Dragons Egg

I understand that it's probably nigh-on impossible to attach a Skywatcher right-angled finderscope to the clamshell of a TeleVue 101 scope. If so, are there any other makes of (non-red dot style) finderscope available that might be able to do the job instead? If necessary I am content to sell on the clamshell and replace it with standard tube rings.

I'll do that. Either way it now looks as if specialist remedial treatment is on the cards.

Yes, that looks to be the way of it. If there's any commiseration to be had, I originally bought the refractor last autumn to serve as a travel scope - it's so compact that it can easily pass muster as flight baggage, Well, of course, Covid 19 has put paid to all that

To prevent any further confusion, my other refractor is a newish NP-101is, and, yes, as has been rightly pointed out, I do treat it like a newborn babe - like the crown jewels, in fact. The pay-off were the fantastic high-power views it gave last night of Saturn and Jupiter at our local (semi?) dark site. And that was without any appreciable cooling down period either - the clouds were already rolling in while setting up the scope, but I'm going off topic here. With regards to the ES 80mm apo. . . 1) It happens with all my EPs, ranging from a Delite 4mm down to an Ethos 21mm. As a matter of fact I started with wide AFOV EPs - the Ethos and two ES EPs (14mm/8.8mm 82 degrees), plus a barlow - and only later branched out into higher power EPs. 2) Yes, that's always possible, of course. Still, I am pernickety about my optics - as I am about other pursuits. Here's another thing: while aligning a new SW finderscope on the refractor in daylight last week, I couldn't help but notice how washed out everything now looked through the scope itself, while the same views seen through the 9x50 finderscope looked bright and crisply sharp by comparison. The contrast was startling in fact. I don't know what that brings to the table, but for me it was an early sign that something was no longer quite right with the refractor. 3) I'll never see 60 again and my eyesight has plainly deteriorated as a result. Indoors certainly I now have to wear glasses when reading books or text on a screen. On the other hand, if the problems I'm having with the ES scope were purely due to failing eyesight, then wouldn't it also manifest on my other two scopes, likewise my binos? When you suggest field curvature as a possibility, does this imply that its effects would be 'global' - that's to say it affects the total viewing experience? Or could it show itself in just one part of the scope's FOV? - which is the case here.

Hi John, although I'm still flogging my brains to remember if it's ever had a knock of any kind, it rather looks as if it might have had one, going on the evidence. Does this imply that the objective lens is now slightly out of kilter as a result?

Yes, it's a triplet.

Hi fozzybear. It's an ES ED80mm apo (f/6). It's just over a year old too, and back then it gave amazing widefield views of star clusters etc, but no longer.

So what would be the cause if the stars aren't uniformly in focus across the field? This is the problem I've had for several months now with my latest scope. All stars now remain stubbornly out of focus towards a given edge of the viewing field, starting roughly 20 percent in from the field edge - whereas previously I received a tack-sharp view right to the very edge. In other words I can no longer get the entire field properly into focus. The end result can be observed by watching a selected star gradually lose its crisp point-like focus as it transits, in this instance, towards the right edge of the scope's FOV. I have checked for dirt or smears on the objective lens in the offending area, but can't see anything untoward there. I also checked the EPs, and they're fine. I will do the Airy test, also swap the scope's diagonal for my TV one; but if all that checks out fine as well, then I don't know what to think, other than accept that something serious has happened to the scope's optics. What exactly, though, has left me completely foxed. As a sidenote, I take great care of all my astro gear, as one does naturally. Thanks for the input. PS. Forgot to mention this, but while inspecting the scope's objective lens yesterday evening I spotted something I've not seen before: traces of what I assume are traces of glue lining part of the lens' protective outer shell? Just a thought.

What are the telltale signs when a telescope, a refractor in this instance, needs collimating? PS. I am aware of how to check whether a scope needs collimating: I just want to know what the signs are. Many thanks.

