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Alan64

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Everything posted by Alan64

  1. The 8mm and 12mm of said brand are said to be the best; or, the most popular at least. As you go up in power, the telescope has to work harder. If the primary-mirror is well-figured, and the entire optical system is well-collimated, you can, in theory, reach 400x on nights of better-than-average seeing conditions, especially on the Moon. Most nights, however, 200x is going to be about the practical limit. But there will be those special nights now and again.
  2. You can compare a Schmidt only to a Newtonian, never a refractor. A Maksutov is the only reflective design that has been described as "refractor like". The only short 100mm-ish refractor that would possess the apochromaticism of a reflector would be an f/6 triplet-apochromat; for example... https://www.firstlightoptics.com/esprit-professional-refractors/skywatcher-esprit-ed-100-pro-triplet.html
  3. There is the option of a 127mm Maksutov. It would have quite a long focal-length, generally the longest of all other designs per millimeter of aperture, therefore go-to is almost essential for ease in aiming it. Otherwise, upon a manual mount, you could add a 8x50 or 9x50 finderscope as a "seeing-eye dog" for it... Go-to... https://www.firstlightoptics.com/maksutov/sky-watcher-skymax-127-az-gti.html Manual... https://www.firstlightoptics.com/maksutov/sky-watcher-skymax-127-az5-deluxe.html The Maksutov-Cassegrain has been described as "refractor like", in image sharpness and contrast, and the only one among all the types of reflector telescopes so compared.
  4. When you receive the zoom, eventually you may hear it rattle a little. This is normal, for current zoom-oculars at least. The Celestron is priced a bit higher there in the UK, but both are the same, and down to their capsule-like cases... Here in the U.S., both are priced equally, and with the Celestron on sale at present for less; no rhyme nor reason. You did quite well, especially in avoiding a no-name 7-21mm version. Those aren't quite as good, reportedly.
  5. In my experience, only discounts of 15% and greater are worthwhile, and that's not going to happen with any astronomical-equipment vendor on the planet. But no matter; no, not at all, as we are presently enjoying the lowest prices in this, the short history of commercial astronomy, and thanks to China. I got this factory 2nd recently: a 90mm f/10 achromat... ...and for only £50. True, it had a sheared-off thumbscrew for the finder's bracket upon its arrival... But that was the only real issue, and the seller sent a replacement after I had sent them that image. Afterwards, I blackened and flocked it throughout, and replaced the doublet's spacers even... 90mm of unobstructed aperture is a wonder-glass under darker skies. My experience goes to show that, beyond discounts, there are great bargains to be had; if you know where to look.
  6. Synta(Sky-Watcher, Celestron, Orion of California, Saxon) does make a 1.25" star-prism, the Celestron #94115-A, and that's about as good as they can do. Mirrors are much easier for Synta to produce, especially in the 2" format, and are therefore more profitable.
  7. You can't beat a fine refractor, and for the sharpest and most contrasty images.... https://www.altairastro.com/Starwave-102ED-FPL53-Refractor.html That one comes with a no-nonsense, tried-and-true rack-and-pinion focusser. It is also an FPL-53 doublet, which would acclimate to the outdoor conditions almost immediately, and ready to ramp up the power. A Maksutov takes about an hour. Maksutovs have been described as "refractor like" in the quality of the images, and the only reflective design so described. In any event, a Maksutov is almost there in that regard, quite close at times, but not quite to the same level in the end. This one is of a practically identical configuration, but with an FPL-51 doublet instead... https://www.teleskop-express.de/shop/product_info.php/info/p4964_TS-Optics-ED-102mm-f-7-Refractor-Telescope-with-2-5--R-P-focuser.html Then there is this 110mm f/7, with a 10mm increase in aperture... https://www.altairastro.com/Starwave-110ED-Refractor-Telescope-RP-Geared-Focuser.html In "refractorland", every single, extra millimeter counts. As for a mount, you could go with a manual alt-azimuth for visual... https://www.firstlightoptics.com/alt-azimuth.html Or, you could get this equatorial now with a single-motor drive for the RA-axis, for automatic tracking, and for visual, but also perhaps for a bit of dabbling with a camera... https://www.firstlightoptics.com/skywatcher-mounts/skywatcher-eq5-deluxe.html https://www.firstlightoptics.com/sky-watcher-mount-accessories/single-axis-dc-motor-drive-for-eq5.html ...and upgrade the mount with a go-to kit in future, when you're ready. I have a 102mm f/8 fluorite doublet... ...and I like to observe the Moon, too...
