adyj1

+1 for this advice. I have a SW 1145p which I am happy with, on which I have also moved the primary mirror inwards with long screws and springs to achieve focus with my dslr. (I also have a catadioptric SW 114/1000 that is consigned to the scrap heap... ) Ady

So, I have understood all the advice here about maximum magnification, etc, but are these calculation changed by the fact that this is (what I understand to be) a catadioptric newtonian (ie it has a built-in 2x Barlow which make the 500mm tube a 1000mm focal length)? Or do the same rules apply? Thanks Ady

@rml63, are you saying you can't get your dslr to focus with your PDS? If so, it may be worth starting a new thread specific to your OTA... Ady

I won't believe it until I see pictures! Ady (pictures of the clear sky, that is - not of you leaving )

I think you were speaking to me and @mikeyj1 at the star party - Mike has the Deep Sky Dad autofocuser; https://deepskydad.com/autofocuser Basically a DIY stepper motor focuser project that has gone into production by the creator. Ady

@Astro Al, who long is the tripod when folded (and the pier extension removed?) Ady

@Helen, she was seriously impressed that I thought of her, which makes me seriously indebted to you and Emma! My wife has even asked me to write down the order of the planets so she can tell her friends - which is something of an Astronomy breakthrough! I owe you a drink at the next SP! Ady

Provisionally sold.

Now sold, mods please archive.

Maybe I'm not explaining it very well in the weights down position there will be no tension on the ra clutch, but the fact that those weights were counterbalancing 5 kilos or more of OTA (say) means that there will be an unbalanced load on the ra bearings. Now I accept that the bearings are probably easily within tolerances and should take this unbalanced load all day long, I'm just thinking with the older second-hand mounts that I tend to have, a bit of mollycoddling wouldn't go amiss

Sky-Watcher Enhanced Dual-Axis DC Motor Drives for EQ-5. £80 plus postage. The enhanced kit includes an ST-4 port for an auto-guider. Includes motors for both R.A. and DEC axes, motor cables, enhanced hand controller and battery pack in the original box. I have a power extension cable so that the leads from the hand controller are all bundled into one 'umbilical cord' and comfortably reach the mount where they then can split out to the different motors and batteries (or 6v mains adapter, not supplied). The only thing missing from the set is the original hex keys. I am attending SGL SP at the weekend, and will be bringing this if not sold. (Pictures to follow) Rgds Ady

For sale 1000D camera modified for astronomy; the IR filter has been removed to allow the important red emission nebula to come through. Includes Canon battery and charger, plus USB battery adapter. £109 + postage. (I will be at the SGL star party this weekend, if that helps) The battery adapter replaces the normal battery and allows the camera to be powered from any USB power source; I used mains for long imaging sessions, but a large capacity portable USB battery would also work. Includes camera body with cap, but no lenses. There is a scratch on the LCD screen which is not visible during normal operation when the LCD is lit. Works fine with APT. This was a great introduction to astrophotography for me, and I have now moved on to bigger and better things Pleiades taken with this camera on my 150PDS: And the horsehead: (I've also been learning how to do processing on free tools, and in doing so I've probably killed these shots ) Rgds Ady

Unless 'weights down' meant perpendicular with the floor, then there must be strain on something - as your equatorial mount is actually perpendicular to the polar axis there must be some strain on the RA bearing... Confession; I never remove the cw from my EQ5, but will start doing so from now - I expect the strain would be within tolerances, but why take the risk?

I'm going to stick up for the plucky little now-you-see-me-noe-you-dont rigel Quikfinder. Because I've got one ☺. It was cheaper and smaller than the telrad, which is why I bought it. I have an extra 3d-printed base, which together with the two that come with it means I can easily mount it on any of my 150PDS, 1145p or ST80. Yes, I once changed the batteries because I thought I had left it on, only to find I wasn't looking straight up the OTA, but surely that's part of the fun? Like most of the rest of my astro kit, now I have learnt how to use it properly I am very happy with it. I wouldn't argue that the telrad wasn't better, though. Mind you, you have to pay even more if you want a flashing reticule on a telrad and the rigel has it built-in. (And to preserve you brnight vision, you can look through the rigel without being able to see the reticule at all! ) Ady

Let's clear this up once and for all The one-hour film made in 2016; "A history of the telescope and a look at the James Webb telescope. A fascinating look at the universe through the eyes of scientists and telescopes since the beginning." Thanks to @Charic for the tip-off. Ady PS - and repeated; Monday 8th October on Discovery from 1:00pm to 2:00pm Monday 8th October on Discovery HD from 1:00pm to 2:00pm Tuesday 9th October on Discovery from 4:40am to 5:30am Tuesday 9th October on Discovery HD from 4:40am to 5:30am Friday 12th October on Discovery Science from 12:00am to 1:00am Sunday 14th October on Discovery Science from 10:00pm to 11:00pm