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Stratis

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Everything posted by Stratis

  1. Hi all, Coming back to astro after a long break, many ups and downs I recently hauled my trusty CEM60 out of limbo and realised I'd like to shift to a smaller mount, as I have never come near the incredible weight limits on this mount for imaging or visual. The new CEM40 really looks perfect in most regards, so I am hoping that will serve as my new main imaging mount. I image with apo refractors, from a 7kg 115mm TS triplet down to a little WO Megrez 72 at only 2kg on an AstroTrac, with both DSLR and QSI 583wsg (so about 2kg camera package). My greatest imaging load has never exceeded 12kg. I already have an amazing Avalon T-110 T-pod underneath the CEM60, with an iOptron adapter atttached, this one in fact: https://www.teleskop-express.de/shop/product_info.php/language/en/info/p10799_Avalon-T-Pod-110-130-Adapter-Kit-for-iOptron-iEQ45-and-CEM60-Mounts.html This adapter has the central peg for iOptron, plus mounting holes set around the perimeter for the alignment pegs. The adapter has two sets of two threaded holes; the first set is 130mm apart across the centre, and fits the CEM60 perfectly. The second set is 120mm apart across the centre, and I think is meant to fit the smaller iOptron mounts like the iEQ30. So the £1400 question; can the adapter accept a CEM40 mount? Can the two threaded holes set 120mm across the centre mate with the CEM40? If anyone has any info on the absolute mounting hole arrangements for the CEM40 alignment pegs it would really help
  2. Hi there, That is really nice work given you're using an ST80. My first bit of advice is to make sure your focus is dead-on and locked-down. Even if it looks ok on the screen, it probably isn't. The difference between in- and out- of focus can be 1/16th of a turn on the wheel I would advise you to buy a cheap Bahtinov mask for your scope, and use that to achieve focus. It is surprisingly easy and very accurate. That will improve all your images from then on. Other than that... it's hard to know which technique will work best with the GPCAM, single-shot or video stacking. I've heard of people installing cooling mods on the outside of their GPCAMs to reduce the noise in the images, usually with old CPU heatsinks etc.
  3. Hi all, After months of back injury, busted ribs and cloud, I finally got to use the CEM60 in anger These are taken with a QSI 583wsg, shot through a 115mm T-S triplet apochromat, and I continue to be amazed by how well this scope controls false colour. Didn't get as much data as I'd hoped for as houses kept getting in the way, but these are decent enough I think LRGB, 10 x 600sec exposures HaRGB, 17 x 180sec exposures total. There are some slightly eggy stars here and there, I still haven't got my flattener spacing right. Can anyone offer any advice on LRGB processing software? I'm using AstroArt but trying to look at alternatives.
  4. Nobody has any idea? Is it literally impossible to do this with available parts?
  5. So I have a quandry. I have a suite of good finders and guidescopes of varying types and sizes, all of them in the Synta-style wedge format foot. As fate would have it however, I have ended up with two of my main lightweight scopes being little William Optics refractors, a Megrez 72 and an 80mm triplet imager. These of course, have the William Optics-style shoe installed. I'd like to know if anyone has cracked the problem of using Synta bases on WO shoes. I can imagine the shape of the adapter in my head, just a question if anyone has made one before... Thanks
  6. As a GT-81 owner I can recommend it, but you must budget for a field flattener; the GT-81 does have a curved field. I have no experience with the Esprit but they produce highly detailed and sharp images competitive with the better imaging refractors on the market, so I doubt you'd go far wrong. I also echo the recommendation for the Explore Scientific 80mm triplet; it is a neat and lightweight platform with good CA control and lesser field curvature than the GT-81, although I'd still recommend a generic flattener. In general I think you are on the right lines!
