Star Ware: The Amateur Astronomer's Guide to Choosing, Buying ...

More documents

Recommendations

Info

The “Eyes” Have It 203 eral high-quality Barlows are available in the 1.25-inch range, including those by Tele Vue, the Meade apochromatic Barlow, and Celestron’s Ultima. Note that the Celestron Ultima is made to very tight specifications because a number of eyepieces that are slightly more than 1.25 inches in diameter can have problems fitting into it. I have yet to experience any trouble personally, but I will say that there is an audible pop when some of my eyepieces are removed. If you own 2-inch diameter eyepieces, the giant Barlows by Astro-Physics and Tele Vue are your best choices, the Tele Vue being a little less expensive. Another option is offered by Tele Vue’s Powermate series. Not conventional Barlows in the strictest sense, Powermates are more appropriately classified as image amplifiers. While traditional Barlows use two-element negative lens sets, the Powermate has both a negative achromatic doublet plus a positive pupil-correcting doublet to correct vignetting (darkening of the field edges) and other optical problems that inevitably crop up when a Barlow is pushed beyond its reasonable limits. The net difference is that a Barlow stretches a telescope’s existing focal length while a Powermate effectively creates a new telescope. This may seem to be a fine point, but for the perfectionists in the crowd, especially those who own short-focus apochromatic refractors but who crave highly magnified views of the planets, the difference is noteworthy. Tests show that the Powermates all create nicely magnified views of their selected targets without introducing false color, edge distortions, or other aberrations. Assuming you go into it with a high-quality telescope and eyepiece, the inclusion of a Powermate will only add to the system’s magnification, and nothing else. Powermates come in three magnification factors: 2.5�, 4�, and the original 5�. The 4� fits 2-inch focusers while the others are for 1.25-inch focusers. All are very well made in typical Tele Vue fashion, with chromed barrels, black anodized bodies, and captive setscrews for securing eyepieces. Table 6.3 lists the most popular Barlow lenses available today. Focal reducers. While the f / 10 focal ratios of most Schmidt-Cassegrain telescopes have great appeal for observers who enjoy medium- to high-power sky views, their long focal lengths make it difficult to fit wide star fields into a single scene. To view large objects, such as the Andromeda Galaxy or the Orion Nebula, many amateurs use focal reducers to shrink a telescope’s overall focal length by 37% (from f / 10 to f / 6.3), thereby increasing its field of view. Modern focal reducers, listed in Table 6.4, do more than just compress the focal length; they also give pinpoint star images across the entire field of view. Although beneficial to all observers, this is especially attractive to astrophotographers, as the reduction in focal length also cuts down exposures by a factor of 2.5. Not surprisingly, both Celestron and Meade offer focal reducers for their telescopes, each designed with its own brand in mind. Consumers should note, however, that both will also fit each other’s SCTs and work equally well, so the choice is yours. Coma correctors. One look through chapter 5 and it should be clear that Newtonians with low focal ratios have become immensely popular—and with
