tombardier

Hi. I just did something very silly. I noticed a tiny amount of fungus at the edge of my TS Optics f/7 ED doublet today, at the end of a solar observation session. Well I decided I would try fixing that will my ultrasonic cleaner. I think the cleaner did an ok job, but I made the fatal mistake of rinsing my warm lens with cold distilled water, and the picture speaks for itself... So; I'm not soliciting any comments on what a stupid, idiotic thing I've done; I realise it. I still have a nice telescope assembly, and a lens cell. I'd very much appreciate ideas on how I can rescue this or turn it into something useful. I've only ever used it for solar work, with monochromatic Ha, so perhaps I can replace it with an achromatic lens cell. Who knows.. hopefully any prospective commentators have ideas on how to turn this mini disaster around! Thank you in advance

BTW, I have a metal lathe, mill, 3d printer, and I am just about capable of using them without injury. Would buying something like and building an eyepiece around it be a worthy endeavour? https://www.ebay.co.uk/itm/304399238976?hash=item46df9bc740:g:hgAAAOSw7OhiMQtw&amdata=enc%3AAQAHAAAAsMZYAl63au949ziAHjHGTF3cuGmqQ1YGRJzDbV5z9FxnZP1Y0YAMkdZSentdCePOzwMOwZEk%2FHduEYlCmJqEAcOGz1r0MrWK1emB9LoVyBcJ81v3HatZn8gT6zXiPpDd6QuFtqHzfau%2BQ1%2BVIll6bGumnTkhToR4fep6Em28Dpx9%2BHCqWqXcOzt69Ymrm5uKTUgMkSeiTTSvwC%2Fk8OM9LHAkfduMxfUTSJvYVV5ve%2FeI|tkp%3ABk9SR5KV8J_0YA

Hi, I was wondering if someone might give me some pointers on how to get in to NV? I gather the PVS-14 is very popular. Where do you find them? I've never seen one come up for sale on the classifieds, or on astrobuysell etc. I guess people don't want to let them go! I was wondering if using analogue NV is a little like looking at a bright CRT screen? If you use NV, is it now the only way you want to observe? Thanks for any advice!

@Highburymark that's definitely a concern I have too! I agonised so much before buying the Quark I have. I know they're cheap in the grand scheme of things, but I didn't want to shell out £1000 on a lemon! The Quark anxiety is real!

Thanks Vlaiv. This makes a lot of sense! I wish I could easily just try it out, and see! I have an F/11 102mm scope as well, which works fine in the Quark actually, but it'd be nice to play with the focal ratio on that to get it dialled in! I might add the 60mm telescope to my repertoire, and see how I get on with the full disk views before thinking about swapping for a Combo. Thanks again.

Thanks Vlaiv, this is good information! I can 3D print aperture masks quite easily too, and I already have done with this scope to experiment with different focal ratios. I use a Denkmeier Binotron with the Powerswitch, and so I can get a .66x reduction from that which will give me full disk views with my normal Quark, but I can't say I can comfortably see the full disk. I was thinking about buying a ~60mm f/7 scope to scratch that itch. The main reason for asking is the limited "field stop" generally, and I do use the term loosely, because I'm sure it's not technically correct, but which, as you say appears as more of a vignetting. I would love to know if the larger BF could improve the size of what I guess is the AFOV? Cheers!

Hi, I have a Quark Chromosphere, and I love it, for observation primarily. I use it in an TS Optics f/7 80ED scope (mostly). I gather the Combo model which eschews the 4.3 telecentric also has a much larger blocking filter, and my question is this. Does the Combo model give you a larger sort of field stop visually than the Chromosphere/Prominence models? If I thought the view would be less restricted, I'd be tempted to get a 4x Powermate and swap my Chromosphere for a Combo. I don't really understand when the Daystar specifications talk about clear aperture being much larger than the blocking filter size! Cheers!

The seeing is awful here right now, same as last night. Trying to look at the moon, but it's just frustrating, I'm afraid. A shame, as I have been trying to put a a new (to me) pair of 12.5mm morpheus to the test (in my Binotron). I'll try again in an hour or so.

Yes, that's why I'm toying with the idea of trying the 1.5s, but I think the dilated pupils test probably recreates that same situation, where my right eye has gone from -1.0 to -1.25. Anyway, if you want to buy yourself some more 1.0 Dioptrx, let me know

