Ben the Ignorant

That 77m Swift has an impressively clean objective for a 1968 telescope, it's very well preserved. You people seem to be after vintage japanese achromats and an italian astro blogger has a few for sale, so take a look at that: http://www.dark-star.it/vendesi-e-cercasi/

There is another glob 1° west-north-west of M22, it's NGC 6642, magnitude 8. It looks nebulous when it's not resolved, and in an inverting scope it seems to be left of M22.

Hello, Zaidi. Any binocular can be used for terrestrial nature and the sky but you need to learn how to assess the quality of binoculars before you buy them. 12x50 are good specs, a rather large diameter and a rather high magnification, but can you test the binocs in person? How old are they? Are the eyecups rigid plastic or soft rubber? How large is the field, how many meters at 1000 meters? Are the coatings pale blue (only one layer), or another color? There are other things to check so please describe the thing in as much detail as possible.

The accuracy and the lack of exaggerations in the description, plus the presence of other witnesses convince me you really saw this. Possible explanations are a very high altitude balloon that might still be lit by the Sun since it was not that much below the horizon at 22:30. Or a military spy satellite, some of the later generations have small engines to keep them above locations of interest, so their motion is not straight. The US military X-37 space plane/shuttle can do it, too. Too bad you didn't have binoculars; are you an amateur astronomer or just someone who noticed something unusual in the sky?

I had completely forgotten about the birding forums, thanks for the reminder.

This is what I asked: I'd like to ask a question about the 10x50 MX binocular which is now labeled as APO ED but the price is the same. A single 50mm ED finder costs 209€, so, with the prisms and eyepieces and armored body, how is it possible that the binocular costs 229€? And their reply: It´s always critical to compare different articles that way. Our sales price always depends on many single reasons.....the prices of the producers and also the number of ordered parts. So when we order a bigger number of articles we will get a better price and so we can sell ich cheaper. Additionally the price of the binoculars is reduced - maybe because we will get new ones or we have a large number on stock and want to sell it faster. I find the answer a little vague, and the pictures in their site don't show any ED label on the binocs but the APM ED does not sport that label either. The APM is lighter and proven but more expensive so I hesitate.

Looked further again and it turns out the 10x and 15x 70mm high-end binoculars from TS have also been upgraded with ED glass without changing the price. https://www.teleskop-express.de/shop/product_info.php/language/en/info/p1405_TS-Optics-15x70MX-Outdoor-ED-APO-Fernglas-mit-Nitrogen-Fuellung.html At 2.550 grams it is way too heavy for me but the apo glass is a game changer, now the value of these versus their APM competitors is different.

I checked Kunming United Optics' website and found they have each of their 7x50, 10x50, 12x50 as well as their 11x70, 16x70 and 20x70 in an achro and an apo version so that's 12 models. However none of the specs and pictures are clickable so no info about weight and glass type. http://www.united-optics.com/showproject.asp?ProdNum=163 I'm assuming they display the achros and the apos together but will phase out the achros since it seems they can make the apos at the same cost.

Yes, I've studied all the versions from all the brands, Orion, TS, Omegon, Oberwerk, William, 7x, 10x and 12x. But if I go through the trouble of selling my MX I won't take chances with edge aberrations (the MX has no center aberrations but the edge is soft), so the APM apo ED is the logical choice when the Fujinon costs twice the cash but is reported to have a tiny, tiny bit less edge sharpness.

I did but no answer yet.

The glass in the objective does make a large difference. I own an 80mm f/7.5 achro and an 80mm FPL-51 f/7 doublet, at medium and higher magnifications the false color halo is three to four times thinner and three to four times dimmer in the apo. Of course the whole achro image is awashed in the unfocused light, not just the edge of bright things, so contrast and resolution are in another league. Not sure about the body quality because the TS is extremely robust, but the APM seems to be as tough while wheighing 300grams less, that would be a nice plus. Indeed the eyepieces have to be better because they contain seven lenses per APM's website, while 65° binoc eyepieces nearly always have only five. You're also right about the coatings, my MX has greenish coatings on the objectives and dishsoap yellow-green coatings on the prisms, but the APM has dark and dim blue coatings, a color to which the eye is less sensitive, so the flaring must be exceedingly dim or absent. (It is very, very, very faint in my MX). I also got a tripod adapter with my MX, don't know if it was a gift for my first order from TS or a standard accessory because it was not featured in the accessories list. All in all I'm leaning toward the APM if I finally decide to go apo.

