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wizz-o-matic
09-10-2007, 02:43 PM
So, as I promised, here's a small explanation of some camera technical stuff (let it be digital or analog) with Wikipedia links.

Aperture of the lens adjustment of the iris (http://en.wikipedia.org/wiki/Diaphragm_%28optics%29), measured as f-number (http://en.wikipedia.org/wiki/F-number), which controls the amount of light entering the lens. Aperture also has an effect on focus and depth of field (http://en.wikipedia.org/wiki/Depth_of_field), namely, the smaller the opening [aperture], the less light but the greater the depth of field--that is, the greater the range within which objects appear to be sharply focused.
The lower the number is the more the iris is opened therefore, more light comes in

Shutter speed (http://en.wikipedia.org/wiki/Shutter_speed) adjustment of the speed (often expressed either as fractions of seconds or as an angle, with mechanical shutters) of the shutter to control the amount of time during which the imaging medium is exposed to light for each exposure. Shutter speed may be used to control the amount of light striking the image plane; 'faster' shutter speeds (that is, those of shorter duration) decrease both the amount of light and the amount of image blurring from subject motion or camera motion.

White balance (http://en.wikipedia.org/wiki/White_balance) on digital cameras, electronic compensation for the color temperature (http://en.wikipedia.org/wiki/Color_temperature) associated with a given set of lighting conditions, ensuring that white light is registered as such on the imaging chip and therefore that the colors in the frame will appear natural. On mechanical, film-based cameras, this function is served by the operator's choice of film stock. In addition to using white balance to register natural coloration of the image, photographers may employ white balance to aesthetic end, for example white balancing to a blue object in order to obtain a warm color temperature.

Metering (http://en.wikipedia.org/wiki/Metering_mode) measurement of exposure at a midtone so that highlights and shadows are exposed according to the photographer's wishes. Many modern cameras feature this ability, though it is traditionally accomplished with the use of a separate light metering device.
Usually every the camera is provided with at least 3 different metering modes. Multi metering (average light on several points on the field), Center-weighted average metering (average light on a small portion of the center field) and Spot metering (average light on a specific spot that usually the photographer picks - some compact cameras may have the spot metering fixed to the very center of the field).

ISO speed (http://en.wikipedia.org/wiki/ISO_speed) traditionally used to set the film speed of the selected film on film cameras, ISO speeds are employed on modern digital cameras as an indication of the system's gain from light to numerical output and to control the automatic exposure system. A correct combination of ISO speed, aperture, and shutter speed leads to an image that is neither too dark nor too light.
In other words, higher the value is less light you need for the photo, but the amount of "grain" increases.

Focal Length - Digital cameras have a different focal length values than the film ones (that's due to the camera sensor being pretty much smaller than the classic 35mm film). The compact digital cameras usually uses the term "zoom" instead of focal length. Tho, when talking about SLR (Single-lens reflex) camera (http://en.wikipedia.org/wiki/Single-lens_reflex_camera) the usage of "zoom" vanishes and gets changed with focal length. Due to different values the SLR lenses falls in several different categories (from wide-angle to telephoto).
Well, in simple words a 50mm (non-macro) lens is around the same as an "human eye sees"

Exposure (http://en.wikipedia.org/wiki/Exposure_%28photography%29) - Is the total amount of light allowed to fall on the photographic medium (photographic film or image sensor) during the process of taking a photograph. Exposure is measured in lux seconds, and can be computed from exposure value (EV) (http://en.wikipedia.org/wiki/Exposure_value) and scene luminance.
In simple words ... exposure is composed out of aperture, shutter speed and ISO value and tells you how light/dark the photo is.
When going under 0 with the EV value the photo will get more and more darker, and when increasing the EV value the photo gets more and more lighter.

For more info check the Photography (http://en.wikipedia.org/wiki/Photography) on wik ^_^

Anything else that I should mention in here?

Capernicus
09-10-2007, 02:47 PM
...none of that helps! @_@

Kaitou Ace
09-10-2007, 04:17 PM
Ah lemme give it a try from a different perspective ^_^;;

(While this is most important for SLR style cameras, all cameras digital and otherwise have to work within this system, and understanding it will give you some ideas to what may be causing the effects you are seeing in your image.)