204 Star Ware Table 6.3 Barlow Lenses Company/ Magnifying Barrel Model Factor Diameter Features Adorama Pro-Optic Short 2� 1.25� 2.25� long Apogee 1.75� Barlow 1.75� 2� 6� long; 46.5-mm clear aperture Apogee 2� Barlow 2� 1.25� 3� long Apogee 3� Barlow 3� 1.25� 4.38� long Celestron #93502 Barlow 2� 0.965� Less than 3� long; fully multicoated optics Celestron #93507 Barlow 2� 1.25� Less than 3� long; multicoated optics Celestron #93506 Ultima 2� 1.25� Three-element optical design; 2.75� long; fully multicoated optics Discovery Telescopes 2� 1.25� Earth and Sky Spectiva 2� 1.25� Hands-on Optics Short 2� 1.25� 2.88� long; fully coated optics Intes 8–01–01 2.4� 1.25� Meade #134 Barlow 2� 0.965� Meade #122 Telenegative 2� 1.25� Multicoated optics Meade #126 Short-Focus 2� 1.25� 2.5� long; multicoated optics Meade #127 Variable Barlow 2–3� 1.25� Engraved magnification scale; multicoated optics Meade #140 Series 4000 2� 1.25� Three-element optical design; multicoated optics Orion #8711 Shorty 2� 1.25� Multicoated optics; 3� long Orion #5121 Shorty-Plus 2� 1.25� Three-element optical design; multicoated optics; 2.75� long Orion #8746 Deluxe 2� 1.25� Multicoated optics Orion #8724 Deluxe 2� 2� Multicoated optics Orion #8748 VariPower 2–3� 1.25� Fully multicoated optics Orion #8725 Ultrascopic 2� 1.25� Three-element optical design; fully multicoated optics Orion #8704 Tri-Mag 3� 1.25� Multicoated optics; 5� long Parks Optical 701–30000 2� 0.965� Parks Optical 701–30010 2� 1.25� Parks Optical 701–30050 2� 1.25� Short Parks Optical 701–30015 2� 2� Sky Instruments UB2S 2� 1.25� Short; multicoated optics Sky Instruments UB3S 3� 1.25� Short; multicoated optics Sky Instruments B2S 2� 1.25� Short; fully coated optics Tele Vue 2� 2� 1.25� Fully multicoated optics Tele Vue Big Barlow 2� 2� Fully multicoated optics Tele Vue Powermate 2.5� 1.25� Four-element optical design; fully multicoated optics Tele Vue 3� 3� 1.25� Fully multicoated optics Tele Vue Powermate 4� 2� Four-element optical design; fully multicoated optics Tele Vue Powermate 5� 1.25� Four-element optical design; fully multicoated optics VERNONscope Dakin 2.4� 1.25� Multicoated optics
Page 2 and 3:
STAR WARE The Amateur Astronomer’
Page 4:
Contents Preface to the Third Editi
Page 7 and 8:
vi Preface to the Third Edition Not
Page 9 and 10:
viii Acknowledgments You, dear read
Page 11 and 12:
2 Star Ware Figure 1.1 The basic pr
Page 13 and 14:
4 Star Ware they are! It’s true t
Page 15 and 16:
6 Star Ware Figure 1.2 The Airy dis
Page 17 and 18:
8 Star Ware Table 1.3 Dawes’ Limi
Page 19 and 20:
10 Star Ware Figure 2.1 Artist’s
Page 21 and 22:
12 Star Ware Figure 2.3 Spherical a
Page 23 and 24:
14 Star Ware Figure 2.4 continued A
Page 25 and 26:
16 Star Ware an upright image, but
Page 27 and 28:
18 Star Ware Sir William Herschel,
Page 29 and 30:
20 Star Ware Cassegrains are design
Page 32 and 33:
3 So You Want to Buy a Telescope! S
Page 34 and 35:
So You Want to Buy a Telescope! 25
Page 36 and 37:
Page 38 and 39:
Page 40 and 41:
Page 42 and 43:
Page 44 and 45:
