Meade Pictor CCD FAQ
Gary Deen
sends this little info for those that ask.
Anyone have any experience with this equipment yet?
========
Meade Pictor Series CCD Autoguider/Imagers
For the beginner, or for the most advanced
observer, the real CCD revolution is here!
Imagine with your telescope capturing an image of Jupiter
that appears to have been taken with a 36" observatory
telescope. Or obtaining, in 2 minutes or less, without
guiding, an image of the spiral galaxy M51 that
out resolves 30-minute photographic exposures. Or
imaging a supernova in an obscure 18th-magnitude
galaxy. Meade CCD imagers can accomplish all of this,
and much more! How such results can be obtained is
explained on a step-by-step basis, from preliminary
definitions to more advanced imaging techniques, in the
following Question and Answer section.
Q. What is a CCD imager?
A. A CCD ("charge-coupled device") is a detector sensitive to light.
When light (consisting of discrete photons) hits the detector surface of
the CCD microchip, electrons are given off and stored in the detector
elements, or pixels. (See figure.) A CCD microchip consists typically of
thousands of pixels. When a CCD camera is pointed at a brighter area
of the sky, a larger number of photons come in contact with the chip.
More photons generate a larger number of electrons. Thus, a brighter
portion of an image has a greater
number of electrons stored in
each pixel.
Q. What materials are CCD
chips made of and what makes
one chip "better than another?
A. CCD chips are made of
semiconducting materials such as
silicon that have been manu-
factured to be sensitive to the
impact of light hitting their
surfaces. Factors that can give
one chip an advantage over
another are physical dimensions
(the larger the chip, the more sky
area that can be imaged at one
time); their pixel sizes (smaller,
more tightly-packed pixels result
in higher image resolution); the pixels' well capacity (the total number of
electrons that can be stored in each pixel before it becomes saturated);
fill factor (the percentage of the chip's area that is sensitive to light); and
quantum efficiency (the sensitivity level of the chip to light.)
Q. What is dark current?
A. In any pixel some undesirable electrons will be stored that are not
the result of light photons hitting the detector surface. Some of these
electrons result from thermal noise, a random effect due to the
interaction of heat with the CCD chip material. The electric charge of
these unwanted electrons---electrons that would exist in the pixel even if
there were no light coming in contact with the chip-is called dark
current. The effect of dark current is to limit the practical length of a CCD
time-exposure: ultimately, dark-current electrons saturate the pixels so
that no additional photon-induced electrons can be generated. Thus, the
lower the dark current, the longer a CCD exposure can be.
Q. But I've heard that it is possible to "subtract out" the effects of dark
current.
A. Fortunately, dark current is highly predictable. By taking a CCD
image with the telescope optics covered (for the same length of time as
the intended image-exposure time) so that no incoming light reaches the
CCD chip, it is possible to measure the dark current-electrons stored in
the pixels when the chip is literally in darkness-that will occur during the
actual image exposure. This dark current value can then be subtracted
from the total number of electrons stored in each pixel well, to obtain the
net number of stored electrons not due to dark current. While this
subtraction process is valuable to eliminate most of the effects of dark
current from the desired total of photon-induced electrons, it does
nothing to solve the problem mentioned above of dark current pixel-
saturation. The only real solution to this problem is to use CCD chips
that have very low dark current, and, as we will see below, that is one of
the important advances incorporated into Meade CCD imaging systems.
Q. What is analog-to-digital (A/D) conversion?
A. The process of CCD imaging converts a smooth, continuous
analog signal (e.g. the image of a galaxy) into a series of discrete digits.
Suppose, for example, that a galaxy's image is divided into a large
number of squares, with each square covering a small area of the image,
and that the varying brightness levels in different squares are
represented by a series of digits, one through eight, where "1" is black
(dark sky) and "8" is pure white (the nucleus of the galaxy); digits in
between represent varying levels of gray. With this "digital"
representation of the galaxy we could compose a "discretized" picture of
the galaxy, replacing the smooth, continuous one that is in fact emitted
by the galaxy.
Q. But isn't a smooth, continuous image better than the discontinuous,
unsmooth one you just described?
