Expensive locks didn’t help me when my office was robbed a few weeks ago, in broad daylight. The thief who made off with the computers was identified and caught through the vigilance of someone in my building who noted a suspicious character lurking about. This experience points to the importance of natural surveillance for crime prevention, one of the principles of CPTED (Crime Prevention Through Environmental Design). CPTED, an approach that originated in the 1960s, is based on a theory that the proper design and effective use of the built environment can reduce crime and the fear of crime. Research into criminal behavior shows the decision to commit a crime or not is heavily influenced by cues about perceived risk of being caught. CPTED strategies increase a criminal’s perceived risk of detection using three main strategies: Natural surveillance, natural access control and natural territorial reinforcement. Natural surveillance, sometimes called “eyes on the street,” is achieved by designing the placement of physical features, activities and people in ways that provide maximum visibility and foster positive social interaction among legitimate users of private and public space. Potential offenders feel increased scrutiny and limitations on their escape routes. Examples include placing windows in active rooms — such as kitchens, overlooking sidewalks and parking lots — leaving window shades open or using the shortest, least sight-limiting fence appropriate for the situation. Lighting design is an important element of natural surveillance. Poorly placed lights create blind spots for potential observers and miss critical areas. Although some areas need bright lighting, too-bright security lighting creates blinding glare and deep shadows, hindering the view for potential observers. Bright lighting can highlight people as targets. Lower-intensity lighting often requires more fixtures, but is generally much more energy efficient. Natural access control limits the opportunity to commit crimes by establishing a clear difference between public and private space. Some ways it can be achieved include things like planting low, thorny bushes beneath ground level windows to deter people from looking in. In most cases, fencing should not obscure views and should make it easy for neighbors to connect, building a sense of social interaction. The closer the neighbors are, the more they look out for each other. Another key measure of CPTED is territorial reinforcement, which employs such design elements as sidewalks, landscaping and porches to help distinguish between public and private areas and help users exhibit signs of ownership that give “hands off” messages to would-be offenders. Physical design can create or extend a sphere of territorial influence that potential offenders can perceive. For example, low walls, landscape and paving patterns can clearly define the space around a unit entry as belonging to the residents of the unit. Territorial reinforcement measures make the legitimate user feel safe and make the potential offender aware of a substantial risk of getting caught. It creates a sense of ownership, since owners have a vested interest in protecting their space. The sense of owned space creates an environment where “strangers” or “intruders” stand out and are more easily identified. Some ways of achieving this include building design and landscaping that communicate an alert and active presence occupying the space. Placing amenities such as seating in common areas helps to attract larger numbers of desired users. Similarly, scheduling activities in common areas increases positive uses, attracts more people and increases the perception that these areas are controlled. Research also indicates that outdoor residential spaces with more trees are seen as significantly more attractive, safer and more likely to be used than similar spaces without trees. On the other hand, a fortress mentality with measures like putting up heavy-duty cyclone fencing and razor wire actually communicate the absence of a physical presence and suggests lower risk of being detected. Good care and maintenance are also important, as deterioration indicates less concern and control by the intended users of a site and a greater tolerance of disorder. CPTED takes more upfront effort but usually involves lower long-term costs, lower losses due to crime and higher quality of life.
There is no one best choice that fits everyone. There are 100s of possible choices, the issue is now to go about deciding. The best telescope for you is the telescope that you will use most often.
- What do you want to look at? How do you decide?
- Astrophotograpy planned? Terrestrial use? Solar use?
- What is your budget? Just how serious are you?
- Does it need to be portable? Fit in an RV? In a car’s trunk? Even just move out from a garage.
- Ease of set-up an issue?
- The Magnification Scam! If the box or ad promotes how much it magnifies, it’s probably junk.
- Aperture Rules! In general, the larger the aperture (main lens or mirror) the more you can see.
- Mounting as important as optics
Types of Telescopes:
- Catadioptric or SCT
Accessories are needed, too:
- Observing Chair
- Star Charts
- Storage case
Telescope Design Issues:
- Little or no maintenance and is easy to use. No cool-down time.
- Reliable simple design.
- Excellent for lunar, planetary or binary star.
- Good for terrestrial viewing.
- High contrast images due to its clear aperture (no central obstruction).
- Sealed optical tube.
- Objective is permanently mounted and aligned.
- Usually more expensive per inch of aperture than Newtonians or Catadioptrics.
- Heavier, longer and bulkier than equivalent aperture Newtonians or Catadioptrics.
- The cost and bulk factors usually limit the maximum size to smaller apertures.
- Less suited for observation of deep sky objects because of aperture limitations.
- Poor reputation due to low quality imported toy telescopes
- Lowest cost per inch of aperture.
- Reasonably compact and portable up to focal lengths of 1000mm 40”.
- Excellent for faint deep sky objects.
- Reasonably good for lunar and planetary work.
- Good for deep sky astrophotography if properly mounted.
- Low in optical aberrations and deliver very bright images.
- Requires regular alignment (collimation).
- The open tube could mean more complicated cleaning compared to other designs.
- Generally not suited for terrestrial applications.
- Slight light loss due to secondary (diagonal) obstruction when compared with refractors.
- Best all-around, all-purpose telescope design. Most are extremely compact and portable.
- Good for deep sky observing or astrophotography with CCDs.
- Very good for lunar, planetary observing.
- Good for terrestrial viewing or photography.
- Closed tube design reduces image degrading air currents.
- Easy to use.
- Durable and virtually maintenance free.
- Large apertures at reasonable prices.
- Best near-focus capability of any type telescope
- More expensive than Newtonians of equal aperture.
- It is not what people expect a telescope to look like.
- Slight light loss due to secondary mirror obstruction compared to refractors.
- May suffer from image shift since the primary mirror is usually moved for focusing.
- Child [<$50]: cheap binoculars and basic star chart
- Teenager [$250]: better binoculars and mount or basic Dob; and observing book
- Adult w/limited budget [$500]: good binoculars, mounting, or 80mm refractor, extra accessories; and observing guides
- Adult w/medium budget [$1-2,000]: mid-size Dob or CAT, w/o GoTo but can be added; and star maps & observing guides
- Adult/big budget [$5,000]: large Dob or CAT on GoTo mount; and computer-aided star charts
- Adult/RV: small CAT or 80mm refractor on basic tripod mount; and observing guides
- Adult/unlimited budget: huge Dob or large CAT on Paramount mounting, CCD, etc. in an observatory with remote computer operation