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I wanted a thread for the long refractor (f/9 or more!) because it is linked to me. I remember when when my grandad bought me a 70mm f/10 scope, the moon was crystal sharp, Jupiter showing its band in some detail, and, most important of all, no CA. (You know there was a little bit of CA but not much to ruin the experience) And so I thought to see your story of the long refractor, so post it below! ( I also had a 60mm f/11.5-ish telescope!)

Hello everyone, I'm relatively new to this hobby and there's a few telescopes I've been looking into across a few budget points. I'm most interested in the planets, the moon and double stars, though would definitely like the ability to explore other things, so a good 'all rounder' would suit me best. The first is the Sky-Watcher Explorer 150P F/5 which is relatively cheap, but seems to have good reviews. The second is the Altair Ascent 102ED F/7 which despite not having many reviews seems to be a solid choice The third is the more expensive option, the Sky-Watcher Evostar 100ED DS-Pro F/9 - which has better glass than the former. If anybody has any opinions on these choices or any additional options that aren't too expensive that might perform better I would love to hear everyone's input!

Hello all, I've bought an old 80ED that had supposedly never been used. It was in its original box etc. There's *something* on the lens that looks white-ish. About 2mm by 3mm. Looking through from the focusing end it's jet black... Apart from that it looks ok apart from one speck of dust - also black when looking through it. What do I do? Also, even though the focuser action seems smooth there's a slight 'up/down' to the knob as it's turned. I wonder if it's been dropped and the rod has been slightly bent. So I'm also worried about 'soft' lenses if that's the right terminology. How can I check the integrity of the lenses? Thanks in advance. Context: I had an 8" dob about 5 years ago. Moon. Saturn. Jupiter. Star hopped to the great Hercules cluster. Failed to see Orion Nebula due to light pollution. I'm slowly gathering cheap gear together to hopefully dabble in a bit of astrophotography this winter.

I recently acquired a Bresser AR-102S, a 4", F5.9 achromat. I was expecting to see colour fringing on brighter objects and that's what I did see, although not as badly as I'd anticipated. It was the usual purple colour extending past the limb of Jupiter, the moon and the very brightest stars. Those observations were done with a Tak 1.25" prism star diagonal, replacing the stock diagonal. Last night I used for the first time a 2" quartz-dielectric mirror diagonal. On the brightest stars I could still see a little violet, but on the moon I was surprised to see instead that the fringe around the edge was now a "fluorescent" green, or sometimes a green/yellow (I tried with several different eyepieces). Also, the fringe was narrower than before, almost a line around the moon's edge, rather than a band extending into the surrounding space. A quick search on here suggests that this green/yellow colouration isn't uncommon, but it leaves me with a question. I had been thinking about getting a filter to tame the CA a bit, possibly one of the milder Baader versions (and if I got one with the neodymium substrate it would also double as a contrast enhancer on the planets). I've tried a cheap yellow filter but I didn't like colour cast. But now that my CA seems to be green/yellow rather than violet, I'm thinking that the usual minus-violet filters aren't going to make any difference, are they? I'm also thinking that the switch from prism to mirror must be instrumental in the change that I see. I know that prisms can introduce some CA in faster scopes, so perhaps some of the fringing I was seeing previously was down to the diagonal and not the scope?

Good evening everyone, I'm looking into buying my first telescope. Interested in planets and DSOs. I've narrowed it down to 2 scopes: the Orion SkyView Pro 8" reflector and the Celestron Omni XLT 150 refractor. A few people on here highly suggest the SkyView pro 8", but I'm curious as to how much maintenance is going to come with it? I'm American living in Sicily, so it's not easy for me to go to a shop and ask for help! From the price and high ratings of it, it's very appealing. But on the other hand I understand the refractors require almost nothing, just keep the lens clean. Any comments?? Thanks

I just bought an Istar 150mm F12 lens and cell and will be building the telescope to hold it. The guy I bought it from has generously given me some excellent advice, so I know where I will get the aluminium tube and how I will cut it, how I will plan the light path and baffles, and how I will flock it internally. He also suggested a couple of focusers that he has used and likes. I think I will probably go for a Moonlite focuser as I have one on a newtonian and I really like the smoothness and precision of it, but I am also considering a couple of others. Do any of you have either the TS Monorail or the Baader Steeltrack? What do you like and dislike about them? I will be using the scope for visual observing only and the heaviest eyepiece I will use on it will be my Explore Scientific 30mm 82° at 1.4kg. Thanks.

