On 14/12/03, [EMAIL PROTECTED] disgorged: >> With istD making all our old primes x 1.5, >> is there any change to the aperature eg: >> >> a 135mm f1.8 becomes effectively a ~=200mm >> but is there any change in the effective aperature? > >Your 135mm f/1.8 is still a 135mm f/1.8. That hasn't changed. What has >changed is how much of the image circle the digital sensor is seeing. >The 135 is a mid length telephoto on the ist D. >You should start trying to think in terms of the new format on it's own. >I find it is less confusing, anyway.
What William is saying is absolutely right. I know it's difficult, but try and think of it in terms of a 135mm lens - it's just that on an *ist D it is a full telephoto (or mid length as WR says) lens. I have sorta got my head around this now, hence my favourite lenses are as follows: 14mm gives me a medium wide angle 24mm gives me my favourite street lens 28-70mm gives me a normal to short telephoto. 50mm gives me a good portrait lens. The 135mm f/1.8 lens to which you refer is still a 135mm lens - the approximate focal length as used on an *ist D is the equivalent of about 200mm at f/1.8. The maximum aperture of the lens does not alter. That's a fast lens at that aperture, no mistake! HTH Cheers, Cotty ___/\__ || (O) | People, Places, Pastiche ||=====| www.macads.co.uk/snaps _____________________________ Free UK Mac Ads www.macads.co.uk
