Posts Made By: Ron Oehlert

Lots of eyepiece time but Jet Stream overhead prevents anything other than detection of albedo features; fine detail not yet observed this apparition. Sinus Meridiani and Mare Acidalium visible for the past several nights. Telescope used is an 8" f/7 Cave @ ~200X with a Zeiss-type ortho. Seeing very poor (1-3) per the Harvard 1-10 scale and Transparency was limiting naked eye magnitude of 4.

Mars is rotating on it's axis as well, so you were looking at a different face with different features from three weeks previous. Sky & Telescope on-line has a program for discovering the face you are or were looking at for any inputted date & time. Since a day on Mars is a bit longer than our own, if you viewed Mars at around the same time each night for about 5 or so weeks you would see the planet slowly rotate completely around. Mars is still large enough in a telescope at 200X to view surface markings when atmospheric Seeing permits. And Mars has an interesting side and a bland side, so knowing which face you are looking at helps identify features.

I have several damaged lumbar vertebrae and find that the small 5-foot high step-ladder that I have for the neighborhood kids to reach the eyepiece of my GEM 8" f/7 & 10" reflectors also serves very well as a lean-upon if I rest my arms on the top platform of the ladder. This safely steadies me and takes the standing strain off my back. I find this method of upper body support while standing to be more comfortable per my backache than prolonged sitting (I also have an adjustable-height observing stool). Actually, it was a friend of mine taking turns observing with his granddaughter and so he didn't bother moving the ladder out of the way when he discovered resting on the ladder's top enabled comfortably relaxed lengthy observing. Pad the ladder's top for the ultimate in comfort and bore some holes in the fold-up paint can shelf to hold eyepieces.

Try showing data from much further back in time in order to actually see what is occurring, after all this is an astro site where time is measured in more than a few years. Since the 1800's Industrial Revolution CO2 has increased in our atmosphere due to man's activity as evidenced by polar ice core samples. You might also educate yourself about Venus & Mars per their current & past climates.

Your *witness* marks are a good idea, Thanks. My vintage 8" and 10" equatorial-mounted reflectors reside in the garage & are easy to roll out for use in the driveway or lawn and an extension cord supplies electrical power. They are covered when not in use with shower caps over the tube ends & plugs in the focusers. I too roll 'em out at sundown but my garage is detached from the house so the scopes are nearly temperature stable to begin with. Amazing how many people taking an evening stroll stop by after seeing those scopes out.

Nice photo, except for all the banding detail displayed in the upper half of the globe it is as seen visually in my 10" reflector (often though the Encke minumum is not so obvious as in your picture).

If you have the smarts to do astrophotography, you also have the intelligence to exchange cord connectors to a cigarette lighter plug or whatever cord connector you want. Just pay attention to wire polarity (positive & negative) when exchanging plugs (which involves cutting off the supplied plug & then re-connecting the two cord wires to the new plug either via soldering, crimp-connectors, or twist-on wire nuts all of which are available at a local Hardware store).

Andy, the 1976 Silver Anniversary Cave catalog lists that scope with the two finder/guide scopes & fully-rotating tube as a newly introduced Astrola Dual-capability 8" f/4.5 reflector available in either lightweight or heavy-duty versions with a null-figured Pyrex primary mirror with enhanced aluminizing & quartz overcoating with a focal length of 36". A 20mm extreme wide-field Erfle (80-degree AFOV = 2-degree TFOV) & 3X tele-negative lens & either a 10mm or 6mm Ortho was included in the base price. The tele-negative amplifier gives very fine definition on the moon, planets & double stars according to the catalog. The same catalog also lists the RFT version without a rotating tube or finder & guide scopes. The heavy-duty version has a full-thickness mirror & 1.5" shafts and the Lightweight version has 1" shafts along with a thinner primary mirror, reducing instrument weight by 25 pounds (HD = 75# & LW = 50#). I have a 10" Meade f/4.5 Starfinder (of 1990's vintage per it's 2.4" secondary) which after 9 months of evaluation has star tested as having a very good figure comparable with my 8" f/7 & 6" f/8 Discovery-made mirrors and certainly it is Seeing-limited. I employ a Barlow with it when observing the planets at high power and it then bests my perfect-optics Cave 8" f/7 due to the greater light-grasp affording more contrast. So I'd expect similar high-power results with your Cave scope when a Barlow is used with it. This Dual-capability equatorial instrument was designed for maximum portability with extremely rapid breakdown or re-assembly (ready for observing in two minutes or less) and can store in the trunk of even a small auto. The Dec. slo-mo on yours appears non-Cave, at least per 1976 or earlier examples (the manual slo-mo on my 1971 Cave & those illustrated in the '76 catalog are the same but not like yours as they have no sector arm but a 4" gear wheel & worm instead for both manual & motorized versions.

Actually using them should provide your answer as to their optical & mechanical quality. Only then consider having them dis-assembled by hopefully a qualified business. Why not go ahead & view neighborhood birds as well as trial them under the stars? Use a broom-handle or other such support to steady your view of the Moon this week. BTW, it is possible to mix-up the left & right lenses or even their rotational alignment and thereby throw-off any factory alignment between left and right making them useless. You can clean the outside same as cleaning eyeglasses; seek guidance from a glasses-wearing friend if you are not so familiar.

Why not do a standard Foucault test yourself or himself? Much more affordable than transport or shipping of such a large mirror to a facility. Such a simple DIY exam will reveal if mounting the mirror is worthwhile and once mounted in a scope the star test is quite sensitive for critical evaluation. Read a mirror-making book and/or Suiter's star testing book for how to do it (public libraries have these books as well as book sellers). BTW, such a relatively thin mirror (1:16 thickness to diameter ratio) will require support when testing similar to that required in the final scope or test results will be in error.