John

My 12 weighs about the same as a Skywatcher / Bresser 10 so it's not too bad. The tube section just about fits into the car with one half of the rear seat folded flat. The base goes next to it in the boot. The car is a medium hatchback.

At some point hopefully the SGL star party will start up again. It's held near you and while the skies are not perfect they can be pretty good. I've had some great fun there with 10 and 12 inch scopes (and even with smaller ones - the skies can be quite a bit darker there than they are at home)

One way to get an idea how a filter might perform compared with another is to look at the band pass charts for them: The above is a couple of years out of date now but it shows that there are differences in band pass width, cut-off profiles and maximum transmittance between brands. Where the profiles are relatively close, the visual impact will probably be undetectable but the larger differences do make a difference that can be seen. Here are similar charts for a group of UHC filters with a bit more information to help interpret them: I have seen profiles for O-III filters which make them practically UHC status and likewise UHC's that are moving into the broadband territory. Apologies if the above is "data overload" on filters

Forums like this provide a constant and responsive flow of feedback and opinions on equipment from those who actually own and use it. Far more influential and pursuasive than magazine reviews and advertising I reckon. As the volume of positive information on a product builds it can be quite difficult to resist the feeling "well maybe I would like that better than the one that I have" and also quite easy to forget the positive experiences that you have had with your existing gear In pre-online forum days the only information that I had on the relative merits of products or even that they might exist was through the pages of the monthly astronomy magazines and the very occasional and usually rather non-committal piece on "The Sky at Night" on buying equipment. The first time I saw the name Tele Vue mentioned was in a small advert in the back of a 1980's edition of Sky & Telescope. I remember thinking what a cheesy name for an astro equipment brand and that their stuff was likely to be rather cheap and nasty

What scope will these be used in by the way ? Sorry if you have mentioned it somewhere but I can't recall it (getting old !)

Slightly worrying that the pic is of an O-III filter but the description is for an H-Beta. If you buy from there, make sure you know what sort you are buying !

The closest focus on the scope is probably a lot further away than 20 metres - probably more like 100 metres or more.

Careful ! - the TV Bandmate and Bandmate II's are very different in quality. The II's are fantastic, the originals rather mediocre.

Astronomy equipment is much less expensive now than it was a couple of decades back. I have catalogues from the 1990's and the prices compared to what you would give today for similar gear are, almost universally, a lot higher.

I have seen this mount before - it's been for sale reasonably recently I think. Interesting that the amazing looking construction does not translate into a good mount to use. I think I was quite tempted by it back when I was looking for a mount for my 6 inch F/12 achromat. I'm very glad that I didn't take the plunge having read Mike's assessment !

Very interesting. I'm always intrigued how Tele Vue managed to control this effect so well in the Ethos eyepieces despite their hyper-wide field of view. It is quite pronounced with the Naglers.

I have a Lumicon O-III in the 2 inch size and an Astronomik O-III in 1.25 inch. The Ethos eyepieces use the 2 inch filter although the 13, 8 and 6mm are actually 1.25" eyepieces so can use the smaller filter size. To keep things simple I've added 2 inch barrel extenders to those so that I can use 2 inch filters on all of them:

No problem - moved into this section

I agree with your opinion Gerry I have a really good older Lumicon O-III but they definitely went through a wobble a year or two ago when they brand came under new ownership. The Tele Vue Bandmate II's are superb I hear - made by Astronomik. I have an Astronomik O-III in the 1.25 inch size which is very good and their H-Beta as well. @Stardaze - maybe another thread on filters would be fruitful ?

Without sample analysis by a recognised lab, there is no way to tell for sure. The vast majority of rocks that are suspected of being of meteoric origin turn out not to be. Try contacting these people, they will be able to advise further: http://www.bimsociety.org/contact.shtml

Good point - I noticed that when I was testing the Myriad 20mm which uses similar soft rubber dust caps on both ends.

I'm not sure either Stu. Generally I prefer a smaller but sharper and more contrasty image but sometimes you need to increase the scale, as you say, to enable the eye to see intricate stuff. I do find very high magnifications useful to pick out faint point source targets such as faint planetary moons.

The concept of "empty magnification" seems to be less relevant today perhaps ?