First up: many thanks for all the helpful comments and friendly advice. No, I never wear eye glasses when observing (I do wear specs, but only for reading purposes). So far I've had none of the above problems, either with my IS binoculars, or possibly more testingly, while looking through a friend's mounted Orion Resolux 15x70 bins. Perhaps more puzzling still is the fact that a recently acquired 6mm Delos works just fine on my ES 80mm triplet. Is this because I've never 'cleaned' it? Or would the 80x magnification/reduced FOV it delivers to the scope render the problems less visible? I have no ready answers to both questions. I've not yet tried the Delos out on the other two scopes, though I intend to do so asap (weather permitting). Yes, as has been pointed out, it's possible the problem could originate with my eyes, after all, especially given that I'm now in my late sixties. Meanwhile, depending which comes first (again largely hinging on the weather) I'll seek a second observer's opinion on my equipment and see what gives, while keeping open the option of sending off the above three mentioned EPs to be cleaned. As a side note, given that the exit pupils of the Canon binos are 3mm, it so happens that one of the above trio of EPs, namely the ES 14mm, offers a 2.9mm exit pupil on my ES Mak Newt. Unhappily it's also the worst offender out of these three EPs, which is a real pain, given that it's the one I use the most often. Finally, I've made a note to get my eyes checked out! Again, thanks for everything. Clear skies!

Due to my proven inability to do this myself, I'm about to send some of my eyepieces (2 ES 82s & a TV Ethos 21mm) off to be professionally cleaned. If that doesn't solve the problem, then I'll submit all three of my scopes to the same treatment, including my NP101. Before I do this, however, I would like to know just how dirt and grease visually degrades the performance of an eyepiece lens. (Google doesn't seem to understand this question). For what it's worth, what I see is astigmatism in a given star-field, especially towards the edges. Hitherto every star was tack sharp right across the field, but now I can no longer keep the ones near the edge of the field properly in focus with those in the centre. The discrepancy is subtle, but once spotted it's impossible to ignore. Also there's a faint 'sparkly' effect whenever I'm panning the scope, which has nothing to do with atmospheric scintillation. Grease? Dirt? Traces of cleaning fluid? This degradation is replicated on my ES Mak-Newt, as well as the two refractors. So I can only put it down to the EPs. . . at least for now. If the problem extends to the scopes themselves, then potentially I could be in real trouble, of course. But, hey, one step at a time. In passing this has been such a disheartening experience that I came close to giving up astronomy altogether. Since then my enthusiasm has rekindled somewhat since buying a pair of small image-stabilised binoculars (Canon 12x36). Even so, as wondrous as these bins are, they also remind me that there's an outstanding issue that still needs attention. My apologies for banging on like this, but stargazing-wise this last eighteen months hasn't been a happy experience for me. So any input would be extremely welcome. Thanks for reading this 'cautionary' tale.

Hi mikeDnight - many thanks for your detailed advice. I'll pay heed to it from now on. Unfortunately, it's come a bit too late for me. To keep it brief, I forgot to uncap the scope one night, and found to my dismay the next morning that the objective lens was covered what looked like dried up condensation marks. I then (very gently) removed these marks, using Baader Wonderfluid and some lint-free Kimwipes, plus a virgin Baader Wondercloth. Having dealt with that issue, I'm now left with a series of faint but seemingly permanent smears across the front of the lens. I could live with that but for the fact that the scope's image quality has now deteriorated markedly. It's become impossible to keep all the stars in a given field of view uniformly focused. Also when I run my viewing eye back and forth across the eyepiece lens, the stars glint and sparkle, and momentarily blur and become unfocused. Quite frankly I'm too alarmed to try and remedy the situation any further. Instead, it now seems that I'll have to get the scope professionally cleaned. . . though in view of the present coronavirus shutdown, it looks as if I'm in for a long wait. PS. I've tested the EPs on another scope, and they check out fine.

According to 'Scope Doctor' (aka Steve Richards) in February's edition of the Sky at Night magazine, he strongly advises upon returning home after an evening's observation to allow the telescope to re-acclimatise to indoor conditions by keeping all its lens caps off, so enabling any condensation on the mirrors and lenses to evaporate at nature's own pace. This is the procedure I follow myself. Now, however, having recently purchased a TeleVue NP101is refractor, it seems that this advice is no longer appropriate, at least according to the manual that came with the scope. Thus I quote: 'To prevent dew formation when bringing the scope in from the cold, we advise to close the cold scope in its case before bringing it into the warm indoors. Do not open the case until the scope has come up to room temperature.' Is there something especially distinctive about the lenses of TV refractors that requires this opt-out, or am I missing something? (which is more than possible, of course). Incidentally, the advice forwarded in the manual fails to mention whether this procedure includes affixing the lens caps back on to the scope, or not as the case might be. . . which may or may not be important. Hmm. Very puzzled.

