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    • CommentTimeDec 1st 2009
    en·vy (nv)
    n. pl. en·vies
    a. A feeling of discontent and resentment aroused by and in conjunction with desire for the possessions or qualities of another.
    b. The object of such feeling: Their new pool made them the envy of their neighbors.
    2. Obsolete Malevolence.
    tr.v. en·vied, en·vy·ing, en·vies
    1. To feel envy toward.
    2. To regard with envy.

    Now that that's done, I would like to know if there are any (other) amateur or professional astronomers out there.

    What is your favorite apochromatic refractor of under 5 inch aperture?
    • CommentAuthortinker
    • CommentTimeMay 7th 2010
    If you could manage 10" as the bishop said to the choirboy, here's a claimed spare Hubble mirror blank for $500. Happy grinding.

    Heh. If I could manage ten inches I'd go into the movie business. Or something.

    No, portability is a major concern, and I am asking about apochromatic refractors here specifically. Even 5 inches is too large, really; I need something in the 90-105 mm aperture range. I am considering the iOptron 108 mm but even that is a bit large (and expensive).
    • CommentAuthortinker
    • CommentTimeMay 7th 2010
    This is around $1000 ....skywatcher ed-pro. Tinker

    * Magnifications with Eyepieces Supplied: x45 & x180
    * Highest Practical Power (Potential): x250
    * Objective Lens Diameter: 100mm
    * Telescope Focal Length: 900mm (f/9)
    * Eyepieces Supplied: 5mm & 20mm LET* (*Long eye relief with Twist-up eyecups)
    * 9x50 Finderscope
    * 2” Star Diagonal
    * Supplied with Tube Rings
    * Dual-fit 1.25”/2” Crayford Focuser (Backlash-Free) With Brushed-Aluminium Hubs & rubber grip rings
    * Fully Multi-Coated Doublet Objective Lens
    * Single FPL-53 ED Fluorite Glass Objective Element

    Voted overall winner in group test of 4-inch Apochromatic refractors under 3000 pounds
    • CommentAuthortinker
    • CommentTimeMay 7th 2010

    Here's the page- towards the bottom. T.
    I like the specs. I think my local dealer stocks SkyWatcher, too. I'll check it out, thanks. The price is certainly attractive.
    • CommentTimeMay 15th 2010 edited

    Vega, through a Bahtinov focus mask, Celestron CCD imager, Registax processing from a stack of about 50 frames at 1/5 sec, ETX 125, 1900 mm f/15.

    Or a UFO exhaust pattern, one or the other.

    False color image, same as above.
    Very Nice..
    Also nice to see some new activity on your youtube page:
    • CommentAuthorthehard
    • CommentTimeMay 17th 2010
    That's the star from Contact, right?
    I don't remember. Vega, Alpha Lyrae, at the zenith around midnight in the US/Canada east this time of year. A blue giant, very bright, not likely to have terrestrial planets. The colors and fringes are from the Bahtinov focus mask; I thought they looked pretty so I photographed them. The star itself is...a star, pointlike or an overexposed disk.
    • CommentTimeMay 20th 2010 edited
    First light through the Meade DSI II cheapo CCD deep space imager.

    Object: Messier 5, a globular cluster; maybe a visitor from another galaxy, it almost certainly has a mid-size black hole at the center. Not visible to naked eye; barely visible as a faint smudge in my best eyepiece
    Telescope: Meade ETX125AT, a 125 mm Maksutov-Cassegrain, 1900 mm focal length, f/15, polar mount.
    Imager: Meade DSI II Pro monochrome CCD, Antares 0.5x focal reducer, Antares deep-sky nebula filter
    Exposure: 64 seconds, 16 x 4 sec, stacked and processed with Meade DSI Envisage, tweaked with Gimp; this shot selected from about 80 attempts, which resulted in 5 or 6 "keepers".
    Seeing conditions: Backyard Mississauga, bright moonlight and much light pollution

    • CommentTimeMay 20th 2010
    Very impressive in that seeing!
    • CommentTimeMay 20th 2010 edited

    We looked at the M5 image that was published in the "AstroStar Suite" software astronomy program that Meade distributes (and which is available for free download from their site)...and my little photo is actually a bit better than theirs !! In the opinion of my co-lunchers around here, anyway.
    My Mak reverses left and right, and I didn't think to flip this image while processing, so it will be a mirror image when compared to other more professional, or HST, shots of the object.

    I thought the seeing would be the limiting factor, but it turns out that my mount's tracking is the limiting reagent. The software requires one to select a bright spot on the image, for stacking registration of the multiple frames. With a 4-second exposure, most of the time all is well, but every so often the telescope's drive jerks a tiny bit to correct position in the Dec axis, and during that small slew the 4-second exposure is blurred, and the tracking box loses the tracking spot and subsequent frames -- even if not blurred -- aren't registered properly or are discarded. So the maximum exposure I can accumulate is about a minute.
    Still, this scope was never intended for long-duration astrophotography, so I am actually quite pleased with this result.

    But it looks like I'll have to be budgeting for a "real" tracking mount, like the iOptron MiniTower Pro, if I want to get real deep shots of dim objects like planetary nebulae, which are my real desired targets.
    This imager is monochrome, and has a filter slide, so a set of color filters and more stacking will allow me to build up full-color images, with one-minute total exposure on each of RGB and L channels. Should be interesting, if I can figure out how to do it.
    • CommentAuthorsonoboy
    • CommentTimeMay 20th 2010
    I've got a camp up in northern New England away from any lights. You never saw a sky so black and so many stars. Clouds of diamond dust.....
    I can count the stars that I can eyeball, from this backyard. Looks like about 2 dozen; I doubt if I can see anything dimmer than 3rd magnitude without aid.

    And buildings and trees block about a third or more of the sky. I've seen some dark skies -- I used to live in the Mojave desert -- but I haven't been to a dark site with this telescope yet.

    M5 is in a lucky spot for me this time of year. But I can't see Jupiter at all, the Eastern sky is blocked totally by the house. It will be August probably before Jupiter is high enough at night for me to see it from here.
    • CommentTimeMay 23rd 2010 edited
    Luna, Mare Serenitatis region, imaged on 20-21 May using the ETX125AT and the Meade LPI imager. This is the result of 27 stacked frames of about 0.03 seconds each.
    The Apollo 15 landing site is in the shadow of Mount Hadley, very near the feature that I call "the Jawbone", Palus Putridinis.
    Posidonius J is really named "Michael Jackson" !!

    • CommentTimeMay 23rd 2010
    Posted By: alsetalokinPosidonius J is really named "Michael Jackson" !!

    Gaak! I had to check, but you're right!
    • CommentAuthorsonoboy
    • CommentTimeMay 24th 2010
    I've got a cheapo 8 inch reflector as well as a 6 inch Maksutov. Now your giving me the itch again. Last time I looked at the moon it was really something. Pictures never do it justice...