  8. This is a rather versatile go-to mount, and can be used in manual mode as well in the event of battery/motor/computer failures; perish the thought... https://www.firstlightoptics.com/alt-azimuth/sky-watcher-star-discovery-wifi-az-goto-mount-tripod.html Every house begins with a foundation, as does a customised telescope kit, and tailored to the user. The next step: what sort of glass shall I place upon it? This ready-made kit includes that go-to mount, and a 150mm f/5 Newtonian... https://www.firstlightoptics.com/reflectors/sky-watcher-star-discovery-150i.html Newtonians require the most work in keeping their optical-systems aligned, collimated; and for sharp, pleasing images throughout the range of magnifications. In return, however, you get the most aperture for the least amount of expenditure. A 150mm f/5 Newtonian is most versatile, in observing the gamut, most everything in the sky, from a low 23x, to 200x and beyond with the aid of 2x and 3x barlows. It's the closest one may come to an all-rounder; a "jack of all trades". I know, as I have one myself; many of us do... The Newtonian of that kit however, to save weight and in being less of a burden upon the mount, is of mostly plastic, yet still quite capable. Another telescope, at or near the stated budget, that might be placed upon the mount is a Maksutov-Cassegrain... https://www.firstlightoptics.com/maksutov/skywatcher-skymax-127-ota.html That one would require less work to maintain, and is designed for the upper range of magnifications; medium-to-high powers. Inexpensive eyepieces, including the wide-angled, would play very well with that design of telescope. Low-power, wide-field views would not be possible with that one however. Although, in future, if such is desired, a short refractor can take care of that aspect of observing... https://www.firstlightoptics.com/startravel/skywatcher-startravel-102t-ota.html That one, however, would not be suitable for viewing brighter objects, only the dim and dimmer of sprites, deep-sky objects and vistas; and due to chromatic-aberration, or false-colour. Refractors require virtually no maintenance at all. They are the least work-intensive of the designs of telescopes -- although I prefer to take them apart, blackening and flocking them throughout, and for improved contrast. This customised kit would require virtually no maintenance, no batteries; just you, the kit, and the sky above... The foundation... https://www.firstlightoptics.com/alt-azimuth/skywatcher-az4-alt-az-mount.html The glass... https://www.teleskop-express.de/shop/product_info.php/info/p2684_Skywatcher-Evostar-102---102-1000mm-Refracor---optical-Tube.html I would've listed a UK vendor for that one, but for some curious reason or other, no one offers it as an OTA. The three daughters(U.S., Canada, and Australia) can get the same OTA, made by Synta... ...but the mother cannot.
  9. Yes, I've seen that older Meade before. It was only after I had gotten my Meade that I discovered that it's identical to the Celestron, save for the silk-screening. The current Meade does have a better focal-length scale.
  10. Later on today I will lightly buff the parts out with #0000 steel-wool and lemon-oil.
  11. Yes, a zoom-ocular is versatile, and serves as a teaching tool in helping to decide upon a set of dedicated eyepieces in future... https://www.365astronomy.com/8-24MM-Synta-Zoom-Eyepiece.html Next up in price, the Meade... https://www.rothervalleyoptics.co.uk/meade-series-4000-8-24mm-zoom-eyepiece-125.html I have that one, and chose it over the ubiquitous Celestron after careful research... I haven't used it much, but it does perform quite well, for a zoom.
  12. Your telescope has a focal-length of 1500mm. That length will play quite well with the 4mm-to-40mm eyepiece range. If you're only able to get one ocular, you'll need to compromise, say 100x... 1500mm ÷ 100x = a 15mm eyepiece... https://www.firstlightoptics.com/bst-starguider-eyepieces/bst-starguider-60-15mm-ed-eyepiece.html
  13. The components were removed from their hangers, lightly-sanded with 220-grit paper, reattached to the hangers, and then the second and final coat applied... 35° F(1.7° C) outside it is, so back into the bog they went.