Page 46 and 47:
Page 48 and 49:
Page 50 and 51:
Page 52 and 53:
Page 54 and 55:
Page 56 and 57:
Page 58 and 59:
Page 60:
Page 63 and 64:
54 Star Ware higher-power glasses a
Page 65 and 66:
56 Star Ware there are still severa
Page 67 and 68:
58 Star Ware for in a camera tripod
Page 69 and 70:
60 Star Ware Those views are incred
Page 71 and 72:
62 Star Ware (known earlier as Edmu
Page 73 and 74:
64 Star Ware evident around brighte
Page 75 and 76:
66 Star Ware however, at the amount
Page 77 and 78:
68 Star Ware Polaris FMT binoculars
Page 79 and 80:
70 Star Ware Figure 4.4 Orion’s V
Page 81 and 82:
72 Star Ware Finally, Parks offers
Page 83 and 84:
74 Star Ware may find too heavy to
Page 85 and 86:
76 Star Ware more thoroughly, but i
Page 87 and 88:
78 Star Ware Fujinon, the patented
Page 89 and 90:
80 Star Ware finderscopes and a ple
Page 91 and 92:
82 Star Ware Refractors are further
Page 93 and 94:
84 Star Ware are sharp and contrast
Page 95 and 96:
86 Star Ware tripod. Slow-motion co
Page 97 and 98:
88 Star Ware for instance, is the e
Page 99 and 100:
90 Star Ware angles to one another
Page 101 and 102:
92 Star Ware Meade has also recentl
Page 103 and 104:
94 Star Ware they are almost always
Page 105 and 106:
96 Star Ware 102’s performance ca
Page 107 and 108:
98 Star Ware eyepieces at any one t
Page 109 and 110:
100 Star Ware and free of spurious
Page 111 and 112:
102 Star Ware may select from their
Page 113 and 114:
104 Star Ware but double-check on y
Page 115 and 116:
106 Star Ware I set earlier, the Ra
Page 117 and 118:
108 Star Ware absolutely textbook p
Page 119 and 120:
110 Star Ware As we will see below,
Page 121 and 122:
112 Star Ware eyepiece that comes w
Page 123 and 124:
114 Star Ware therefore, their vers
Page 125 and 126:
116 Star Ware The only optical prob
Page 127 and 128:
118 Star Ware German equatorial mou
Page 129 and 130:
120 Star Ware Figure 5.3 The NGT-12
Page 131 and 132:
122 Star Ware As the name implies,
Page 133 and 134:
124 Star Ware Meade also offers two
Page 135 and 136:
126 Star Ware beefier version. All
Page 137 and 138:
128 Star Ware eyepiece of the 20-in
Page 139 and 140:
130 Star Ware All four XT telescope
Page 141 and 142:
132 Star Ware In my opinion, if you
Page 143 and 144:
134 Star Ware rings (an important c
Page 145 and 146:
136 Star Ware Figure 5.5 The 4.25-i
Page 147 and 148:
138 Star Ware can be built around e
Page 149 and 150:
140 Star Ware problem on damp night
Page 151 and 152:
142 Star Ware axis. Takahashi descr
Page 153 and 154:
144 Star Ware The Classical design
Page 155 and 156:
146 Star Ware Takahashi also offers
Page 157 and 158:
148 Star Ware In practice, the view
Page 159 and 160:
150 Star Ware you upgrade to that 8
Page 161 and 162: 152 Star Ware 40,000 objects (50,00
Page 163 and 164: 154 Star Ware any means. The 26-mm
Page 165 and 166: 156 Star Ware 6 � 30 straight-thr
Page 167 and 168: 158 Star Ware reflector of similar
Page 169 and 170: 160 Star Ware off-axis, as with mos
Page 171 and 172: 162 Star Ware employee. I thought t
Page 173 and 174: 164 Star Ware Meade Instruments. Th
Page 175 and 176: 166 Star Ware Perhaps the Mak’s b
Page 177 and 178: 168 Star Ware manufacturer states t
Page 179 and 180: Table 5.2 Telescope Mounts 170 Manu
