Zeiss, Fujinon, Istar
Celestron Edge 8"
9/11- Never Forget.
Quote:I took apart the lens to see if it would fit in a Surplus Shed cell, they are same diameter. No luck, the Istar lens is an incredible 1.5" thick vs. the SS at just under an inch. The 3/4" thick ring to mate the cell to the 5" tube just ads to the front heaviness. Might polish and leave tube bare aluminum, they sure look rough as delivered.The blue haze decreased as the powers went up on Jupiter. At 250x there was very little blue, but the planet had a yellow-reddish cast that was faint but odd. Didn't seem to cloud out any details and I'm sure the scope will go above 300x when the atmosphere permits. When this next cold front passes will have to set it up next to the SS 5" just to see how much better it is than an ordinary achromat.Feel sorry for the guys on the east coast of usa, no end in sight from winter, enjoy!
Kmart 40mm-Thanks Mom|Jason60mm-Thanks Dad|C80SS-Thanks Wife|C90|C102|C6XLT|AP130EDFGT|C-11XLT EQ-2|EQ-3|CG5GT|Mach 1 & Eagle "For once you have tasted flight, you will walk the earth with your eyes turned skywards, for there you have been and there you will long to return".-Leonardo da Vinci "We're all in the gutter, but some of us are looking at the stars."-Oscar Wilde ~RIP Dad, you were my best friend...Godspeed!~
... and still the best wife I could wish for!
Quote:...but the planet had a yellow-reddish cast that was faint but odd.
ATM Nut.6" F15 Jaegers Refractor on Homebuilt EQ mount12.5" Homebuilt NewtProjects:16" F7.2 Reflector
Refractors Reflectors Two Cats A few eyepieces
7x35 and 10x50 sears tower binocs, 3" f/10 edmunds reflector, 2.4" f/11.7 manon refractor, 6" f/8 jaegers refractor, 10" f/11 R30 Istar refractor, 3" f/15.8 sans&streiffe refractor, 3.1" f/15 selsi refractor(towa 339), 2.4" f/15 sears refractor, selsi 30x30mm spyglass, criterion 5-draw 25x45x75x spyglass(1957), 4.25" f/14.8 tasco 20te.http://cleardarksky.com/c/OmahaNEkey.html
Quote:Not to be a negative nancy but I noticed the Istar 127 R30 OTA is about $2k. What would be the advantage of this scope in comparison to, let's say, an Explore Scientific 127apo?
Matt in Oz
Takahashi Mewlon 210 F11.5 = 2415mm
Takahashi TSA120 F7.5 (out on loan) = 900mm
Takahashi FC76CSV F7.5 = 570m
Takahashi FS60CB F5.9 = 355mm
Quote:That clears it up! So, the opposite...now the question...WHY? If planetary detail is mainly in the red/green channel as Roland confirms, why, why, why let the red go out?!?! The only reason to do so is to preserve star color information (blue)and grab up the visual primary of green I suppose...so technically, the standard c-f achromat is still going to perform better than this R30 lens for planetary. Let me ask it this way, what is the R30 supposed to accomplish, what is its virtue? Maybe that will make it crystal clear... Is it simply to reduce/eliminate the defocused blue CA one sees and trade it for defocused red which the eye is less sensitive to? To me, that tradeoff is not worth the price of giving up the red channel information if I use the lens for planetary. What am I missing?