  7. Well, alright. Personally I think a small frac is always going to be easier for the beginner than a medium-sized newt, for the reasons you mention. Narrow FoV, wind and balance issues, collimation, all that jazz. Yes, I advise you to go for a small refractor, they are excellent and vanishingly easy to use. Your setup time is halved, your troubleshooting time is near-zero because there's only about three screws on the whole thing. If it's an 80ED or bust, then yeah, go for it but make sure you have the 0.85x r/c, as far as I'm concerned that is an essential item. You will get good data out of it at a low price. Buuuuut.... If I can persuade you to look into f/6 scopes, I think you will have an easier road of it. With a standard 0.8x R/C unit (also essential...you DO need one) that goes way down to f/5 or thereabouts. You will be able to create lovely images with the SkyWatcher so please don't feel like you can't buy it or that it'll let you down; it won't. But I also know that if you can start your imaging train with that extra f stop under your belt, it will make a lot of headaches go away. Also consider that lower f/ratio almost always means a shorter focal length, translating into an even wider field of view. I tend to image between 500 and 700mm and the difference at the lower end is remarkable, although objects do tend to get a bit small. Either way you'll be better off than mosaics with a large wind-catching tube.... that way be dragons
  8. Actually I don't advise going for the 70ED. A large number of optics are sourced from Taiwan and China, which in itself is no bad thing; these companies (Long Perng, Kunming Optics) are the reason we can buy a sharp, unadorned apochromat for less than the price of Sky TV. The optics are generally good, but not equally so. The 70mm series, in my experience, is a bit of a black sheep in the small apo market. They're nice for travel scopes, but honestly they suffer from an unusually great amount of chromatic aberration, specifically a green/purple halo around stars. The 72mm however, for some reason known only to whichever optician came up with the formula, fairs a lot better. Altair produce the 72ED-R which I heartily recommend, as it contains the same lens group as the William Optics Megrez 72 you see in my signature. It's the lightest scope I can image with, and it's at a nice quick f/6. One thing; it's a doublet, so you will still see some residual halos around stars. Nothing much to worry about really, at small apertures CA is usually well controlled, but it won't stand up to a triplet on colour correction. I advise you to search on Astrobin for the scopes you're looking for, to see images made with them (make sure you're looking at the *imaging* scope, a lot of people with huge telescopes use a 72mm as a guidescope!). The 80ED would serve you well, but as Ive said in another thread, I am not a fan of its focal ratio; f/7.5 for me is just way too slow.
  9. Oh absolutely... I do my photography between f/1.8 and f/4 and even going up to f/4 bothers me when I shoot raw and see all that extra noise. Even with a cooled CCD, every f/stop you advance is not so much robbing signal as it is adding noise. Your final images will always be that much muddier, requiring that much more processing, more subs, more time to bring them to the standard they could have been already in half the time. There are plenty of imagers able to overcome this and process truly spectacular vistas out of data captured at f/8 and above, but they walk a very difficult road, and generally have observatories
  10. I thought of having a go at that, but if you look at the response curve, only the very highest blue frequencies are permitted by the red filter, so simply adding blue to red won't work, as that would effectively make *all* blue stars purple rather than those with a bias towards the upper blue/ultraviolet range. I guess that's the problem they're trying to address, a standard B filter treats all 'blue' light the same, and thus cannot actually make that jump to violet that the rods and cones in the human eye actually show us.
  11. I'm going to offer what may be a controversial piece of advice for an imager looking for a beginning refractor, but its one that I've come to over many nights of amateurish fumbling with imaging setups; Do not bother trying to image above f/7 native I know, I know, thousands of people do it well and someone's almost certainly doing it right now, but honestly, focal ratio is the single most irritating and immovable obstacle to satisfying imaging as a beginner, at least in my case. I see the value of RC and Cassegraine setups at extreme focal lengths for really high resolution, but very rarely is the beginner in possession of the craft and experience to handle that kind of setup. A beginner needs simplicity, and a setup that aids the learning process rather than impeding it with a panoply of possible failure modes. With a fast scope of f/6 or lower, you will accumulate data like nobody's business. One single night of imaging will yield twice as much data, or twice as many targets, as a similar experience at f/8. As a beginner, particularly considering a refractor (I own far too many refractors, I love em ), I advise you to look into faster optics. William Optics do some lovely ED scopes at f/6, as do Altair Astro, with reducer/flatteners available to get you down closer to f/5 even. This will allow you to pull more light and detail out of your target faster, and all else being equal that is always a good thing. As others have said, the 80ED is a cracking scope and gives wonderful views, but it has always struck me as a refined 'classic refractor' concept for visual work rather than an imaging platform.