A. If we use a large enough number of squares to cover the galaxy's
image (i.e. if the squares are small enough) and if the quantity of digits
used to represent all of the gray shades between pure black and pure
white is large enough, then the digitized image becomes, for all practical
purposes, smooth and continuous. In the Meade Pictor 416 CCD
Imager, for example, the squares (pixels) used to cover the incoming
image are about 0.0004" (0.01mm) on a side and shades of gray from
pure black to pure white are represented by 65,536 digits. In such a case-
the digitized image is so smooth as to be virtually undetectable from a
smooth, continuous, analog image.
Q. That still doesn't explain why it is desirable to digitize an image as
you just described, instead of working with a continuous image.
A. The answer to this question goes to the basis of all CCD imaging.
Once an image is digitized, an important range of operations, called
image processing, become possible. Such image processing is also
possible with analog-sensitive procedures, such as traditional
photographic film imaging, but the possibilities with photographic film are
vastly more limited than with the digital image output by a CCD chip.
Rather poor digitized images of celestial objects that are hardly
recognizable as originally imaged can be processed into magnificent,
beautiful images with good image processing techniques. Digital image
processing enables the extraction of a weak signal from a large amount
of noise.
Q. What are the other advan-
tages of CCD imaging as com-
pared to photographic imaging?
A. Because of a CCD chip's
greatly increased light-sensitivity
compared to film, exposure times
are typically much shorter, as
stated above, a 2-minute un-
guided exposure of the Whirlpool
Galaxy (M51 ) with the Meade 216
CCD Imager, for example, out-
resolves photographic exposures
of 30 minutes' duration. The
CCD image provides instant
gratification-the image is
immediately visible on your PC
display as soon as it has been taken, without the normal darkroom work
required of film. In addition film suffers from a phenomenon called
reciprocity failure: the photographic emulsion becomes less and less
sensitive as exposure time is increased; by contrast, the response curve
of a CCD imager is linear: twice the exposure time yields exactly twice
the results. And,
post-exposure image
processing provides
an amazing level of
image enhancement,
an enhancement that
is simply not possible
with film. With ad-
vanced image pro-
cessing techniques,
CCD images through
amateur telescopes
have been taken of
Jupiter, for example,
that exceed the level
of detail that can be
photographed
through the largest
telescopes on earth.
Q. Are you saying, then, that photography, and particularly astrophoto-
graphy, is an obsolete science?
A. Absolutely not. Even the largest CCD chips are small compared to
the formats of common films. The Meade Pictor 1616 includes one of the
largest CCD units (13.80mm x 9.20mm in dimensions) currently
available, and yet it images an area less than 20% of the standard 35mm
film format. (This problem is, however, significantly reduced in
importance by the mosaic feature of the four Meade Pictor imager
models, as we will see below.) And in a sense, photography with a
35mm camera is perhaps more convenient to the average user, since a
PC and external power source are not required. Notwithstanding the
preceding words, however, there is little question but that the future of
imaging, whether for astronomy or for recording a family gathering, lies
in the CCD chip: simply put, the boundaries of CCD imaging are almost
endless; the boundaries of photographic imaging, for all its rich history,
are not.
Q. You mentioned above that a large number of gray scales is highly
desirable in a CCD system. How does this relate to the design
specifications of a CCD imager?
A. The basic specifications of any CCD system state whether it is has,
for example, an "8-bit," "12-bit," or "16-bit," register. An 8-bit register (i.e
.
an 8-bit analog-to-digital conversion register) permits 2 to the 8th,
or 256, varying
levels of gray to be digitized. CCD cameras (e.g. the Meade Pictor 208)
that include 8-bit registers yield a reasonably satisfying level of
smoothness and continuity to the image, but more advanced cameras
with 16-bit registers (e.g. Meade Pictor Models 216, 416, and 1616)
present, by comparison, vastly enhanced images in all respects.
Imagers with 16-bit A/D registers yield 2 to the 16th, or 65,536, gray scales.
