The Tutorial Thread!

[MTVision]

But/borrow the book Understanding exposure by Bryan Peterson.

Www.cambridgeincolour.com

[Ads]

[dazind]

But/borrow the book Understanding exposure by Bryan Peterson.

Www.cambridgeincolour.com

I can really recommend that book too!

[SrSLR]

It's one of the first books I picked up, before moving away from point and shoot to SLR, great advice!

[acantonyclark1]

Good Photography books:

BEST BOOKS FOR PHOTOGRAPHERS

Thanks for the photography book!

[Reactiveye]

Hi everybody!

I am a passionate of photography and I regularly post some aids for photography beginners here: Photophile-toi - Page profil YouScribe

(oh, and sorry for my english, I'm french.. Is it bad doctor?)

[hannabell]

Do you have anything about working with a bridge camera? Or is there a section on that I can't find a link to?

[pgriz]

Would like to recommend the following: Amazon.com: Light Science and Magic, Fourth Edition: An Introduction to Photographic Lighting (9780240812250): Fil Hunter, Paul Fuqua, Steven Biver: Books, following Keith's suggestion to me. I got it and it is very effective in teaching lighting theory and practice.

[davidewing]

An excellent collection of questions. A great place to start!

Cheers David

Photography Studies Learn Digital Photography

[King Mango]

---

THE DukeScrotum? Formerly the Earl of Fomunda?

[The_Duke]

a lot of great info, thanks.

[Thanasis_gs]

Thanks for this thread!! It is going to help me a lot

[vinuwilfred]

A picture says better than thousand words. Photography is a great art which can manipulate the real world. It is a spiritual experience. Every human being must have a camera and have lots of cool clicks. This forum will help everyone to have good photographic skills and learn about latest techniques in photography. We can also share our photos and let the world see it...

Check this URL also:-
Progetto 100 fotografi | Fotografare in Digitale
Anchor text:
100 Photographer Project

[CanonJim]

This is something I put together about a year ago for another forum, and it seemed to help many out. Very basic stuff here, but very important to grasp.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~

A (very) Basic Lens ~ Aperture ~ Shutter Speed ~ ISO Primer

Updates and corrections may be direct to me via PM - Thank you

Introduction:
We all (well, almost all) know how a camera works - you press a button, which opens the opens the shutter in the camera for a brief moment, which lets light in through the lens, which strikes a sensor in the back of the camera (or film, if you prefer) and makes the pretty picture of your grandchild, favorite pet, flower, bug, Aunt Matilda, or Yosemite valley, if you're into that kind of thing.

However, and behind the scenes, there is a fairly complex relationship between the parts of the above equation that goes a long way towards what that final picture actually looks like. Modern DSLRs on "Auto" take care of everything for you, more or less, but conditions often fool the camera into a setting that is not actually the best for your scene. And, of course, for learning, "Auto" is not the best choice.

Let's take a look how the three basic parts of the process work together, and how you can adjust them to learn how things work, and to take better pictures than your camera alone would. After all, you ARE smarter than your camera, aren't you?

1. The LENS and APERTURE

Note : there is no trailing "E" in the word LENS, singular. Many people think it is a British variation, but every British photographer I spoke to disclaimed any knowledge of that. The British add a "u" to words (e.g., colour, harbour, et cetera), not an extra "e". Read any book by Scott Kelby, Ansel Adams, Tom Ang, or Bryan Peterson, and tally up all the times you see "lense". Answer: 0

A lens is simply a device that focuses and gathers light rays and concentrates them to strike a smaller area in the camera. It does this through a combination of glass elements and something called an APERTURE. The aperture is similar to the pupil in your eye, in that it opens or closes depending on the amount of light coming through. Your eye does it automatically, your lens does not.

Here are the salient points:

When the aperture is very wide open, a lot of light gets through to strike film or the sensor.

When the aperture is closed down, a much smaller amount of light gets through.

WIDE OPEN and CLOSED DOWN are actual terms used by photog's to describe these instances.

A lens that can open very wide, compared to other lenses, is called a 'fast' lens. "Fast" can also be used to describe how quickly that kind of lens sucks money from your wallet.

The amount that the lens is open, compared to something called the focal length (which we'll get to) is noted by the 'f-stop', and usually written or typed "f/xx", where "XX" is the ratio of those two distances to each other. You don't really need to be too concerned with the actual numbers, per se - "f/1.2" doesn't really mean anything, after all, it's only the RESULT of the "f/1.2" or "f/4.5" or "f/8" that we're concerned about.

2. Focal Length, Prime and Zoom lenses

The focal length of a lens determines what kind of a view it presents to the sensor. Different lenses have different focal lengths for different purposes. A lens with a focal length of 15 millimeters, or "15mm" gives your camera a very wide view of the surroundings. A lens with a focal length of 400mm gives a telephoto view, and is used to photograph far-off objects. A lens around 35-50mm approximates the field of view of our own eyes, and is often used as a baseline when comparing lenses.

A lens with just one field of view setting, e.g. "35mm" or "100mm" is known as a PRIME lens.

A lens with an adjustable field of view, e.g. "18-135mm" or "24-70mm" is a ZOOM lens. Simple.

Prime lenses usually supply better image quality than zoom lenses because the glass elements can be manufactured to focus light at just one setting, and can therefore be more precise and accurate. A few decades back, the technology to make zoom lenses was far less precise than that for prime lenses, so most photographers used a set of primes covering various focal lengths - 28mm for wide angles, 35mm for medium wide, 50mm for "normal" shots, 100mm (and above) for telephoto, etc.

However, Time (and Newsweek) Marches On, and manufacturing technology has improved to the point that many zoom lenses are of very high quality now. Given any particular price point and focal length, a prime lens will USUALLY provide better optical performance, but a shot from a good quality zoom is almost indistinguishable from one taken by a prime lens. Generally, the wider the zoom range, the more compromise has been made in manufacturing. A 24mm-70mm zoom is probably not so bad, a 10mm-500mm zoom just can not deliver the same optical quality. (Owners of 10-500 lenses, please don't message me with "my lens is perfect" - I understand your statement and I'm not picking on owners of wide range zooms. Just stating an optical truth.


3. How the LENS and the APERTURE work together

Simply put, the wider the aperture is open, the more light gets through in a given amount of time. What this means to YOU is that in any given scene, the wider the aperture you're able to use, the faster your shutter speed can be. This means that you can stop action, for example, in a sports environment, or a hummingbird flying by, or your dog chasing a Frisbee. It also means that you can take a picture in less light - say, candlelight around your kid's birthday cake.

So wide aperture ----> allows fast shutter ----> freezes action,
as well as
wide aperture ----> more light ----> indoor pictures possible without flash

As noted above, an aperture number like "f/1.2" is considered pretty wide open. An aperture of "f/8" is not, relatively.

If you want to shoot action indoors, such as gymnasium activity like basketball or volleyball, you will need a 'fast' lens - these areas typically do not have very good bright light, nor do they allow flash photography.

There is one other characteristic that comes into play with the lens and aperture settings - DEPTH OF FIELD, or DEPTH OF FOCUS, often abbreviated "DOF".

Depth of field is the idea that, for any given aperture opening, a certain part of the scene in front of you will be in focus, front-to-back-wise. Picture a picket fence, receding into the distance. At a wide aperture opening, just a very small part of that fence will be in focus. At a narrow opening, a much longer stretch will be in focus. Don't worry about the physics of the optics and all that involved in this, just remember that the WIDER your aperture, the NARROWER your depth of field.

Most good landscape photos are best with a narrow, or closed down aperture - it's not uncommon to see a sweeping vista across miles and miles to taken with an aperture of f/16 or f/22 - not much more than pinholes in your lens' aperture. You need to be careful though, as in most lenses, once you climb above f/18 or so, light diffraction within the lens itself can cause image degradation, and there's no way around it.

Portraits, on the other hand, are often taken with fairly wide open aperture, because you don't need a lot of depth to take a picture of a person's face. But still, you need to be careful, because at wide open apertures, it doesn't take much to get out of focus - you can take a picture of Aunt Matilda where her nose is perfectly in focus and her ears are out of focus. Generally, if you focus on the EYES of a person, you'll get most of their head in as well.

Also, with portraits, a out-of-focus background helps to concentrate the viewer's vision on the person in the picture, and not a background element. There's a reason studio portrait photographers use bland backdrops.

So our next set of relationships is

Wide Aperture ----> Narrow depth of field ----> nice, blurry background (called "bokeh", a Japanese word meaning 'blurry background')
and
Narrow Aperture -----> Wide Depth of field -----> Close and far all in focus, used in nature and landscape photos.

4. Shutter speed - quick, blink!

The shutter speed is pretty simple - it's how fast the camera blinks. The faster the blink, the better you're able to stop action, if that's what you want. The slower the blink, the more light hits the sensor or film. Shutter speeds are measured in tenths or hundredths or even thousandths of a second, e.g. "1/10th sec" or "1/500" or something to that effect. Most cameras also allow you to set a longer shutters speed by hand, from 1 second to "'as long as you hold the shutter down".

The main thing to remember about shutter speeds is that FAST freezes action, and s.......l.......o.......w may cause blurriness due to camera shake if you don't use a tripod.

Modern cameras or lenses with "Vibration Reduction" or "Image Stabilization" can help reduce camera shake by overcoming your natural shakiness. It's important to note that these things reduce the effect of CAMERA movement, not SUBJECT MOVEMENT. If you've got a fidgity 2-year old child in front of you, VR or IS will not keep him from being blurry or fuzzy.

The old rule was that your shutter speed had to be at least as fast as the focal length number, e.g. if you were zoomed to 200mm, your shutter speed should be at least 1/200th of a second to eliminate camera shake, or if you were at 50mm, you could shoot at 1/50th of a second. VR and IS have changed this a little bit, but it's still a good rule to follow when you can. Also, if you follow this rule, remember that this rule was devised for 35mm sized film and sensor - a crop sensor camera would need to multiply by the crop ratio as well. For example, the shutter speed for a 100mm shot on a Canon Rebel or similar would need to be 1/160th of a second, not 1/100th.

You need a fast shutter speed to stop action - sports in particular. For landscapes, bug close ups, portraits, or most everyday kind of shots with static subjects, you don't need a real fast shutter speed - getting things in FOCUS and eliminating camera shake are much more important in those situations.

5. ISO Sensitivity

One last little part that enters in to the equation : your camera's ISO setting. The ISO rating determines how sensitive your sensor is to light in the first place. In the days of film, it was called the ASA rating. (ISO = "International Standards Organization", ASA = "American Standards Association". Big deal.) In the old days, an entire roll of film was one ASA rating - but thanks to the glory of digital, we can change our ISO setting from picture to picture with hardly a thought. Ratings range from a standard, daylight or sunny environment of 100 or 200, to the 'you can take a picture of a raisin in a dark room in the middle of the night' number like 12000

The higher the ISO rating, the more sensitive your sensor is to a given amount of light. However, the down side is that the higher the ISO, the more 'grain' or 'noise' you will see in your picture, especially in dark areas.

Setting your ISO number higher is one way to take a picture in low light without having to use a flash, and you can also use a faster shutter speed as well.

ISO only affects how sensitive your camera is to light. It does not have any effect on, nor is it affected by, aperture, focal length, or focusing.

Generally, you should try to use the lowest ISO possible, given the conditions. Unless you're trying for a particular effect, such as digital noise, the lower the number, the better the image quality.

6. Putting it all together

Ok, so now we know how the aperture setting relates to both shutter speed and depth of field (focus), and how ISO affects light sensitivity, and how shutter speed affects motion, movement, and potentially, focus.

As I said at the beginning, when your camera is on AUTO, it does all of that for you, based on what you're pointing the camera at. However, it can't read your mind. It doesn't know that you're trying to capture really speedy football action by your grandson, all it knows is that it's kinda dim outside, there's not much light, so it sets the aperture about mid way open and uses a long shutter speed, and maybe even bumps up the ISO. Oooops. Instant blurry kid, because of the narrow depth of field, long shutter, and high ISO.
This is why "Auto" may not always be the best choice. Many people recommend that, for most cases, you use your camera's APERTURE PRIORITY, or sometimes, SHUTTER PRIORITY modes. Cameras vary, so check your manual for how to set each mode.

In Aperture Priority (Canon's "AV" mode), you set the desired aperture, keeping in mind the depth of focus you need, and the available light, and the camera will set an appropriate shutter speed, and if you have ISO set to AUTO, an appropriate ISO setting.

In Shutter Priority (Canon's "TV", time value mode), you pick a shutter speed that you want (perhaps to freeze action at a sporting event or similar), and the camera will select the appropriate aperture and ISO setting.

So, at your kid's fall afternoon football game, or that rather dimly lit gymnastics meet, you think to yourself, 'Ok, low light here, but I need to freeze the action. I need a fast shutter speed. So you set your camera to shutter priority mode, set it to 1/250 or faster, and take a sample shot. Depending on lens, light, and some other factors, you might have nailed it. If not, adjust the speed up or down as necessary.

In other cases, getting good focus is most important - most flowers, for example, don't need a fast shutter speed. They're not going anywhere. And, usually the light's pretty good. Few people shoot flowers in the dark. In this case, you think to yourself, "I want a good crisp focus, and a blurry background to draw attention to my flower. Shutter speed isn't important, and there's plenty of light." So you set your camera to Aperture Priority, dial in the aperture to a nice wide setting, stick the ISO at 100, and let the camera pick the shutter speed.

So take your camera out of "AUTO" and put some of your knowledge to work. Have Fun!

[480sparky]

........Note : there is no "E" in the word LENS, singular. ...........

I see one!

[CanonJim]

........

Note : there is no "E" in the word LENS, singular. ...........

I see one!

AAACK! Physician, heal thyself! Somehow I dropped the word TRAILING. Fixed. Color me chastened!