Posts by BenWilson
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Capture: Someone, Somewhere, In Summertime, in reply to Jarno van der Linden,
A certain minimum amount of light has to fall on a CMOS cell in order to be registered at all
Sure, but we're talking about a moving image here anyway. If it's only one pixel wide, then it's not being exposed to the CMOS for very long as it is. Check out this shot. The smears formed by the planets are 37 pixels wide. That means it moved around about a pixel every 200 milliseconds (the exposure was 8 seconds long). Notice also that the shape of the pixels at both ends of Jupiter is quite sharp? I'd expect a greying in at each end if 200 millseconds wasn't long enough to capture the light coming from that object.
I guess the shorter question is "why does Registax work, then?". If it's not possible to build a clearer picture from a number of overlapping pictures of low exposure time, then that software shouldn't be able to work. So what I'm asking is why the camera can't just do the same thing, in real time, to save me having to muck around setting up a hundred photos.
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Capture: Someone, Somewhere, In Summertime, in reply to Jarno van der Linden,
Thanks a lot for that detail, Jarno. Does makes sense, although I'm still not entirely clear why averaging out a whole lot more shots doesn't add up to a long exposure in effect (which is what RegiStax would be doing). I wasn't talking about 8 frames in 8 seconds, I was thinking more along the lines of clearing the CMOS as rapidly as it can, building up an image with a shifted capture. Doing this, there should be no limit on exposure time at all, beyond that of the object of interest moving out of the field of view. I can see that for a wobbling image, the image processing to do on this would be huge. But a starfield is moving at an entirely predictable speed along a curve, so it's only having to translate and rotate in exactly the same way on every shot. You could build up a table of which pixel maps back to which for every consecutive shot, and the data is just poured back into the master shot, which would slowly gain detail. At short exposure, of course each individual shot will only contain a small amount of detail, lots of stars will not show up at all. But this will not be the case on every shot, intermittently a burst of photons from that star will get through, and add to the master picture.
I will check out RegiStax. It sounds like it could be fun to play with.
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Capture: Someone, Somewhere, In Summertime, in reply to ChrisW,
Might you consider trying this photographically, and showing us all a sequence of cropped images (ie enlarged)?
BTW, sorry I didn't respond to this. Yes, I'm doing just that. It's taking a while to collect those images though. I'll prove there are moons around Jupiter yet. My greatest challenge at the moment is the movement of the starfield itself. It's taken me some time and maths, and research to prove this to myself (the biggest clue is that the lines are always parallel to the celestial equator). At the highest zoom with the longest exposure, which is only 8 seconds (looked this one up), they all become little lines. Which is a pity because the zoom is sufficient that Jupiter would have noticeable detail, if only it would sit still! But shortening the exposure cuts the light received so you get a crisp but dull image. Quite different to the moon shots because the moon casts a serious amount of light, so high shutter speeds do work.
However, for the purpose of working out where the objects are relative to one another, it's excellent.
I'm curious if anyone is aware of an astronomical camera mode that doesn't require a mechanical solution (turning the camera slowly to keep up with the starfield). Considering that the camera is receiving a steady stream of images, it could basically slide the images digitally to keep up, interpolating as it goes, preserving detail. It's a technique that would only work for something like this - an object moving at a very slow but steady speed, without changing in itself in any noticeable way.
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Legal Beagle: A four-year parliamentary term?, in reply to Kyle Matthews,
I don’t think it’s too bad here, but the US 2 year congressional term, combined with the horrendous influence that money has in their electoral system clearly isn’t working for them.
There's so much that's broken in the US system, that it's hard to pinpoint anything in particular. It's a highly exceptional nation, being the richest and most powerful, and one of the largest, physically, and in population. Their system seems to have served them for hundreds of years now. To me Congress looks like a very real check on the incredibly large power of the President, something we might not be so concerned about under Obama, but there have been American presidents who were bad enough that a check like that is well worth keeping around.
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Capture: Someone, Somewhere, In Summertime, in reply to Jos,
Apparently they ripen at the same rate but are more flavoursome and a better colour.