  12. Hi chaps, While waiting for the seemingly-interminable bad weather stretch to clear up, I've spent some time looking into my imaging setup. I'm using a QSI 583 mono CCD, so rely on LRGB for my colour data. The filter set I currently use is the Astrodon E-series, which is alleged to be colour-balanced specifically towards the 8300 sensor, but I ended up doing a lot more narrowband than broadband and haven't had much opportunity to test that. I've recently run across a somewhat esoteric filter set from IDAS, which comes with a most unusual feature; the red filter actually permits some very low-wavelength blue light along with the red: IDAS claim that this gives hot stars a 'violet' colour by boosting the red channel on a hot blue-white star... My question then, is this a good thing or not? On the one hand my scientific brain feels this is somehow 'corrupting' my colour data... but on the other hand, it is true that the human visual system perceives the upper blue frequencies as purple, not the pure blue that a standard B filter would give you. I'd appreciate the insight of my elders on this one, if anyone has any experience with them
  13. I paid under £400 for mine, which is less than their original RRP so I feel quite fortunate. I've seen them offered at £450 and £500, including one bloke who had a full set hinting at a £600 price for the 30/40 that I doubt I would go for given how close it is to 21mm Ethos territory! I have to agree with John's characterisation of the XW30, it really does give an impression of restrained excellence. I'll be selling about five 20-40mm eyepieces from my collection now that I have such a remarkable piece.
  14. Got this out under the stars briefly.... amazing. The view was very similar to the Zeiss surgical eyepieces I reviewed recently, but much wider and more engaging (if a touch softer). This is the best mid/wide eyepiece I've ever used; I will now have to begin selling off all the lesser EPs I bought to cover the 30mm range
  15. ...I have it! Perfect condition, still in the original box This is one massive strike off my bucket list, been searching for over two years for one of these little beauties!
  16. Hmmm... I have a 1145P 'Skyhawk', that's an F/5 parabolic Newtonian, if a little baby one. Will that be a sufficient test, will the aberrations be comparable to a big one?
  17. Yeah well same can be said for those lucky so-and-sos with that wooden-cased BGO set, or the TMB SuperMonos, or Pentax XW30/40s Me too, and to be honest I need to go back and check that. I am not immune to being an idiot and looking at the wrong thing, and I only had ~30secs at a time to make an observation before having to switch. If I've been staring at something totally different but nearby I shall not be amused... Just so; they are obtainable, it just takes a bit of persistence and luck. If you want to shell out, APM would probably track some down for you.
  18. Aye well it's very easy to be enthusiastic about these! I remember being impressed by the scientific sharpness in the Meade RGO and Baader Classics, but wishing they would give a more pleasing, 'cinematic' view. These wide, flat and sharp EPs grant that wish and then some, I almost wish I could provide them to a few more people and compare impressions etc so I know it's not just my opinion. There are astronomers out there with a much broader experience of top-shelf eyepieces than me! Sadly seems to be a matter of sheer luck of the draw. Following this review I know one other SGL member managed to track down a pair in Germany, and there was a bloke selling a pair on AB&S for a rather steep price. If you see some of these with the wider field stops (above 20), I'd advise buying them if the price isn't too eye-watering. With the barrel conversion these have run me £70 each, which isn't bad at all; I suspect I'd pay up to twice that, going any further would make me a bit nervous but then the TMB Aspherics sell for considerably more than that. The 'little' Zeiss in this review tends to be a lot more obtainable, I've seen two go by on eBay. The 18mm field stop is actually just a bit of plastic, the lenses themselves are much larger, so I am going to try to modify this one to increase its field diameter. If I succeed, it might be a more accessible route to this sort of sharpness, as the view even in the cheaper one was really quite lovely, just restricted to an annoyingly narrow field, around 45deg or so. That seems to be the party piece of the 10x/22s... flat, sharp but also Plossl-like AFoV.