Page 181 and 182: Table 5.2 (continued) 172 Manufactu
Page 183 and 184: 174 Star Ware indicates German equa
Page 185 and 186: 176 Star Ware on “street” price
Page 187 and 188: 178 Star Ware had been received and
Page 189 and 190: 180 Star Ware Table 5.3 Some of the
Page 191 and 192: 182 Star Ware Figure 6.1 A selectio
Page 193 and 194: 184 Star Ware Table 6.1 Telescope A
Page 195 and 196: 186 Star Ware (a) Narrow Field of V
Page 197 and 198: 188 Star Ware of the brighter objec
Page 199 and 200: 190 Star Ware Kellner. It took over
Page 201 and 202: 192 Star Ware the 55-mm requires a
Page 203 and 204: 194 Star Ware The consensus from al
Page 205 and 206: 196 Star Ware quite sharp with exce
Page 207 and 208: 198 Star Ware very tall. The 10-mm,
Page 209 and 210: 200 Star Ware Cheapest of the cheap
Page 211: 202 Star Ware 8 mm, enabling it to
Page 215 and 216: 206 Star Ware Okay, are they worth
Page 217 and 218: 208 Star Ware Figure 6.5 Celestron
Page 220 and 221: 7 The Right Stuff Congratulations o
Page 222 and 223: The Right Stuff 213 Some telescopes
Page 224 and 225: The Right Stuff 215 Table 7.1 (cont
Page 226 and 227: The Right Stuff 217 Table 7.2 Unity
Page 228 and 229: The Right Stuff 219 Figure 7.3 Tran
Page 230 and 231: The Right Stuff 221 either a narrow
Page 232 and 233: The Right Stuff 223 Table 7.4 (cont
Page 234 and 235: The Right Stuff 225 of the Sun (foc
Page 236 and 237: The Right Stuff 227 Table 7.6 Solar
Page 238 and 239: sunspot intricacies, and erupting p
Page 240 and 241: The Right Stuff 231 Tectron, AstroS
Page 242 and 243: The Right Stuff 233 view from the s
Page 244 and 245: The Right Stuff 235 Rubber Eyecups
Page 246 and 247: The Right Stuff 237 just like regul
Page 248 and 249: The Right Stuff 239 Amateur Astrono
Page 250 and 251: The Right Stuff 241 Introductory Bo
Page 252 and 253: The Right Stuff 243 Miscellaneous R
Page 254 and 255: The Right Stuff 245 Digital Setting
Page 256 and 257: The Right Stuff 247 Celestron’s A
Page 258 and 259: The Right Stuff 249 Table 7.12 Sugg
Page 260 and 261: The Right Stuff 251 Table 7.13 Film
Page 262 and 263:
The Right Stuff 253 Figure 7.8 Came
Page 264 and 265:
of imaging you are interested in do
Page 266 and 267:
The Right Stuff 257 dynamic range i
Page 268 and 269:
The Right Stuff 259 that the ST-10E
Page 270 and 271:
The Right Stuff 261 to be desired,
Page 272 and 273:
The Right Stuff 263 Flip Mirrors On
Page 274 and 275:
The Right Stuff 265 No doubt about
Page 276 and 277:
The Right Stuff 267 Table 7.15 Astr
Page 278 and 279:
The Right Stuff 269 Figure 7.11 Tut
Page 280 and 281:
The Right Stuff 271 Table 7.16 Anti
Page 282 and 283:
The Right Stuff 273 Kendrick Astro
Page 284 and 285:
The Right Stuff 275 The Sky / mount
Page 286 and 287:
The Right Stuff 277 Although the mo
Page 288 and 289:
The Right Stuff 279 Pro Domes come
Page 290 and 291:
Figure 7.14 The Kendrick Astro Inst
Page 292 and 293:
8 The Homemade Astronomer Amateur a
Page 294 and 295:
Table 8.1 QuickCam Astro-Imager Par
Page 296 and 297:
The Homemade Astronomer 287 image o
Page 298 and 299:
Figure 8.5 Plans for the Kratz char
Page 300 and 301:
The Homemade Astronomer 291 sily ma
Page 302 and 303:
The Homemade Astronomer 293 drawing
Page 304 and 305:
The Homemade Astronomer 295 Figure
Page 306 and 307:
The Homemade Astronomer 297 a 0.25-
Page 308 and 309:
The Homemade Astronomer 299 Once yo
Page 310 and 311:
The Homemade Astronomer 301 Figure
Page 312 and 313:
The Homemade Astronomer 303 as well
Page 314 and 315:
Table 8.7 Planet Blocker Parts List
Page 316 and 317:
The Homemade Astronomer 307 Table 8
Page 318 and 319:
The Homemade Astronomer 309 Dremel
Page 320 and 321:
Table 8.9 Crombie Observing Chair P
Page 322 and 323:
The Homemade Astronomer 313 back in
Page 324 and 325:
Figure 8.22 Plans for the Trott min
Page 326 and 327:
Figure 8.23 P.J. Anway’s Lookum O
Page 328 and 329:
Table 8.11 Lookum Observatory Parts
Page 330 and 331:
9 Till Death Do You Part If this we
Page 332 and 333:
Till Death Do You Part 323 Having a
Page 334 and 335:
Till Death Do You Part 325 Consult
Page 336 and 337:
Till Death Do You Part 327 Some clo
Page 338 and 339:
Till Death Do You Part 329 on a lar
Page 340 and 341:
Till Death Do You Part 331 houette
Page 342 and 343:
Till Death Do You Part 333 To learn
Page 344 and 345:
Till Death Do You Part 335 substant
Page 346 and 347:
Till Death Do You Part 337 in size
Page 348 and 349:
Till Death Do You Part 339 carton.
Page 350 and 351:
10 A Few Tricks of the Trade A tele
Page 352 and 353:
A Few Tricks of the Trade 343 To he
Page 354 and 355:
A Few Tricks of the Trade 345 well
Page 356 and 357:
A Few Tricks of the Trade 347 Figur
Page 358 and 359:
Table 10.1 (continued) Oregon Star
Page 360 and 361:
A Few Tricks of the Trade 351 the s
Page 362 and 363:
Tri M33 A Few Tricks of the Trade 3
Page 364 and 365:
A Few Tricks of the Trade 355 Polar
Page 366 and 367:
A Few Tricks of the Trade 357 even
Page 368 and 369:
A Few Tricks of the Trade 359 on th
Page 370 and 371:
A Few Tricks of the Trade 361 Altho
Page 372 and 373:
A Few Tricks of the Trade 363 on. I
Page 374 and 375:
A. Binoculars Appendix A Specs at a
Page 376 and 377:
Appendix A 367 Aper- Field of Exit
Page 378 and 379:
Appendix A 369 Aper- Field of Exit
Page 380 and 381:
Appendix A 371 Total Focal Tube Wei
Page 382 and 383:
Page 384 and 385:
Page 386 and 387:
Page 388 and 389:
Page 390 and 391:
Page 392 and 393:
Appendix B Eyepiece Marketplace Foc
Page 394 and 395:
Appendix B 385 Focal Apparent Compa
Page 396 and 397:
Page 398 and 399:
Page 400 and 401:
Appendix C The Astronomical Yellow
Page 402 and 403:
Campmor 810 Route 17 North, Paramus
Page 404 and 405:
Web site: http://www.dewshields.com
Page 406 and 407:
Product(s): Binoculars, reflectors,
Page 408 and 409:
Web site: http://www.starlight-xpre
Page 410 and 411:
United States Arizona Astronomy Sho
Page 412 and 413:
New Hampshire Rivers Camera Shop 45
Page 414 and 415:
Canada Alberta The Science Shop 316
Page 416 and 417:
Phone: 61-02-9211-1606 316 St. Paul
Page 418:
Appendix D An Astronomer’s Surviv
Page 421 and 422:
412 Star Ware Telescopes and Equipm
Page 423 and 424:
414 Star Ware Include the To Join,
Page 426 and 427:
Star Ware Reader Survey To help pre
Page 428:
Any particular likes or dislikes? (
Page 431 and 432:
422 Index D&G Optical refractors, 8
Page 433:
424 Index reflecting telescopes. Se
show all

Star Ware: The Amateur Astronomer's Guide to Choosing, Buying ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?