Q. What is thermoelectric cooling?
A. As stated above, dark current, one of the chief enemies of any CCD
imaging system, is the undesired random generation of electrons into the
pixel well, stimulated by heat in the environment of the CCD chip. Dark
current can be very significantly reduced by lowering the chip's
temperature. In CCD specification tables dark current is specified at a
certain temperature-e.g., dark current of the Meade Pictor 216 is "less
than 8 electrons per 5 seconds at a chip temperature of -5°C. Achieving
this low chip temperature requires a cooling system. Thermoelectric
cooling, the most common method of CCD chip cooling, entails the input
of an electric current to two metal plates separated by a semiconducting
material; the result (the so-called Peltier Effect) is to make this
thermoelectric module act as a heat pump, pulling heat out of the CCD
chip that rests next to the module. The efficiency of heat dissipation is
augmented by radiating fins, included with all Meade Pictor CCD's. On
more advanced CCD systems, such as the Meade Pictor 416 and 1616,
thermoelectric cooling is cascaded with two similar modules, resulting in
2-stage cooling which thereby reduces the chip's operating temperature,
and resultant dark current, still further. The cooling systems on all
Meade Pictor imaging models (#208, #216, #416, and #1616) are
regulated, meaning that the cooling system automatically turns ON and
OFF to keep chip temperature close to the desired temperature.
Q. What is flat-field compensation:
A. Due to manufacturing considerations in the production of any CCD
chip, not all of the chip's pixels have the same level of sensitivity to light,
small variations in the thickness of the chip can affect sensitivity. In
addition light does not hit the chip uniformly due to natural optical
vignetting, however small, of the image by the telescope's optics Total
sensitivity variations can easily reach 5% to 10% from place-to-place on
the chip, variations which become apparent in the imaging of faint
objects. To minimize these vignetting effects, Pictor models facilitate
combining a flat-field exposure with the actual image; this process is
called flat-field compensation.
Q. I've heard that an effect called blooming can also be a problem with
CCD's.
A. CCD images of bright objects, such as first-magnitude stars,
sometimes show the effects of blooming. This effect, visible as a trail of
light emanating from the illuminated pixel (similar in appearance to one
spike of a "spider diffraction" pattern in a Newtonian reflector), is due to
a spillover of electrons from a fully saturated pixel. All Meade CCD
systems have built-in blooming correction, reducing the probability of
streaking in an image.
Q. How is a CCD imager actually used with the telescope?
A. CCD imaging requires three basic components: the telescope, the
CCD imaging system, and a personal computer (PC). In the simplest
format, the CCD head, containing the CCD chip itself, is placed into the
telescope's eyepiece-holder in place of an eyepiece; the object to be
imaged is centered and focused on the CCD chip; the image is taken,
and the image data are transferred and processed by the PC. The image
is immediately displayed on the PC's monitor. (With all Meade CCD
models, CCD operating and image processing software is included on a
floppy disc that is loaded into the PC before starting.) Meade Pictor
Models 208 and 216 include all of the associated control electronics
inside the same CCD head; Models 416 and 1616, because of their
larger, higher-resolution chips, and consequently more sophisticated
control systems, utilize a separate control box. (This separate control
box has important implications, discussed below.)
Q. Is it really that simple? I've heard that CCD imaging can be
something of a chore.
A. Before the advent of the Meade Pictor Series your statement was
often true: CCD imaging usually required a knowledge of PC techniques
and a flair for working with a rather complex piece of hardware. Using a
Pictor system, CCD imaging is accessible to anyone with an interest in
astronomy or photography. To illustrate the contrast between any of the
four Pictor models and other CCD imagers, consider this summary of the
imaging procedure required of typical competing units, even very
expensive ones: after the telescope, imager, and PC are set-up, the
operator must set the imager temperature, take a flat-field exposure (see
below); use an eyepiece to center a medium-bright star in the field, focus
the star in the eyepiece; re-check focus of the star with the imager in the
telescope; center on the CCD chip the object to be imaged, if not
centered, use the telescope's drive
corrector to center the image; re-
check focus of the object; specify
image exposure time, take dark
frame exposure; take actual image
exposure. Keep in mind that the
foregoing is a summary of what
required without a Pictor CCD and
without a Meade LX200 telescope.
It is not uncommon for an operator to
spend one hour simply preparing to
take the image exposure!
By contrast, Meade Pictor Models
208, 216, 416, and 1616 are "point-
and-shoot:" to take an image, cen-
ter and focus it on the chip (more on
this operation below) and click on a
button on the PC display. The
imager automatically determines the
appropriate exposure time, takes the
required dark current frame, ,and
stores it in memory. The imager
gives the user the option of taking a field-flattening image and storing it
in memory, then takes the actual exposure, and stores the resulting
image, again after automatically subtracting out the dark current
compensation frame.