  19. DSO and Barlow Update! With the planets just out of reach recently whenever the sky has been clear, I took tonight as a chance to get in a few quick DSOs, and to see how well the Zeiss responds to barlowing. In addition, I have just received my 1.25" barrels, internally blackened and machined by eBay seller Micro_Crystal; this guy has quite a lot of good microscopy stuff. These are well-made, with filter threads and a striated barrel surface to reduce friction when mounting. Finally, I found on eBay another Zeiss eyepiece, this one somewhat different; this little guy is labelled 'PI 10x/18 B', so I expect good eye relief, technically a longer focal length than the 25mm (if it has the same 10x mag but a smaller 18mm field stop, it must be a longer FL), and whatever 'PI' is meant to mean This EP is much smaller and lighter, has a curved lens surface vs. the planar 10x/22s, clearly of at least a slightly different optical formula. Inside this eyepiece (the lens elements just fall right out if you foolishly unscrew the barrel...) are two cemented elements, paired with a single-element eye lens, which to me says it's likely to be a very fine Koenig design (although I thought Koenigs had planoconvex field lenses?) rather than anything more exotic. Testing Another irritating windy night but at least some clarity between the fast-moving cloud banks. I figured I'd do a quick test on the DSOs within reach, then switch back to double-splitting but this time with some extra kit in play. I have a pair of 1.25" Astro-Engineering barlow lenses, which both contain ED glass and have proven well superior to any other barlow I've used with the exception of TeleVue Powermates. On this particular night I chose the AC710 'Supreme' 2x barlow, and the AC519 'ImageMate' 4x. Neither have ever shown a hint of false colour or distortion, I personally rate them up there with TeleVues in terms of optical quality at a much more sensible pricepoint, and I say this as a guy with two Powermates in the bag The scope today is my new Explore Scientific 80mm triplet, which has yet to receive a proper run-out thanks to the weather. This matches nicely the previous instrument in the first test, also an 80mm triplet. On the side, I am quietly figuring out which one of these two little beauties to actually keep Please note, the DSO images herein are not eyepiece projection photographs, they are just there for a bit of flavour. DSOs I popped the 10x /22 into the scope and started a hunt for some easy DSOs for the 80mm on a manual Alt-Az... this took a little longer than I'd have liked without a finderscope (anyone know how to attach a standard finder shoe to an Explore Scientific scope?) but I guess I must be learning my way around as I managed to track down a good number. For each I spent at least five minutes with the bigger Zeiss, then swapped out for the baby one as a comparison. On the Andromeda Galaxy, I was impressed straight away and remembered my previous comments... the view was utterly crystal sharp, I was able to use even the dim stars surrounding the object as focus references, when many eyepieces make that a vague and difficult experience. Focus attained, I could clearly make out the traces of the dust lanes draped around the bright, bluish core and even (with effort) trace outwards to the extremities of the spiral arms. This view exceeds any of my other eyepieces in clarity; I found myself wishing for a big, fast Dobsonian to really give this eyepiece the light grasp it needs to make the best of itself. Swapping to the 'Baby Zeiss', I was gratified to see a really very similar view, albeit at a smaller scale. The dust lanes were still visible, but I felt they were a little less distinct; the outer reaches of the galaxy were harder to visually pin down. I noticed, very strangely, a notably different colour cast between the two eyepieces; the bigger Zeiss were more neutral white, while the smaller gave a slightly cooler, bluer impression. Overall a nice little eyepiece, but much closer to an 'average' orthoscopic with a much narrower field and a slight contrast loss against its big brother. On to a much lesser-known open cluster, M29, the 'Cooling Tower'. The view was beautiful... all members fit within the field of view, and shone out as tiny, bright points. Again, I have seen this cluster before but found it unremarkable, this eyepiece rendered it really quite enchanting. In the little Zeiss, the blue cast repeated; star shapes were kept under superb control just as in the larger eyepiece, but the narrower rendition did rob the view of a little spectacle. I also noticed something for the first time; the baby Zeiss was much less accommodating of eye position. The big Zeiss showed no kidney-beaning and a nice big sphere of space to park your eye in without any degradation, but the little one demanded laser-focus, perhaps betraying its more humble microscopic origins. I managed to get a quick view of the Cygnus Veil before a huge cloudbank closed off that section of the sky. The contrast advantage of the Zeiss was clear and unmistakable on this faint gossamer object, I was able to locate some filamentary features with a broadband view. I added my favoured