I managed to use my existing mini-clamp to affect the same result, but thanks for the Starwave link anyway (I've now filed it for future reference). Meanwhile I've now got three bolts securing the clamp to the mount's camera plate, though it necessitated the removal of the rubber plug (which I've carefully stored for safekeeping). All in all, I feel a lot more relaxed about the setup now. Moreover, as with yourself, the addition of the mini-clamp means that I too can better balance the scope on its mount. So a win-win all the way down the line. Thanks for the pic - it made a big difference!

Well, as the pic reveals, Amazon has promptly replaced the original Manfrotto geared head with one that actually functions, and does so extremely slickly, I might add. I now strongly suspect that the original head was a returned item, which somehow evaded Amazon's scrutineers. Certainly it was unusable, and add to that the ignorance I had back then about how these geared heads operate in practice compounded the problem still further. Re. johninderby: one other thought. At present my scope is joined to the mount head by a single shortish 1/4 inch bolt. It's true that Manfrotto gives this head a maximum payload allowance of 5kg. It's also true that the scope itself, including its diagonal, but minus a sighting scope (I don't really need one for this small wide-field refractor) weighs just 3.1kg - or a whisker over 4kg when it has onboard my biggest/heaviest EP. On the other hand I do enjoy slowly panning through the Milky Way, which means the scope spends a fair amount of time pointing up at the zenith. It's then I wonder about that 1/4 inch bolt.* So I was intrigued by your solution to the 'problem'. Did you find it hard or easy to achieve? Do you consider it a safer way of securing your scope to the mount - assuming, of course, this was part of your remit in the first place? I ask these questions because I have a similar Vixen-style clamp going spare, but without all the drilled holes yours possesses. Still, I am giving it some thought now. * I can't safely use the 3/8" bolt additionally supplied by the head. To do so creates a worrying overhang, which itself stems from the design of ES scope's built-in shoe-style dovetail bar.

I'll be sure to bear this advice in mind when I receive the replacement junior head unit from Amazon. I've had to return the original one, for quite aside from anything else, upon opening up the package I did see some ugly looking scratch/wear marks on the inner end of the camera mounting plate's locking key. Seemingly I'm not the first person to have landed up with this item. At any rate, I'll see what the replacement head has to say for itself. I do hope it arrives in one piece this time. Thanks again for all the helpful advice. Gray

I'm afraid the camera attachment plate doesn't snap shut at all. Instead it wobbles around ill-fittingly on the head plate, no matter what I try. Worse still, the second small silver locking lever has now mysteriously separated itself from the larger lever, and in doing so presented me with a loose spring! This is simply awful!

Well, the Manfrotto mount and its junior head has arrived, and I'm deeply, deeply disappointed with it. Maybe I'm lot more stupid than I give myself credit for, but I cannot for the life of me get the junior head's camera-attachment plate to work properly. Whenever I try to secure the locking plate via its lever (which itself is a real struggle!) the plate itself lifts up at an ugly looking angle, which I'm sure isn't intended (see pics). Certainly I've NO intentions of risking my scope on the mount as it stands at present. I suspect a fault of some kind. I say this because it seems significent to me that the camera attachment plate itself was disconnected from the rest of the head assembly when the parcel arrived. So it looks like a return to Amazon, and a possible replacement? Damn.

That's a fine set-up you've got there. Looks very impressive. It also gives me enough confidence to take the next step and go for a photo mount myself now. I'll send some pics as and when it's hooked up to the ES scope. Thanks for putting me right on that score.

Ah! I did wonder about that, but not enough make it stick around in my mind. Thanks for clearing that one for me, Bright Giant!