Q. I've heard that centering and focusing the image on the CCD chip
can be a frustrating task.
A. Indeed it can be, but again the Pictor Series has made great
improvements on both of these points. Once an object is placed any-
where on the chip, imaged, and downloaded to the PC, the Pictor's
autocenter feature allows the user simply to click the PC's mouse on the
PC display at the desired center of the image. The Pictor then
automatically moves the telescope to center the object on the chip and
retakes the image. If you're using your Pictor CCD with a Meade LX200
telescope equipped with the Meade electric focuser, images can be
automatically focused. Trial-and-error focusing, taking test shots, and
refocusing are no longer necessary. Even without an LX200, a Pictor's
fast-frame mode enables viewing an-image-a-second to facilitate
focusing.
Q. Could you elaborate
on the special advantages
of using a Meade LX200
Schmidt-Cassegrain with a
Meade Pictor Series CCD
Imager?
A. In fact the advantages
are almost overpowering,
since Meade LX200's were
designed with an eye
toward the requirements of
CCD imaging. These ad-
vantages apply to all
Meade Pictor imager
models and all LX200
models. (a) Autocentering:
use your PC's mouse to
click on to an object at the
edge of the CCD chip, click
on the centering tool, and
the telescope microslews
automatically to center the object on the chip; (b) Autofocusing:
Accurate, hassle-free focusing was perhaps the biggest single
headache in pre-Pictor imaging. With the Meade electric focuser
attached to any LX200 model, by actuating Autofocus, the image is
automatically, and precisely, focused in seconds. (c) Automosaicking: In
the Automosaic mode the LX200 moves automatically to image an
arbitrarily large number of operator-specified sky areas adjacent to the
originally imaged area. In this way image montages can be created to
stunning effect. (d) High-Precision Pointing: With their pointing
accuracy of two arc minutes or less, Meade LX200's can be used to
place even the faintest objects on any Meade CCD chip, first time, every
time. There are no other commercial telescopes and no other CCD
systems currently manufactured that permit the above operations or the
above-stated pointing accuracy.
Q. Can Meade ED Apochromatic Refractors, or other telescopes
mounted on Meade LXD 650 and 750 equatorial mounts, achieve all of
the above LX200 advantages as well?
A. Yes. All of the above-listed, unique LX200/Pictor advantages apply
equally as Well to telescopes mounted on Meade LXD 650 or 750
equatorial mounts, provided the mounts are equipped with the Meade
#1697 Computer Drive System.
Q. As stated above, Meade Pictor Models 208 and 216 have their
control system electronics housed within the CCD head that is attached
to the telescope; there is no separate control box. Other CCD systems
in the same price range as these models have separate control boxes
with many more push buttons on the box than is the case with the Meade
models. What control capabilities am I losing with the Meade 208 and
216 that I would have with other brands?
A. Absolutely none. The other CCD systems you mention were
designed up to 5 years ago, and the pace of hardware and software
advancement in this period has been phenomenal. The push buttons you
refer to are generally required for the many cumbersome manual
autoguider settings of older CCD units. To actuate the autoguide mode
with all Meade CCD systems, you simply push one button to make the
system GO: the onboard controller automatically sets the integration
(exposure) time for autoguiding.
Q. Meade Pictor Models 208 and 216 use the Texas Instruments TC-
255 CCD chip. I notice that this same chip is used on competing CCD
models that sell for much higher prices. How is this possible?
A. The TC-255 CCD chip is the most advanced CCD chip available for
imagers in the mid-price range, and, without qualification, Meade Models
208 and 216 permit the highest levels of performance of any imagers
available in this range. All four Meade CCD imagers are generally less
expensive, and yet with far more features and performance, than
competing units for several reasons. Meade Instruments budgeted large
sums of money for more than one year to develop the Pictor Series; one
result of this large capital outlay is that we can manufacture higher-
quality CCD's at much lower unit costs than our competitors. Our design
philosophy in developing the Pictor Series was not to offer "just another
series of CCD imagers," but to make Meade imagers the finest such
units on the market, a design philosophy that was carried out by Meade
engineers in collaboration with some of the world's premier CCD
consultants. And yet, because our operating overhead is spread out
over such a wide range of astronomical products-including over 40
telescope models and 250 accessory products-our unit costs put us in
an extremely competitive position.