nebula filter to the optical train, the 2" DGM Optics VHT freshly imported, and was rewarded with a clear perception of around 70% of the arc. As observers of the Veil will note, seeing it at all in an 80mm scope is not always easy, and the Zeiss didn't waste a single photon. If anything, the restricted AFoV made it easier to see dimmer objects, as the light is concentrated into a smaller surface area and not spread out (my chief complaint of the Ethos line) too much to register. I would still prefer the view through my 8" SCT for sheer light grasp, but the 80mm did really well here, and I could recognise (if not really explore) what I was looking at. Sadly I could not try the smaller Zeiss on this target. The final target was another little cluster I quite like (and one of the only targets available with that cloud bank smothering Cygnus), M35 in Gemini. It's tough to find and rewarding to be able to do so manually, although I did have to resort to a 2" 38mm SWA to do my sky-scanning . Once found and back under the Zeiss, it was tiny and pretty and perfect as a little postage stamp constellation. The various stellar spectra were strong and gorgeously contrasted. The baby Zeiss again did alright, very sharp and correct, although the cooler tone seemed to rob the members of the same colour contrast I now knew existed. Overall, this is a spectacular DSO eyepiece; contrast is clearly its greatest asset, it really does feel like every single photon is being captured and brought to you, no scattering, no flare, no drama. You really do miss the wider immersion that a 2" can grant you, but in giving that up you gain so much in terms of sharpness and contrast I can think of no better companion for those really tough Caldwell objects. I really, really want to try this eyepiece in a bigger scope, if anyone in the Oxford area has a huge, fast Newtonian and can predict the future weather, I would love to hear from you Barlow Response In my initial review I speculated that a barlow lens would really synergise well with the Zeiss, given the Airy disk plunging below the limits of my visual acuity. If the barlow is particularly finely made and does not compromise the view in any way, the Zeiss should simply keep offering tiny star shapes with ever-darkening and widening gulfs between. I tried first the double-double of Lyra Epsilon, but at 480mm of focal length they remained as stubborn points. Upping to 2x helped not a bit, even 4x (for a magnification of 77x) started to show some elongation and dark shading between, but couldn't quite separate the pairs. I guess the 120x recommendation for this pairing is accurate, I have little trouble viewing the partners in my Cassegraine scopes. I suspect a nice long-focus refractor like the Lyra Optics or Tal 4" would work very nicely with the Zeiss on double-splitting, but I'd find it hard to beat a fine Mak at this particular challenge. The smaller Zeiss did no better, and actually failed to control star size as well as I went to 4x. This does make me think that the 10x/22s are a superior optic. What I did note was that the stellar shapes actually got smaller and more compact-seeming as I upped the magnification; I suspect this is an artifact of the dimming of the view. At 4x in particular, the star images were really quite refined and delicate indeed, reinforcing my determination to try the Zeiss in my 150mm Rumak which gives the most refractor-like view of any scope I own besides an actual frac. Next I tried familiar Albireo as I had a strong basis for comparison owing to the first test. I was rewarded at native power with another glorious view, partners cleanly separated and vibrant in their respective spectra. Barlowing up simply blew the partners apart, opening a deep black chasm between the two. The star shapes were simply divine. Being mid-magnitude to begin with, the images shrunk to a delicate filigree, with colours still perfectly reproduced but restrained to a tiny little speck. Unlike my earlier Plossls and so on, the stars did not bloat out to a spherical-looking orb when heavily barlowed up; they retained a fine, almost spiky appearance, simply at diminished intensity. Perfect. The baby Zeiss replicated this performance albeit with less authentic colours; the cool cast really screws up Albireo, particularly coming from the dead-on neutral of the 22s. The slightly larger star shapes were also in evidence. After that I simply went binary-hunting, swinging around the sky with the barlow mounted so as to increase chances of spotting a separation. I found a number I doubt I'd ever seen before, mostly very dim, and the Zeiss just ate them up; every barlow was used and was useful, I longed to try my 5x Powermate but the clouds were getting worse. I particularly enjoyed the many, many spectra revealed as I roamed the Milky Way; even at a fast pan, I was able to distinguish between stellar types with relative ease. The smaller Zeiss showed up slightly less effective transmission, very dim stars seemed slightly more difficult to pick out. Bonus Round - the Moon again! I noted as I went to pack up that a low-hanging cloud front had cleared for a while, revealing the crescent moon; I swung around for