Camera's Functions

[ziploc]

Originally posted by revenant

oh ya, what's exposure compensation? those -1 , 0, +1

To understand exposure compensation, first you need to understand what is a "stop". Each stop will allow half or double the light entering the camera. So eg, at f/5.6, one stop down will be at f/8 (remember higher f-value = smaller aperture), and at f/8 the light is half of that at f/5.6. Same goes for shutter speed. 1/250s allows only half the light comparing to 1/125s.

Eg. aperture values are number as: 2.8, 4, 5.6, 8, 11, 16, etc. Each step is a stop. Similarly, for shutter speed: 1/30, 1/60, 1/125, 1/250 etc. and each is a stop difference.

Now note this: f/5.6 at 1/125s = f/8 at 1/60s. Get it? In terms of aperture, you have 1 stop less light, but in terms of shutter speed, you have 1 stop more, so the end result is that the exposure is the same. Try this with your camera, chose a scene with constant lighting, then set your camera to aperture priority and change the f-stop, meter the scene and you can see what I just mentioned. You can do the same with shutter priority.

Each stop = 1EV, so 1 stop down = -1EV (less light), and 1 stop up = +1EV (more light). One easy way to remember this: + = more light, - = less light.

So what is exposure compensation? It is simply to deviate from the camera's metered exposure value. For example, if in aperture priority mode and your camera metering says the exposure is f/5.6 at 1/250s, setting a -1EV compensation will make the camera set the exposure value at f/5.6 at 1/500s (remember, less light). Note that most modern cameras allow you to set 1/3 compensation.

Hope that helps.

 

[revenant]

Originally posted by ziploc


To understand exposure compensation, first you need to understand what is a "stop". Each stop will allow half or double the light entering the camera. So eg, at f/5.6, one stop down will be at f/8 (remember higher f-value = smaller aperture), and at f/8 the light is half of that at f/5.6. Same goes for shutter speed. 1/250s allows only half the light comparing to 1/125s.

Eg. aperture values are number as: 2.8, 4, 5.6, 8, 11, 16, etc. Each step is a stop. Similarly, for shutter speed: 1/30, 1/60, 1/125, 1/250 etc. and each is a stop difference.

Now note this: f/5.6 at 1/125s = f/8 at 1/60s. Get it? In terms of aperture, you have 1 stop less light, but in terms of shutter speed, you have 1 stop more, so the end result is that the exposure is the same. Try this with your camera, chose a scene with constant lighting, then set your camera to aperture priority and change the f-stop, meter the scene and you can see what I just mentioned. You can do the same with shutter priority.

Each stop = 1EV, so 1 stop down = -1EV (less light), and 1 stop up = +1EV (more light). One easy way to remember this: + = more light, - = less light.

So what is exposure compensation? It is simply to deviate from the camera's metered exposure value. For example, if in aperture priority mode and your camera metering says the exposure is f/5.6 at 1/250s, setting a -1EV compensation will make the camera set the exposure value at f/5.6 at 1/500s (remember, less light). Note that most modern cameras allow you to set 1/3 compensation.

Hope that helps.

hmm.....I know what it means roughly already. Needa some time to absorb

thanx once again

 

[Goondu]

Flare, you have my vote for the most detailed and elaborate explanations in this thread, like what revenant has said.

3 cheers to Flare. :thumbsup: :thumbsup: :thumbsup:

 

[Flare]

Hee Hee... thanks... the rest did great jobs as well...

 

[Flare]

Originally posted by revenant


Correction! Larger f-stop is not f/2.8

Anyway, thanx for ur help

Hee Hee... You are right revenant...

 

[revenant]

Originally posted by Flare


Hee Hee... You are right revenant...

heh~~

Still looking for 2nd hand cam
Better get it before next year, GST

Oh btw, is there an exact 4R size photo paper? Or need get the A4 size and print then cut away?

 

[Flare]

Depends on what printer you are using... Canon has these photocards that has these tear away white border which tears the border, and some of the pic away to get borderless picture. For Epson, they have 10cm by 15cm paper (Is it a roll? i'm not sure) for you to print in borderless mode.

But a more economic mode will be using A4 size paper and cut it yourself. For example, 30 sheets of A6 (index card size) cost around 14 dollars... 20 sheets of A4, which can fit in 6 to 4 pictures cost 20-30 dollars...