Thank you all. A lot to go through. I was sure I'd already responded w/ref to the Dioptrx, but I can't see my reply now! I do happen to have two 1.0 Dioptrx correctors already, but they haven't worked for me (and they are for sale!). On the prescription before last, both eyes showed -1.0, and on the next prescription, my left (primary) eye was still at -1.0, but my right (lazy) eye had changed to -1.25. Now when doing this consultation the other day, I had some eye drops which dilated my pupils massively, and that showed my left eye to also be at -1.25 (he referred to it as a slight "hidden prescription"). So anyway, I'd love to try some 1.25 Dioptrx, but I haven't been able to find any for sale. I still feel a bit sore after buying the first pair, because I got stung for nearly £60 in import fees a couple of weeks after importing them from Germany! I have had a wanted advert on astrobuysell and on here for a couple of months now. It seems like the 1.25 ones are discontinued by Tele Vue! I'd try the 1.5s, but I don't want to throw even more money down the drain I also tried some contact lenses, ones which could apparently correct to within 5 degrees of the angle of my astigmatism, but didn't find they corrected the problem as well as my glasses. I'm sure I would have got used to them, but I really did find them quite uncomfortable, and very difficult to remove! I also found them rotating when I was looking straight up at zenith with binoculars (reclined, using my parallelogram mount). So anyway, I'm not wholly convinced by the idea of lens replacement surgery, and I feel like the main option at the moment is to stick with glasses! I think I'll buy some new glasses, because I have varifocals right now with transition/reactive tints, and that's a bit of a PITA when I do solar observation! Also a bit of a pain with normal observation, as I have to make sure I'm at an angle where I won't be looking through the transition through to the reading part of the lens! Thanks for all your advice and for sharing your experience!

By "As routine as", I meant to say, it's basically the same procedure.

Well, I don't know. The consultant said it was basically as routine as cataract surgery. And then I read this! Eek! https://www.thefreelibrary.com/Clearing+the+clouds%3A+cataract+surgery+for+astronomers%3A+one+amateur's...-a0378249222

Thank you Keith. Have you found your reading prescription changing over the years since due to an increase in presbyopia, or has your actual astigmatism changed too, and/or your distance prescription? I don't mind wearing glasses day to day, but I do want the best correction possible for the astigmatism, for my observation. I don't like the sound of vitreous detachment! I should just clarify, its Optical Express, the ones best known for laser eye surgery, not Vision Express, the high street optician!

Hi. I have prescription like so: Left sphere +3, cyl -1.25, axis 55 Right sphere +4.25, cyl -1.25, axis 130 In other terms, I am far-sighted, with an oblique (diagonal) astigmatism. I've recently undergone a consultation at Optical Express, with a mind to getting my vision corrected, mainly for astronomy. Optical Express have recommended that I could have single-vision lens replacement surgery. They've said it will correct my astigmatism, and far sightedness, but may mean I need to start wearing reading glasses (which I don't mind). I'm 41, and they've said that in 6-7 years time, I could have a kind of concentric ring varifocal lens instead, but that it could cause halos. I'm basically against anything that could compromise my astronomical observation, so that just sounds like a non-starter to me! The thing I really want to correct is the weird spikes and things I see on stars, which is worse at low power/large exit pupils. My main question is whether there is anyone here who has undertaken the surgery, and whether they think it was worth it? One advantage to wearing glasses, I find, is that my eyepieces don't steam up nearly as often, but of course, the choice of eyepiece is more restricted. Any advice/experience appreciated!

It's been very nice to have two whole nights of good seeing and transparency! On Thursday night, I decided to try out my fairly new to me Altair Starwave 102 f/11 (shortened for binoviewing). I was looking at open clusters like m36, m37, m38, and m44, as well as globular clusters m3, and m13, and galaxies m81/m82. I decided to have a go at some double star splitting too, which I've never done before. I just went through the "Tour" section in the synscan handset on my AZ-EQ6 GT. The stars all resolved very nicely, and were as still as I've ever seen them, I think. I was just finding things at 35x, and then switching to 160x magnification, and managed to split everything very successfully. I really love the refractor. It's got a really nice construction, it gives me perfect pin-point stars, and nice contrast. I mainly love it on the moon. m3 and m13 just never quite resolved enough through it for my liking though. Because thsoe globulars weren't resolving as well as I knew they would with my 10" f/4.7 reflector, that's what I used last night. I spent a lot of time of m3 and m13. Both very nice, but I can't wait for m13 to get higher. I also spent a good amount of time on M51, and M81/M82, as well as doing a tour of a bunch of other DSOs using the "Tour" list on the handset again. All in all, I had two very successful nights of viewing!

Using low mag eyepieces on the 102mm f/6.66 does show large amounts of distortion at the edges. I've not been sure whether that's SA, or pin-cusion distortion, or what! I've not really used it for any astronomy, just with the Daystar Quark. I've got a TSO f/7 ED doublet too, which has quite nice colour correction when lunar viewing (blue star bloat if you try imaging with it though). I bought that for Ha viewing too. It looks like I'm going to be waiting 4-5 days to try out this f/11, which is really annoying! Anyway, once I've figured out what's good for what, I'll be thinning down the herd of telescopes. Too much overlap between the 3 refractors, and too much overlap on my 200P and 250P too. I do need to try a maksutov at some point

The heat is concentrated where it's focused. At the objective, where the rays are parallel, it's not too dissimilar from sun coming through the window in your house. That's the way I understand it anyway!

