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derekorion

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Everything posted by derekorion

  1. I got the Star Adventurer (SA), and it looks great. I’m just familiarising in the house before use; the dials look a bit daunting but I suppose it can be at first until I know what does what. I actually decided on a First Horizon 8115 tripod (sorry to the recommendation of the DV tripod but I wanted the orders unsplit and I got a good price on the tripod), which has pan and tilt and a quick release plate with a 1/4" slot head bolt. I have a few questions/comments if anyone has a view. There are several mounting options. I'm first attempting to use the mount on tripod with Wedge to mount Canon 1100d camera with 70-300mm Tamron zoom lens. [I’m not using the pan and tilt of the tripod to adjust altitude. I may as well take advantage of the Wedge). But I fixed and tightened the pan and tilt to stabilise the quick release plate as horizontal as possible - by eye only (the tripod has a bubble level). There was a 3/8 to 1/4" converter plug in the bottom of the SA. As instructed, I removed it and screwed it into the base of the Wedge. Then I screwed the 1/4" bolt pushing up through the bottom of the tripod’s quick release plate into the converter plug. That made the Wedge sit on the tripod and is easy to quickly remove by undoing the quick release plate from the tripod. The SA then slides onto and clamps on top of the Wedge, secured by the SW base plate that has the 3/8” slotted bolt. I noticed that the 3/8” to 1/4” converter plug can screw deeper than flush in to the Wedge base. That is, I can screw it further inside which means it’s too far inside. OK, so I thought, well it must have to be flush with the Wedge base surface, so I did that. The 1/4 “ bolt from the tripod quick release plate screwed into the converter plug. Initially it wouldn’t screw because there’s a spring stud on the quick release base plate (which I don’t know what it does, but think it’s for a video camera). But I pressed the plate hard up against the Wedge base, then screwed in the 1/4 “ bolt (that has a big slot head that I used a 20p coin to tighten it with). It seemed to pull in tight. I tightened until I couldn’t turn the SW plate sideways. Does it matter that the little converter plug is loose when screwed into the base of the Wedge so that it is flush? It’s not screwed up to anything so it can turn of its own free will (whilst no bolt is screwed into it). How can the converter plug go from loose to tight when a bolt is screwed into it? Is seems to be being pulled up against the quick release plate base by the action of tightening the quick release plate bolt. But it’s the tightening mechanism that I don’t understand. A converter plug that screws in clockwise till flush, then a quick release plate bolt that also screws in clockwise with the base plate in between. How does that tighten? OK, maybe that’s how it works, the mechanism of physics, I don’t know. My biggest worry was, the slot head 1/4 “ bolt from the tripod quick release plate only has a few threads that go into the converter plug. I can’t remember how many without taking it to bits again, but possibly 3-4 threads worth and possibly (by eye, about 4-5 mm’s worth of bolt). Now if that were to strip the thread/fail at some point, the Wedge carrying the SA and camera (on ball head), would fall off. Now, that said. But because I said earlier that the 3/8 to 1/4 “ converter plug can screw further inside the base of the Wedge, it means the hole depth could afford to take a longer 1/4“ bolt. But can it? Would a longer 1/4" bolt make any difference at all, if the tightening function is that the threaded converter has to be flush with the Wedge base surface? I suppose a longer bolt could still fail where it snapped at the surface of the Wedge base surface, leaving a snapped bolt inside the hole and difficult to remove. There’s a lot of expensive kit sitting on one 1/4” bolt which is only screwed in by a few threads. Is there an engineering guide to what is regarded as suitable and sufficiently acceptable? That way and compliance with that means I should have no worries. But as said, getting a longer 1/4 “ bolt for the tripod quick release plate would require some tweaking around with the plate itself. I’m not sure if that is fiddly. Also, thinking about this as I go along, a longer 1/4 “ bolt is not actually screwing into anything other than the 3/8 to 1/4 “ converter plug, so it wouldn’t be threading into the thread of the hole because the hole is 3/8” threaded. So my conclusion could be, if the shortness of the 1/4 “ bolt is not compliant with accepted guidance, then I need a quick release plate with a 3/8” bolt, which is longer, so it goes deeper into the Wedge base hole but shorter than the hole depth [and to NOT use the 3/8 to 1/4 “ converter plug]. Is this a better idea? Where can I get a quick release plate with a 3/8” slot head bolt? [I haven’t looked to see if the tripod maker supplies them because I’ve just concluded this idea by writing this post now]. Note. The reason a ball head is used to mount the camera, is I’m just following the SA instruction booklet, but there were some other mounting options with a plate and counter weight, but they were for telescope or two cameras and I’ve not got there yet (I thought I’d start off with one thing at a time). The Fotomate H28 ball head itself has a 3/8 “ threaded hole, but comes with a slotted 3/8-1/4 converter plug that looks the same as the Skywatcher one. But the Skywatcher photo bundle kit also comes with a 3/8 to 1/4 “ adapter plate that accepts the ball head (3/8 to 1/4 converter plug removed). The 3/8” bolt is about 7 mm long with 5 or 6 threads and looks more substantial and longer than the 1/4 “ bolt, but its purpose is to fit a ball head onto the SA. The camera fits onto the other end of the ball head by the ball head’s 1/4" bolt – which ironically also looks shortish, 