  14. Barring an older, long-focus refractor... https://www.cloudynights.com/uploads/monthly_06_2014/post-203511-14074310658996.jpg ...the next best thing would be a 127mm Maksutov-Cassegrain. Maksutovs have been described as being "refractor like", in contrast and sharpness, which is ideal for viewing the Moon, the planets, the double-stars(the splittings of same), and at the higher powers. That long-focus refractor is then reduced down to a short, compact tube... https://www.firstlightoptics.com/maksutov.html Besides the kits listed therein, I would choose this OTA... https://www.firstlightoptics.com/maksutov/skywatcher-skymax-127-ota.html ...and then to mount upon this... https://www.firstlightoptics.com/skywatcher-mounts/skywatcher-eq5-deluxe.html You don't really need go-to to find the Moon and the brighter planets, and you can motorise the mount to automatically track, hands-free; just the RA-axis... https://www.firstlightoptics.com/sky-watcher-mount-accessories/single-axis-dc-motor-drive-for-eq5.html There is also a go-to kit for that mount, and as a future consideration. If you'd prefer a lighter mount, and with go-to... https://www.firstlightoptics.com/all-mounts-motors/sky-watcher-star-discovery-wifi-az-goto-mount-tripod.html Either of those combinations would make for a first-rate kit.
  15. The first coat of urethane has been applied...
  16. I use barlows with my 150mm f/5... Those two Antares, a 2x and 3x, have blown me away... https://www.rothervalleyoptics.co.uk/antares-x2-achromat-fmc-barlow-lens-125.html https://www.rothervalleyoptics.co.uk/antares-x3-achromat-fmc-barlow-lens-125.html If you had seen what I had seen through my own, you would already have them. I have the Vixen NPL 30mm, and as recommended to me by our Mr. Huntley... I'm not one much for low-power observations, but otherwise it's quite the looker.
  17. Getting ready to apply the first coat of urethane. I can't do it outside, as it's much too cold... When I did the legs, I had a few relatively warm days then.
  18. Given the focal-ratio, f/7.5, you could make good use of a star-prism diagonal... https://www.altairastro.com/Altair-2inch-Positive-Lock-90-Degree-Prism-Diagonal.html That one should be the same as this one... https://www.apm-telescopes.de/en/optical-accessories/stardiagonal-mirror--prism/apm-2-inch-diagonalprism-fast-lock-ultra-broadband-coating.html I don't know how well it would play, however, with 2" oculars of the longest focal-lengths, 32mm and longer.
  19. You had asked the same within a PM. I've replied to you there.
  20. Agena Astro, in California, offers a collimation-cap, and with every item they sell with free shipping... https://agenaastro.com/rigel-systems-aline-telescope-alignment-eyepiece.html The collapsible's tube would need to be sealed, with a shroud I imagine, then a white cloth or other over the opening at the front. Then, a lamp in front of that to illuminate the telescope's interior... It is then that the entire optical system can be seen, although I use a small camera to zoom in and snap a shot. It's all there within this image, and with the collimation thrown out slightly to illustrate and describe... 1. The hole in the center of the cap, and through which the image was taken with a camera 2. The center-spot of the primary-mirror 3. The reflective underside of the cap 4. The silhouette, or shadow, of the secondary-mirror 5. The secondary-assembly's spider-vanes; nasty things those are. 6. The reflective surface of the primary-mirror; all of the white area in fact 7. The primary-mirror's clips; all three, or however many, should be visible, and evenly. 8. The interior of the drawtube
  21. There's nothing like receiving a package from the UK, like that time I had sent a sample of questionable tea to Twinings, its having been packed here in the States, whereupon they discovered that it had indeed been adulterated. They then, much to my surprise, sent me a box of several different flavoured teas of theirs that were absolutely wonderful, whilst they lasted. I don't think I'll ever receive anything that nice again... https://www.firstlightoptics.com/other-collimation-tools/premium-cheshire-collimating-eyepiece.html That's the best Cheshire in the world, at present, although not due to its anodised colour; but that does make it a bit special nonetheless. You won't misplace it. If you want to give another one of these a try, there's something you should know about them... They're improved now, and with a triplet-lens, for a tighter dot... https://www.ebay.com/itm/1-25-SVBONY-7-Bright-Level-Next-Generation-Laser-Collimator-for-Astro-Telescope/263812604382?hash=item3d6c74e1de:g:zHsAAOSw3vFbWh6T:rk:2:pf:0 But, as with all entry-level laser-collimators, it will most likely require collimation, and before it's used to collimate the telescope... https://www.youtube.com/watch?v=5ZsgNlgIrqQ When you have trouble with slop, with a telescope's visual-back, you shim it. For example, I have this focusser, but it's not a 1.25", a 1.26" instead... That's a shim of .005"-thick PVC... https://www.ebay.com/itm/Midwest-Products-70406-Blue-PVC-Sheets-005-x-7-6-x-11-4-sheets-/183636053625?_trksid=p2385738.m4383.l4275.c10#shpCntId#shId https://www.hobbylobby.com/Crafts-Hobbies/Hobbies-Collecting/Tools-Blades/Brass-Sheet---0.005"/p/21620 You get the idea. If in a pinch, a layer or two of clear packing tape will serve. However, you may need a shim that's thicker, I do not know. In that event, and if you don't have one already, get one of these calipers. I have one myself, and I wouldn't be without it when working with my telescopes... https://www.harborfreight.com/6-in-digital-caliper-61585.html That would enable you to determine the exact deviation from the norm, then to shim accordingly.
  22. The components have now been stained, although not yet sealed... I can't wait to see them after they're urethaned.
  23. The hunting of comets requires a wide field-of-view, the widest possible, and at the lower if not the lowest of powers. An f/5 refractor is ideal for that very thing. Somewhat recently, I had my 80mm f/6 out observing Comet Wirtenan... Over the course of time, fifteen to thirty minutes, I was able to notice the comet's movement in relation to other objects nearby, and quite close to the comet those were, thereby making the detection that much easier. All in all, not a bad show, not at all. A 200mm f/2.4 achromat would've been far better, of course, if such were possible; ever hopeful I am in that fantasy. The f/5 achromat in question, an "ST80" I believe, comes with a 1.25" focusser. A 32mm Plossl would provide the lowest power(12.5x) and the widest view practical. 80mm f/5 achromats are routinely re-fitted by amateurs with 2" focussers, for this purpose and that. This one from China appears to be viable, and with a 78mm threaded interface; naturally, a bit of DIY work is to be expected in its integration... https://www.ebay.com/itm/New-2-Manual-Gear-Focusing-Focuser-for-Refraction-Astronomy-Telescope/323419115167?hash=item4b4d480e9f:g:PwsAAMXQDK1RtT2P:rk:27:pf:0&shqty=1#shId I changed the country to "United Kingdom", then selected "Get Rates": £54, and with free shipping. However, it would be for the user to decide if the effort would be worth the while. To wit, a view of the Moon with an 80mm f/5 achromat, a 1.25" 32mm 52° Plossl, and a 2" 32mm 70­° wide-angle ocular... https://goo.gl/fCQkdG Then, if the views through the achromat have been beyond satisfactory, that is, if the achromatic doublet is of an above-average figurement and polish, then it would most certainly be worth the while to upgrade it. If the level of quality of the doublet is presently unknown, get the power up to 150x or greater, aim it at the Trapezium within Orion, for one, and note the thinness of the first-diffraction rings of the brightest stars. You want them as razor-sharp as possible, and the atmospheric seeing is to be at least good, or better. If said upgrade is not possible or practical, a 32mm Plossl does, after all, offer a reasonably wide field-of-view. Although, I would not suggest spending a lot on a 1.25" mirrored star-diagonal, if you're going to stick with the 1.25" focusser. You may, however, want better, a dielectric, and for the specialised purpose at hand.
  24. All of the components received their final sanding with 150-grit paper, and then wiped down with 91% rubbing-alcohol... Staining and sealing during the winter is not the easiest thing to accomplish, but done it must be. The only place where I can get it done, is within that smallest of rooms within a home, and with the ventilation-fan running.
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