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Cat 5 cable is pretty amazing stuff. It’s built to carry very high data rates with minimal dispersion over long distances, and it works!
I know somebody who wanted to have a PC they could access in their shed and indoors. He wired the keyboard, mouse and SVGA data signals down 30 metres of CAT 5 cable buried under the lawn. Normally SVGA deteriorates even more than USB over long distances, but his set up worked perfectly.
Then again, I think he paid an arm and a leg for the connectors (impedence mismatches can be a nightmare if you bodge the cables together), so probably best to try a simpler solution first.
Roy is right.
5 metres is right at the limit of how far USB signals can travel without dispersion leading to an unacceptable error rate. So you really need to have something on the end of the cable acting as a repeater.
An active USB cable does exactly this: there’s a small repeater in the plug furthest from the computer. I’ve used cables like this and they seem to work.
I imagine that plugging the far end of a passive 5m cable into a powered (or even unpowered) hub would have the same effect, but I’ve not tried it.
As Jeremy says, Data Protection means that the BAA couldn’t do this without getting permission from members. We could potentially have an opt-in members’ directory, but I fear a lot of our members would be very uncomfortable about putting their addresses in the public domain — especially those with very expensive telescopes in their back gardens!
I am keen to develop the BAA website into a more social platform where are members can share images and send messages each other. Perhaps it would be worth giving members the option of specifying a home town that we could plot on a map…
OK – Yes, I think it was those images I was thinking of. It was something I saw scroll past on twitter a couple of months ago, so I can’t go back and check!
I suppose the selling point of a Goto system for me is that I’m often giving people tours of the sky, and you’ve usually only got half an hour before they get bored/cold, so a Goto system lets me show far more objects in that time than if I was finding them manually. Perhaps I’m just slow at star hopping…
What really annoys me about Goto is not being able to declutch and yank the telescope around without losing alignment. I’m quite tempted by the SkyWatcher FreedomFind thing which solves that by putting encoders on both axes. But I think the cheapest FreedomFind mounts are about £950, and at that price it’s not exactly top of my wish list…
Callum,
That’s interesting to hear! I’d assumed the EQ3 was quite a popular wide-field imaging mount.
If I recall correctly, Ian Sharp uses an NEQ6 as a slightly-overkill DSLR-mount-with-autoguider, and a few people seem to use the HEQ5?
Not seem too many people use an EQ3, but then I guess it limits your options if you want something you can also put a telescope on. And I have no idea how stable it is…
Dominic.
I’d be curious to know how many widefield DSLR astrophotographers do or don’t callibrate their frames. I think a lot comes down to what camera you’re using.
About 10 years ago, I started out (I would imagine like many beginners) doing astrophotography with a very low-end camera. I found a compact Canon Powershot can get you nice pictures of M31, M42, etc, but I absolutely had to callibrate those frames because the sensor was rubbish. The same seems to be true of low-end DSLRs, e.g. a Canon EOS 1000D produces rather scratty frames at ISO 800 or 1600, yet I’ve seen many astrophotos in online forums taken with it. Yes, you can get impressive images without callibration, but you can do a lot better with.
I don’t doubt that if you use a Canon EOS 5D (I think the camera Graham uses?), you can push it to a very high ISO setting and still get nice clean images. But I wonder how many beginners are willing to splash out on such an expensive camera?
When we were talking about this at the Winchester weekend, someone raised the question of what images Astronomy Picture of the Day should or shouldn’t use.
I think yesterday’s image is a rather unfortunate example: <http://apod.nasa.gov/apod/ap140419.html>.
Of course, any astronomer knows this is an artist’s impression. And the discovery of this exoplanet is a big news story that NASA will have wanted to cover. So perhaps with suitable warnings attached, it was reasonable for NASA to choose this (wildly speculative) artist’s impression.
But the general public does not know this isn’t a real observation. Most media outlets were well-behaved in making very clear that this image isn’t to be taken too seriously, so it seems extremely unfortunate that NASA say nothing at all.
Hi Phill,
There do seem to be a few problems with the forum pages as they stand, both to do with the layout of the individual pages, and also that forum posts don’t have “breadcrumbs” at the top to show where they sit in the hierarchy of forum topics. We’re using a standard Drupal forum implementation, but it seems rather rough around the edges.
At the moment, clicking “back” on your browser sometimes works, but it’s no replacement for a proper breadcrumb at the top. I’m trying to figure out at the moment how much needs to be done, but I fear some of this involves rewriting their code… From what I can see, Drupal’s forum implementation has code which is intended to produce a breadcrumb, but it isn’t doing anything particularly useful at the moment…
Dominic.
Thanks for reporting this. I’ve fixed the stray close div tag on the Who’s Who page.
I think you’re right that there are a few problems with the forum pages as they stand. both to do with the layout of the individual pages, and also that forum posts don’t have “breadcrumbs” at the top to show where they sit in the hierarchy of forum topics. We’re using a standard Drupal forum implementation, but it seems a bit rough around the edges. I’m trying to figure out at the moment how much needs to be done, but I fear some of this involves rewriting their code…