 

[revenant]

Alright, done my bid on the A20 at the buy/sell forum

btw, if I were to take a photo like the below one. I need to use slow shutter speed. But how slow is slow? Any idea what's the aperture of this photo?

Fast shutter speeds to freeze action

Then why is the above picture taken with slower shutter speed?

oh and also, that motorist is travelling at high speed, I supposed the photographer is using a tripod for that? But then he must be very fast to wait for the bike to go into the camera's focus and shoot it?

 

[Flare]

The slow isn't that slow... maybe 1/125 (My guess)... This pic is shot using a technique called panning where the camera man follows/track the movement of the subject and snap while still tracking... Done well, the subject will be sharp with a motion-blured background... Look at Street Shooter's Shot of his son running, the one that got on the papers... Its done using panning as well... A slower shutter speed is required so that you get a blur background... too fast you'll freeze your own movement liao aand will not have the sense of motion like these panning shots.

For the focus, you'll need to judge and guess a bit especially if you are using a DC... the AF's not fast enough to track the subject..

Unless you use Manual ABS..er... I mean Manual focus to track the subject... (Stress~~~~)

 

[revenant]

Hey, have something to ask again.

What's "soft" in images? Kept seeing people using the word to describe some pictures but don't really understand it. Something like underexpose?

 

[icube]

newbie here...

wat is SLR camera..?? high end camera..??

2nd post here:embrass:

 

[revenant]

Originally posted by icube
newbie here...

wat is SLR camera..?? high end camera..??

2nd post here:embrass:

SLR = Single Lens Reflex

Yes. Higher end / professional cameras

 

[ziploc]

Originally posted by revenant
Hey, have something to ask again.

What's "soft" in images? Kept seeing people using the word to describe some pictures but don't really understand it. Something like underexpose?

"Soft" is the opposite of "sharp". Softness can be due to the lens design and/or quality, focusing that is slight out, or softening filters added intentionally. It has nothing to do with exposure, nor underexpose for that matter.

 

[revenant]

Originally posted by ziploc


"Soft" is the opposite of "sharp". Softness can be due to the lens design and/or quality, focusing that is slight out, or softening filters added intentionally. It has nothing to do with exposure, nor underexpose for that matter.

Thought opposite of sharp is blur? :dunno:
hmm......

 

[ziploc]

Originally posted by revenant


Thought opposite of sharp is blur? :dunno:
hmm......

Not necessarily in photography term. Blurness can be caused by either out of focus or camera shake. When a pic is not sharp due to camera shake it is called "blur" (similar to as in "motion blur"). "Soft" is when the pic/subject is still more or less in focus, but not as sharp as it can be. Contrast comes into play too, and generally a contrasty pic looks sharper while a low contrast pic looks softer.

 

[revenant]

Originally posted by ziploc


Not necessarily in photography term. Blurness can be caused by either out of focus or camera shake. When a pic is not sharp due to camera shake it is called "blur" (similar to as in "motion blur"). "Soft" is when the pic/subject is still more or less in focus, but not as sharp as it can be. Contrast comes into play too, and generally a contrasty pic looks sharper while a low contrast pic looks softer.

orh icic.... thanks

 

[revenant]

Hey, 2 more questions.

Can someone tell me more about camera's metering and auto-focus and manual-focus?

 

[revenant]

Originally posted by Flare
The slow isn't that slow... maybe 1/125 (My guess)... This pic is shot using a technique called panning where the camera man follows/track the movement of the subject and snap while still tracking... Done well, the subject will be sharp with a motion-blured background... Look at Street Shooter's Shot of his son running, the one that got on the papers... Its done using panning as well... A slower shutter speed is required so that you get a blur background... too fast you'll freeze your own movement liao aand will not have the sense of motion like these panning shots.

For the focus, you'll need to judge and guess a bit especially if you are using a DC... the AF's not fast enough to track the subject..

Unless you use Manual ABS..er... I mean Manual focus to track the subject... (Stress~~~~)

oh btw.... hmm...... by using the technique called panning, and the shutter speed is less than a seconds, then we must be very fast with our cam?

then while moving and snap, thought the pictures turned out will be blur due to the camera's moving or hand shake?