We all know how big f/1.4 is compared to f/1, f/1.8 compared to f/1.4, etc... (relative sizes), but does anyone knows how big exactly is f/1? What's the diameter of the f/1 aperture? :embrass:
showtime said:ok so i have a 24-85 f3.5-4.5
thus the apperture size at the wide end is 1/3.5 of 24mm, which is 6.8mm? not even 1 cm?
that seems EXTREMELY small and i think visualy, the apperture seems bigger than that... maybe the theory is wrong? can anyone confirm?
yaoxing said:We all know how big f/1.4 is compared to f/1, f/1.8 compared to f/1.4, etc... (relative sizes), but does anyone knows how big exactly is f/1? What's the diameter of the f/1 aperture? :embrass:
sehsuan said:the EF 50mm f/1.0L should have a filter size of 77mm if i remember correctly.
No, but it would mean it can accomodate a 5cm-wide aperture.blurblock said:A filter size of 77mm does not mean the diameter is 77mm mah .
yaoxing said:No wonder the 200-400mm f/2.8 looks like a flower pot! :bigeyes:
yaoxing said:No wonder the 200-400mm f/2.8 looks like a flower pot! :bigeyes:
The actual aperture diaphram (sp) can be bigger than say 6.8mm, however, the diameter of the rays of light passing through the diaphram is at guranteed to be at least 6.8mm. That is why at the other end of the lens (85mm), due to the focusing and zooming lens elements, the diameter has increased to 18.9mm. The diaphram does not change at all, but the circle of light does...ckiang said:Yes, at the 24mm end, it's 24/3.5 = 6.8mm. Visually it seems bigger coz you're viewing it through a series of lens elements, which have a magnifying effect.
And yes, a 50/1.0 will have an aperture of 50mm. Which is why a 50/1.0 is so big.
Regards
CK
That is why the high cost of this pro lens, with a f/2.8 constant aperture. The design of the lens is very tricky...sehsuan said:to add on to ckiang's answer... do note the nikon 70-200 VR. its aperture diameter ranges from 25mm to 71+mm, of which is house somewhere in the lens body. of course, needless to say, the filter is a 77mm
typically screw-in filters are a little larger than the largest aperture of a lens (or quite a bit more especially for variable aperture lens) since there has to be some leeway to account for vignetting.
Or are you talking about the 400 f/2.8? That one is large... The 200-400 f/4 is already 124mm. I seem not to be able to find the diameter of the 400 f/2.8 out from Nikon's SG and US website... :dunno:yaoxing said:No wonder the 200-400mm f/2.8 looks like a flower pot! :bigeyes:
Heh, slightly bigger. Specs from Nikon's site give it 12.4cm (124mm)...sehsuan said:you mean, the nikon 200-400 f4G? only 10cm across max, the aperture. not f/2.8