4 threads visible above the cork plate. Now that is a ball head made for cameras, so, although the 1/4" bolt seems shortish (to me without engineering judgement), presumably it is enough to accept a camera with a long lens. If so, then the shortish 1/4" bolt on the tripod quick release plate that screws into the Wedge base (with 3/8 – 1/4 converter plug in place), might actually be sufficient (to take the SA plus ball head plus camera with long lens). But me being belt and braces, I just felt that the tripod quick release plate 1/4” bolt seemed too short, and from a risk assessment, is the only connection. If it failed, there would be nothing else to stop the SA and camera (or even guide telescope) falling off. I did a run of the SA with nothing mounted, in the house for 3 hours at 12x speed, and 1 hr at 1x (sidereal) speed, then the two R and L LED’s started flashing. I measured the voltage across the 4 AA batteries in the SA and it was about 4.2 V (individual cells were 1.27V each; strangely, V1+V2+V3+V4 didn’t total exactly the voltage across the SA whilst switched off and still not under operating load). I assumed the flashing lights was just the fresh set of batteries had become spent – 12x speed for 3 hours. I assume the batteries will last more than 3 hrs at sidereal rate. I installed a fresh set and the voltage across the 4 cells was about 4.6V, and individually, each cell was 1.6V (not sure why it wasn’t 4 x 1.6V mind, with cells being in series). There is a clutch on the SA. It can be loose, or tightened. I’m not sure how it should be, but on the test runs with no ball head/camera combo attached, I left it as it was when it arrived (loose). On the test run, I rotated one end (not the freely loose clutch plate) whilst looking through the eyepiece of the polar scope. I could see the etched clock rotate, so I rotated it so that zero was at top as best as vertical as I could. On the dial side, I rotated the dial so the zero matched up with the zero hour on the fixed 0-23 hour dial. I was just familiarising myself. I saw the etched clock slowly rotate over time. On sidereal rate in one hour of real time, I could see the dial had moved 1/24 th, which sounds about right. When I load the ball head and camera, do I need to tighten up the clutch plate, or keep it loose? The SA really does look a nice piece of equipment and I’m looking forward to using it. With that alone, it will let me get longer exposures from a simple camera, because of the tracking (I know it has a guider facility as well, which may come in with longer focal length camera lens of 300mm but may be not needed for the exposures I would aim for of 90s or less). I’ve been able to get to 12-13th magnitude stars with unguided shots with 300mm lens at ISO 6400 at 10-20s exposure (trails obviously), but tracked would be even better. At a later stage, I may use my Altair Astro 60mm finder guider (with QHY5Lii CC) as guidescope for longer exposures (if light pollution is acceptable).
  2. Those plane composites look amazing. Did the original individual frames look much worse than the composite video? Also, when the plane is not changing angle in the video, can you make a stacked image of the frames during that period of the video (or from the best original frames from the original video, from more than one period - say if the altered angle then came back to the same orientation a number of seconds later)? Brilliant ideas. You could effectively do retrospective visual examination in more detail of the planes than you get in live time. Can the software be applied to small things, like images or videos taken through a microscope? Again, there is movement of cells, but the movement could be too much, if those cells rotate 360 degrees and in an infinite number of different axes I suppose. But when slides are prepared and the things being examined are fixed, then I wonder if improved images could be go by stacking. The only thing I would say is, fixed slides illuminated by a constant bright light, and no changes in the atmosphere, would be that unlike in astronomical imaging where there are moments of good seeing, I guess the opposite would be true of microscope imaging of fixed specimens - lots of good seeing, plus rare moments of poor seeing (e.g. accidental or natural environmental vibrations during imaging).
  3. Im thinking of buying this SW star adventurer. ive read all the thread on the topic, so thanks to all, helpful info for me. I saw a tripod Vebon DV7000 was recommended. I have a Velbon Stratos 450 (purchased in thelate 1980's). I wondered if anyone knew whether mine was a baby compared to the DV7000, or mine was better. The 450 has a head whichleavers upwards from horizontal - and has what looks like a 1/4" nut that slots from the bottom, which a tightening ring once the nut is screwed into the base of my DSLR Canon 1100D. Should I buy the Velbon DV7000 tripod, will it be better than my current Velbon Stratos 450? I saw a 19 minute video on the SWSA and the chap mentioned not to skimp on a ball head, to get one with a ball of at least 40 mm in diameter. I dont know how these work until I see one in use. But can someone recommended a decent ball head that is adequate for use on the SWSA. Or, is it not the SWSA that determines what ball head is needed, but instead, the camera and lens to be mounted? My camera canon 1100d and 18-55mm kit lens, and, a fairly lightweight Tamron 70-300mm f5.6 zoom lens. I may not need the ball head in order to mount the camera - if I understand correctly, the camera could go on the L bracket which doesnt use a ball head, yes? Is a ball head only needed when two cameras or one camera and a guider scope is added? I have an Altair Astro 60mm finder guider, and qhy5Lii colour camera which feasibly could be the guider system - IF I chose to try using it guided, which, by the thread, doesn't seem necessary. but its still an option from the kit ive got. Thank you Derek
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