I'll report back! I'm looking forward to trying it on the moon too. I want to see what all this 'contrast' people keep on going on about looks like (compared with my reflector).

I bought an Altair wedge just before winter, and it's only been used once! That's primarily because of the weather actually, which is the same reason I haven't used my Daystar Quark for 3 months or more, up until the Sunday just gone! I have an ES 102mm AR102 which I bought specifically for h-alpha viewing, but I found the CA a bit off-putting when using white-light. I bought a 102mm f/11 Altair Starwave just yesterday. It's been slightly shortened, and it only cost £120! Was thinking I might try some side-by-side white light and h-alpha, as it's mounted on an AZ-EQ6 GT. I was hoping it might be shortened enough to binoview without the corrector, but not quite I would like to try white light some more. I think the CA was bad enough on the AR102 (f/6.66) that it smooshed any granulation detail. Not sure. This f/11 scope will reduce the CA significantly, I'm hoping, and get me in closer! Of course, I could try a Baader film on the 10" newtonian pictured too! I'm going to try the OIII filter, in lieu of a continuum filter.

Thank you all. I haven't settled on anything yet but with I should be able to do at least a couple of fun things with two pairs of binoculars. I'm certainly going to rig something up so I can play with the relay lens idea! @strayring, believe it or not I joined that group yesterday. Lots of great information, and I really like what Red Henry has done by sending eyepieces to people! I bought some more of the 20x80s, because I really liked the star field views, and they'll do me until I get around to buying some slightly more apochromatic 45 or 90 degree angled ones with swappable eyepieces. Thanks again.

Hi @Astrobits, and thank you. That's just the sort of thing I was after. If I can double check what you're describing, would it look something like this arrangement? The images is 1.5x the size, and I guess that means I'm losing light from the periphery, as shown in this diagram? Link to the online tool I used is here - https://ricktu288.github.io/ray-optics/simulator/?en. It's quite slow, and very frustrating to use, so any suggestions for something similar are appreciated!

Hi, I have two pairs of Celestron binoculars that are basically junk. I bought some 20x80s just a week or two ago (very very cheaply), but as with my previous 25x70s, they lost collimation literally after my first session. It seems that the prisms have been pushed too far in, and the screw adjustments won't bring them out again. I've got cats-eye exit pupils on the 20x80s, and can't get a merged image, and on the 25x70s I can get a merged image, but I don't think it's collimated at all properly, and it's making my eyes go a bit squiffy. Rather than repair them, I want to use the parts to make fun things. I thought I could make telescopes, making use of my 3d-printer and various other tools. I could probably repair them, and that's not entirely off the cards, but I'm seeing what my options are first. I was wondering if anyone could school me in whether there are any interesting ways of combining the 4 objectives I have? I guess they're achromatic crown/flint? Is it possible to increase the focal length? Is there any software I could use to simulate the effects of different combinations? Any advice welcome.

Thank you, John. I've been enjoying it tonight, albeit not under dark skies. Just casually gazing at the moon before tea. It really is a pleasure! After tea, I got my 10" newtonian out for some lunar binoviewing. Also a pleasure!

I have to add; I stole the tripod from my EQ6-R Pro. I was in the right place at the right time the other day when a chap advertised a brand new, unused 2" stainless legged tripod from an EQ6-R Pro, for £65 on the astrobuysell website! It arrived today. What an absolute bargain!

Hi @RobinH, Thanks for sharing that. I read a number of posts/build logs, and the hand tightening knobs sounded like a winner. I bought some normal plain-shanked 110mm M8 bolts [https://www.ebay.co.uk/itm/254937460261], and then found the hand knobs separately. These ones house the hex head of the bolt: [https://www.ebay.co.uk/itm/255243420182] and then I've used these in place of nuts [https://www.ebay.co.uk/itm/403304899314]. The shanked portion of the bolts was the perfect length to go through the 3 1" thick pieces of oak, with 4 teflon washers (two on the outside, two on the inside), which are 3mm from memory. I probably could have done it all a lot more economically, using a local fasteners store, but I was impatient! All of the rotating surfaces throughout are using teflon washers (with the exception of the azimuth bearing). I haven't tried it all out since modifying the droop and the bits that were catching on the hinge mount, so I'm going to see how I get on with it, next time the flippin' clouds clear off again! I want the binocular l-bracket to be adjustable up and down to ensure it can be balanced properly, with the binoculars centre of gravity rotating around the fulcrum. They don't move by virtue of the tension on the teflon washers at the moment. I'm not very happy with the thread insert the counterweigh bar is screwed into, so I'm going to come up with something more robust there. I have some angle grinder handles to attach too. It's all very usable without doing any of this though. Cheers!