We realize
this may be confusing. Here's some info which could be useful.
PAN TILT ZOOM CAMERAS & EQUIPMENT
1.
What is the difference between fixed focus
and varifocal / zoom lens type cameras?
2.
What does pan / tilt / zoom equipment actually
do?
3. What is the difference between digital
zoom and optical zoom cameras?
4. Can I obtain panning and tilting ability
without using a zoom camera- or vice versa?
5. Do I need to manually control a zoom lens
type camera- and how?
6. How can I remotely view or control PTZ
camera functions from another location?
7. What is a DC auto iris and why should
it be considered?
Q1: What is a varifocal
or zoom lens camera?
A1:
Fixed
lens cameras have a set field
of view and cannot be manipulated to produce a wider or narrower
angle. These are generally found as 3.6mm, 4.3mm, 8mm, 12mm, etc..
The higher the number of the focal length, the more telephoto
the effect. *However- this has nothing to do with the actual size
of the lens itself. You can obtain a 3.6mm lens which can range
in physical size from 1mm (on a micro pinhole
type camera) to the size of a soda can (for much larger security
type cameras).
Variable focus (or varifocal)
lens
cameras allow the user to modify the field of view from its widest/
most panoramic to the narrowest and most telephoto views that
it is capable of. Some lenses provide a 4-8mm (widest at 4mm and
most telephoto at 8mm)- whereas others may provide 5-50mm for
a super zoom in ability.
Many are set up to interface with a variety of optional lenses.
However, there are also cameras with built-in lenses that cannot
be removed or replaced. The removable type mounts are referred
to as "C"
or "CS" mount because of the type/ size which is
an industry standard. Many lens choices are available and the
decision should be based on actual requirements for the application.
For instance, if a wide field of view is required, there may be
no reason to include a feature which allows a zoom to a tighter
shot.
It should be noted that most varifocal cameras are not weatherproof
and will require a suitable enclosure for outdoor use. However,
we do carry these outdoor housings, including those with built-in
heater/ blower. Also, we have an incredible weatherproof integrated
PTZ
camera available (DN-PTZ)
which allows you to facilitate pan,
tilt
and zoom
functions all from a SINGLE control- with all parts protected
inside a weatherproof dome with thermostat controlled heater/
blower inside! Back
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Q2:
What does PTZ or pan / tilt / zoom equipment actually do?
A2:
This can be a big point of confusion as many people tend to group
this type of camera into a single category when there are actually
a wide spectrum of features, abilities, options, and performance
issues to consider. Some are faster than others- some are more
compatible with certain external equipment. Panning is simply
the ability to go from side to side and tilting the ability to
go up and down. PAN
& TILT
are both accomplished by some type of external motor, while the
zoom
function (whether manual
or remote)
is inside the camera or lens itself. We do carry different cameras
that integrate ALL 3 functions (pan, tilt and zoom) into a single
control- in both indoor and outdoor versions.
Weatherproof PTZ equipment can be rather expensive. Even decent
quality pan/ tilt housings designed for actual outdoor use are
very expensive- and don't even include a the camera or camera
housing. We offer a unique solution to this problem. It's a special
PTZ outdoor spherical dome system with a 220x zoom (22x optical,
10x digital) with a Sony G5 chip that is the best we've ever seen-
and at a price that is actually affordable to most security budgets!
Please click
here to see our integrated Pan / Tilt / Zoom weatherproof
dome camera (DN-PTZ). Back
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Q3:
What is the difference between 'digital zoom' and 'optical zoom'?
A3:
Optical zoom is the traditional method of physically manipulating
the distance between 2 lenses
to create a different camera view. Digital zooming is a technique
in which an electronic processor literally magnifies size of the
pixels imaged by an optical lens. There are different techniques,
but "grainy" appearance is typically associated with
digital zoom, especially when the camera. Of cameras that have
the ability to zoom
(aka varifocal
lens cameras), some are optical, some are digital- and some are
both (such as our TV-C270)-
which means that the mechanical lens movement and internal digital
magnification are both taking place (22x optical and 10x digital
= total 220x zoom capability). It should be noted that not all
digital zooming technology is the same. We've seen all ranges
from extremely poor to excellent and are quite pleased with the
equipment we carry. Back
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Q4:
Can I pan & tilt without a zoom camera- or vice versa?
A4:
Absolutely. In fact, many systems referred to as PTZ
are actually the combination of a pan
- tilt
housing with the addition of zoom camera. However, there are also
truly integrated PTZ systems in which the user can choose one
or all functions. Back
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Q5:
Do I need to manually control a zoom lens type camera- and how?
A5:
It all depends on the camera. Most variable focal (varifocal)
"zoom" lens cameras actually do require the user to
set the optimum adjustments by hand. Some zoom cameras, like our
TV-C270,
have the ability to control the zoom and focus the camera with
a wired remote controller from 125' away. The TV-C270 camera is
ALSO available integrated into a pan/ tilt unit to control all
functions with a SINGLE REMOTE! Also see our DN-PTZ,
which is A FULLY INTEGRATED PAN/
TILT & POWER
ZOOM CAMERA in a compact, attractive weatherproof dome (complete
with thermostatically controlled heater/ blower built in). Back
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Q6:
How can I remotely view or control PTZ camera functions from another
location?
A6:
Remotely viewing one or many cameras over is not a huge challenge.
However, remotely controlling functions of specialized camera
is where it can get tricky. The problems are generally the result
of incompatible equipment. If the internal software protocols
of the site driver are not recognizable to the camera- or vice
versa- the result will be a functional camera with no ability
to function. This is a strong warning of why it is necessary to
do your homework before designing or purchasing any type of complex
equipment. Again, as with most things- there are a wide variety
of products out there to suit a variety of needs. Please contact
us for specific or advanced PTZ issues. Back
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Q7:
What is a DC auto iris and why should it be considered?
A7:
A DC
powered "auto
iris" function is basically used to regulate the amount
of light entering the camera in different lighting conditions.
They are often used to amplify light for a lens
to obtain a more defined picture view for the camera. Use of such
a camera and lens outfit can dramatically improve performance
in lower lux conditions. You can often spot such a setup by seeing
a cord between the back of the camera body and the lens itself.
It is there to provide a means to deliver the DC voltage from.
You cannot simply attach such a lens to any camera- even if the
mount is a perfect fit. DC auto iris lenses require voltage and,
therefore, a camera with a compatible DC auto iris output port.
This is why it is recommended that you purchase a lens and camera
together from the same company. Back
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