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Practice beats theory every single time.
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As I have always done. Take a test exposure using an educated guess of what is suitable. Adjust subsequent exposure times such that the peak of the histogram is about one-third of the way up from zero. It doesn't matter too much if the histogram peaks at one-quarter or one-half. A "ball park" exposure time is all that is necessary. This works no matter what camera, telescope, filters or sky quality you have.
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I'd question that. The one in the Amazon link plugs into AC mains power. The device in the video looks like it measures the DC current to the mount. Something your digital multimeter will do, once you have the correct cabling for it.
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All I can offer is non-specific advice that applies to many areas. Whether computers or not. The first step is to strip everything down to basics. Make sure your mount has no rattles, sticky spots or loose connections. Give them a good shake. Nothing should move or disconnect. Then connect your computer. Do the same. Wave it in the air. Turn it upside down. It has to work unconditionally. Cable-up the mount and make sure it talks to the computer 100% of the time. Wiggle the cables, check for drop-outs. Run the CPU up to 100% and convince yourself that everything is solid and continues to work. Be aware that none of the connectors used in most budget equipment are designed for outdoor use. Nor do they stand up to unplugging frequently. They are generally cheap garbage. As are the cables! Do slews. Do flips. Add weights and repeat. Make sure that no cables snag at any point. Add your OTA. Do all the same again. Ensure everything is tight - no slack, no play. Continue the same with your camera. Use the simplest possible optical path. No adapters. No filters or correctors. Satisfy yourself that the images are exactly what you expect. Add guiding. Recheck everything and continue adding one item at a time and retesting. Then, when everything is satisfactory MAKE ABSOLUTELY NO CHANGES EVER AGAIN. 😆
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I'll tell you what I want, what I really really want...
pete_l replied to Ags's topic in Discussions - Scopes / Whole setups
I have a Borg 101mm f6.5 and it's .... nice. Though I couldn't tell you what model it is. Borg gear is a bit like IKEA. You get a collection of pieces and have to work out for yourself what goes where. As for upgrading it ... a parts number nightmare. -
I did the same thing, many years ago. On advice from the optician I bought a second pair with ½ dioptre more correction - just plain lenses: no varifocal or photochromic finishes. Be aware that at night when your pupils are fully dilated, focus becomes more critical. Just like with short focal length telescopes. So it is more important that your prescription is accurate. I presume that is why eye tests are carried out in a low-light room. Of course, for astrophotography it doesn't matter.
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DIY Stepper RA Drive Using Raspberrypi - Stepping Issue
pete_l replied to Juju's topic in DIY Astronomer
As rotatux says, there is some arithmetic involved. One specification of a stepper motor is the steps per revolution number. For example, it might be 200. So with your 32 microsteps you would have to send 32*200 pulses to turn the motor's axis 1 revolution. There will almost certainly be further gear reductions after the stepper motor. You will need to find out what they are and therefore how many revolutions os the stepper axis it takes to turn your RA drive one complete revolution. -
I asked that question (actually: what is the image circle from your model ... ) of Meade, quite some time ago when I was considering buying a 5-figure rig from them. The sum total response from their assembled experts was that nobody knew. I didn't continue with the purchase.
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I've had a 3D printer (Geeetech A10) for about a year. What I've used it for is to print some eyepiece "bottles" and cases for electronics projects, such as Raspberry Pi boxes that need extras, such as space for backup batteries, USB accessories and such. I have two observations. First, if you are budget-conscious, don't forget to account for the cost of the spools of material to print. Second is that 3D printing is mind-numbingly slow. Several hours for anything of a significant size. Coupled with my experience that it always takes me several attempts to get the print right, it quickly becomes a chore. I have also found that quite a few of the ready-to-print designs you can download don't quite work. Maybe that is due to variation between printer types, materials or even having all three axes of the printer "square".
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Probably because people collect sufficient data for a nice looking end result and then move on to a different target. It is, after all, a hobby. Nobody is being judged or assessed on the forensic detail of what they produce.
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Excellent Cover for a mount permanently outside
pete_l replied to Catanonia's topic in Discussions - Scopes / Whole setups
Completely agree. The goal of a scope cover is to keep moisture off the scope, mount and electronics. That is irrespective whether the cover is made of fabric or is an observatory dome. The other key function of amy sort of cover is to stop the contents from cooling to below the dew point. Since a night sky is very, very, cold, metal especially cools quickly due to radiative cooling just as an exposed windshield attracts dew and frost before one that is under a shelter. -
Researching into stargazing at an emotional level
pete_l replied to JamieQ's topic in Observing - Discussion
I feel that one aspect which would make this research stand out from the crowd, would be to consider the needs of people of different ages and personal mobility - or joint stiffness -
Is the advice "The HEQ5 is the entry point to AP" just plain wrong?
pete_l replied to wuthton's topic in Imaging - Discussion
The problem is that the world of amateur astronomy is overflowing with advice. Almost none of it is verifiable and lots of old stuff that should have been buried years ago keeps popping up. Part of the problem is internet search algorithms that put stuff with lots of hits to the top. And the older something is, the more hits it will have. Another issue is that almost none of the advice (particularly where mounts are concerned) is testable or quantifiable. Is mount "X" better than mount "Y"? At best this will just start a fight, Where those who have purchased each type will wade in to its defence. Even when there is no data either for or against - apart from price, which seems to be used as a proxy for quality, or a buyer's "seriousness". The thing about the HEQ5 is that it is the Ford Transit of mounts. It has been around for a long time. It has sold very many. Even if there are mounts that are "better", it is at least a known quantity. The safe option. I am sure that there are now better mounts. If only someone could come up with an objective measure of goodness. One that everybody agreed with (see above about people defending what they have already purchased) and that could be publicised without suppliers threatening to pull their advertisements (or not send "influencers" free stuff) if unfavourable reviews were made. -
Have you considered a dolly? In case that is a term limited to British culture, I mean something like this: