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xtin88

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Nov 3, 2009
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#1
Hi i've been reading from the net and some treads in this forum but i still cant understand whats the len's aperture purpose? what does it do?

Take for example the 50mm f1.8, i understand that aperture 1.8 means the hole is big. I read about it affecting the shutter speed and the dof too.

Any one can explain to me? Really very confuse over this.
 

xtin88

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Nov 3, 2009
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#3
Yes i read there b4 but i still cant realli understand. is there any simple way to understand and get it stuck to my brain
 

wdEvA

Senior Member
Sep 1, 2006
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#4
reading up and understanding will get stuck in your brain longer.

google up on aperture, shutter speed, depth of field
u shld be clear after that
 

Rashkae

Senior Member
Nov 28, 2005
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#5
Read you manual, it explains it too. Read the newbies guide, it explains it too. Research on google, it explains it too.

If after all that you still can't understand, then maybe you're not ready to venture beyond "auto" in your DSLR.
 

kaixiang

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Feb 4, 2009
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Bukit Batok, Singapore
#6
Hi i've been reading from the net and some treads in this forum but i still cant understand whats the len's aperture purpose? what does it do?

Take for example the 50mm f1.8, i understand that aperture 1.8 means the hole is big. I read about it affecting the shutter speed and the dof too.

Any one can explain to me? Really very confuse over this.
Hole bigger means collect more/less light? If there is more light should the shutter be faster or slower? Alternatively, what if there is less light?

If you can figure this out, just try memorizing until it becomes second nature....
 

xtin88

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Nov 3, 2009
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#7
Hole bigger means collect more/less light? If there is more light should the shutter be faster or slower? Alternatively, what if there is less light?

If you can figure this out, just try memorizing until it becomes second nature....
If hole bigger, it will collect more light. and if there is more light, shutter speed will be faster. and if there is less light, means hole smaller and iso have to be high and that will make the shutter speed slow?

I don't know if i'm making any sense.
 

two200

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Nov 19, 2004
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Eunos
galleria2200.blogspot.com
#8
If hole bigger, it will collect more light. and if there is more light, shutter speed will be faster. and if there is less light, means hole smaller and iso have to be high and that will make the shutter speed slow?

I don't know if i'm making any sense.
Photography is about light (exposure). To get a good photo, you need a certain amount of light, say X. For X amount of light to reach the sensor, is dependant on the aperture and the shutter speed (ignore the ISO first)

If aperture smaller (f no bigger) you need longer time (longer shutter speed=f/smaller number) to achieve X amt of light.

But if the sensor is more sensitive (higher ISO), this X amt of light can be achieve faster given the same aperture/shutter speed setting

It is all physics ;)
 

limwhow

Senior Member
Jun 9, 2009
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Life revolves arOnd East Coast
#9
If hole bigger, it will collect more light. and if there is more light, shutter speed will be faster. and if there is less light, means hole smaller and iso have to be high and that will make the shutter speed slow?

I don't know if i'm making any sense.
Yes, yes, xtin88. So far so good.
 

xtin88

New Member
Nov 3, 2009
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#10
Photography is about light (exposure). To get a good photo, you need a certain amount of light, say X. For X amount of light to reach the sensor, is dependant on the aperture and the shutter speed (ignore the ISO first)

If aperture smaller (f no bigger) you need longer time (longer shutter speed=f/smaller number) to achieve X amt of light.

But if the sensor is more sensitive (higher ISO), this X amt of light can be achieve faster given the same aperture/shutter speed setting

It is all physics ;)
Okok i think i got it!! but just get confuse with so many things goin through my mind right now.

So if its small f/no, shutterspeed fast cos got alot of light for the picture already. Whereas if is big f/no, shutterspeed slow as it need to take a longer time to collect light into the lens. Am i getting it?
 

two200

New Member
Nov 19, 2004
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Eunos
galleria2200.blogspot.com
#11
Okok i think i got it!! but just get confuse with so many things goin through my mind right now.

So if its small f/no, shutterspeed fast cos got alot of light for the picture already. Whereas if is big f/no, shutterspeed slow as it need to take a longer time to collect light into the lens. Am i getting it?

That is correct!
 

xtin88

New Member
Nov 3, 2009
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#12
Great! ok i got a last qn. if a lens indicate e.g 50mm f1.8. It means the hole is big and it is in its maximum opening size already right? what if my camera i set my aperture to over 1.8?
 

J-Chan

Senior Member
Sep 21, 2005
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#13
Great! ok i got a last qn. if a lens indicate e.g 50mm f1.8. It means the hole is big and it is in its maximum opening size already right? what if my camera i set my aperture to over 1.8?
what do you mean by over 1.8? the lens can't physically open up its aperture any further past f/1.8, so it stops at f/1.8 if you turn the dial in your cam..

if you mean a larger no. past 1.8, the blades close to whatever aperture you set it at when you take the pic..
 

xtin88

New Member
Nov 3, 2009
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#14
what do you mean by over 1.8? the lens can't physically open up its aperture any further past f/1.8, so it stops at f/1.8 if you turn the dial in your cam..

if you mean a larger no. past 1.8, the blades close to whatever aperture you set it at when you take the pic..
Okae! i got it. Thanks alot guys for your replies and pms. It realli made me understand from all ur explanations. I'm a slow learner so need more time to absorb.
 

#15

If you have an eye (even two) you'll understand easily the concept of aperture: an eye has an iris that regulates the amount of light that the brain will finally interpret. If it is dark, like in a romantic dinner, the pupil will become bigger to gather more light. No wonder the eyes of your beloved looked stunning. But at a very sunny day, those pupils will need to get reduced to avoid the entrance of extra light. The same goes with a camera, there is a mechanism (diaphragm) that controls the amount of light reaching the sensor.

The aperture combined with the ISO sensitivity and the shutter speed, the degree of exposure to light is regulated. Now, the thing is that your eyes don't work exactly like your still photographs camera. In your camera there will be a combination of parameters to expose correctly the image: for how long the shutter will be opened, how sensitive the sensor of the camera will be and how big the hole (aperture) that allows light into the sensor will be.

The lens aperture is usually specified as an f-number. Although it may sound tricky, if the "f" number is small (like f/1.2, f/1.4 or f/1.8) the aperture is very big. If the "f" numbers are higher (e.g. f/11, f/16, f/22) the aperture size is smaller.



Read up the following to get better understanding:
http://www.photoaficionado.com/situationroom/aperture.html
http://en.wikipedia.org/wiki/Aperture
 

xtin88

New Member
Nov 3, 2009
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#16
Hey really helped me with the simple explanation and showing me images. Thanks!
 

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