The main thing in photography is light. The word "photography" literally means painting with light. When you take a picture, you have three mains ways of controlling how much light comes in. Looking at the information from a shot, you usually get something like this:

1/100s f4 ISO200 35mm

These numbers are:

1/100s - Shutter Speed

f 4 - Aperture

ISO200 - ISO/ASA speed

35mm - Focal length

The Shutter Speed

The first, is the shutter. Whether mechanical, or electronic, it opens and closes, usually in much less then a second.
The shutter speed is given in fractions, as 1/125 which means it stays open for 0.008 seconds. The longer it stays open, the more light comes in, you get a lot more light at 1/8 of a second then you do at 1/4000 of a second.

The trade off when using longer shutters is blur. While 1/125th can capture most motion, anything moving really fast will still have blur. At 1/60th of a second you will get blur from people walking, and 1/30th even breathing can produce blur. However to catch high speed water spray, you may need to go as high as 1/2000 of a second.

Also you have to worry about camera shake at very slow shutter speeds. It's very hard to hold the camera steady at 1/8th of a second or slower, and your own breathing can get blur.

Good camera technique can let you hold the shutter open longer, but there are limits to what a person can handle. Other camera/lens features like optical image stabilization can help you deal with camera shake, but nothing can stop subject movement except for a fast shutter speed.


http://lh6.google.com/saitou/RuWr2OtsV3I/AAAAAAAAAiY/uiJp5YBIDew/s144/IMG_5719.JPG (http://picasaweb.google.com/saitou/Demos/photo#5108678300472727410)

http://lh5.google.com/saitou/RuWr2-tsV4I/AAAAAAAAAig/Ar9XcP1RXUc/s144/IMG_5718.JPG (http://picasaweb.google.com/saitou/Demos/photo#5108678313357629314)

For example these two images were taken with different shutter speeds. The first one, at 1/160th of a second captures water droplets in place, while the bottom one was shot at 1/10th of a second, and turned the water into smooth streams. I used other methods of controlling light to make the images look nearly the same, but the 1/10th of a second image let a lot more light in.

Aperture

Aperture is the second number usually give, prefaced with the letter "f" The "f" is used because it's called the f-number, or the ratio of focal length to lens diameter.

Lenses have a set amount of such "f-stops" which control how much light comes into the lens. The smaller the f-number is, the more light is allowed into the lens.

http://www.igorbass.com/snips/Aperture_diagram.png

Lenses have a minimum and a maximum aperture, The larger the max aperture is (and the lower the f-number) the "faster" a lens is considered, and when talking about lenses it's always the maximum aperture that is considered. So for example Canon has a few lenses at the 50mm length.

50mm f1.0
50mm f1.2
50mm f1.4
50mm f1.8

And while the 1.8 lens can be easily bought for $70, you'll end up spending close to $2,000 for the 1.2, and the 1.0 is a lot more expensive then that. The more light a lens lets in, the more expensive it is as a general rule.

Zoom lenses may have more then one aperture. For example the Canon 28-135mm lens (it goes from 28mm at the wide end, to 135mm at the telephoto) has the f-stop listed as f3.5-5.6, which means that while you can open up to 3.5 on the wide end, by the time you zoom in to 135mm your maximum aperture is only 5.6.

The tradeoff: However, the more wide open your lens is, the less of the image is in focus. At 1.8, you can take a portrait, and have the eyes in focus, but the nose blurry.

This is known as the "depth-of-field" and as you open up the aperture, it gets narrower. The blur here is known as bokkeh and it can be very pleasant to look at, if you control it well, you can make the focused part of the photo jump out at the viewer.


... And I'll put up the ISO and focal length bits later ^_^; have to head off now.

Queen Dopplepopolis!
09-19-2007, 07:55 PM
i understand the shutters, but would you be able to change the settings on a regular digital camera?
and how?

Megumi Oaks
09-21-2007, 09:50 AM
A lot of compact digital cameras (the ones most bought) are more of a point and shoot kind. Meaning that a lot of it cannot be changed. With others compacts, it's harder to change. You have to go through your menu settings to see what it will allow you. My compact digital only allows me to change my ISO speed and it automatically decides what shutter speed and aperture to use. I would suggest looking through your menus.

wizz-o-matic
09-23-2007, 05:01 AM
Even among the cheap compacts you can find some that have a manual exposure program (usually marked with the letter "M"). Then, some may even have Av (aperture priority (http://en.wikipedia.org/wiki/Aperture_priority)) and Tv (Shutter priority (http://en.wikipedia.org/wiki/Shutter_priority)) modes (the so called semi auto modes). The most rare settings among the cheap compacts would be the B one, which lets you take much longer exposures (more than 30s). Cameras are usually limited to max of 30s exposures.
The "letters" are usually on the main jog button on the camera, if not there, they are usually in the menu. I'm pretty sure that most of your cameras have at least the "M" mode.

