Posts Made By: James Barnett

Last night was awesome in Sonoma County, CA. I spent a couple of hours prior to moonrise observing with my FS-78. Among other things, I wanted to try out some new University Optics eyepieces. Evaluated were the following: 40mm Konig MK-70, 2"; 16mm Konig II, 1.25"; 16mm Super Erfle, 1.25"; and 4mm Orthoscopic, 1.25".

Targets included the Pleiades, M42, M1, Double Cluster and NGC 2362 (around Tau CMa).

I may get around to writing up my notes on the eyepieces (my fave was the 40mm MK-70!), but the purpose of this post is really to alert other users to a potential focus problem with the FS-78.

Specifically, using the 2" William Optics "New Generation" mirror diagonal and the TNR 2" visual back adapter for the FS-78, the 4mm University Optics Orthoscopic would not come to focus. There was insuffcient in-travel with the set up I've described. It was so close that I suspect had I used in in straight-through mode focus would have been achieved.

I was wondering whether anyone else had experienced anything similar and if so whether there might be a bit shorter 2" visual back adapter than the one offered by TNR?

Periodically I see posts asking about D&G achromat OTAs and and achromatic objectives.

I ordered one of the most recent "Limited Run" 5" f10 OTAs from D&G almost one year ago. I had intended to use the scope for the Mars opposition last summer.

Unfortunately I didn't receive the scope until December, well after the opposition. I am still waiting for the Astro-Physics focuser which is on backorder (surprise, surprise). D&G did everything possible to make up for the delays, including installing a generic 2" Chinese focuser as a temporary while I wait for D&G to receive the A-P unit.

The scope arrived in two separate parcels - lens cell and finder with brackets in one box, OTA in a long cardboard tube. The lens cell was wrapped in tissue paper with cardboard discs over each glass-to-air surface. I mounted the objective to the OTA, per the enclosed directions. My fingers are crossed as to whether it is properly squared off and retained collimation. Not a tragedy if it dodn't since the objective uses nice push-pull allen screws for collimation. Another glitch was that the Parallax tube rings ordered with the OTA oh-so-many-months-ago didn't come as didn't the objective dust cover. Those were sent proptly upon e-mail request.

The objective is MgFl coated rather than multi-coated. It appears to be a very nice coating job, with no sleaks or imperfections apparent. The OTA assembly itself is quite large, even at f/10. The whole thing looks a little "home brewed" but that adds to its charm. For example, the dust cover for the objective looks like a cookie jar lid, is paitend flat black and is made of wood.

I have the scope mounted on a Losmandy GM-8. She sees first light this weekend. I'll report back on the optics then.

Hi folks, I have had an FS-78 for about 4 months now. It was purchased new, so presumambly it's the most recent generation in terms of tube length, focuser tube length, etc. Last month, I purchased the 2" adapter for the FS-78. Previously I used the 1.25" visual back and teh 1.25" Takahashi prism diagonal. On Saturday night I used a William Optics 2" mirror diagonal. Everything worked spendidly until...

I discovered that my 4mm University Optics could not come to focus. There was just barelt insufficient "in" travel to achieve focus. All of my other eyepieces, 1.25" and 2", achieved focus no problem.

The 2" adapter also seems to add about 1.5" of extension. I'm guessing that if I placed the 1.25" adapter from the 2" diagonal directly in the 2" adapter, I could have achieved focus in straight through mode. It was that close. Has anyone else experienced anything similar?

Periodically we all obtain old (i.e., no longer manufactured) equipment on a whim or out of curiosity.

The purpose of this thread is to solicit information and feedback on older equipment from others who may have experience with the same.

My list of "keep it or sell it" equipment is as follows:

(1) 6mm University Optics Plossl circa 1984. Labeled "multi-coated" and "Japan."

(2) Orion 9mm "Ultrascan" eyepiece. 77 degree apparent field. Labeled "multi-coated" and "Japan." Circa 1990.

(3) Meade 20mm "Research Grade" Erfle. 65 degree apparent field. Circa 1982. Labeled "multi-coated" and "Japan." Very, very light.

(4) Celestron 26mm (Vixen) Plossl. Silver top with orange lettering. Japan. Commonly included with 1996 vintage Celestron scopes.

(5) Celestron 15mm Ultima Wide Angle (Axiom predecessor?). 70 degree apparent field.

Let me know what you know about these items, and whether you think they are treasures or trash. Thanks!

As far as the optical and chemical properties of different glasses, I am a newbie, so please be kind in responding to this post.

We've all seen "ED" doublets that are branded "APO" or "Semi-APO" (e.g., Meade's ED line or the new Orion 80mm ED). We've also all seen high quality "conventional crown and flint" achromatic doublets (e.g., D&G, Alvan Clarke, Vixen, Carton, etc.).

While ED doublets are rarely true APOs at the commonly offered focal lengths (f5 through f7), I have to believe that if manufactured at equivalent quality at a more conventional f/10 through f/15 focal length, these ED doublets would be superior in color correction and therefore resolution (because all visible light comes to focuse at the same point) to to the high quality conventional crown and flint doublets. At longer focal lengths, wouldn't they approach true APOs at least in the 5-6 inch O.D. flavors?

Now the questions: Are modern glasses very much more expensive than conventional materials? If so, for comparison how much more expensive (i.e. 20%? 200%?) Are modern glasses harder to work with and figure accurately?

I for one would love to buy a D&G quality "ED" doublet. Especially if it was 6" and multi-coated. I wonder if Barry at D&G or even Roland at A-P would consider a "co-op" order where 20-30 buyers subsidized the materials for ED doublets through advance payment and commissioned them to create ED "apo-achromats."

Feedback encouraged!

Currently I have both an FS-78 (on a Lapides modified Teegul alt-az mount) and an FS-60C (on a Sky Patrol II eq mount). The FS-78 has the Tak 6x30 finder and bracket combo. I am looking to upgrade that finder to a Tak 7x50 finder with bracket. Question #1: Is the Tak 7x50 finder bracket compatible with the FS-78 mounting holes? Question #2: If I replace the 6x30 with the 7x50, is the 6x30 compatible with the FS-60C mounting holes? (The FS-60C and FS-78 are 90 miles apart, or else I'd just measure.)

I ask because I ordered the Tak 5x25 finder and bracket for the FS-60C and was sent the FS-60 finder bracket insted which had different mounting hole spacing. If I can retro-mount the 6x30 on the FS-60C, I may just send the entire 5x25 finder and bracket back to the retailer.

Thanks!

A quick (unscientific) review of the Astromart Refractor classifieds reveals that of just 116 ads, fully 10-11 of them are for 3" Stellarvue refractors. About 8 months ago I parted with my own Stellarvue 80/9D when I bought a Takahashi FS-78. At that time there were more refractors listed (220+ if memory serves) and only 3 or 4 other 3" Stellarvues available.

When the Orion 80ED arrived at just $429 to good reviews, rapidly sold out, bounced in price to $499 and then sold out again, many on these forums, including me, speculated that the 80ED could have as much of an impact on the similarly-priced 3" premium achromat segment as it would on the much pricier high end 3" APO segment. Is the high availability of 3" Stellarvues in the Classifieds evidence of Orion 80ED impact? Alternately maybe the loyal Stellarvue faithful are upgrading to the newly available Stellarvue TMB 3" units. Something to think about...

Folks, I have an FS-60C that I use on a Teegul Sky Patrol II equatorial and on a Teegul Lapides Modified alt-az. I also have an FS-78 that I use on the Teegul Lapides alt-az and a Losmandy GM-8. The Teegul Lapides alt-az seems to be pretty beefy. Is it suitable for an FS-102? Same question for an FS-128. Thanks!

the 9mm Orion Ultrascan eyepiece.

I know that (1) it is no longer made, (2) has a 77 degree apparent FOV, (3) was made in Japan, (4) purports to be "fully multi-coated," (5) sold originally for about $100, (6) has 5 lens elememnts and is light in weight and compact in size, (7) has pretty short eye relief, and (8) seems to suffer some edge of field distortion.

What I don't know is whether any of you have used or are currently using this eyepiece, what your subjective experiences are with it, how you feel it stacks up to other similar focal length wide field eyepieces, etc.

I am planning on doing the upcoming Messier Marathon with some "vintage" equipment (Celestron Ultima 2000, Meade Research Grade Erfles and Orthos, UO Plossls, etc., and need to pack light. I'm debating whether to take the 9mm Ultrascan along. I've used it only about 3-4 times since the mid-90s.

Thanks for your feedback in advance.

Harold:

Obviously at one time, you were happy with your astronomy hobby. Ask yourself what exactly it was that pleased you then. I will bet you find that back then astronomy wasn't about equipment and things, or materialism, but about actually doing. Getting out there under the deepening dusk and watching day expire into night. Seeing, smelling and hearing nightfall. Then undertaking an "adventure" shared by an elite few people on the planet. The adventure isn't a GOTO destination, but rather is made up of the interaction of human and machine in the hunt for your subject. After the thrill of the capture, came the contemplative, meditative quiet study of your subject. Teasing out as much detail through adjustment and method as possible given your tools and skill.

My gut feel is that you would be happier with a nice, super-portable, simple scope and a set of reasonable quality "pedestrian" eyepieces; 3 of 'em and a barlow. No more fixation on brands, costs, complexity, cumbersome transportation logistics or "things," but rather abandon all of the obsessiveness regarding the tools, and actually re-engage with the craft.

My $0.02. Best of luck to you, sir.

Jim