Greetings from cloudy and cold NJ! I recently had a lens replaced on a 102mm refractor, 1000mm FL, f/9.8, due to undercorrection of something more than 1/3 λ. The Ronchi lines seen in the double pass autocollimation test with an oil flat were significantly curved. The test is, of course, quite sensitive and allows one to see spherical aberration very easily. The new replacement lens is far better in that respect and a definite improvement over the original. It also shows a measure of undercorrection and I'm wondering if anyone familiar with the test and reading the images would hazard a guess as to the approximate wavefront quality of the lens. Nothing precise, just an estimate would be very much appreciated. Here are the specifics: Lens: 102mm, 1000mm FL, f/9.8 achromat. Ronchi grating: 150 lines per inch or 5.9 lines per mm. Oil flat, Double Pass Autocollimation. The distortions in the shape of the images are due to imprecise alignment and the variations in the line thickness from uneven illumination and slight oil movement. Of course, the 3 image diffraction overlap of the test gives a false impression of the poor edge quality. As I say, anyone who may have a knowledge and experience with the test and an idea as to what these results might translate to would offer an opinion as the the wavefront quality, or a range of same, I would greatly appreciate the information, for nothing else than curiosity about the new lens and a feel for the test. I'm quite happy to have received a much improved lens and I am sure it will be very satisfactory for use. Thanks very, very much! Joe.

Hi all. Living in Cadiz, Spain I have to walk a mile to a great dark site and my two telescopes ( see below) are too heavy and cumbersome unless I get a gang together. Can anyone suggest a good refractor that along with tripod would not put me off heading out at night? Not too restrained on budget. Up to £400 but it seems the better the scope the more the weight from what I've seen. Do like to find a few DSOs and here recently excellent Saturnn and Mars. OK I'll look at anything I can find really ps: I get back to uk so no probs buying there. Cheers for any thoughts.

Hi all, As the title says, is it possible to make my own triplet apochromatic refractor? I've made my own Newtonian reflector before, and I've heard of people making their achromatic refractor, but what are the difficulties of making a triplet apochromatic refractor? Thanks! Fishie

I bought this second hand, but it was almost untouched, and a relative bargain to boot. New it costs 1199 EUR from TS (approx. £1035 as of 08/03/2019 but who has any idea how this might fluctuate). Highlights: Apo air-spaced triplet with FPL53 Multiple focus positions thanks to removable tube segments 2.5” rack and pinion focuser, rotatable, dual speed controls, 6kg payload, with printed scale CNC tube rings and dovetail supplied Retractable dew shield First impressions: It’s a really nice box. Whilst it’s described as a ‘transport case’ the supplied storage box is sturdy and well made. Inside, the foam fit is precise bordering on tight. It’s actually mildly difficult to get the scope out of the box. Things get a little easier if you loosen the tube rights slightly, allowing for some tube rotation, and a longer term fix will be some straps to aid lifting the scope out vertically. The scope itself feels very well made, and is what I’m choosing to refer to as ‘reassuringly weighty’. At just over 4kg (without diagonal, eyepiece, or finder) there are definitely lighter options available, but it’s hardly a heavyweight. The finish is powered coat white, which looks and feels very nice. The focuser is very smooth (compared to my SW ED80) and feels pleasingly solid. I’m not going to be testing the stated 6kg payload any time soon, but I can easily believe it will be able to handle it. The dew shield is held in position with a single thumbscrew, and whilst it’s retractable credentials are clearly warranted, it only seems to extend a couple of centimetres. As it happens, this takes the overall length down to 450mm which was the very top end of my acceptable range in order to meet my ‘travel’ requirement. The focuser body also incorporates a finder shoe, but if you wanna finder then you have to supply your own as there’s nothing included. The idea of having additional tube segments is that you don’t have to rack out the focuser so far, and so improves stability. This also allows for multiple reducer/flattener options for imaging use. The TS website details the specific configurations using their recommended equipment which provide a faster f/4.9 option for sensors up to 36mm, or a full frame flat image at the standard f/6.6. I might be exploring these options later, but for now, this is going to be for visual use. First light: OK - this barely counts, but I was impatient. Predictably enough, first evening with a new telescope and it’s raining. But I did manage a pretty decent look at my neighbours TV aerial and chimney stack. They need some re-pointing. … The following evening (9th March 2019) was less rainy, but much the same for cloud, all but for about 30 minutes of relatively clear sky, interrupted regularly by patchy cloud. So still not great. However, my ambitious setup to allow for cooling paid off and I did manage a few minutes of actual use with a SW 28mm eyepiece. The Baader Zoom I also treated myself to for my travel use is frustratingly still not dispatched. And when I say set-up, I mean just carrying everything outside. I’m using this on the SW AZ-Gti mount, and a Manfrotto tripod I had already, so it’s very easy to pick up and take outside. I was using the scope with one of the two removable sections in place (this is how it is stored in the supplied case) and was able to achieve focus with a 2" diagonal without having to rack out excessively. Sirius was an obvious target to the south, and an easy hit. Brilliantly bright, as expected, and a blue-ish white colour. The upper half (the rest was below my sightline from home) of Canis Major was easy to see, with several of the background stars also visible. Despite the less than great seeing, the view was impressive. Stars were tight and there was no obvious chromatic aberration. Moving up to Betelgeuse, it’s orange-red brilliance was very pleasing, and again I was able to make out some of the fainter surrounding stars. Overall the view was very impressive, and bright. My only real comparison is with my SW80, and of course I now have over 25% more light, so that’s to be expected. But still, it makes an obvious difference. I wasn’t able to note any CA or distortion, and a quick full visible spectrum (no filters) star test reflected spot on collimation and no apparent astigmatism. Alas, the break in the patchy clouds did not last long, and I was soon packing up for the night and heading out for a beer. I’m looking forward to getting some more quality time with this kit, and who knows, I might even align the AZ-Gti next time and write a brief review for that too.