Edit: and a bit more of help, a good explanation of terms
http://www.kevinwilley.com/l3_topic01.htm
1st topic is Aperture, 2nd is Depth of Field, 3rd is Focal Length

Famahama
02-21-2008, 11:51 AM
Lenses have a set amount of such "f-stops" which control how much light comes into the lens. The smaller the f-number is, the more light is allowed into the lens.

http://www.igorbass.com/snips/Aperture_diagram.png


Haha, i always have thought about this. and i was wrong. i always thought of it as... the larger it is, the more light it gets in. blagh.

I learned quite a bit on the Aperture and Shutter section. Thanks!

Getting interested in photography!

Kaitou Ace
03-28-2008, 04:56 PM
The larger it is the more light does come in. However the number gets smaller as the aperture gets larger.

-akichan-
09-17-2008, 12:32 PM
I'll be taking Photography one this coming fall quarter, so i felt like checking this forum.

Well...because i still havn't got the basics yet, so the stupid brain of mine just confused me a little while i was reading those instructions. But i just love taking pictures of things, and have my friends to be my model often.

Recently, i've been trying to take pictures for my friends outside during the night. It was in front of the pier, and behind is all the buildings with beautiful lights. I've been trying to take pictures that shows everything perfectly. When i use the flash light, the photo only show the person, and not the background at all. However, when i do not use the flash light, it goes blurry even when i don't shiver. Hmmm i wonder if it is the camera, or it is really my below-beginning skills.

The photos i've seen in other photography classes, and the photos i've seen in this forum just look simple to me, but i never knew that there are so many to learn to take a photo. o.o;;

MuZ0NaZ
09-17-2008, 06:01 PM
Recently, i've been trying to take pictures for my friends outside during the night. It was in front of the pier, and behind is all the buildings with beautiful lights. I've been trying to take pictures that shows everything perfectly. When i use the flash light, the photo only show the person, and not the background at all. However, when i do not use the flash light, it goes blurry even when i don't shiver. Hmmm i wonder if it is the camera, or it is really my below-beginning skills.
What you need is to balance flash light with the ambient light, which your point and shoot camera does not do by default. It's probably only possible if you have manual control over the exposure, with the flash on, but you probably have to use a tripod AND to set the exposure properly by hand if you want decent portraits at night.

evansmoochie
09-08-2009, 08:00 AM
try Olympus PEN !

adolph3560
02-24-2010, 09:56 PM
i chose Nikon-lenses..


:closedeye:closedeye

cristeto1981
06-07-2010, 05:42 AM
Yeah. Nikon lenses are rad.

ToddQuevedo
06-21-2010, 03:48 AM
@GangstaKermit,
Good explanation but it seems like man did not understood you,thanks for the good research but next time be short and to the point to avoid this.Great work GangstaKermit

fch987
08-29-2010, 03:07 AM
I think what you say in the message is very interesting.

Watery
03-06-2011, 04:57 AM
Well that helped understand a little of the things about my camera, but they do sound pretty complicated i mean i thought high light exposure got a sharper image and a larger iris could make a good replaceal for a dim flash or no flash to gain clarity.

kapsystem
07-01-2011, 01:18 AM
Useful points to know about photography

DeathBlade/13.666
12-04-2011, 09:20 AM
Now I can understand Kaitou and Wizz in Chat when they start talking about cameras. :D

UltimaChaos
01-09-2012, 03:32 PM
What are some good camera cases for DSLR cameras? I am trying to find one in stores, but none of them are that good for the steep price.

Kaitou Ace
01-09-2012, 07:48 PM
Hm... Honestly, I don't really use a camera bag, but check out Crumpler or Targus, both make pretty good camera bags of all different styles.

robertmedina
04-17-2014, 02:40 AM
good explanation,but most of the people only know pressing of a button, to click a picture,and they do well with that knowledge,