What does 2.8-4.3 mean ??

Sorry for the simple question. But im just a novice.
Just trying to understand lenses. What does it mean when a lense gives
two f stops in a range. eg when buying a lense.
Is this the largest and smallest that the lense will go eg from to ?
2.8 to 4.3
I have searched on the net but cannot find anyone who has answered this
simple question.
Thanks.

Steve

Re: What does 2.8-4.3 mean ??

While not a fast lense, it is not horribly slow either. At f3.5 wide open, it
does a pretty decent job. The Canon equivalent is MUCH slower throughout its
range.
--
Thomas T. Veldhouse
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Thomas T. Veldhouse

Re: What does 2.8-4.3 mean ??

No -it looses on many details in low-light even for still subjects.
I haven't decided to move to a DSLR as yet. Maybe I will first buy some
lenses, and then switch at the right time.
Yeah the problem with inexpensive lenses is that they aren't fast. Im
looking for fast lenses , some wide-angle, some macro and some
telscopic. Wide-angle would be for landscape in low-light, macro for
architecture with dim lighting and telescopic could be a slower one
-but for shots of wildlife.
I very much do have budgetary constraints.
Ive asked someone to get me a 50 mm f/1.4 brand new and this is for my
N75 film slr.
Agreed.
Yeah -Im looking around for suitable primes for <$500. -preferably with
AF.
thanks
-kamal

Kamal R. Prasad

Re: What does 2.8-4.3 mean ??

Useful in low light but not for action in low light.
The D70 18-70 kit lens gets good reviews and it's not particularly cheap
at around $300. It's not a fast lens, for that get the $1,700 17-35,
24-70 and 70-200 f/2.8's.
See above if you don't have budget constraints. Another option is prime
lenses, that's the only way you'll get faster than f/2.8 anyways. And
any f/2.8 zoom will cost you a mint. I just bought an old manual 28mm
f/2.0 AI-S for $200 or for AF on a budget look at the 35mm f/2 used or a
24 or 28mm f/2.8. A classic 50mm f/1.8 is nice & cheap but too long on
digital for normal field of view landscapes. I have a 12-24 and I just
love that wide andgle for architecture and certain landscape scenes.
It's rarely necessary to have a fast lens that wide. If you aren't
shooting wildlife, you don't need a particularly fast or long telephoto
and your 24-120 should be fine. If you want low light performance get a
fast normal prime.
--
Paul Furman
http://www.edgehill.net/1
Bay Natives
http://www.baynatives.com

Paul Furman

Re: What does 2.8-4.3 mean ??

yes -its a VR lens. Its still not useful in low-light conditions.
kit lenses? The ones that are bundled with the dslr body? More often
than not, they are the cheaper ones and don't function well in
low-light. Its a marketing stunt to bundle the cheapest lens with the
body and show them that we are giving you a giant zoom lens which is
all you will ever need.
which of the Nikkors would you recommend? I like sunset shots [and
sunrise too -but can't get up on time] and some lit-up architecture.
thanks
-kamal

Kamal R. Prasad

Re: What does 2.8-4.3 mean ??

I think the Tokina 12-24 is supposed to be pretty good. I have been very
impressed with the Tokina 80-200mm and I don't expect that the 12-24 will
disappoint me if I should get hold of it.
--
Thomas T. Veldhouse
Key Fingerprint: D281 77A5 63EE 82C5 5E68 00E4 7868 0ADC 4EFB 39F0

Thomas T. Veldhouse

Re: What does 2.8-4.3 mean ??

