What is SLR?


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GenXBoi

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#1
I'm quite confuse what is the difference between SLR cameras and other normal or digital cameras. Can someone enlighten me?
 

Jayan

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#2
Originally posted by nicson
I'm quite confuse what is the difference between SLR cameras and other normal or digital cameras. Can someone enlighten me?
SLR = Single Lens Reflect.

The image of the subject can be seem TTL (Through The Lens) and reflect thru a series of prism or mirror places behind the lens to the eyepiece.

When the shutter release is pressed, the mirror moved out of the way to let light onto the film.

Lao jiao....my explanation correct???
 

Falcon

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#3
What abt the lens? It seems that slr does not have 3x, 10x, etc optical zoom? It uses measurement like 100, 200,.. etc mm instead. Can someone explain what is the equivalence to the optical zoom?
Tks
 

Tweek

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#4
Originally posted by Falcon
What abt the lens? It seems that slr does not have 3x, 10x, etc optical zoom? It uses measurement like 100, 200,.. etc mm instead. Can someone explain what is the equivalence to the optical zoom?
Tks
haha this has been explained to death already....but I'll do it again cos I never explain before. ;)

Interestingly only consumer-level digicams talk about 10X, 3X zoom. Digital SLR lens, film SLR lens, and even film P&S compact cameras specify the lenses according to the focal length, which is the 100mm, 200mm etc that you cited.

The "X" used in digicams actually is a ratio of the max telephoto focal length to the max wideangle focal length offered by the lens. For e.g., Canon G2 has a lens of 35mm (max wideangle) to 105mm (max telephoto). That's why it's rated at 3X optical zoom, 105/35 = 3. Canon Pro90IS has a lens of 35mm to 350mm, that's why it's rated at 10X optical zoom.

So, the how many "X" zoom is relative to the base focal length of the lens, or the max wideangle focal length. As rueyloon always preaches, it's meaningless to compare telephoto prowess of lenses using the "X" convention, as their base focal length may not be the same. It's more meaningful to compare by their max telephoto focal length.

Clear enough hor? ;)
 

Jayan

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#5
Originally posted by Tweek


haha this has been explained to death already....but I'll do it again cos I never explain before. ;)

Interestingly only consumer-level digicams talk about 10X, 3X zoom. Digital SLR lens, film SLR lens, and even film P&S compact cameras specify the lenses according to the focal length, which is the 100mm, 200mm etc that you cited.

The "X" used in digicams actually is a ratio of the max telephoto focal length to the max wideangle focal length offered by the lens. For e.g., Canon G2 has a lens of 35mm (max wideangle) to 105mm (max telephoto). That's why it's rated at 3X optical zoom, 105/35 = 3. Canon Pro90IS has a lens of 35mm to 350mm, that's why it's rated at 10X optical zoom.

So, the how many "X" zoom is relative to the base focal length of the lens, or the max wideangle focal length. As rueyloon always preaches, it's meaningless to compare telephoto prowess of lenses using the "X" convention, as their base focal length may not be the same. It's more meaningful to compare by their max telephoto focal length.

Clear enough hor? ;)

Ok. Like C-2100UZ is 7mm ~ 70mm...eguivalent to 38mm ~ 380mm in a conventional 35mm camera.
 

Flare

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#7
Hee Hee... as mega web puts it clearly... "X" is not usefull. So a prime 1200mm, since it cannot zoom, will be 1x, but then it can give much better magnification then the 10x zoom in digital cameras.
 

Falcon

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#8
Originally posted by Flare
Hee Hee... as mega web puts it clearly... "X" is not usefull. So a prime 1200mm, since it cannot zoom, will be 1x, but then it can give much better magnification then the 10x zoom in digital cameras.
So there are lens with fixed value like 1200mm only instead of having a range? Then what is the use of such lens? Kind of limited isn't it?
 

Goose

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#9
Originally posted by megaweb
dunno got 10mm to 200mm ... wah 20 X dc .. hee hee .. :) max still 200mm only
hehehhe...but it will be quite wide at the 10mm end eh??? dunno if got this sorta lens or not...
 

megaweb

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#10
Originally posted by Falcon


So there are lens with fixed value like 1200mm only instead of having a range? Then what is the use of such lens? Kind of limited isn't it?
we call these lens as PRIME lens ... it gives sharp quality shot ...

1200mm :eek: .. for for Bluestrike stalking :D
 

ziploc

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#13
Originally posted by Tweek


haha this has been explained to death already....but I'll do it again cos I never explain before. ;)

Interestingly only consumer-level digicams talk about 10X, 3X zoom. Digital SLR lens, film SLR lens, and even film P&S compact cameras specify the lenses according to the focal length, which is the 100mm, 200mm etc that you cited.

The "X" used in digicams actually is a ratio of the max telephoto focal length to the max wideangle focal length offered by the lens. For e.g., Canon G2 has a lens of 35mm (max wideangle) to 105mm (max telephoto). That's why it's rated at 3X optical zoom, 105/35 = 3. Canon Pro90IS has a lens of 35mm to 350mm, that's why it's rated at 10X optical zoom.

So, the how many "X" zoom is relative to the base focal length of the lens, or the max wideangle focal length. As rueyloon always preaches, it's meaningless to compare telephoto prowess of lenses using the "X" convention, as their base focal length may not be the same. It's more meaningful to compare by their max telephoto focal length.

Clear enough hor? ;)
Well written! Think we should include this paragraph in the FAQ :)
 

#14
Originally posted by Falcon


So there are lens with fixed value like 1200mm only instead of having a range? Then what is the use of such lens? Kind of limited isn't it?
Actually a lot of people prefers these prime lens over zoom lens, and many people use a mix of it. Prime lens can be smaller in size and gives better quality images. And comparing with a zoom lens of the same built, I think prime lens may sometimes be cheaper.
 

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