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Friday, August 10, 2012

Photography 101 {the 411 on lenses}

Brought to you by majority vote, (Ok not really.  It was a 3 way tie so I just picked one!) a primer on lenses.
We could get deep here.  We could go on and on about Galileo and optics and physics.  But I promise I'm not going to.  Just the basics.  There are also SO many more lenses than the ones that I have mentioned below.  But I'm keeping it to the basics with a few more thrown in to explain some terms you might be hearing.

Before we start we need to cover 1 definition that's going to come up
Focal length - how much (or little) magnification a lens has.

So here it goes.

When we categorize lenses by whether or not there is an adjustable focal length, there are two types of lenses.
1) Prime lens (sometimes called fixed) - The focal length cannot be changed.  If you want to get closer or farther away form your subject you have to actually use your feet and move your body.  Prime lenses are usually sharper and produce crisper images.
These are just 2 examples of prime (or fixed) lenses.  There is no ring to adjust the focal point because prime lenses are not adjustable.  They have a "fixed" focal length, in this case 50mm and 85mm.

2) Zoom lens - A range of focal lengths that can be changed by rotating the ring around the lens.  Zoom lenses offer more flexibility, but typically aren't as sharp as a prime lens.  Zoom lenses do not necessarily let you take photos of things that are far away.
3 example of zoom lenses.  Zoom lenses can be longer and heavier than prime lenses, but not always.  They have a ring on the outside, that can be rotated to adjust the focal length, thus increasing or decreasing magnification.  
So "zoom" and "prime" just indicates if you can adjust the focal length or not. Easy peasy so far, right?
Wait... there's more!

When we speak of how much magnification there can be on a lens, lenses fall into 3 categories.
1)  Telephoto - Brings the subject closer.  Telephoto lenses are typically a focal length of 70mm up to 300mm+. Telephoto lenses will let you see "close up" what is far away, like looking through binoculars.  A telephoto lens also narrows the view.
2)  Standard - A "normal" lens, if there is such a thing, approximates what the human eye sees, although it doesn't have the puerperal vision of the human eye.  A 35mm or a 50mm (depending on what camera you are using) is considered a standard lens.  Standard lenses usually have lower apertures available, and are smaller and light weight, (Some of the many reasons I recommend the nifty 50 as a first lens to folks.)
3)  Wide angle - Usually a lens with a focal length under 40 to 35mm.  A wide angle lens can view a large scene.  It's the equivalent of backing up to view more of the shot.   Landscapes are most often shot with wide angle lenses.  But wide angle lenses can also distort images.

Still with me?
But wait, because there's still more!

We can also combine these two types of lenses and come up with many combinations of the two.  For example
---a wide angle zoom
---a regular prime
---a telephoto zoom
---a regular wide angle
---a fixed wide angle
etc.
And to compound the issue further, all of these lenses can be found in inexpensive, moderate, and expensive price ranges.

For the overachievers in the group...  keep reading for even more lens info.
But if you're brain is full stop here.

Here are a few more lenses that you may be hearing about.

Macro - Usually a fixed focal length lens that enables you to view extremely close up of usually very small objects from a close distance.

This was taken with my 100mm macro.  The end of my lens was only about 6-10 inches away from the crayons when I took this shot.  A macro lens lets you get really close to take a photograph.


Fisheye - A super-duper wide angle lens. Fisheye lenses produce much distortion and usually have a focal length of 4 to 16mm.  A fisheye lens can usually view 180+ degrees.
A stock image from Canon
This fisheye lens distorts the horizon to a curve, but captures 180 degrees into a single frame..

Tilt-shift lens - a lens that actually "tilts" and gives the final image selective focus.  This effect makes things look miniature.  This effect can also be somewhat replicated with post processing.  Tilt-images are quite popular right now.
An image from Wikipedia
This tilt-shift lens creates a miniature effect by blurring out the outer edges of the image.  It's kinda like looking at a doll house.

Teleconverter - A separate lens, mounted between the camera and the other lens, that increases magnification of the first lens.  For example, a 2x teleconverter would turn a 50mm focal length into a 100mm or a 24-70mm into a 48-140mm.  However, teleconverters exaggerate the flaws of the original lens, may reduce the possible aperture choices, and usually produce softer images.
This pic is kinda old but perfectly shows how a teleconverter fits in between the camera and lens.  
And just a couple terms that you'll frequently hear in association with lenses.

Image stabilization - (called "vibration reduction" in Nikon) a sensor in the lens that helps stabilize a lens and thus reduces the "camera shake" of the photographer.  Lenses with image stabilization make it easier to take photographs at slower shutter speeds.  Lenses with image stabilization usually cost more than those without.

Manual focus - The photographer has to adjust the lens by hand to achieve focus.
Auto focus - A sensor in the lens that automatically focuses for you.
This is the toggle switch to switch the lens between auto and manual focus.
There are times that manual focus is necessary.
Any questions?  Shoot!
The new poll is over there on the right, so let me know what you'd like to see next.

Photography 101

5 comments:

  1. Great primer on lenses! I think I have one of most of those. Not a macro though.
    Would love to know more about what types of shots I would capture with each. I know the 50mm is a portrait lense, but the others, I am sometimes baffled.

    ReplyDelete
  2. I only use a point-and-shoot;
    I left my intensity with my film Nikon F2 back in the 1970s and 80s.
    However...
    I'm sending this post to my daughter-in-law; she will LOVE it.
    Thanks.
    (here via Shutter Sisters)

    ReplyDelete
  3. BusyMomofTwins--a little trick that I use frequently to see what type of shots each lens can capture... go to Amazon and pull up a specific lens that your interested in. Underneath the main image of the lens, are photos, submitted by folks taken with that lens. You can scroll through them, and it'll will give you a good idea of all sorts of things that lens can do, from pros all the way to regular ol' folks.
    I used to do this all the time, to figure just that out.
    nancy

    ReplyDelete
  4. Thanks for the info! I enjoy reading your photography posts, and of course, seeing pictures of your cute kiddos!!

    ReplyDelete
  5. Oh how I love Photography 101! Thank you, thank you, thank you, Nancy!

    ReplyDelete

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