Recently Browsing 0 members
No registered users viewing this page.
Hi, Just wondering whether collimation is necessary on a smaller Telescope like mine (https://www.astroshop.eu/telescopes/skywatcher-telescope-n-76-700-astrolux-az-1/p,5010#tab_bar_1_select)? If so, how often do you need to do it, and how do you know when it needs doing? Any other tips on how to do it are welcome.
Note: This scope is in the USA, so international shipping may prohibit a sale. However, without the heavy Scopeguard case the shipping cost will be substantially reduced.
I can provide a full frame image taken with this scope if anyone is interested.
Reduced to £3155 for the complete package. I will consider offers, but this is already close to my bottom price.
I’ve decided to sell my Takahashi Epsilon Ɛ-180. The scope and optics are in good cosmetic and optical shape. There are a few minor tool marks around the collimation screws but otherwise no issues. The primary mirror is centered with a Catseye Hotspot.
The scope will come with the Takahashi corrector, rings and top plate ($457 add-on), front cover, Scopeguard case ($500 add-on), BT Technologies dovetail bar ($150 add-on) (has a blemish but is super solid), Astrozap dew shield and cap with focus mask ($175 ad-on), Precise Parts Tak corrector to M48 adapter ($110 add-on), the Takahashi collimation tools, an M68x1 male to M54x0.75 female and a M54x0.75 male to 2" compression ring adapter ($100? add-on) (these allow you to use the scope visually with 2" eyepieces.)
I replaced the stock focuser (included) with an Optec TCF-Leo focuser with temp probe. With the included scope adapter and Tak corrector adapter this is a $1400 add-on.
Total new cost = £5900
All of this for £3155 plus shipping.
I am thinking on grinding my own lightweight mirror (first f4 16", later f4 24"). The lightest and cheapest option is to get a thin blank and slump it in a decent kiln.
Anyone has longer term experiene with slumped mirrors? Overall doesn't seem to be more work than a normal (not pregenerated) blank.
Do I have to grind the backside as in case of normal flat back mirrors to avoid astigmatism? How do people support a convex back while grinding? Does it make sense to grind a hole in the middle for additional support? I am remotely considering a convertible Newtonian/Cassegrain system anyway...
By Kevin Francis
Purchased the Orion Astroview 6 three years ago. Found out later that I could not attach my Canon EOS XTi and obtain focus. Everything I saw online required sawing and drilling the OTA. That makes the scope a single purpose telescope. After reviewing the primary mirror holder I created a holder that moved the mirror 25 mm. This way I can keep the scope ready for visual observing and sell later if I desire. If you're interested in saving a few dollars in this hobby check out the link below.
How I Moved Prime Focus: Link to the detail.
Photo from this telescope
So I picked up a classic... a 1970's - 80's edmund optics f6 150mm newtonian...
... like this one but mine has a different mount. It was cheap. Very good condition. The focuser is pants. The mechanics of the secondary holder is (IMHO) brilliant and apparently the primary is 1/10th wave.
But its f6 and I trhink I'd rather swap it out for a faster synta f5 mirror. . The thing is its a one shot job bc to make the f5 mirror work I will have to saw off a good few cm from the barrel of the scope.
So the question is: Is a high quality f6 mirror better than a faster synta f5 mirror for wide deep space astrophotograhy?
All comments gratefully received. 😉