Hi Guys, I thought I would share with you my first hand experience of the Skywatcher ED100 Pro Esprit Telescope, I have only had it a few months, but so far I am extremely happy with the results, it is so sharp and the contrast is very high. I live in a small town, Stowmarket, Suffolk, UK, where the light pollution is not to bad, but still I have to be cautious with the direction I choose to point the telescope. All my astrophotography is done from the back garden on my patio. I have had a few different telescopes over the years, but I always found myself moving more and more into astrophotography, so after some research I selected the Skywatcher ED100 Pro Esprit, as many of the other users had commented on the sharpness and contrast. As I wanted to focus on more wide field astrophotography the F5.5 speed giving 550mm seemed the right choice, I also use an ED50 Skywatcher Guide Scope with an Altair Astro ASI130mm camera for the guiding and of course PHD2 software, all mounted on my Skywatcher HEQ6 mount. Here is a shot of the Andromeda Galaxy, 20 x 30s stills at ISO 800 on my Sony A7Rii, no filters just RAW images processed with Photoshop, Stacked Mean option. I used the Trevor Jones video on his BackyardAstro You Tube page for processing DSO's and it seems to work very well. What you will see from the image is just how sharp it is, something that really surprised me when I processed the images. This has inspired me to spend more time outside in the garden to photograph more objects, plus I have recently purchased an Astronomic CLS Filter for my Sony A7Rii, so I am looking forward to using this to see if it improve the contrast. I will keep you informed. Also I am looking forwarded to trying my Olympus EM1 MK2 camera, yes I know it does not have the capabilities of the Sony A7Rii for light gathering, but it does have a really clever mode where it can stack the images in camera to reduce noise, so I will also let you know how this went as well. Best Regards Jamie