Q. What is the value of the SCSI interface included with the Pictor 416
and 1616?
A. The SCSI (pronounced "scuzzy") interface permits data from the
large Kodak CCD chips used in the Pictor 416 and 1616 to be
downloaded to the PC in a fraction of the time required by serial
downloading, the type of downloading included with other brands of CCD
systems. For example, on one competing (and rather expensive) CCD
imager, after each attempt at focusing the image, the user must wait for
a period of 5 to 20 seconds before the image appears on the PC display,
and then, through repeated trial and error, ultimately try to reach correct
focus. The fast SCSI downloading of the Pictor 416 permits focusing
virtually in real time: focus and see the result immediately. The Pictor
1616, with its extremely large, high-resolution CCD chip requires a
maximum of 4 seconds for full-frame downloading.
Q. I understand that some competing CCD models can not practically
be used for imaging the Moon and planets, or are badly compromised in
doing so. Is this also true of the Meade Pictor Series?
A. No. Some CCD chips are downloaded (i.e. data is read out from the
pixels to the PC) without any shutter mechanism to block light from
hitting the CCD during the
readout. As a result,
images of bright objects,
such as the Moon and
planets, can be badly
smeared. Meade Pictor
CCD's solve this problem
in one of two ways: on
Models 208 and 216, the
TC-255 chip uses a
frame-transfer system
that rapidly moves the
image from the chip's
active area to an inactive
area not affected by
incoming light, thus
creating an electronic
shutter that can image in
exposure times as short as 4 milliseconds. Pictor Models 208 and 216
are as a result excellent lunar and planetary imagers, in fact the best
available short of the Pictor 416. On Meade Pictor Models 416 and 1616
a sophisticated electromechanical shutter is provided that can image
exposures as short as 1/100-second. Combined with small (9.0vm
square) pixels, low readout noise (see below), and 2-stage
thermoelectric cooling, Pictor Models 416 and 1616 are truly awesome
in their imaging capabilities, whether for lunar, planetary, or deep-space.
Q. You have mentioned dark current as a potential problem in CCD
imaging. Are there other sources of unwanted electrons that can affect
imager performance?
A. The answer to this question is a bit technical, but it is vital to an
understanding of why Meade Pictor CCD's are such an improvement
over other CCD systems currently available. In fact there are numerous
sources of random noise in and about each pixel: noise caused by the
A/D conversion discussed above, as well as, among others, readout
noise, the noise caused simply by reading out a pixel's electron value
and sending this value on to the PC for processing. Readout noise is
independent of exposure time and complicates the taking of very faint
images. The TC-255, KAF-0400, and KAF-1600 CCD chips used in
Pictor Series CCD systems all have very low readout noise (see table,
this page). Most other noise sources increase as the square root of time
(sqrt( t ) ). Stored electrons which are the result of incoming photons (i.e.
desirable electrons generated by the incoming image signal) increase
directly proportional to time. The effect of the preceding statements is
that the longer the CCD exposure time, the less the relative effect of
noise on the desired incoming image signal. Equivalently, CCD
engineers say that signal-to-noise ratio increases with exposure time.
Thus longer CCD exposures have an added value beyond the fact that
they result in more incoming signal value: they also result in relatively
less noise than do shorter exposures. And, because all Meade Pictor
CCD chips have such low dark current, long exposures (often impossible
on other CCD systems because of dark currents that are 5 to 20 times
higher) are not only practical, but highly desirable.
Q. How should Meade CCD systems be used in the field, where there
is generally no source of alternating current?
A. All Pictor Series CCD units operate from 12 volts DC. A cord for
powering each CCD from an automobile cigarette lighter plug is included
with each model; optional Meade adapters are available for operating
from standard 115v.AC outlets. For safety reasons only a laptop PC
should be used in the field, since this type of PC can also be
powered from the 12vDC auto cigarette lighter plug. (AC-powered
PC's are not designed, and are not safe, to use outdoors.)
