Please, show me (in/on an unassailable website), that precise statement about ("unavailable aperture"):
Sorry M8, but that's what you've ben saying all along. You have siad that a lens that has a max aperture of f/2.8-3.5 can use f/2.8 along the whole zoom range and that is using an unavailable aperture because at the long end of the zoom f/2.8 is "unavailable as its max aperture is f/3.5.
Google, Ask-you know, any URL I can search and read for myself.
Gladly. but first, you do know your question is mainly gobbledygook, incoherent? As for the "maximum aperture" you and others have fastened onto:
Can you please explain to all of us what a max aperture of f/2.8-3.5 really means if it doesn't mean that the max aperture is variable and changes as the lens zooms. Why would manufacturers lable their lenses this way if it is not true?
The above quote says all there is to say about "maximum aperture", which can be f/1:1.2 for my 55mm asph. CANON FD lens down to f/32 to f/45 at the smallest openings for small format to large format*.
+"F" numbers actually go up into the hundreds, not just f/45
*Each lens always-ALWAYS has only 1 (one) "maximum aperture" and it is ALWAYS stated somewhere on the barrel of the lens: that is, there is only one “maximum” aperture per lens.
I'm amused how each of you, in turn, fasten onto the others misunderstandings about the brute calculus in photography. I'd venture 98% of you have no idea about things photographic. Especially since you all seemed to have followed along like sheep with your misconception about what part of the camera does what when you use any thing but "P" mode.
The operative phrase in the Wikipedia quote is this:
, "Force (look it up) the camera to use an optimum aperture, "force" clearly stating the photographer can choose and shoot with any aperture within the limitations of the lens.
allows the photographer to force the camera...
Let's look at this little blurb:
Don't you think if the lens could be set to f/2.8 across the entire zoom range, the manufacturer would advertise this as to sell more of the product.
You might want to point out that a dinky COOLPIX 995 P&S may not always be able to hold a set, constant aperture, though you and the rest should get the drift of my thesis by reading the COOLPIX blurb again, this time for its content.
Coolpix 995's Way of Achieving "Constant" Aperture
To partially overcome the problems caused by the variable aperture feature, Coolpix 995 can maintain aperture within 1/3 stop in effect before zoom operation started, if possible.
More precisely, the camera will do its best to keep the selected aperture with 1/3 stop as you zoom.
However, if the camera can maintain this 1/3 stop error range, aperture changes.
Consequently, constant aperture while zooming may or may not be maintained.
Note that this fixed aperture is only available in the Aperture-Priority mode and Manual Exposure mode when you can set aperture manually.
Better for my thesis, just because a P&P cannot, may not hold a constant aperture, I assure you any SLR (shooting with automatic lenses in Av mode)most assuredly can (and easily does).