Hi All. I am new to the group. I am looking into the purchase of a low end refractor and would appreciate your advice. I would Like feedback and opinions on...
The CR6, the Orion 120, the Meade AR5 and AR6 can all be fine scopes with a little tweaking. The CR6 and AR6 will most likely have a little more false color...
Here is my image of M86 and surrounding galaxies: http://home.att.net/~dpersyk/new.htm Finder maps from SkyMap Pro included. Kepple and Sanner ("The Night Sky...
Hi Johnny, Achromatic refractors are not the best choice for imaging, especially with a one-shot color camera. It will be difficult, if not impossible, to...
Tim; Most early large refractors used wood tubes. Examples include the Dorpat refractor from the 1820's and the 15" Harvard refractor from the 1840's. These...
I cannot find the image of M66. When I click the link I end up with an image titled "M86 et al.", and although beautiful, it is not have much coulour. Looking...
Hello Heinz, The image was on my New Images page which gets updated every week or so as I take new images. Sorry you missed M66. Now there is a comet movie on...
Comet movie (dial-up modem-friendly), images and supporting data at http://home.att.net/~dpersyk/new.htm New comet C/2005 K2 LINEAR was discovered on May 19th...
It wasn't too long ago that I read somewhere in which someone wrote ;-) that if it were for the efforts of Roland Christen and Al Nagler (referring to their...
... Sounds great Bill ;-). Indeed, 'em "dinosaurs" have been coming more and more alive each year. The more choices, the more chosing ;-). Ron B[ee]...
I've recently read that at some point Takahashi switched from calcium fluorite to ED glass for their objective lenses in their doublets. Apparently one can...
Could very well be that the short Apos have helped revive the refractor in popularity, at least in the smaller sizes. Due to price however they are at the...
... If I remember the ads correctly they also claimed in the early/mid '90s that a 100mm Tak fluorite telescope would give an image as bright as a or 140mm ED ...
rnapo
rnapo@...
Jun 11, 2005 9:24 am
14676
There always seem to be a market for high end cars, boats, country club memberships, etc. I think there will continue to be a market for fine telescopes ...
rnapo
rnapo@...
Jun 11, 2005 9:32 am
14677
... Texas Nautical, Takahashi Japan, and the Takahashi literature claim genuine Calcium Fluorite crystal is used in the front element of the FS series...
Rich, You did the comparison wrong, you were supposed to leave the lens cap on the AP :o) Ed T. ... early/mid '90s that ... 140mm ED ... an AP 130mm ... ...
Tom, Thanks for the reply. I know the official word is emphatic about the use of CaF, but doubts persist so I became curious about where the truth really...
The Tak FS refractors are outstanding. I just don't understand their marketing given the speed and depth of the net. I guess Tak made their name with...
rnapo
rnapo@...
Jun 11, 2005 5:13 pm
14681
Correction: The reference to Optec should be "Optron". Sorry. Ed T....
Rich; Most marketing includes a large qualtity of BS. It seems to go with the type of personality attracted to the job. Few marketing types seem to get into...
... of the ED glasses. I have noted in the TEC line that the Flourite versions of their triplet scopes can be made about 1 F number faster than the ED versions...
Hi Rich, We were talking about the Tak FS series and if it really is CaF. FPL 53 has virtually the same dispersion index as CaF. If the TEC fluorite is so...
rnapo
rnapo@...
Jun 11, 2005 6:13 pm
14685
Hi Roland, I assume you are referring only to the 200mm ED? My TEC 140 manual states that its glass is FPL53. NL...
Here are the dispersion index numbers for three popular ED/fluoro glass types and Fluorite. Numbers kindly supplied by Thomas Back several years ago FPL-51 =...
rnapo
rnapo@...
Jun 11, 2005 6:33 pm
14687
... Yes, I was referring to the 200. The reaon it is F9 and not something faster is because this ED would have extreme internal curvatures at F7, with...
... We are giving our customers two choices one with ED: glasses APO140/7, APO160/8, APO200/9; and Fluoritres APO160/7 and APo200/7 for this year and APO180/7...
... We should devide designs here on two categories: oil spased and airspased, in last one designer has more freedom to get better color correction, but how...
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