NOISE

In message ,
paul wrote:

Am I understanding this wrong? A fast lens should shoot at a faster
speed at the same f-stop as a slow lens as I understand. It's not just
that it's capable of going to a lower f-stop number. Please clarify if
I'm mistaken.

The term "fast lens", as I understand it, derives from the fact that all
other things being equal, a lens with a larger aperture (lower f-stop)
will allow a faster shutter speed, but only at that aperture.
--


John P Sheehy

In message ,
Owamanga wrote:

Noise is purely a factor of ISO & shutter duration,

Technically, this is true, but a lower f-stop may increase the
signal-to-noise ratio, and a larger one may increase it, at any given
ISO and shutter speed.
--


John P Sheehy

In message ,
Owamanga wrote:

Noise is purely a factor of ISO & shutter duration,

Technically, this is true, but a lower f-stop may increase the
signal-to-noise ratio, and a larger one may increase it, at any given
ISO and shutter speed.
--


John P Sheehy

paul wrote:

Stacey wrote:


You should be able to do this with a slow lens as well unless it is a
poor quality one. F8 is F8 no matter if the lens is a F5.6 max lens or a
f2.8 max lens.


Am I understanding this wrong?

Yes you are!

A fast lens should shoot at a faster
speed at the same f-stop

Nope, same f stop need the same shutter speed no matter what lens is being
used.. Doesn't matter what lens or format. F8 at 1/60 is the same on a tiny
sensor digicam or an 8X10 film camera.

as a slow lens as I understand. It's not just
that it's capable of going to a lower f-stop number.

That's ALL the difference, to get the faster shutter speed, you have to use
the larger lens opening.

--

Stacey

Confused wrote:
On Thu, 17 Feb 2005 08:23:23 -0800
In message
paul wrote:

snip

I do have patience to sort through a billion pics
later though.

That sounds awful!


Indeed.


I'm usually doing documentation, not strictly looking for art photos so
yes I want a lot of pictures. Obviously I don't want to sort a lot of
rejects.



Well, we all have our personalities. For me spending time in the field
fiddling with a tripod would drive me nuts, once I settle down on the
computer in the evening, I have no problem with patience.


Try a compromise, and don't settle for a cheaper smaller head, or a
non-rotating lock monopod. Find and try a Gitzo mono pod with a
NOVOFLEX CLASSICBALL 5 BallHead.


Wow, that alone is $500. I'd rather pay for an Image Stabilized lens.


It will serve as an "almost" tripod,
won't slow you down, can be used without touching the ground (it acts
like a stabilizer)


Hmm, that makes sense, just the weight & bulk would stabilize things
considerably hand held.


and will actually save you time composing shots.
If you find a better, smoother, easier to use and more functional ball
head let me know... and do NOT settle for a small jerky light weight
head.

(there are a couple other heads in this class, but it's the only one I
could get my hands on. gonna get one for my gitzo explorer tripod,
too, so I can keep them tightly and permanently mounted. don't forget
quality quick releases and spare camera/lens side adaptors. ;^)

Jeff

Stacey wrote:

paul wrote:


Stacey wrote:


You should be able to do this with a slow lens as well unless it is a
poor quality one. F8 is F8 no matter if the lens is a F5.6 max lens or a
f2.8 max lens.


Am I understanding this wrong?


Yes you are!


Better late than never. I had photography 101 in college 20 years ago
grin.




A fast lens should shoot at a faster
speed at the same f-stop


Nope, same f stop need the same shutter speed no matter what lens is being
used.. Doesn't matter what lens or format. F8 at 1/60 is the same on a tiny
sensor digicam or an 8X10 film camera.


as a slow lens as I understand. It's not just
that it's capable of going to a lower f-stop number.


That's ALL the difference, to get the faster shutter speed, you have to use
the larger lens opening.


Hmm, so any lens at f/8 will need the same shutter speed under the same
lighting conditions. A 'Fast' would necessarily have to be wider, larger
I guess, and probably longer?

http://www.armguard.com/security%20terms%20glossary.htm
" A term used to describe the speed of a lens, or its ability to pass
light through its lensing and onto the imager. It is determined by
dividing the focal length of the lens by the diameter."

paul wrote:

Stacey wrote:

That's ALL the difference, to get the faster shutter speed, you have to
use the larger lens opening.


Hmm, so any lens at f/8 will need the same shutter speed under the same
lighting conditions.

Exactly.

A 'Fast' would necessarily have to be wider, larger
I guess, and probably longer?

"Fast" means it opens up to a larger F stop opening in the diaphram. This
normally requires larger lens elements to acomplish and is optically more
difficult to maintain quality. That's why they cost $$$$




--

Stacey