it immediately. The same three-dimensional feel returned, the crater walls were just so crisp.... in fact the seeing was causing me more difficulties than anything, and thanks to the fidelity I could really see the seeing. I popped in the 4x barlow and was rewarded with a very accommodating view, no loss of sharpness and enough clearly visible lunar features to keep me busy for hours, had the clouds not started to roll back in. The range of shades and the tiny hints of craterlets and ejecta was beautiful, and honestly bested my experience with the Pentax XW series on this target. The baby Zeiss was decent, again rendering a bluish-white moon rather than the yellow-neutral in the 22; it then occurred to me that despite having spent a lot of time bashing this little EP against the legend of its bigger brother, it was actually a damn fine long-focal length ortho-a-like. The view surrendered little to the 22, and I would have been equally happy with either had the AFoV been constant. As it was, reduced image scale was a little harder to deal with, making the moon feel 'far away' down a tunnel rather than reflected in a perfect mirror. Conclusion All in all, a resounding success for the Zeiss and a very rewarding classical night of observing; no widefields, no fancy electronics, not even a star map to guide me. Just the sky, my memory, and a little 80mm refractor on a Vixen Mini Porta. The beauty in the Zeiss made this experience really a little bit special, it took away that feeling of directionless frustration and slight malaise that can haunt you when viewing the sky in a small scope with a subpar eyepiece; it is this feeling of not-quite-disappointment that I feel robs a lot of beginners of their future in astronomy. The Zeiss brought a little bit of magic back to this very ordinary experience. If I hadn't seen such riches I could live with being poor; I know now I will be unable to ever return to my Plossls, except perhaps very fine examples. My 1.25" selection will simply be Pentax XW on the low end, scaling up to Zeiss on the mid range and I guess a 30mm Takahashi LE for scanning. With a good little barlow I can cover all the ranges I will ever need, and this gives me the chance to really simplify my eyepiece case: XW7, XW20, Zeiss 25mm, Tak 30mm. Four eyepieces, all with something special to offer and no looking back for me. I also know I can cease my ortho hunt, as ultimate sharpness in an ergonomic optical package is now within easy reach. The Zeiss really is a superb general-purpose eyepiece, from double-star to DSO and lunar viewing. I suspect it would be a stunning partner for planetary work. Perhaps the focal length is a little long for really hardcore double-splitting, but if you are serious about that discipline you almost certainly have a long refractor or Maksutov and can bear a 25mm for the sake of comfort, which the Zeiss also delivers in spades with no kidney-beaning or blackouts unless you get really, really far off. The little guy there on the left, I have been quite tough on tonight, but to be honest is still a superior EP to many in my collection and cost very little on an eBay auction. It feels more like a long ortho than the 'Plossl crossed with an ortho' feel of the 22, but plenty of people have cases full of orthos and this would make a fine cast member in that performance. Both pieces delivered superior, sublime sharpness and what has to be best-in-class contrast. Control of optical aberration was absolute, the fields were flat as a pancake, sharp all the way to the edge and free of glare, flare, ghosting... you name it. In each performance category save flare control, the 18 lagged behind the 22. I suspect they are simply built to different price points and tolerances, but if the 18 was all I had I'd still love it. I'll be keeping these forever and probably passing them on to the next generation, they are artifact-grade and I love them to bits Paul
  20. I concur. I have a 127XLT which is just a C5 with a nicer paint job, (not quite a C6 in terms of aperture but much, much more feasable as a travelscope/grab-n-go). I also have an orange-tube C8. I've bought many add-ons for the SCTs, including a Starlight Micro-focuser which is fantastic, but the focal reducer is the one item I really couldn't live without. Shifting to f/6.3 almost feels like the intended performance of an SCT to me. I am aware that the field of view does dim towards the edges and the field stop can get fuzzy in some eyepieces, but everything besides planets and double-stars which benefit from large focal lengths are much easier to detect and appreciate. With the C6 you'll find that the baffle tube diameter limits your maximum field of view, so don't expect to use a 38mm 2" ultrawide and utilise the full field, it will be cut off slightly by the baffle. In practical terms, this means you need to do some maths and find some wide EPs with the same true FoV as your baffle tube can deliver. I'd like to warn you off the Antares and Meade versions though; despite them often being thought of as the 'same' as the Celestrons they aren't, in my experience the Celestron model is easily the best, with the earlier Made in Japan versions better still.
