wulfrun

I also have a pair, they focus just fine. My eyes are identically presbyopic (yes, old!) and the dipotre correction remains on zero.

Just to point out, the 78xx regulators do require an output capacitor of about 10uF to keep them stable. Without it, the internal amp can (and often does) oscillate. You may have got away without it blowing up but is it oscillating? It's not an optional component on the spec sheets.

I have a 32mm Plossl and the 7-21mm zoom. The zoom is not bad for the price and I can't really fault the Plossl. No-one's going to say they are equal to the top brands but they are good value. EDIT: I forgot I have a UHC filter too but nothing more expensive to make a valid comparison comment

No, it should work anywhere between 11V and 16V and 12V is within that range. The way I read it, 11V is the least it'll work from and 16V is the most it will tolerate.

I've relubed camera focus helicals with a light, lithium-based cycle grease (readily available from cycle shops, Halfords etc). It's likely to be suitable for this application too.

I was out on Tuesday night, late on, since the skies looked particularly clear. From my backyard Ursa Minor usually shows me 3 stars, Polaris and the brighter 2 at the end of the "saucepan", Kochab/Pherkad. However, I could see a couple in the handle (just) so I knew I should be good. Seeing seemed moderately good too. I was using the 150PL and after visiting Lyra and the double-double (split, good and proper but only at high mag) I swung round for a look at the beehive, only to realise halfway over that I'd be too late, it's gone way over down below rooftops. However, by chance I peeped in the RACI and spotted that, fortuitously, I'd landed on an intriguing asterism at the end of Coma Berenices, including a double, which I later found to be HR4698. Coma B is just about invisible in my skies but I'd spotted the "something's there" a couple of times before and failed to get the Telrad on it. Lucky night! After a mooch in the area, I went over to Cygnus, having noticed some recent threads on here about its delights. I failed miserably to find anything in the way of nebulae, not unexpected given the light pollution and lack of proper darkness so no disappointment there. Albireo got a visit, naturally but then I had a look at what seemed a very "busy" area down towards the Zeta end and a bit towards Lacerta. My eye was drawn to a small red dot in the RACI so I centred it for a better look. Hmm, that IS red indeed! Blood-red was my thought so I made a note to look it up. Wikipedia calls it ruby-red but it turns out to be a carbon star, V460 Cygni, HIP107129 (SkySafari reports it as DS Pegasi). I'll own up to stumbling across it but I'll settle for that!

That's because most camera lenses have an adjustable iris, so the aperture can be varied. Usually the maximum is quoted (and often the minimum too). The effective aperture is focal length/focal ratio. So, the abovementioned Samyang 135, f/2 lens has an effective aperture of 135/2=67.5mm...but only when it's "wide open". You can still calculate it for any desired setting with the formula above though.

As above, hacksaw a slot and use a flat-blade screwdriver. It shouldn't be that tight since you only had a small knurled head to do it up with. Replace with one not made from cheese!

I was out about a week ago when there was serious dew, to the point that I gave up. Eyepieces, finder, Telrad, OTA, you name it it was dewed. I looked down the empty focuser and could see a dewy haze on the secondary, using a torch. It's the first time I've had that but my point is, just use a torch down the draw-tube and have a look.

There's nothing especially damaging about sunlight in particular*...except that when looking at the sun it's bright enough to cause damage. The moon is bright but is massively less bright than viewing direct sunlight. EDIT * meaning it's not "special light"

Not really, it's negligible I'm afraid.

The simplest solution would be to measure the current on 2x AAs, set to full brightness, then calculate a resistor to drop the excess voltage from a fully-charged Li-ion cell. Then you could also estimate the discharge time, worst-case and know how often to recharge. I have a Telrad, I can take the measurements if it helps... EDIT: my test-meter says the Telrad draws 21mA at full brightness with new batteries (reading 3.2V). In which case a 47-ohm resistor will drop approximately the required excess 1V. Power dissipation in the resistor is low so you won't need anything exotic. If you're using a typical 18650 cell, you'd drain it in about 100 hours at full brightness. Far longer in typical use, of course. If you have a meter, I'd keep an eye on the cell voltage and recharge at 3.3V, minimum, to avoid damage. HTH.