My understanding was that they actually ripened faster after picking, particularly if you remove the stem. I have not actually measured this, and look forward to your results, but I certainly attest that they will continue to ripen after picking – it’s a useful trick, it means you can do all your picking in one go, and it also means less chance of pest damage. Furthermore, other growth on the vine is encouraged. It’s also much easier to find the ripest tomato in a bowl than on a jumble of vines.
I’ve had plentiful tomatoes this year. Been getting a bowl like this every week (I’m the only one who eats them here, so that’s quite a lot) for the last 5 weeks.
Remember this little baby? It filled that little greenhouse in no time, so I ended up having to stake it up (Pic 1). That a single plant. BONUS: They’re the long yellow ones that were so delicious last year.
I went a little bit tomato crazy this year, although this is partly the fault of my little boys, whom I tend to involve in garden decisions – their choice of punnets in the last visit to Kings was more tomatoes, so I planted out the main garden in them. Pic 2, companion planted with basil and marigolds, and the established nasturtiums and thyme, mulched in with lawn clippings and the leaves of the giant magnolia that overshadows this spot. Also, spring onions, a strawberry that so tenaciously hung on after I culled the entire patch that I took pity on it, and weeds (which I think are mostly Sorrel, an edible)
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Capture: Someone, Somewhere, In Summertime, in reply to Islander,
Which has been the ANZ way since- o, I dunno – 80 years before my mother was born? (In 1927…)
Ironically, undies from those days look like togs from these days.
Before that - nobody wore anything-
You keep this tradition alive? Long may it last. Every other animal in the water is starkers.
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Legal Beagle: A four-year parliamentary term?, in reply to Martin Lindberg,
Well, apparently a change can also be dismissed by a popular vote (i.e. referendum) coinciding with the election.
The referendum is not automatic, though?
I’m finding that more than a little creepy
Me too. There aren't a whole lot of times I can think of when I've gone "If only they had a couple more years to slip that one through, things would be so much better now". But quite a few times where I've gone "If only there had been an election looming, this wouldn't have happened, and things would be better".
Unfinished business can be finished, if it's something that people want. Finished business, on the other hand, can't be unfinished, if it's something that people don't want.
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Legal Beagle: A four-year parliamentary term?, in reply to Martin Lindberg,
Wow, that's a really low bar for a constitutional change. So you just have to be elected twice? And for the people to reject the change they have to reject the entire government?
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Legal Beagle: A four-year parliamentary term?, in reply to Martin Lindberg,
Sweden reverted back to 4-year terms in 1994 after having had 3-year terms since 1970.
This was not done by referendum, so far as I can tell. Nor, however, was the drop to 3 years. I can't find much information on the whys of that one, but it coincided with their joining of the European Union, so presumably it was done to line up with something there.
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Legal Beagle: A four-year parliamentary term?, in reply to Kyle Matthews,
That’s the one valid argument for a longer term as far as I can see
Not sure, to be honest. They need to be "given a space", definitely. But that's not the same as "given more space". They get an extremely long space already, by comparison to practically any other kind of work. I don't see what's so exceptional about being a politician that it requires a whole different standard than, say, the directorship of a gigantic company, or the engineering team on a vast project. It's just something we've come to accept because that's the way it's always been.
I don’t think that need be looked on as anti-democratic.
No, but it can be looked at as anti-democratic, because it does actually get used that way.
Governments are elected to govern and I have no problem with wanting them to get on and do that.
I don't have a problem with them wanting that. It's human nature to want power. I wouldn't expect anything different, which is why I asked:
I have a question for wonks: How many times has a change in the length of term has been offered to a populace, and they have opted for a longer one? And vice versa? Also, similar question, how many times has it been changed by legislature without recourse to referendum, and which way did it go, longer or shorter?
Rich answered the question for NZ alone, but that wasn't what I was asking about, why I addressed it to wonks, because it's not just a matter of looking up NZ history. I want to know whether there is always pressure in general to increase term lengths, coming from politicians, and whether this is always resisted by the populations.
But I do have a problem with them getting their power it based on such a weak argument (that they want it). I want a billion dollars too, but that's not a good enough reason for you to just give it to me.
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