Prime lens (filters, Canon EOS, polarizer, 50mm)

[skywind]

Hi,

I am new to photography. Just bought a Canon EOS 400D and keep wondering what all these numbers on the lens means.

(1) What is prime lens? Can you focus (??) or zoom out (apparently not?) from the objects? Let says, you bought a 200mm telephoto lens. You brought it to the zoo and aim at the lion and you find that what is in the viewfinder is only part of the lion (says its head), how then can you take the full picture of the lion?

(2) How to read the number on the macro lens?
Does 50mm or 100mm means anything for the macro?

(3) How to choose a polarizer for my 400D?

[Claire_F]

1. A prime lens is a fixed focal length, meaning no zoom. You "zoom" with your feet, so to speak. In your example above, if you want to take a picture of the full lion, you would back up.

2. The difference between 50mm and 100mm (aside from other factors) is the distance you would be from your object. If you wanted a macro shot, you would have to physically be a lot closer to it with a 50mm than you would with a 100mm.

3. You will want a circular polarizer. I have Tiffen and like them, but I've heard good things about Hoya as well.

[RayinAK]

Not all lenses are "macro" lenses. A lens can have a "macro" setting to allow the user to get very close to a subject. However, one can use a lens without the macro setting to take such photos.

There are close-up filters one can attach to any lens, but these filters could be as expensive as some macro lenses depending on the level of quality. I have some cheap close-up filters I purchased trying to save some money, but they are pretty much useless. A good quality Hoya close-up filter could cost from $200.00 to $400.00.

There are some lenses without a macro settings you can use for macro photography. For example, Canon's 50 mm f/1.8. Just attach a Kenko tube to the camera, and mount the lens on the Kenko tube. This will allow you to get as close as a few millimeters for a lady bug or something like that. The kenko tubes are sold in a set of three tubes, and cost around $160.00 at B&H and some other camera stores. The "nifty 50" (lens above) costs around $80.00 (as far as I remember).

A macro lens such as a Sigma 105 mm one allows you to get just as close to the subject, and without having to use a close-up filter or a Kenko tube. It also allows you to close the distance (twice) to a far subject over the 50 mm lens. However, for taking pictures of people near you, the 50 mm gives you a wider field of view than the 105 mm one.

A zoom such as the "kit" lens (17-55 mm) allows you for a much wider field of view at 17 mm. For example, when taking pictures of your family indoors. In this case you may at times be not able to use the lens at 50 mm if you want to show their whole bodies from head to toe, but set at 17 mm may sometimes allow you to do so.

Take a look at this photo. I set the kit lens at 17 mm to attain a wide view. The trees and other parts of the subject look far away, and small:


This one was taken with a Tamron 17-50 mm lens, set at 50 mm. As you can see, the subject looks much closer or larger:


I took this one with a Sigma 70-300 mm lens that has a macro setting. The lens was set at 300 mm, because that's how the macro switch works with this lens. Notice how subject takes most of the picture. This is a close-up:

[skywind]

Claire, thanks for the tip on lions. what is the cost of a Tiffen? Does Canon make its own polarizer?

Rayin, your photo of the lake is fantastic considering it is just a kit lens, how did you get those cloud so distinct on the sky. Did you put on any accessory on your camera for this shot?

[RayinAK]

Originally Posted by skywind

Claire, thanks for the tip on lions. what is the cost of a Tiffen? Does Canon make its own polarizer?

Rayin, your photo of the lake is fantastic considering it is just a kit lens, how did you get those cloud so distinct on the sky. Did you put on any accessory on your camera for this shot?

All parts of a subject (clouds, sky, trees, etc.) look smaller and farther away when an wide lens is used. The lens was set at 17 mm. If you want to show everything in focus, ether set the lens to f/22 or so with the camera on M (manual) mode. But on a sunny day like it was when I took the photo, with the camera set to "P" mode, it automatically switches to f/16-22.

Also, there is an automatic Landscape mode on your camera. This mode maintains the foreground and background in focus. For now you can set your camera on the green rectangle. This is a fully automatic mode. But you can also set it to a full auto mode such as P, except that on "P" you can manually control the white balance, ISO and a few other things. The wheel by your right thump can be used when the camera is set to P and the rest of the modes all the way to M.

I had a cheap circular polarizer on the kit lens, and it did a nice job. However, I now use a Hoya circular polarizer. Hoya and B+H make some the best quality filters, but they are expensive. The polarizer filters a certain amount of light that is being reflected straight into the camera. For example, when taking a photo of somebody behind a glass window to make the person show more, or in the case of my photo above, to show more of the water, or even the river bottom. It also enhances the sky and the clouds as well as any reflective object.

Have you ever wore polarizing eyeglasses when fishing? Do you remember how much easier is for you to see the fish in the water? That's what the circular polarizer does for the camera's sensor.