there r so many different diameter sizes for lens, i'm wondering what's the significance behind it all? bigger = better?
Originally posted by shidenx
He's asking about the diameter of lenses. Not mount Size. how can a 58mm uv filter fit a thread size smaller or larger than that of 58mm
nope, it's to do with aperture size. generally the bigger the aperture range (e.g. f/2.8 and bigger), the bigger the lens element. that's why you can have a massive 70-200 f/2.8 while the f/4.0 version is so much smaller.Originally posted by shuy
my 3100Z has a lens size of 46mm only, but it's wide enuff to allow a aperture of 2, n it doesn't have any vignetting, at least to my untrained eye. so y r there lens that r sooo much bigger? has it got to do wif zoom capability? i.e more zoom = longer focal length = wider lens needed? wild guess...
Originally posted by Larry
nope, it's to do with aperture size. generally the bigger the aperture range (e.g. f/2.8 and bigger), the bigger the lens element. that's why you can have a massive 70-200 f/2.8 while the f/4.0 version is so much smaller.
the lens size on the 3100z is much smaller cos simply put, the sensor is so much smaller than say the 35mm standard. it also means that the f/2 aperture on the 3100z allows in the same amount of light that a f/2.0 lens delivers to a 35mm camera, relative to the size of the film/sensor. meaning, smaller sensor needs less light, bigger sensor needs more light.
of course the absolute size of the apertures and sensors/film directly affects the DoF, which means the smaller sensor of the 3100z will give more depth-of-field. but that's another confusing matter altogether.
hope that helps...
Originally posted by shuy
so size does matter eh?
Originally posted by shuy
so size does matter eh?
so the bigger the sensor, the better the quality of the pic?
does sensor size correspond to MP size in any way?
the fuji S304 has a bigger lens size than mine, tho the MP is the same. does that necessarily mean it has a bigger sensor n therefore better picture quality? the other main diff. between them is that mine is 3X zoom, while the 304 is 6X.
Originally posted by shuy
so size does matter eh?
so the bigger the sensor, the better the quality of the pic?
does sensor size correspond to MP size in any way?
the fuji S304 has a bigger lens size than mine, tho the MP is the same. does that necessarily mean it has a bigger sensor n therefore better picture quality? the other main diff. between them is that mine is 3X zoom, while the 304 is 6X.
Originally posted by Andy Ho
For certain lenses, especially zoom lenses with many glass elements, it is of paramount importance to calculate the exact angle that light will travel within the lens to hit the film precisely where it should be hitting. Part of the calculations demand that the front lens diameter be big so as to "compensate" for the angle that the light will need to move thru the many lens elements inside.
Originally posted by Andy Ho
The other reason is that by allowing a bigger diameter on the front, more light is let in so as to counteract vignetting. Vignetting is a darkening of the edges caused by not having light hit the film surface uniformly from centre outwards to the edge of the film. It is especially prominent with lenses that has big aperture to begin with, eg: f/2.8.....and coupled with long lens body.
Originally posted by SianZronG
it has a bigger lense size cause more distance is required from the CCD to the lense acuse of the higher zoom. you need more distance so more magnification. so small camerea usually don't have much zoom.
for example the C-4000z VS C-730uz same design one 10x Zoom one 3x Zoom the C730uz has a huge barrel compare to the C-4000z.
Originally posted by shuy
so is the sensor bigger in C730 than C4000? or is it the same size? any difference in quality?
no it's just to fit in more elements -- it's longer not wider...Originally posted by SianZronG
same sized CCD. but to get higher Zoom ratio the lense must have a bigger construction to allow in more light .