Ships and Stars

Thanks Phil! Camera arrived today - it's tiny! That's a good thing actually. Sorry for the slow reply - didn't show up in my notifications, will change setting. Here's what I have so far: -Watec 902H2 Supreme - If I want to use it - Yamano Japan 3.5mm f1.4 lens and auto-iris plug -C-mount to 1.25" adaptor with (removable) 0.5x focal reducer - 10m of shotgun RC59 coaxial cable/DC power cable (handy!) - CVBS to USB converter/capture device Waiting on BNC to RCA adapter, then should be able to fire it up. I was wondering about reaching focus - I have a 300p non-tracking but it is flextube, so could always drop trusses for binoviewer mode if all else fails but would prefer not to for max light gathering. I've a Baader quick lock low profile 1.25-2" that fits flush with the drawtube, or could screw on 1.6x glass path corrector. My bigger dob has tracking, so we will see what a 20" dob under dark skies can pull out with this little camera. Should be interesting! PS thanks for the tip on Virtual Dub 👍

Well said, the types of new lighting being installed without shields, too high power (cheap but incredibly powerful LEDs) and left on all night is prolific and getting worse.

When York flooded a few years back, I saw where they compared a medieval map of York to a modern map showing the flooded areas. The entire medieval part was dry! (or at least not submerged). Just takes that one in 50 or (25) year storm to expose weaknesses in planning, esp flooding. External lighting is my nemesis, I've really had a lot of problems with local businesses by me who only have limited hours and nothing inside to pinch! None of their lights have shields on them. Ah well, at least dark sky sites are too terribly far away...

Article on all-night lights at Brighton & Hove stadium drawing ire of locals. Main emphasis in article is on disturbing local humans and wildlife behaviour patterns, though stars get a brief mention. I couldn't imagine the frustration of living near this for astronomy. Who designs this and thinks great, let's leave the lights on? Similar problems here, but on a much smaller scale (though the lights are much closer as well!) https://www.theguardian.com/uk-news/2020/feb/02/brighton-stadium-put-that-light-out-plea-all-night-glow

There's only one solution to this aesthetic dilemma, bigger binoculars! My poor humour aside, that's a truly impressive rig, bet the wide field views are amazing with the NV, even under LP.

Ah, I've only managed to figure out what cables and converter to order so far. Cvbs to VGA converter/upscaler, RC59 coaxial cable, and a USB frame grabber device (which might replace upscaler/converter, not sure on that yet) and a C-mount to 1.25" adapter with a detachable 0.5x focal reducer of dubious quality. Who knows, might surprise me. All in, I'm still well under £100 and the watec camera is new. Still need to sort 12v power supply, but that should be fairly easy picking through my mountain of cables. Busy week work-wise next week, so will be the weekend before I can play around with it. Not expecting a great deal, to be honest, but if it shows more than I can normally see, then fair enough. Still prefer looking through the eyepiece but who knows, maybe this will provide a significant boost?

Sorted!

Hi all, Note - think I've everything I need now for it to work - please see photos below. I just picked up a Watec 902H2 Supreme for a good price (I think) - my first proper step into EEVA to see if I like it. For all intents and purposes, I honestly know very, very little about adapting this type of camera to either of my scopes (300p and 500p SW dobs) for near-live viewing, other than I'll need stable 12V power in and some kind of composite output cable to my laptop I'll be 'near-live' viewing on. Sorry for all the questions, but may I please ask: 1. How do I connect this to my scope, and where might I find an adaptor? Can I run it through a 2x Powermate or eyepiece, or is it best (and brightest) just use the OTA at prime focus? 2. What kind of cable will I need to connect to my laptop for viewing? Composite to USB? Is there some kind of analogue to digital converter I'll need as well? 3. Do I need some kind of 'frame grabber software' and is stacking software involved? I have never used either of these programmes. If yes, which software would you recommend? (hint - free and simple is good!) Is that it? Once it's connected to my laptop, I hope I'll be able to have near-live views of fainter objects that I could see through the scope alone, yes? Thanks for any help here with any of the above questions. Time is a bit limited at the moment for extensive online research, though I briefly saw the NEMETODE meteor observation group uses these with fast primes lenses, not through a scope as far as I know... Cheers all 👍

I think it's fairly common for some shift in collimation when slewing up and down in altitude with large dobs. My 500p changes ever so slightly when I have the collimation laser in the focuser, but again, it's very minimal and not anywhere close to detectable through the eyepiece to me. Other 500p owners have noted a lot larger range of shift, but it turned out to be the large nut on the bottom that holds the primary in place or the injection material that is used in the base of the mirror around the centre nut. You'd have to see a Stargate mirror in person to see what I mean, it's a different type of retention system (as is the ribbed mirror support which reduces mass and lets the primary cools down very quickly, I don't bother with fans), but mine works brilliantly. I simply cranked the centre nut on mine hand tight and check it about twice a year. That's the 450/500p mounting system, not seen it on other dobs. Not sure what system obsession uses, maybe they use the standard strap that runs under the bottom of the mirror or holder tabs at 90 or 120deg intervals, but perhaps the ultralight dobs do it differently.

