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Astro-Physics 1200GTO / APM 16" f/10 Mak-Cass / Takahashi FC-125 This is the primary observatory "stack". The bulk of my observations are done with the 16", while the 5" Takahashi doublet fills in for wider-field work. I also use the FC-125 to evaluate the seeing*. The Mak-Cass houses Intes-Micro optics in a custom Mattias Wirth tube. The primary is fixed, with focusing done by a 5" travel, 3" Van Slyke Crayford focuser. * The Pickering seeing scale, devised by William Pickering (1858-1938), is based on the view through a 5" refractor. |
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Eyepieces and Accessories¹ On the right are my widefields, which I use pretty much exclusively for deep sky observing: s4000 6.7 & 8.8UWA, 12 & 17T4, 26T5 and 36T9². On the left are my bino pairs, used for planetary viewing: AP SPLs in 10 & 12, TV Plossls in 15, Pentax SMC orthos in 18, and CZJ orthos in 25. (The somewhat dated picture shows RKEs in place of the CZJ orthos.) The center compartment holds my Baader MkV binoviewer, a 55mm TV Plossl, and my filters (Lumicon DeepSky, UHC, OIII and Hbeta). Underneath are some planeary filters and an illuminated reticle, none of which I use often. (Again, the picture is somewhat old and shows my Denkmeier binoviewer.) |
1. The case was made for me by Roy Hess of AstroWood. I've installed some dew-heater strips inside under the trays to keep the eyepieces a bit above ambient to retard eyeball fogging (and to reduce the humidity inside the case). (See Heated Eyepiece Case for details.) 2. The 36T9 is a 31T5 with an Astro-Physics CCD telecompressor screwed into the barrel. |
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Astro-Physics 600EGTO / Takahashi Mewlon 250 I keep this scope at our condo in Breckenridge, CO, and it is normally used at about 11,000' under dark, pristine skies. While most people wouldn't consider Colorado to be much of a "southern sky" site, it beats the hell out of Rokeby Observatory's 54°N. I use a slightly different set of widefields in Colorado to save funds and reduce the amount of equipment I have to lug around: 9T1, 12 & 17T4, UO 32Mk80. My site is not blessed with terribly good seeing, so I don't employ a bino setup for planetary there. |
| I machined a custom adapter to mount the Takahashi "hockey puck" clamp to the AP600E. (See Custom Mewlon Adapter for details.) Like the bigger observatory scope, the Mewlon also has a rotator and focuser mounted on the back. The Mewlon is, however, a bit tight on back-focus in this configuration. (See Mewlon Backfocus for details.) |
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Astro-Physics 400QMD / Solarscope SF70 / Tele Vue Pronto This is my current solar setup. The SF70 is an "old school" sub-0.7 angstom H-alpha Fabry-Perot etalon. I use it mounted on a TV Pronto with an AP Barcon and AP/Baader glasspath compensator to bring the focal length up to 1610mm. Most of my observing makes use of 19mm Panoptics (for 85X), with occasional use of 15mm Panoptics (for 125X). |
| Nikon 18x70 / Universal Astronomics Millenium Ireland has many nights in the winter that are clear but quite windy. While the observatory dome has withstood 140 kph winds closed, it's not rated for anything over 50 or so when open. Thus this setup -- which was originally intended to be my "wind rig" -- but which has spent a lot more time chasing comets. |
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| Previous Setups
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Meade 16" LX200GPS OTA in Parallax rings. The predecessor to the 16" Mak was an SCT mounted in a set of Parallax rings. The main flaw to this system was the SCT's moving primary -- even with the mirror lock on, the collimation would subtly change as the orientation of the tube changed. Still, this was a lot of bang for the buck, and I completed a good many sketches with this instrumentation. This picture also shows the Van Slyke Zerotator and Crayford focuser on the back of the SCT. My Takahashi doublet came to be (via AstroMart) with a camera angle adjuster, which turns out to be a very addictive piece of equipment (especially when using a GEM-mounted scope). It wasn't long before the SCT got its own. |
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Meade 16" LX200GPS OTA on Losmandy dovetails. With the better part of 100 lbs riding on it, a Losmandy dovetail flexes, resulting in pointing errors and collimation "flop" from tube/dovetail twist*. I highly recommend rings or a cradle for 14" and larger SCTs. * If you're picky about collimation, I also recommend a fixed primary, as primary mirror flop also contributes to collimation errors. A truly premium moving-primary implementation such as Questar's linear bearings or Astro-Physics' belt-drive might also work -- send me one and I'll be happy to test it for you. |
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And before that, the Meade OTA resided in its forks on a BC&F wedge. The wedge was a nice piece of kit, but my particular example of a fork mount was a lemon. When alt-az mounted, it exhibited periodic tracking vibration that was so bad that it would turn stars in some parts of the sky into 8 arc-second-wide barbells. The problem was entirely in the Dec axis, so a wedge was procured. This did remove the troublesome drive from the tracking equation, but mass market fork mounts lack sufficient positive location along the RA axis* for me. Settling times from a bump went from 2 - 3 seconds in alt-az to around 10 seconds on the wedge. My current GEM setup (with the same OTA) settles in 1 second. Most GEMs, even mass-market ones, employ either conical bearings or (more commonly) separate thrust bearings, either of which will positively locate the assembly axially. |