polishing out to the very edges, which in turn means very high prices.

Take Canon’s 300mm “L” lenses as examples:
The EF 300mm f/2.8L IS USM has a front element with an active area about 107mm in diameter and sells for about $4340 at B&H.
The EF 300mm f/4L IS USM has a front element with an active area about 75mm in diameter and sells for about $1269 at B&H.

A lot of effort goes into that 32mm difference.”