@Chaz2b One Lithium-ion tends to be 3.7V nominal and 4.2V fully charged. Two AAs only comes to 3V. I think the LED should survive but you might want to avoid turning up to "full", just in case. A voltage regulator would be a better idea but probably overkill and not worth the bother. Edit: one thing to consider, there's nothing in the Telrad's circuitry to stop you running the cell to "flat", which would ruin it. Best recharge reasonably often or use a protected cell.

I'm pretty new to observing, only having had a scope for about 6 months. I actually can't recall a single evening when at least one satellite hasn't passed through my EP view, usually many more. I saw a train of about 50 a few nights ago, naked-eye (I lost the exact count), covering a good 120 degrees of view. I wonder about a few things... Do the powers that be actually care about the visibility of the sky and the protestations of a (small) minority? Are these things actually agreed multi-laterally? At what point can we not send anything more up because "threading the needle" becomes unfeasible? What's the "carbon footprint" of these constellations (consternations?), including launch vehicles and how will we achieve "net-zero" with these things to offset? And lastly, when (hopefully soon) an incoming meteorite takes one out and the debris cascades into all or most of them, what then?

There's a whole article on the ABC (Aussie) website, why it's called what it is, how to get the best photos blah blah.

As per above, it's meant for night-time use so it's not very bright. Try it at night, you'll see it then.

Yes, you get 3 circular "bullseye" rings at 1/2, 2 and 4 degrees diameter. Centre your target in the inner circle, it's not obscured by a dot. You can use the circles to move a known distance or use them in conjunction with star maps or Stellarium software etc too. Not sure what you have as standard but it's likely to be an RDF, red-dot finder. As the name implies, you just get a red dot to place over your target. Personally I find them too bright, even on the lowest setting but some people get on fine with them.

The Telrad isn't very bright, that's normal and expected - it's intended for use at night. You'll find it is plenty bright enough at night and you only need it on a low setting, especially in dark skies. Align it at night, ideally on Polaris so it doesn't move too much as you fiddle.

You won't see the yellow, orange and red ones very well on a white background, using a red torch. You also may find the blue ones hard on a black background. Can you not use (say) all blue ones on white?

Seconded! I've just been out for an hour with the bins, about 11.50 I saw a train of satellites file over. Just above the Moon, I lost exact count of them but approximately 50. At one point they spanned almost my visible-horizon-to-visible-horizon view. Certainly spanned from Leo right over to Cygnus. Yes, very pretty BUT...

Folk spend a lot of time and money whacking a small, dimpled ball around some greenery to try and get it in a hole. Is that insanity? They consider it a challenge. People buy old rust-ridden vehicles, dragged out of a field or barn and then spend a fortune in time and money restoring them. Is that insanity? They consider it a challenge. I'm sure I could fill pages on "insane" things people do, for the challenge. Why is AP any more or less "insane"? Presumably you consider it a challenge and enjoy it...or you'd pack it in. On the other hand, asking the question on an astro forum is probably only going to get you some biased replies!

Postie brought me some solar-filter film from FLO, so I'll be Partial-Eclipse-Ready. Explains the grim daytime weather today. We've had sunshine/showers for a few days but I've banished the sun now, of course 🙂

I haven't yet been to a star-party/camp but if/when I do I'd take this. For reference the shed is an 8x6ft. Takes 60 sec to put up the main dome and a couple of minutes to peg out and guy the rest. If the doorway were higher you could get a family car in there so it's nice and roomy.

If you're a complete newbie, I'd say a long FL, widefield eyepiece for low-power use plus a budget zoom wouldn't be a bad place to start. OK, you aren't getting premium gear but if it turns out you don't get on with one it's not a big outlay. It'll do a reasonable job and teach you what FLs work for you whilst keeping things simple. Once you've got the initial experience, you can upgrade to fixed EPs that you know you'll use OR upgrade to a premium zoom if you're sold on the zoom idea. Even a budget zoom as a starter could be re-sold or indeed kept for when you don't want to risk premium gear (e.g. letting kids loose with it).

Something of this ilk, off an RC rock-crawler I have. This one is a 14-tooth but other sizes are readily available: