Image of the day

Captured by
Douglas Rollain

M20 Trifid Nebula in LRGBHa

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Posts Made By: Thomas Dey

September 4, 2015 07:18 PM Forum: CCD Imaging and Processing/Deep Sky

12 panel Milky Way mosaic

Posted By Thomas Dey
Hi Rolando. Rod's comment got me laughing out loud. Magnificent as always. And I LOVE the aesthetics of non-color format. I did ambitious astrophotos back in the film days to mental and physical exhaustion. Now I only dabble with digital and do mostly visual ... returned to my roots. But I LOVE to savor and admire work like yours. Thanks for sharing! Tom Dey

September 9, 2015 03:34 AM Forum: Refractors

AP130 GT and flared stars....

Posted By Thomas Dey
Hi Greg! Your post piqued my interest because I live nearby (Springwater, NY), am interested in getting a good refractor, into physiological optics and researched 15 Star Diagonals - including your make and model! Here are (images of) 3 pages from the report, including page 23 that gives the results for the AP MaxBright...superb. But I would indeed suspect that any diag that gets disassembled and put back together back can indeed risk stressing of the mirror...which usually results in (severe) astig. Anyway - here are the 3 pages. I can send you the whole thing on a CD or DVD. My papers tend to be big files because the images are usually high-res. To any readers: I've got dozens/scores of informal papers like this e.g., but they tend to be lengthy and technical so I haven't submitted to the ATM/avocational Astronomy community. Tom Dey (Thomas Dey)

September 9, 2015 03:35 AM Forum: Refractors

AP130 GT and flared stars....

Posted By Thomas Dey
page 23

September 9, 2015 03:36 AM Forum: Refractors

AP130 GT and flared stars....

Posted By Thomas Dey
page 32

September 10, 2015 01:12 AM Forum: Telescope Making

1974 Cave Mount Worm Drive Problems

Posted By Thomas Dey
Hi Michael! Is your scope well-balanced in all orientations? I had (the same?) make and model mount with a 12.5 Astrola on it that I did a LOT of refurb on. I got it for near nothing ($1800) about 35 years ago and put another $3000 into it. The drive was indeed junky: very COARSE pitch on the gears and terrible tracking even with perfect polar align. Dec tangent arm same problem - poorly designed and hopeless backlash. Anyway, I replaced the RA with a Byers 11 3/8 Sidereal and drove that thru a freq box and replaced the Dec with a tangent arm of my own design and build. Those I automated thru the SBIG ST4 tracker that had just come out. Long story short: Tracking went from frustrating to perfect! I tracked on off-axis star at 2200mm and it just locked on like a bulldog for hours on end! Imaging at 1900mm with no smear at all. Back then film was still king so continuous exposure times were 2-4 hours! Your scope: If you are determined to keep it Stock - would need to have the gears worked/lapped? and it still won't work very well. If it's function you want --- replacing the RA drive and tangent arm would make sense. PS The RA and Dec bearings were excellent on mine - silky smooth and true. I never touched them - hope that's true of yours. Good luck with your project! Tom Dey

September 13, 2015 03:00 AM Forum: CCD Imaging and Processing/Deep Sky

Andromeda Galaxy in narrowband

Posted By Thomas Dey
Beautiful! Amazing what the narrowband can do. And your rendition also captures the "milky" affect that I get visually with a big scope under decent skies.

September 13, 2015 11:47 AM Forum: Equipment Talk

collimating a Maksutov

Posted By Thomas Dey
If it's relatively sharp against the diffraction ring and convolves across it as you tease pointing --- I'm thinking the roof in a prism close to the image. Are you using a prism in front of the eyepiece? If so - that's it and would be benign/go away when you are AT best focus. You can also tell by just looking in without an eyepiece against a bright sky or wall. and you will see a skinny little line bisecting the field. Or look in thru the front of the scope for that line. Let us know! Tom Dey

September 13, 2015 10:36 PM Forum: APM

APM for Exoplanet Search

Posted By Thomas Dey
Hi Markus, Fascinating! Couple decades ago we needed field AND res for some aerospace application and I suggested a "Fly's Eye" matrix of cams with overlapping fields. The other engineers kept trying to design single lens that got very ugly, very fast, very $$$! Now the sensible parquet is used successfully. Granted, software makes the stitching much easier. Beautiful instrument AND indeed $400K for the mount seems a real bargain to me! Other advantage is 1 or 2 spare cams/lenses can keep the whole thing up and running even if one module needs servicing. Very Cool! Glad to see you/they are using FLI focusers - FLI is right down the street from me. Tom Dey

September 15, 2015 09:02 AM Forum: AstroMart FAQ

Fraud ?

Posted By Thomas Dey
I thought the same thing for many reasons. Could be wrong...but sure looks fishy.

September 16, 2015 03:31 AM Forum: CCD Imaging and Processing/Deep Sky

NGC7822

Posted By Thomas Dey
It's a Gas! - Very nice indeed. Maybe a blush of plasma mixed in else we wouldn't see it!? I wonder what % of the atoms/molecules are ionized. I'll bet it's generally miniscule except for superactive regions. Lota stuff out there. Thanx for sharing. Tom

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