I am interested in what the views and opinions are about using camera/video tripod mounts for smallish 'grab-and-go' refractors. I recently bought an ES 'Essentials' 80mm apo (and a wondrous little scope it is too). Right now it's perched on my hulking Sky Tee-2 alt az mount; but that's just a temporary lash-up until I can find something more suitable: I do my astronomy out in the fields, so lightness is always a major virtue. So I'm thinking of buying a lightweight photography mount, in particular a Manfrotto 055C carbon-fibre tripod/geared head. This weighs in at about 3.3 kg, which is a bag of feathers compared to the Sky Tee. In addition it can support up to around 5 ~ 6 kg (allegedly quite a bit more according to some reviews). Whatever, it's well within the comfort zone of the ES scope (3.4 kg) plus EPs. Also, the scope itself being a fast refractor (total tube length, including diagonal, being a mere 430mm*) means that it's no bulkier length-wise than these monster telephoto lens and their ilk favoured by some photographers. Even so, it's a leap in the dark for me. One proviso: I don't expect an entirely tremor-free viewing experience. Many of these cf photo mounts might be considered rigid enough for most terrestrial purposes, but there's no way (or so I gather) that even the most rigid of them can compare with a sturdy astro mount. My own Sky Tee is like a brick pillar by comparison. I just don't get tremors or the shakes with it, ever. . . not even when it's got onboard my ES Mak Newt and its TV 21mm EP. Nevertheless, given the above situation, I'll be interested to learn who else uses these photo mounts, and just what I might be letting myself in for were I prepared to pay out a fair sum of money for one. Thanks in advance. * I still don't understand how an 80mm f/6 scope (and a refractor at that) can be as optically short as this. Shouldn't it be 480mm in length, minimum? Or am I missing something vital here?

Pete - just to say, many thanks. . . much appreciated. Gray

Hi johninderby. Thanks for getting back to me. Your suggestion looks like a good workaround, but I'm concerned about the extra weight. The Vixon saddle on my Porta 2 mount (which looks somewhat different to your one?) plus a photo-type dovetail, could add nigh on half a kilo to the overall weight, and I'm already pushing the boat out with my current OTA/EP setup. Still, I'll certainly consider if all else fails. Nice photos. PS. I'm pretty sure the bolts I need are 5/16" UNC. I'll find out for certain in a few days time, and I'll post the results, come what may.

I've just come into possession of a Vixen Porta 2 Mount, only to realise that that the saddle that comes with it is inappropriate for the dovetail bars that my two scopes use. I therefore went to replace the saddle for a spare ADM "Vixen style" dovetail plate adaptor I happen to have (see link below). It seemed a simple enough solution, but for an unforeseen problem. The Porta 2 mount's outer threaded bolt holes don't line up with those of the ADM plate adaptor. A partial solution is to use two of the mount's four inner bolt holes instead. These do line up with those of the ADM adaptor in question. . . but now there's another issue - two in fact: 1) The Porta 2 mount's bolts are all in Imperial! 2) Meanwhile the mount head's inner bolt holes are visibly larger than the eight outer ones (which appear to be 1/4"). How much larger I don't know for certain. . . 5/16"? Also, are they UNC or UNF? I have tried to contact Vixen by email, but for some reason the link on the company's webpage doesn't work for me. So it comes down to this: does anyone know what size (and type) of bolts I need to get? Thanks in advance. https://www.rothervalleyoptics.co.uk/adm-vixen-style-dovetail-plate-adaptor.html

Thanks for all the helpful responses. I think part of the issue is having a refractor that's not really all that grab-and-go friendly. Saying that, I can (just about) get by with my current Skytee mount. At least it's sturdy enough not to worry about ever having the shakes. It's fairly rock-like in that respect. And that applies to the ES 6" Mak-Newt, as well as the considerably less weighty TV 4". As for a carbon fibre mount, assuming a suitable one can be found, the wallet will need some serious consulting. So the adventure continues. . . A closing thought: if funds were forthcoming and I were living in a big open country like Australia, say, one idea would be to buy a 4x4 and turn it into a mobile observatory. But, hey, dream on! PS. I'm now actively seeking out a possible carbon-fibre mount/tripod, such as are those used for terrestrial camera work. I'm aware of the different requirements that exist between a camera and a telescope. . . how the length of a given scope can create balancing issues. . . the moment arm, etc. Even so, I'm impressed both by the fantastical lightness of these c/f mounts (2-3kg) plus their equally fantastical load-bearing capabilities. The Benro GoPlus Travel Tripod, for instance, is claimed to have a 14kg - I'll restate that: a FOURTEEN kilogram - capability. Hell, this is almost three times more than the weight of my 101 OTA! In fact it's so extraordinary that I'm sure I'm missing out on something fundamental. What it is exactly, I know not, at least not yet. Therefore, I'd be very interested to know if anyone else has pursued this c/f line of enquiry, and all being well, can offer some sage advice on the subject.