Thanks! Took longer to dig out my tools than it did to drill a few holes and paint it. Forecast just went from cloudy to clear from 10pm-2am, will try out seated astronomy tonight! Just need a cupholder for my coffee now...

This Ikea Molte chair was an eye-watering £9 or so seven years ago when I bought it. My wife disliked it, so it's been outside for well over six years with no protection and was looking sad. I needed a simple, light adjustable observation chair for my new 300p flextube which is really low for me except near zenith, so decided with a few very easy mods, this would fit the bill. I drilled extra adjustment holes in both the post and base to gain as much height as I could. The lowest setting was already adequate. To lock the height in place I now use a phillips screwdriver with a 6mm shaft in place of the original small adjustment key (easy to lose), so height changes are fast and easy in the dark, as the chair now has a decent-sized plastic handle (and a built in screwdriver!). I then took the plastic seat off, quickly scuff-sanded the base and post, and then sprayed it with leftover red zinc oxide primer from a car repair, dried that with a hot air gun in a few minutes, then laid on a heavy coat of clear lacquer (also leftover stuff). One last touch today - a Harris Tweed seat cushion my wife made from a £5 remnants bag from the outlet at Tarbert, Harris a few years ago. Posh eh?! 🤣 Final touch later this week, but not an absolute necessity, is to add some 2-3 cm tall furniture feet on the bottom of the legs to gain an extra few cm height, and a roll of black closed-cell foam is coming tomorrow for my DIY flextube dewshield, (sorry Astrozap, you are too dear!). I'll cut the foam to fit the seat and glue two layers on, with the tweed cushion thrown on top that should be pretty comfy for some relaxed observing 👍 I also have glow in the dark tape, might put a few bands of that on the feet. NB - If you want to try something similar, note I'm fairly tall so didn't need a ton of height, so you might want to take measurements to determine what your min/max seat height is. Fortunately no one was home to see me do squats while measuring how far off the deck my gluts were, a disturbing scene, no doubt 🤣 What DIY observing chairs do others use?

One thing I don't miss is chromatic aberration and all of that! I'll take coma any day over false colour. Go for the coma corrector then and a good widefield eyepiece 👍

Zoom binos are say 12-20x zoom x 50mm objectives lenses, not a fixed magnification. I don't think there much difference between 8x42 and 10x42 to be honest, I prefer more magnification personally, they would both be good for astronomy but do some shopping around online and see what others recommend.

I've the ES HR coma corrector, works a treat on my eyepieces, especially the 21 Ethos, in a f4 dob. Bought mine second-hand for around £160-180 (can't recall exactly), couldn't find a single used Paracorr 2 online after months of searching - which speaks volumes about how good those are too! The ES has a tunable top similar to the paracorr, so no faffing around with extra extensions and spacers. For a 130PDS I don't know if it makes sense though?

I have some cheap and cheerful Celestron Cometron 12x70s that I picked up second-hand on ABS for £30. They have sharp views and excellent light gathering capability with a tripod adaptor for longer observations without fatigue and shake. They also have fairly wide-angle eyepieces which give the full field of view with glasses and are a pleasure to look through. I think they have now been replaced by Celestron 15x70s. Needless to say, the general word is avoid zoom binos at all costs - if someone knows of a good zoom bino, please let me know! Also have 12x50 Bushnells, but the Cometrons are miles better. Prior to the 12x70s, I had some massive 25x100 Celestron Skymasters on an AZ4, but were a lot to lug around and set up, you might as well just use one of your scopes by that point, though I still liked the views from the 25x100 but felt like I wanted more magnification most of the time given the weight and bulk (hence just use a scope). I've not tried any higher-end binos like Nikon or Pentax, but both of those understandably get great reviews. I've been tempted to try the Pentax range (the S or SP series), they are a lot more affordable than I thought they would be (£85-£290), but I don't feel the need just yet. With binos in general, I have a couple of decent-sized dobs, and I always take a break during a viewing session to sweep the sky with the 12x70s and then do it again at the end of the night after the scope is loaded up. Binocular astronomy is just a blast, I saw so many star clusters last time at my dark site and scanned the Milky Way back and forth a few times. It's total freedom, like flying after aiming a bulky scope at tiny bits of the sky. Also binos are great for a quick look outside from home if you don't have a chance to set up your scope or the weather is just hit and miss but a clear patch rolls through. Am sure others will add their experiences, binocular astronomy in general is simply brilliant.

