chiltonstar

Nice shot Steve - a lot better processing than my attempt! I caught the transit earlier on (23:30 to 0010). Io is to the right of the shadow in this prelim image. The splodge to the right of the GRS is interesting? Chris

You were lucky to get out Doug - no luck here. I have my ED80 and Vixen Porta2 waiting as a grab 'n go in this kind of weather, as it is ready to go in a minute or so unlike my maks, and can give some glorious views. This kind of weather is dangerous, as we all end up window shopping supplier websites! Chris

When I've looked at the moon at low mag without a moon filter, I've occasionally had a visual migraine afterwards. I do have a moon filter now, but I have to say it's not very good optically and reduces visual detail a little. Chris

Quite impressive, even with cloud. Chris

As I was in London at the time, I assumed it was over Southend...... Chris

When I started in astronomy there was a very bright star in the east........... Chris

TVM for this Stu - very useful indeed! Now all we need is a clear night or two! Maybe if FLO close down for the Summer to prevent the new kit jinx? Chris

The Stelle Doppie figure for PA is 277 degrees which matches what we both saw I think. The blue of the secondary may be aperture dependent as I would say with 180mm it was definitely blue-green 'ish, although of course with atmospheric refraction and seeing wobbles, colour is always a bit subjective! On my original, the intensity ratio looks right, but shrinking the file and copying across has made the intensities look more similar. Unfortunately, my laptop was also trying to perform a couple of updates (G knows what) which corrupted the image file slightly. This is the 100mm simulation with the blue-green intensity reduced to something more like the correct ratio (it makes the colour slightly more Blu Tack'ish maybe?):- Chris

I've done it in the past with an 80ED - I don't think aperture is the main issue really, it's more about seeing and as John says, having a clear S aspect (and of course having any clear nights). This is a simulation (Aberrator) of Antares with a 180 mm Mak and a 100mm frac - you can see both can split it easily; I've added a bit of colour for fun! Chris

At UK elevations for the gas giants, normally x150 to x250 seems to be the best range of mag, although I have used much more when they are higher in the sky. Chris

The rain cleared the murk here a little and Jupiter was visible as it should be - a worthy competitor to Venus! At 11 degrees elevation though, the seeing was far from perfect, with fractions of a second of detail every minute or so, with the GRS nicely visible. Later, when Jupiter is higher, I have a house and some trees inconveniently positioned so it was 11 degrees or nothing! Best seeing I've had for Jupiter so far this year though. This quick image shows the amount of detail I could (intermittently) see (180 Mak, AS1224). Oh for a more southerly location! Chris

With their excellent reputation, I was a little surprised by the optical test comparison by Wolfgang Rohr of the Mewlon 180 and the standard SW 180 Mak, in which the Synta product had the better optics apparently:- http://r2.astro-foren.com/index.php/de/12-beitraege/04-zweispiegel-systeme-astrofotografie/789-d069b-vergleich-180-mewlon-dall-kirkham-und-180-skywatcher-maksutov I may have an opportunity soon to look up both scopes side-by-side, which will be interesting. Chris

60 degrees ........wow! I split it again two nights ago, and I had to use a much lower mag because of the near horizon seeing - x90 gave the sharpest view of the blueish-green secondary, nearly due West of the primary. Chris

I've split the pair twice with my 180 Mak - not easy though. A neighbour has an annoying tree which gets in the way, but I have found a spot in a field with a low southern horizon which is ok. There are not many evenings though when Antares is in the right place, there's no low cloud, and the seeing is excellent or better! Chris

Might be the ozone generated by the uv of course? I UV irradiated my lens after assembly with a mercury vapour lamp I have. Chris

In older lenses, it used to be the Canada Balsam which cemented the components together. In an air-spaced achromat, I suspect it is the organic residues (bloom) which gradually form on any glass surface (pollen, tars and compounds from plants etc). My 102mm f13 had this problem a year or so ago. I dismantled the doublet, cleaned it with solvent and then a lens cleaning compound and reassembled the crown and flint components with new spacers which bizarrely improved the resolution cpd with when it was new (thinner spacers I think). To avoid the problem with my 180 Mak, I store it outside in a sealed B&Q storage box with three or four silica gel sachets. Chris

With the 180 Mak, a 7mm EP is giving x385 - I wonder if this is probably near the limit for the scope (50x per inch of aperture), so the scope optics may predominate over EP optics? Mine certainly starts to run out of steam over x350, although this is sometimes helpful for doubles. Chris

I use a 9x50 RACI with an RDF mounted on it, ie find the area with the RDF and then use the slomo to center the target with the RACI. To avoid the problem of the two eyepieces being too close together, I have my 127 Mak mounted in rings so that the scope EP can be rotated to the right and the RACI EP to the left slightly. Chris

Interesting! I bought mine from Vixen just as an achro doublet, and made the cell and tube assembly. The lens was pretty good, but eventually fungus invaded the edge of the lens and one of the Al tabs moved so last year I disassembled it, cleaned up the surfaces and re-assembled it. I experimented a bit with the spacers and found that a slightly thicker spacer worked a lot better than the original, and I've since had some very impressive views of 1 arcsec doubles with it, as well as Saturn and Jupiter. I have heard that sometimes the pair of lenses are not properly lined up and positioned in the cell - maybe just a rumour. Chris

It appears on the web in several places with that name. Obviously one of the OP's favourites! Is is a superb double star though - even my grab 'n go 127 Mak shows it in its glory with a little diamond pinpoint secondary; my 180 Mak shows more of the associated stars/companions (see other posts on this site for details, eg by John). Chris

This is my garden - seems accurate'ish. Chris

Quite a challenge this one and one for larger scopes! Fairly easy to locate near the North America Nebula, and perfectly positioned at the moment well above the horizon. The separation is given as about 1 arcsec and the magnitudes 3.9 and 6.8, which I reckoned should be do-able with a 180 Mak. First try, Tuesday with good seeing (4/5), nearby Delta Cyg was easily split and showing the secondary as a diamond pinprick, while Tau Cyg showed no sign of a secondary. The next evening (Wed), I got the faintest hint of something in about the right place, and third try (last night seeing 4.5/5) there it was in moments of good seeing at x270 and x450. Clearly separated from the primary, but messed up a bit by the diffraction pattern causing to hop in and out of view, as the secondary lies close to the first diff ring. I can't sketch very well, but the Aberrator simulation below is a fairly accurate eyepiece view at x450. A good one to try if you are bored with looking for some detail on Mars! Chris

Indeed yes, mine will show the division all the way round when Saturn is high enough and appropriately tipped. They are lovely scopes for the size and weight! I use a 3.7mm orion EP for planets. Chris

Horses and courses, I find. I love the clear views from a frac of planets, doubles etc, but as stated above, they cost a lot more per inch than a Mak and the convenience of a short tube, 180mm Mak is something a frac could not deliver. Fracs are better though when the seeing is poor as the more visible diffraction pattern from the Mak can end up as a bit of a visible jumble, for example around double stars - an issue with any scope with a significant central obstruction. The resolution of my 127 Mak (it's actually 119 mm clear aperture) is visibly better than the resolution of my 102 mm long tube frac, but in terms of brightness on a DSO like M1, they are about the same because of the obstruction and more optical surfaces of the Mak. Nowadays, I get the best of both worlds - I put both my 180 Mak and my little ED80 on a SkyTee2. Chris Chris

Welcome - don't worry about your English as it's a lot better than my Italian, and I worked there for 8 years! Chris