what the numbers mean plz?

[Dropy]

SO i am trying to figure out what them numbers mean. Thanx to the article about aperture i now know what the f2.4 type stuff means and how it works. THANX!!

My question for this thread is...... When i see a lense that says 50-500, or 150-500 i know that it has the long range of a 500mm lense. But is the first number how close you can be to the target and still get a reasonable pic of it? In other words a 50-500 costs more because you can be closer than in you used the 150-500 and still take a good shot?

[savona]

50-500 means the zoom goes from 50mm to 500mm.

There are three basic lenses:

1) Wide Angle
2) Normal
3) Telephoto

A 50mm lens is considered (or referred to) as a NORMAL lens. This is because a 50mm lens has the closest field of view to human eyes. A lens with a focal length of less that 50mm is considered a wide angle lens. lenses that have a focal length of over 50mm is considered a telephoto lens.

So with a 50-500mm lens you would have a lens that can go from a NORMAL field of view to a telephoto or zommed field of view which is pretty far onto the long side.

There are drawbacks to a lens with such a long zoom range. For one it is hard to make a lens sharp (really crisp) all the way across the zoom range (from 50-500). Second, the lens must move in and out in order to zoom. Since it has to go all the way from 50 to 500 it kind of creates a vacuum inside the lens which sucks and pushes air. This causes more than usual amount of dust getting inside the lens. My BIGMA (Sigma 50-500) shows signs of dust after just a few months of average use.

I hope this helps!

Also, if you are not all that familiar with photography terms we have a glossary with just about every term and its meaning. You can find that here:

http://focusfaction.com/forums/faq.php?faq=terms

[Dropy]

So, by what your saying, a photographer is better off getting a lense more dedicated to its use. Such as getting a 200-500 for longer range because the lense will keep its quality for longer? And the pics will be better?

[Adaptive]

yes

The more wider the field of view the less sharp the pictures you will produce. (in most cases)

Lenses with a fixed focal length (prime lenses) are the sharpest but they can not zoom and are "fixed" at their zoom level
(ex. 50mm lens, 200mm lens, etc...). Because prime lenses have fixed focal length they are not always the most useful or practical.

[JohnQ]

Another thread with good info here, Keep asking questions so I can learn!

[Adaptive]

Back to what I was saying about wider field of view = less sharper lenses in most cases.

Here are a couple examples.
Disclaimer, I only really know about L lenses.
So I'm not sure about non-L lenses or sigma and other brands but I think it's all the same.

Sharper lens in red!

Canon 24-70L
vs
Canon 24-105L

Canon 70-200L
vs
Canon 100-400L

Here's a close one...
Canon 16-35L
vs
Canon 17-40L

oh snap!