Alternately, the telescope-with-CCD head may be set up outdoors and
the (AC- or DC-powered) PC remotely operated indoors by a cable link
between the CCD and PC. Such cable links up to 100 ft. are possible
with any Pictor model.
Q. I note that a video card and disc drive are available optionally for the
Pictor 416 and 1616. What is the purpose of this option?
A. With the Meade #505 Video Card/Disc Drive (sold together as one
option) attached to the control box of the Pictor 416 or 1616, a range of
possibilities becomes available, For example, the user can take a small
and inexpensive 12vDC television set into the field to use as a video
monitor-no PC display/CPU or laptop computer is required, images as
they are taken can be stored to a floppy disc loaded into the disc drive
now seated in the control box. In this way a full night of imaging far from
the city can be accomplished with a minimum of equipment. Images on
the floppy discs can be processed on the PC after returning home.
Q. You call all of the Pictor Models 208, 216, 416, and 1616
"Autoguider/Imagers." Can all of these systems independently
autoguide and image?
A. Yes. All four models, including the least-expensive Pictor 208, can
be used to (a) autoguide a photographic exposure, and (b) autoguide the
imager itself in a track-and-accumulate mode the imager takes a series
of, say, 2-minute exposures and after each exposure the image is stored
(accumulated) on "top" of the previous images; between image
exposures the Pictor briefly autoguides, making any necessary position
corrections. The track-and-accumulate mode of all models is automatic:
just input from the PC keyboard the number of exposures desired and
the exposure time, and Pictor software does the rest, even calculating
the proper integration time for the autoguider.
Q. How about color imaging with the Pictor Series. Is this possible?
A. The Meade #616 Color Filter System connects directly to Pictor
Models 216, 416, and 1616 and enables superb tri-color imaging, fully
automatically, without the tedious trial-and-error approach of other CCD
systems.
Meade Pictor 201 CCD Autoguider
The first ultraprecise, moderately-priced
CCD autoguider.
With the Pictor 201 in place on your telescope, tedious
photographic guiding is a thing of the past. Now you can
take long-exposure astrophotographs, knowing that the
telescope will precisely track the object being
photographed, even during the longest exposures.
The Pictor 201 Autoguider can be used on any telescope
equipped with a dual-axis drive corrector. On Meade
LX100 and LX200 Schmidt-Cassegrains, #1697 CDS-
equipped ED/APO Refractors, and on other telescopes
that have a phone-jack "Autoguider" connector, the 201
simply plugs in to the telescope's control panel. On
telescopes with retrofitted drive correctors (i.e. telescopes
where the drive corrector is not integrated into the
electronics of the telescope itself) the optional Meade
#520 Electronic Relay permits interfacing between the
201 unit and the drive corrector.
The Pictor 201 is an autoguider only and can not be used
for imaging. No personal computer or separate control
box is required. Used with an off-axis guider or auxiliary
photo-guide telescope, the 201 automatically locks-on to
the brightest star (as faint as magnitude 8) in the guiding
field, sets the autoguider's integration (exposure) time,
and actuates all required dual-axis corrections for
perfectly guided astrophotographs. Use it once and you'll
never guide manually again!
Specifications: Pictor 201 Autoguider-Includes autoguider body with
1.25" barrel for insertion to standard 1.25" eyepiece-holder, coil cord for
connection between autoguider body and telescope's phone-jack autoguider
inlet or to optional #520 Electronic Relay; operates from 12-volts DC; includes
25 ft. power cord for operation from 12v. DC auto cigarette lighter plug;
instruction manual. #541 Adapter for operation from 115v. AC available
optionally.
Meade Pictor 208 CCD Autoguider/Imager
For the demanding first-time CCD user.
Although the Pictor 208 is the least-expensive Meade
CCD imager, it yields impressive, exciting results on a
wide range of astronomical subjects, from the Moon and
planets to deep-space. As an autoguider, operation is
identical to the 201, above, except that, because of the
208's cooling system, guide stars as faint as 9th
magnitude may be employed.