I've been thinking of switching to apo binoculars, and the APM 10x50 ED is the one I'm ogling the most, it seems to be better than even the deified but non-ED Fujinon FMT-SX 10x50. However, nearly at the same moment I started pondering the upgrade from my TS achro 10x50 MX, it seemed to be offered with that extra-low dispersion glass for exactly the same price. https://www.teleskop-express.de/shop/product_info.php/language/en/info/p1403_TS-Optics-10x50MX-Outdoor-ED-APO-Fernglas-mit-Nitrogen-Fuellung.html So, what is going on? Has TS' supplier (Kunming, right?) stretched the definition of their high-performance achro glass, or do they really have switched to extra-low dispersion glass, and managed to keep the price at the precise same level? William Optics has offered clones of the 7x50 and 10x50 MX for a long time, but labeled as "ED", and priced higher. Are they really apo binocs with FK-61 (what APM uses) or FPL-51 glass, or are they the same with William's usual higher price for everything? APM's instrument costing twice as much as the apparently new TS, the question is serious to me.

https://www.skyandtelescope.com/astronomy-blogs/explore-night-bob-king/texas-amateur-detects-possible-impact-on-jupiter/

That's typical but the first instrument should a binocular, the most popular and multipurpose stargazing binocular is an 8x40 or a 10x50. Going straight from the naked-eye, full-sky view to a 40x or 50x magnification that's typical low-power for a scope is too much of a jump. Imagine you want to examine small insects in a large expanse of dead leaves, going straight to a microscope without first looking with a magnifier will have you wonder what part of the space you're looking at. And it will be difficult to find a target again after you've left it.

Give them away to kids and beginners.

I often wondered what inside the solar dynamo could cause that superficial and extremely long sunspot cycle that doesn't match any known phenomenom within. Well, if it's not inside, it's outside.

I hope you have a wide-field, long-focal-length eyepiece for your C6, to see the largest possible piece of sky.

I would refuse to have only one scope.

I use a light red #23A to get the same effect in visual, wouldn't it or the middle-of-the-road #25 be dense enough for photography, but with shorter exposures than the dark red #29?

A little bit of gentle solvent, very soft rag and gentle pressure can't fail.

Unless the dirt is between the lenses any user can clean them, just make sure you're not pouring the solvent on the lenses, but only on the rag, preferably microfiber. Absolutely use non-abrasive tissue, cotton balls are ok but other fibers, picker-upper paper, paper handkerchief and such are not safe. Lately the pure cotton pads (make-up remover for the ladies) that used to be pure cotton have been replaced by a mix of cotton and synthetic, good thing I read the description before I used them, not sure if it's more abrasive than pure cotton but not taking any chances. And, of course, rub very, very softly, and dump or rinse the rag every time it has picked up some grime.

I don't think you'll find many owners of this scope on this side of the Atlantic but look in the Cloudy Nights forum and you should find personal reviews.

I reduced the secondary housing on my 130mm f/7 newtonian and contrast improved, just looking at the darker areas of pine trees at dusk made it clear more leaves and shades or colors were visible. The guy who couldn't tell the difference probably didn't have experienced eyes. These are the only pictures I got now, the spider job is not finished on these photos. About that stray light, adding a coat of rough black paint and/or ribs to the outer and inner tubes takes care of most of it, and accepting the larger obstruction is also a compromise, anyway.

This baffle can be removed, as professional optician Davide Sigillò has done, obstruction went from 37% to 29%. http://www.davidesigillo.eu/test_10.html I'll translate the relevant paragraphs: Io una volta smontata la cella avvitata al tubo che contiene il menisco ed il secondario ho rimosso il paraluce che è semplicemente incollato con una specie di adesivo spugnoso circolare. L’ostruzione, avendo calcolato la riduzione effettuata, scende con questa modifica sotto il 29% e una volta puliti li specchi (polverosi in questo esemplare) e rimontato il tutto l’ho puntato di nuovo sul cielo. Incredibile sembra di guardare con un altro strumento!! Immagini più brillanti, più contrastate e più luminose, l’ostruzione non si avverte più come prima, le immagini stellari sono più piccole e secche ed i pianeti e la luna mostrano più dettagli e contrasto. Unico neo togliendo il paraluce si introducono ovviamente dei riflessi interni che possono essere eliminati montando dei diaframmi nel tubo o nel focheggiatore. Once the cell that contains the meniscus and the secondary has been unscrewed, I removed the baffle which is simply glued with a ring of some kind of spongy adhesive. The obstruction, having calculated the reduction, shrinks down to less than 29%, and once the mirrors (dusty in this case) were cleaned I pointed it at the sky again. Incredible, it feels like observing with another instrument! Brighter and more contrasty images, the obstruction is not noticeable like it was, stellar images are smaller and tighter, and the planets as well as the Moon show more details and contrast. The only minus is the removal of the baffle introduces internal reflections that can be eliminated with ribs in the main tube or focuser tube.