  21. I imaged with Baader filters for about two weeks, then switched to Astrodon 5nm (not got deep enough pockets for the 3nm Ha just yet ) I noted an immediate increase in SNR, but a decrease in overall signal. With a noisier chip like the KAF8300 this is significant, it means I need to run the cooling at the maximum practical level in order to increase the sub length without adding too much noise and eliminating the gains made by the superior filter. Going from an 8min Baader sub to a 15min Astrodon sub was just night and day, and even on equal-length subs the difference is notable. Of course 15min subs turned out to be more than my HEQ-5 could manage reliably, so I bought a CEM60 and have had weeks of overcast skies ever since
  22. Well I can echo the words of Dr Michael Lalk, a reasonably well-known German astronomer, who performed a detailed at-the-eyepiece comparison of several Abbe Ortho families including the Baader Genuine Ortho, which were from the outset designed to be a widely-available but optically-equivalent version of the ZAO-II series. He had this to say; So from a performance perspective, it seems that a BGO or SMC-Ortho will do you, although they perhaps lack the collectable element of the ZAO-IIs. The BGOs are available if you look about, and are a notable step up on the BCO series which is basically a cheaper, more mass-reproducible version. I would be very interested to see these Zeiss 25mms in a direct comparison with a BGO... sadly the BCO and Meade Research Grade Ortho are the only ones I own. The RGOs are considered essentially equivalent to the BGOs in that once you have the Abbe design down to micrometer perfection with modern multicoatings there really is very little to 'improve', but I only have the 10.5mm which isn't a fair comparison.
  23. There has been some scuttlebutt that the Zeiss lens groups used in the construction of these 25mm micro eyepiece is actually the same (or similar as makes no difference) as the TMB 25mm Aspheric Orthos, simply in a different housing and field stop. A guy who owned both says they are exactly the same visually. If that is true, and the Zeiss lenses are the TMB Asph Ortho lenses (or rather, TMB use the Zeiss), they are one of the sharpest eyepieces ever offered to the general public. That would certainly fall in line with the user descriptions of the TMB Aspherics, which are held as truly legendary examples of the optician's art. The defeat of the BCO, itself a fine lens but still built to a cost (The BGOs and Meade RGOs are both superior to the Classics), is less surprising if you think of the Zeiss as a TMB. Amazingly it's easier and cheaper to source the Zeiss versions than the TMB Aspherics these days
  24. Thank you for the kind words I confess I was somewhat hesitant to post my findings after just looking through the Zeiss in isolation.... I felt like I must be biased somehow, or it's actually no better than my other 1.25" pieces but I haven't used them in a while so I've forgotten... I didn't think they could possibly be as good as they seemed. That's when I decided to do the shootout, for my own peace of mind as much as everyone else's They really did stomp the competition... whatever Zeiss did here, they've created a near-perfect median-AFoV ocular, I cannot imagine an improvement on this besides just... more AFoV at the same level of sharpness, which is probably a mathematical impossibility. I'm still sort of in shock at the focal sharpness and Airy disc size, in two years I have always assumed the star size was a function primarily of the telescope, not the eyepiece. I still can't really believe it, even though I've since tested them on terrestrial targets and found the exact same result, much superior sharpness and contrast. The only eyepiece I have that approaches (but falls short of) this level of sharpness is a 37mm 2" ex-NATO Konig that was pulled off a battle tank gunsight and converted; that includes some un-named heavy metal glasses which are probably against an EU regulation by now, but that one does come close to the Zeiss; same sort of good (but not inflated) field, great colour reproduction and total absence of aberrations. They are rare obviously, but there is a guy on AB&S selling a pair with a Baader Mk V binoviewer, he's willing to split the items I think.
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