Incorporating the Texas Instruments TC-255 CCD
microchip, the Pictor 208's 3.3mm x 2.4mm active area is
comprised of a 336 x 242-pixel array of 10-micron-square
pixels-by far the largest, highest-resolution chip
available in any CCD unit in its price range. Combining
low (less than 36 electrons) readout noise, very low dark
current, and an 8-bit analog-to-digital (A/D) register
permitting 256 shades of image brightness, the Pictor 208
is ideal for the serious beginning CCD user.
Operation of all Meade imagers, including the 208, is
through any Windows or Macintosh-based personal
computer. And, with the automatic exposure settings,
dark current exposure, and flat-field compensation
common to all four imager models, the 208 is quick,
simple, and hassle-free to use. The thorough instruction
manual takes the user step-by-step from beginning
applications to more advanced imaging.
Specifications: Pictor 208 Autoguider/Imager-Includes auto-
guider/imager body with 1.25" barrel for insertion to standard 1.25" eyepiece-
holder, coil cord for connection between imager body and telescope's phone-
jack CCD autoguider inlet or to optional #520 Electronic Relay; cord for
connection between CCD head and PC; operates from 12-volts DC; includes
25 ft. power cord for operation from 12v.DC auto cigarette lighter plug;
instruction manual. #541 Adapter for operation from 115v. AC available
optionally.
Meade Pictor 216 CCD Autoguider/Imager
Advanced capability at a reasonable price.
Identical in operating characteristics and in external
dimensions to the Pictor 208, the Pictor 216 includes one
very important difference: a 16-bit analog-to-digital
conversion register permitting 65,536 gray-scale levels in
the final image. In situations calling for faster data
transmission to the host PC or for reducing image file
sizes, the 216 may alternately be used in a 12-bit mode,
with 4096 gray-scale levels.
The Pictor 216 is the most advanced CCD imager
available in its price class; in fact, competing units with far
fewer features that utilize the same TC-255 microchip sell
for almost twice the 216's price. With the same "point-
and-shoot" simplicity of other Pictor models, the 216 is a
powerful imaging camera on any telescope. Used in
conjunction with a Meade LX200 Schmidt-Cassegrain the
capabilities of any Meade Pictor system are greatly
expanded, with features as Autocentering, Autofocus, and
Automosaic performed quickly and precisely. In addition
the LX200's High-Precision Pointing mode capability
enables the location of even the faintest objects-objects
so faint that they can not been seen without the imager's
capabilities-and their placement on the 216's CCD chip
first time, every time.
Specifications: Pictor 216 Autoguider/Imager-Includes auto-
guider/imager body with 1.25" barrel for insertion to standard 1.25" eyepiece-
holder, coil cord for connection between imager body and telescope's phone-
jack CCD autoguider inlet or to optional #520 Electronic Relay; cord for
connection between CCD head and PC; operates from 12-volts DC; includes
25 X power cord for operation from 12v.DC auto cigarette lighter plug;
instruction manual #541 Adapter for operation from 115v.AC available
optionally.
Meade Pictor 416 CCD Autoguider/Imager
Professional-level imaging performance.
Armed with the powerful Kodak KAF-0400 CCD
microchip, the Pictor 416 is, without qualification, the most
advanced high-resolution CCD system available under
$5000.
The 416 includes more than four times the pixel quantity,
more than twice the pixel density, and about one-tenth the
dark current of competing units. The result is high-
resolution images of the Moon, planets, and deep-space
with amateur telescopes that match or exceed the
photographic images obtained with large observatory
telescopes. The Pictor 416 is truly the amateur
astronomer's dream of incredibly fast, professional-level
imaging capability.
Notwithstanding the enormous data collection power of
the 416, the system's standard-equipment SCSI interface
enables full-frame download to its host computer in one
second, permitting virtually real-time object acquisition,
focusing, and centering.
Note on the Meade #520 Electronic Relay: All Pictor CCD models plug in
directly to the control panel jacks of Meade LX200 telescopes or to other
telescope brands with similar "autoguider" ports. Telescopes with separate,
retrofitted drive correctors (e.g. Meade Models 2080A/B) may be used with
any Pictor model by means of the #520 Electronic Relay. The #520, a
microelectronic device without internal moving parts, consists of a small
(cigarette-pack-size) box with telephone jack input on one side and
connectors for a wide range of drive corrector directional controls on the
other.