Sure, unless you are doing very large prints. I get nice results with
6MP at 13x19 inch.
Is that the VR lens? If not it may not be all that useful. If so, it
would be handy but you would still probably want a wider lens such as
the kits lenses. A used D70 with the 18-70 lens is your best affordable
option though the D50 is smaller if you like that and a tad better low
light performance but a lesser kit lens. Or look at a D80 for the big
bright viewfinder and then maybe just get the body & wait till you can
afford a 12-24 lens. Some of the 3rd party wide zooms are not bad.
For nature photography (wildlife) you'll want a fast expensive long lens
some day but the digital crop frame will give you a 1.5x advantage on
your old lens to start with.
--
Paul Furman
http://www.edgehill.net/1
Bay Natives
http://www.baynatives.com

Paul Furman

Re: What does 2.8-4.3 mean ??

That is the wide open f-stop as well (maximum apeture).
In short, the maximum apeture for the shortest focal length is f2.8 and the
maximum apeture for the longest focal length is f4.3.
Having said that, I haven't seen a f2.8 - f4.3 lens before.
--
Thomas T. Veldhouse
Key Fingerprint: D281 77A5 63EE 82C5 5E68 00E4 7868 0ADC 4EFB 39F0

Thomas T. Veldhouse

Re: What does 2.8-4.3 mean ??

"Kamal R. Prasad" <kamalp@acm.org> wrote in
I don't use digital myself but from what I've seen pretty much ANY of the
current crop of digital SLRs will give outstanding results.
I suppose the advantage for nature is the smaller sensor gives a narrower
angle of view for a given focal length, so a 200mm lens will give the same
magnification factor on the frame as a 300mm lens on a 35mm camera.
You could spend about 500 pounds on a body but you'd need to splash out a
bit on a longer fast lens. As you already have Nikon kit, I suspect you'll
be better off sticking with them as your existing lenses should be
compatible, if effectively a bit longer.
--
invalid = com

Richard Polhill

Re: What does 2.8-4.3 mean ??

Thanks for the info. Im thinking of switching to digital for nature
photography. Do you think that the technology is good enough? How
expensive a camera wuld give me reasonable images? I have an N75 with
24-120mm f/3.5-5.6 Nikkor and a point and shoot 28-120mm canon film
camera
thanks
-kamal
http://www.flickr.com/photos/kamalpr

Kamal R. Prasad

Re: What does 2.8-4.3 mean ??

"Kamal R. Prasad" <kamalp@acm.org> wrote in
To a certain extent, yes. If you're trying to capture a moving object,
however, no amount of VR or IS will help.
Well yes. That is what film speed means = speed of reaction to light.
Manufacturers go to great lengths to ensure that the characteristic
curve of a film is flat for a given exposure range that conforms to a
known rating - ISO rating. That way you can think of one stop of ISO
change as having the same affect as one stop of shutter speed or
aperture.
1 stop wider aperture = twice the light entering camera.
Meaning that half the exposure time or half as sensitive film is
required for correct exposure.
1 stop longer shutter speed = twice the exposure to the incoming light
Meaning that a half the incoming light or half as sensitive film
is required for correct exposure.
1 stop faster film = twice the sensitivity to the incoming light
Meaning half as much incoming light or half the exposure time is
required for correct exposure.
This reciprocity means that:-
To get a 1-stop faster shutter speed either open aperture 1 stop or use
a 1 stop faster film (100 -> 200 ASA for instance).
To get a 1-stop smaller aperture (for greater depth of field) either use
a 1-stop slower shutter speed or 1 stop faster film.
To get less grain, use a 1-stop slower film (100 -> 50 ASA for instance)
and either 1 stop wider aperture or 1 stop slower shutter speed.
This continues through to the development as well. As long as your
exposure range falls within the flat part of the characteristic curve of
the chosen film, you can also get a stop or two's adjustment by over- or
under-developing the exposed film. Known as push (or pull) processing,
this usually results in harsher, more contrasty negatives when
overdeveloping, or smoother, more pastel images when underdeveloping
(you can switch these for reversal - slide - film.)
I rather like the pictorial effect of the increased grain and contrast
resulting from 400ISO Ilford HP5 underexposed by 2 stops (as a 1600ISO
film) and commensurately overdeveloped by 2 stops, although I am
experimenting with some superfast B&W emulsions.
--
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