Thanks Gerry! I'll check it out just out of curiosity, I know the BVs are capable for most objects. Might have a few partial clear nights coming up, but mostly cloudy. Tuesday night looking potentially ok!

No I sure haven't, how do you check that? I'm familiar with screw-on rotating polarizing filters for camera lenses, but not anything astro-related. Can you simply look into the binoviewer body and see if the mirrors have a certain type of coating? Another facet I wasn't aware of! Haha. Edit - I do note my right side EP is often darker than the left, but rotating the ep holder on that side seems to alter that. Perhaps that's a clue one side is polarized?

I indeed have the WO binoviewers, but I use a Baader clicklock adaptor to insert the 1.25" nose right into my SW focuser without using the standard adaptor which sticks out maybe 25 or 30mm - that adds a fair bit of inward travel. I looked at the low profile focusers and that would add another 30-40mm inward travel (estimated, not 100% on that), so that should allow you to use just the 1.6x barlow, but try a flush-mount 1.25" adaptor first - might do the trick! You are right about the very restricted FOV with the 40mm plossls, I was using those mainly for exit pupil and target mag (80x). There is a mile of eye relief, so a pair of 32mm EPs might be more comfortable and practical, but worth a shot with the 40's on faint DSOs and see if you have any luck! I'm using standard WO binoviewers which are basically the same as all the lower end BVs on the market I believe, so the prism and clear aperture are going to be basic fare. My 500p is f4 so apparently there is quite a large light cone coming out of the focuser. Considering the 1.25" nosepiece is right the way in to allow focus, I am probably missing a fair bit of light there, and some loss from within the binoviewer body/prism itself - the question is how much, and if light loss is concentrated around the periphery of the FOV, or across it. Having said all of that, as Gerry mentions, it could be fairly negligible! Perhaps just a few percent? Or less than 10%? Have to do more research on that, but if I had the money right now, I'd just get some Binotrons and the 45mm OCS (sorry, think I was calling it an OCA earlier!). But I'll play around with the WO setup and my cheap plossls a bit more and see what I can squeeze from them. I'll have to ask the fellow in Croatia who supercharges BVs and see if he has calculated it, and how he would set up BVs specifically for faint DSOs? (same goal as any object though - as much light as possible is the desired result). Lots of details to consider here. If I ever make it to a star party and someone has the Binotrons, I'd like to do a rough comparison between the Binotrons/45mm OCS and standard WO binoviewers regarding brightness - it may not be a huge difference, but the Binotrons must give a noticeable boost! The 40mm plossls are really only the means to an end - detecting the HH. I'll have to try the 32mm plossls next time I have the big dob at my dark site, am hoping eye-relief is greatly reduced. I figure that splitting the light from a 20" dob would equal a 14" dob for each eye, minus some light loss from the BV mirrors themselves, so under really good conditions it would be like using a 12"-13" binoscope to view the HH - entirely plausible! Again, I think getting the right exit pupil is critical here, but at the expense of FOV which is frankly terrible unless you are concentrating on planetary nebula or small galaxies, etc. Dropping to 32mm plossls reduces the exit pupil almost a full mm, would be interesting to see what effect that has. I need a good night again with all three pairs of plossls. So many tests, so little time! Making slow progress though. A lot to digest here! Thanks all!

Very nice indeed!

Amazing! The detail is superb.

That's excellent! I'm in NE Scotland, some dark spots here but not that dark, requires a bit of a drive to get to mine. Light pollution map shows somewhere around 21.98-21.99 SQM for Knoydart, in other words, Nirvana!! (when weather cooperates of course). Bet it's amazing there.

I'd love to make it down but no promises yet with family things - I was just working near there last week in a rural spot near Dalmellington, excellent skies. Will see what I can arrange...👍

Thanks Geof! I spent a lot of time that night just trying to do an alignment and waiting for the wind to drop at times, but the binoviewer experiment was really interesting, I'd been wanting to try BVs on the fainter objects for some time under good conditions. They are not a replacement for single EP viewing, but do provide a different sort of view with stereo vision, less contrast, but more information, if that makes sense? Next time I'd like to try them on the Virgo Galaxy Cluster and Markarian's Chain etc.

Thanks Gerry! Seems like everyone over here was desperate for a few decent, clear nights, some good observation reports coming in at last. Hope it's ok your way.