Vixen 140mm Neo-achro, 2" AP Maxbright diagonal, 50mm Celestron Vixen Silvertop plossl, 35mm, 18mm, and 15mm Ultrascopic/Ultima, 28mm & 20mm ES 68, 19mm TV Panoptic, 5.5mm Meade UWA, 2.4x 2" Dakin barlow (prototype barrel).
APM 105/650 Travelling Visual Observer
Syed - Dob guy for sure Teeter STS 11 f/4.3 Zambuto | XT8i | XT8g | XLT 150 | C90 | EON 80mm
Ed Jones EQ Platform; AT Voyager and Nexstar SLT mountsEyepieces: Mostly TeleVue and PentaxDenk II BV'er, Earthwin PFS-SE, Pentax 10x50 PCF WP II
Quote: Sooooo, I'd like to get some general comments on this "process" and also see what people think about AFOV, eye relief, quality, etc.
Johnny FS152 15" Obsession Classic w/ 14.5" f/4.65 Zambuto
Quote:So being an ex-engineer and somewhat anal, I read everything I could on eyepiece optics, and of course I put all the spec's of all the EP's I could find on a spreadsheet, actually a worthwhile exercise I think. The result is a "lot" of variables in terms of focal length, AFOV, eye relief and cost, not to mention the actual quality of the products that can only be appreciated by reading reviews or testing yourself.
Jeff Morgan - Wile E. Coyote School of Telescope Making
Quote:Quote:So being an ex-engineer and somewhat anal, I read everything I could on eyepiece optics, and of course I put all the spec's of all the EP's I could find on a spreadsheet, actually a worthwhile exercise I think. The result is a "lot" of variables in terms of focal length, AFOV, eye relief and cost, not to mention the actual quality of the products that can only be appreciated by reading reviews or testing yourself. If you have not already read it, I would highly recommend "Visual Astronomy of the Deep Sky" by Roger Clark (out of print but still available on Amazon). It is the classic in the field and covers the scientific research on human visual response under low light (astronomy) conditions. AFAIK, it is the only science-based approach to choosing your eyepieces. And it will definitely save you a bunch of money on redundant purchases.
MarkEON 80 - Twilight 2 | C11 - iEQ45 | Astro Physics 175EDF - 900GTO | Powered by Televue
My eyepieces are made from the waste product of exploding stars.
10XTi 102XLT ST80A(2" Focuser); President, Eypieces Anonymous, Denver Chapter (Hello, I'm an eyepiece junky, what's your excuse?)
DAS Dark Site
The opinions expressed herein are solely mine as an amateur astronomer hobbyist & consumer. Information herein was correlated from experience, discussions with others, & research from multiple sources freely available at time of posting. All reasonable care & skill was used, but no warranty is made as to accuracy, & liability cannot be accepted for errors/omissions. This is for information only and not intended nor implied to be a substitute for professional advice.
17.5" Dob "Beta Version"
NP 127 on a CG-5 and CGEM DX
25x100 and assorted other binos
Naglers, Ethos and various others.
Quote:There are a couple of ways to go. Frankly though, being new to it all and if you are not that short on funds, then I think it is a good idea to get a set of EPs to get your feet wet, that later in a few years you will replace once you discover your real likes and dislikes. So without breaking the bank at all, a 5mm, 8mm, and 13mm Hyperions will nicely satisfy the higher magnifications and give you a comfortable 20mm eye relief so you can keep the glasses on. And these three will cost you about $420 total new. So about the cost of a single expensive eyepiece you were figuring. A top line recommendation would be a 5, 7, 10 XW or 6, 8, 12 Delos, but these three new will set you back $840-$1200!! And if it ends up after a year you think you really like 82 degree or 100 degree eyepieces with shorter eye relief then you are not out so much cash.After the 5mm, 8mm, and 13mm Hyperions, I would go with a Explore Scientific 28mm 68 degree series (21mm eye relief and $150).These 4 should provide some very satisfying viewing. Only thing missing would be a maximum TFOV eyepiece. The 28mm ES68 will get you about 1.5 degrees TFOV. You could get about 2.2 degrees with a 40mm eyepiece with a 68-70 deg AFOV. So if you wanted to add a 5th max TFOV EP to the stall instead of waiting, then could get a 40mm Titan-II ED for around $160.So the lesser price but 80-90% of performance of the premiums would be:5mm, 8mm, 13mm Hyperion ($420)28mm ES68 ($150)40mm Titan-II ED ($160) - Optional as you may be able to live without this just fine.Total Price - $720 (or $560 without the 40mm)Move this to a premium level and you get something like:5mm, 7mm, 10mm Pentax XW ($840)17.3mm Delos ($335)26mm Nagler T5 ($655 - and gets you "near" max TFOV)So total for the premium lineup is $1,830.If it were me, and I was not so strapped that I can afford to experiment, I would go with the lower priced lineup as it is really quite good performers, gets you nice wide fields, and good eye relief. Then after a few years...and possibly a new scope, you will know you likes and dislikes better and move up as needed.
Quote:Linux,You are on the right track, but there is no need to jump in the deep end! I would recommend to start with a basic set of three or four eyepieces and then build on that. Maybe around 6, 12 and 30mm focal lengths (exit pupil about 1,2,5). Russell's recommendations above are good. Looking to the future, if you get a larger scope it will have a faster mirror which will be more demanding of your eyepiece. If you do this, I'd recommend getting the better eyepieces now rather than needing to upgrade eyepieces as well. Hermie
14" Strut; 10"XT; 102ES; 22 in Process; 3.5,5,7,10,14,20mm Pentax XW; 17.3 & 12mm Delos; 27mm Panoptic; 20&24mm ES 68; 24mm ES 82; 30mm ES 82; 6&10mm BCO;
Quote:Please correct me if I am wrong, but doesn't Clark's results support the idea of having many eyepieces of focal lengths close together attempting to find the exact magnification that produces the optimum size of the object? It goes against having just three or four eyepieces and encourages eyepiece choices that differ by very small differences in focal lengths meaning an observer would have to have seven or more focal lengths at minimum.