Hi everyone, about a month ago i got my first telescope. Wasn't sure what to get but i wanted something portable and easy to setup and use. After some internet "research" i decided to go for a refractor on a manual alt/az mount. The telescope was on a 50% sale so i decided to go for it , the Meade infinity 90. The package: The scope came in one big box, everything was inside. Included was the optical tube, the mount, 3 eyepieces (6.3mm, 9mm and 26mm), a 2x barlow lens, 90 degree diagonal, red dot finder, an eyepiece holder for the mount and a few manuals. The optical tube: The tube has a 90mm (3.5in) aperture and 600mm focal length. It looks and feels as a quality instrument, it has a small dew shield and the focuser is smooth when you move it back and forward. As expected the lens looks to be coated. It has a dovetail bar on it with 3 holes for screws. The mount: Light but stable, made of aluminium. It has 3 extendable legs, and 2 slow motion cables (alt/az). One screw to mount the tube on on top (adjustable back and forward). The eyepieces and barlow: All 3 are modified achromat eyepieces, the lenses are made of glass and are OK for the beginner, but i would suggest upgrading if you can. The barlow is bad i even think that the optics are plastic (not sure), it is usable if you don't have other options but this should be the first upgrade in my opinion. Observing: First light: The telescope arrived in the morning so the first thing i did after a quick setup was to adjust the red dot finder. I looked at some mountains about 20km away, the view was nice and very detailed using all eyepieces. Combining the 6.3mm with the barlow got me a bit blurry view, but the barlow in combination with the other eyepieces was ok. Night came and it was a moonless and clear night (only light pollution from the city i live in). I saw orion right infront of me, "marked" it with the red dot finder where i thought M42 should be and looked through the 26mm eyepiece. It was a bit blurry but after adjusting the focus i could see some nice pinpoint stars and also something fuzzy, i realized it was the orion nebula. After letting my eyes adjust to the view for a few minutes i started seeing 2 faint "wings" on both sides and in the center were 4 very tiny stars, i didn't expect to see that on my first night. I followed my target for about 15 minutes using the slow motion controls , it was easy to do. Also tried the 9mm eyepiece and with it the 4 stars were more easily seen but the faint clouds got fainter so i moved back to the 26mm. Next target was venus, i tried all eyepieces + with combination with the barlow. It looked like a very bright half moon without any details. When using the barlow the view was ok but purple glow was showing around the planet, without the barlow the purple wasn't noticeable. I also looked at the star Sirius which looked nice, bright and much bigger then any other star i could see that night. After Venus went down i decided it was enough for day one. Moon: I expected it to look good, but not this good. I was observing the moon for a couple of nights until it got full. I could see a lot of details at the terminator , with low and high magnification. When the moon was full it was very very bright and it looked best with the smallest magnification using the 26mm eyepiece. Jupiter and Saturn: I got 2 opportunities to look at these 2, the first time i think the "seeing" was bad. I could only see Jupiters 4 moons and the planet was a bright disc without any details at any magnification i tried. Saturn also wasn't very good, i could see the rings but they were blurry and "dancing" around. But the next time i had the chance to look at these planets the conditions were much better, first target was again Jupiter. With the 26mm eyepiece i could see a white disc with 4 moons.With the 9mm i could see the moons again but now the disc had very faint 2 bands without any color. The view was best with the 6.3mm eyepiece, the 2 bands were clearly visible and on the upper belt on the right side there was a small dark dot, i am not sure if it was anything . Next target was Saturn, event with the 26mm eyepiece i could see that it has rings, i switched to the 6.3mm right away and wow there it was, Saturn and its rings clearly visible, i even think i could spot the cassini devision, but it might have been my eyes playing tricks. I tried using the barlow on both targets but it was making the image blurry, but at this point i had purchased a higher quality barlow and the views were very nice with it , but the max magnification i could use that night was 133x, anything higher and the image was getting wobbly (probably that was due to the atmosphere that night). After that some clouds came in and it was time to get back to bed (got up just to see the planets in 4am). Conclusion: I think i got what i wanted, a small and very portable telescope for some basic amateur observing. I do recommend this telescope to anyone as a first telescope or even to an experienced astronomer who is looking for something light, portable and being able to set it up and start observing in 2 minutes. Also i would recommend you replace all of the eyepieces and the barlow. I got me a few plossl eyepieces and a nice barlow, it was worth it. Feel free to ask me anything regarding this telescope i will be more than happy to answer. Sorry for any spelling mistakes this review probably contains Also i am attaching a few images i took directly off the eyepiece using my smartphone (handheld). The Telescope The Moon: The Moon: Venus: Saturn: Jupiter:

I have been waiting for this telescope for almost five months. Since May, 19th, to be precise. The day I went to the TS Italia store and saw for the first time the SLD model, model now discontinued. I even missed the last available piece just for a few days, once I finally placed my order, June, 25th. It was to be replaced by a newer model, available at the end of the Summer. Boy, am I glad I did miss it. The wait was definitely worth it. The new and improved model is simply beautiful. I fell in love with it as soon as I saw it on the Tecnosky website a few weeks ago, when they posted the product sheet. But in person, it's even more beautiful. So, the people from the store emailed me Friday, October the 2nd, telling me that it was finally available for pickup. I read the message only a whole hour later and it was soon going to be closing time. I started calling at 4:30 PM and I finally managed to get my phone call through at around 5:05 PM. The store closes at 6:00 PM and doesn't reopen until Monday. And it's 40 minutes away from where I live. I made it there in 35. There was no way I was going to have to wait till Monday, knowing my scope was only a few minutes away. So, here's the pre-unboxing picture: - top left, brown box, behind: Vixen clamp for guide-scope - top right, white box: 60mm f/4 guide-scope - top left, white boxes: T2 Nikon ring, 30mm spacer, adjustable spacer - center, behind white boxes: Optolong L-Pro 2" filter - right of filter: spacers mounted and already calibrated for 55mm backfocus, for eventual use of the ZWO ASI 224MC camera with the refractor - top right, Bahtinov mask - underneath the white boxes, top left: Losmandy bar to attach telescope to my NEQ6 Losmandy saddle - big box underneath all of the above: Tecnosky 80mm f/6 FPL-53 OWL Triplet, with carrying case and 0.8x 4 elements flattener/reducer - ZWO black case: ZWO ASI 224MC guide-camera / planetary camera - front left: Talisker 57° North and two glasses (don't mind the shape of the glasses, they are the closest to Whisky suitable glasses that I currently own...) ready for me and my wife to celebrate the end of the wait - front right: box for the aforementioned Whisky I actually waited for yesterday (Saturday, the 3rd) for the unboxing, because I wanted my best friend Omar to be present and help me with filming and taking pictures. We have been friends since we went to kindergarten and we always have had astronomy as a common interest. It just so happens, to my immense surprise, that my telescope is actually SN. 0001, so I own the first telescope ever produced of this new series. The certificate is also very promising, with a Strehl ratio of 0.974 and a Ronchi test that seems very well behaved. I like a little less the red edges on the lenses, but I guess only time and a proper visual - and astrophotographic - session will be able to tell. Obviously the "new equipment curse" didn't help, but we got almost a whole hour with clear sky patches and obviously I couldn't pass up the opportunity. I quickly setup with the bare minimum necessities for a visual observation and me, my wife and my best friend Omar - who helped with the staging, recording and directing of the unboxing event - took a quick look at the Moon, Saturn, Mars, M31 and Perseus Double Cluster. I can definitely understand now, even if the seeing wasn't perfect, and my eyepieces didn't offer enough magnification (25mm and 10mm give me 80x and 200x, with my C8, but with a native focal length of 480mm, even with a Barlow 2x, we could only achieve about 38x and 96x, respectively), what people mean when they say that an apochromatic refractor brings out the objects from the background sky. The contrast was stunning, the stars were absolute points, pinpoint, small and sharp (with my C8 they always have kind of a "blob" feeling), the contrast on the Moon was fantastic and I could see many details, despite it being almost full, and only at 48-96x. I think it passed the visual test with honors. I was also very happy to be able to see the Double Cluster all in the same field of view for the first time. Saturn was well defined, could clearly make out the rings - don't recall, in all the excitement, rush and cycling between me, my wife and my friend, if I saw the Cassini division, but I'll definitely try again next clear sky night. Mars was also beautiful, could clearly see its rusty red color, the polar cap and some darker, black features on the surface. I really can say it's a beautiful telescope, very well made and machined. The attention to details is really of another level, the paint finish is very nice and matte. Also very lovely all the different red and black anodized surfaces, they really give it a nice finish and personality. The focuser is also the best I have ever had on a telescope. Very smooth, precise, with no backlash. Coming from a C8 where every touch of the focuser throws off the image all over the place and the backlash is quite significant, I really appreciated how easy it was to fine tune focusing with a proper focuser, especially with the 10:1 focusing knob. I can't wait to be able to take the first pictures of some star field, to check if even photographically the telescope lives up to my expectations. I hope to get pinpoint stars corner to corner and that the backfocus won't be something too hard to make perfect. Here's some accessories. Optolong L-Pro 2" filter, Bahtinov mask, Losmandy dovetail to replace the Vixen one the telescope comes with, Nikon T2 ring and spacers to use the ASI 224MC with the correct backfocus directly on the telescope, instead of a guide-camera. Here's the 60mm f/4 guide-scome, with Vixen clamp. And the ZWO ASI 224MC guide-camera. Here's the mandatory celebration beer, at Corte dell'Orso (the Bear's Courtyard). It's a Belgian sour beer, lambic style. Oudbeitje by Hanssens Artisanaal, with added strawberries. A very nice beer, sour, tart and fruity. Could definitely taste the strawberries. Cheers! Here's a couple of pictures of the full setup, with everything mounted on my Sky-Watcher NEQ6 Pro. The setup is in its astrophotographic configuration: mount, telescope, guide-scope, guide-camera, filter, flattener/reducer and at the end the Nikon D5300 astromodified. All controlled by Astroberry on my Raspberry Pi 4 4GB, conveniently mounted on a bar across the two telescope rings. And finally a close up of the rig.