Specifications: Pictor 416 Autoguider/Imager-Includes auto-
guider/imager head with 1.25" barrel for insertion to standard 1.25" eyepiece-
holder, control box with digital readout display, keypad, and direction
al
buttons; SCSI interface; connector cord to telescope's phone-jack CCD
autoguider inlet or to optional #520 Electronic Relay; special thin cable for
connection between CCD head and control box; operates from 12v.DC;
includes 25 ft. power cord for operation from 12v.DC auto cigarette lighter
plug; instruction manual. #542 Adapter for operation from 115v.AC available
optionally.
Meade Pictor 1616 CCD Autoguider/Imager
The finest imaging system ever made
available to the amateur astronomer.
The Meade Pictor 1616 imaging system utilizes the Kodak
KAF-1600 CCD microchip, one of the largest (13.80mm x
9.20mm) such chips currently in commercial production.
With the same pixel density, ultra-low dark current (less
than one electron per 5 seconds), and ultra-low readout
noise (less than 15 electrons rms) of the Pictor 416, but
with four times the pixel quantity and chip area, the 1616
permits professional-quality imaging of very large sky
areas: attached to an 8" f/lO Schmidt- Cassegrain, for
example, the 1616's chip encompasses a sky area of
23.3'x 15.6', a field that allows imaging almost one-half
the lunar surface in a single exposure.
Pixel size of the Pictor 1616's KAF-1600 chip is only 9
microns square, about one-eighth the area of competing
CCD's. The result is a vastly increased level of image
resolution, a level previously unseen in any but the most
specialized and costly systems.
Specifications: Pictor 1616 Autoguider/Imager-Includes auto-
guider/imager head with 1.25" barrel for insertion to standard 1.25" eyepiece-
holder, control box with digital readout display, keypad, and directional
buttons; SCSI interface; connector cord to telescope's phone-jack CCD
autoguider inlet or to optional #520 Electronic Relay; special thin cable for
connection between CCD head and control box; operates from 12v.DC;
includes 25 ft. power cord for operation from 12v.DC auto cigarette lighter
plug; instruction manual. #542 Adapter for operation from 115v.AC available
optionally.
Note on the Meade f/6.3 Focal Reducer: Used with any Schmidt-
Cassegrain telescope, the Meade f/6.3 Focal Reducer significantly reduces
the image scale of the main telescope-e.g. from f/10 to f/6.3, or from f/6.3 to
f/4. In CCD applications with any Meade Pictor model, such image scale
reduction is highly desirable because it enables the imaging of a wider sky
area and easier acquisition of the object on to the CCD chip.
Meade Pictor 616 Color Filter System
The Pictor 616 Color Filter System connects directly
without any adjoining cables, to the CCD head of Meade
Pictor 216, 416, and 1616 imaging cameras. The 616
includes 6 rotatable filter positions, with filter rotation
driven by a small, internal DC motor powered through the
CCD head.
The 616 rotating filter system receives electronic
instructions from the CCD imager head. The system auto-
matically initializes itself when connected, and, after first-
time-only instruction from the user as to the relative
locations of the color filters, operation of the filter system
can be either completely automatic, with exposure times
and filter rotation directed by the imager software, or
manual, depending on the user's wishes.
The following filters are included with each 616 unit: B-440
Blue; G-550 Green; LA-200 Red; NA-45 Clear. A special
RT-830 Infrared bandpass filter is also provided,
permitting very effective CCD imaging of the near-
infrared. One filter position is left open, so that the filter
system need not be detached when unfiltered CCD
operation is desired. Importantly, all of these filters are
inteference filters, not the more common, and less
expensive, Wratten filters; as a result, Pictor 616 filters
have much higher peak transmissions, and more closely
resemble the color response of the human eye, than do
other CCD filter systems.
Combined with a Meade Pictor CCD imager, the 616
Color Filter System brings stunning, high-quality tri-color
imaging to the average amateur, and without the
extremely tedious trial-and-error approach previously
required.
Meade Instruments Corporation
Worlds Leading Manufacturer of Astronomical Telescopes for the Serious Amateur
16542 Millikan Avenue, Irvine, California 92714 - (714) 756-2291 - FAX: (714) 756
-1450
The name Meade and the Meade logo are trademarks registered with the
United States Patent Office - and in principal countries throughout the world.