Most of the time I use Ethos with the dob and the 1.25" with the fracs. For high powers in the dob (300x plus) the Pentax XW's proved a touch better than the short focal length Ethos (took me 6 months of comparing them to come to that conclusion !) so the 5mm and 3.5mm XW's get used in the dob as well. The size and weight of some of these hyper-wide eyepieces can come as a surprise if you are used to smaller ones:

To be fair I have a set of Panoptic / Delos / Pentax XW's as well so I can use whichever I'm in the mood for Ask half a dozen folks what their preferences are and you will get half a dozen differing opinions I think. Eyepieces are very personal choices.

The only X-Cel LX that I've owned was the 25mm which I was not all that impressed with I'm afraid. Maybe it's not the best in the range ? I compared the 8mm BST Starguider with my 8mm Ethos at a star party a few years back (both in my F/5.3 12 inch dob) and found the Starguider did rather well.

I guess the single arm dob mount will have it's limitations re: tube length.

Very dangerous items:

This is not mine but it was posted on another forum by the experienced amateur David W Knisely. It might prompt some discussion anyway: USEFUL MAGNIFICATION RANGES FOR VISUAL OBSERVING IN ASTRONOMICAL TELESCOPES LOW POWER (3.6 to 9.9x per inch of aperture)(7mm to 2.6mm exit pupil): Useful for finding objects and for observing ones of large angular size like open clusters, large faint nebulae, or some larger galaxies. For lunar work in modest apertures, it is generally somewhat on the low side, but can show the crescent moon with background starfields well. This is also the range where Nebula filters tend to perform the best. Some of the wider double stars can also be best appreciated in this power range. MEDIUM POWER (10x to 18.9x per inch of aperture)(2.5mm to 1.3mm exit pupil): Useful for observing somewhat smaller deep-sky objects such as galaxies, some diffuse nebulae, smaller open clusters, and moderate to large planetary nebulae. Also useful in apertures 6 inches and larger for getting at least partial resolution on the brightest globular star clusters. Often used in moderate to large apertures for detecting very small galaxies which may be invisible at low powers and for revealing details in some galaxies like dark lanes, mottling, and star-like nucleii. Very useful for wide area views of the moon, or for showing the moon systems and some of the larger features of the planets. HIGH POWER (19x to 31.9x per inch of aperture)(1.3mm to 0.8mm exit pupil): A very useful power range for observing fine planetary and lunar detail. This is the range where the full theoretical resolving power of the telescope is becoming visible. Also useful in moderate to large apertures for getting better star resolution in tight globular clusters or for viewing detail in the smaller planetary nebulae, as well as resolving tight double stars. This power range is sometimes compromised in apertures larger than 5 inches by seeing effects (ie: disturbances in the Earth's atmosphere which can blur fine detail). VERY HIGH POWER (32x to 46.9x per inch of aperture)(0.8mm to 0.5mm exit pupil): Useful for study of certain specific planetary details, and resolving very tight double stars near or just above the resolution limit of the instrument. Also useful in larger telescopes for resolving the cores of some very tight globular clusters or for detecting the finer detail and faint central stars in the smaller planetary nebulae. Quite useful for telescope collimation tests or rough star-testing. This power range is not as frequently usable with larger apertures due to seeing disturbances. For planetary viewing, eye defects like motes and floaters (along with the somewhat lower overall light level), begin to become visible and slightly annoying in the upper half of this range. EXTREME POWER (47x to 75x per inch)(0.5mm to 0.3mm exit pupil): Mainly used for resolution of double stars at the resolution limit of the instrument, or for detecting elongation of unresolved doubles. Powers up to 60x per inch are sometimes usable in rather small instruments for making gross planetary detail easier for beginners to see (ie: Jupiter's main belts or the Cassini Division in Saturn's rings). This power range is not often used in apertures above 6 inches due to seeing limitations, and requires very good optical quality in the instrument. Even when conditions are good, lunar and planetary views using this power range can sometimes seem less pleasing overall than at somewhat lower powers due to the lower light intensity and increasing interference from eye defects like floaters. However, this range can be somewhat useful for certain *specific* targets or details which require extreme scale. Examples include (for large apertures) seeing Encke's Division in Saturn's rings, the central star in M57, detail in some brighter planetary nebulae, or for resolving a few small specific lunar details. Powers from 75x to 90x per inch are occasionally used for very close double star elongation, micrometer measurements, or for optical testing, but otherwise, powers well beyond 75x per inch can often be nearly useless, especially in inexpensive "department store" telescopes.

I see they have used a 3 vane secondary support on this new model. Can't see it in the photo but presumably the same helical focuser. It would make a great scope to have on holiday under dark skies