ONIKKINEN
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Posts posted by ONIKKINEN
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11 minutes ago, McQ said:
Lasers are easy to use safely, all you have to do is not point them at aircraft or people on the ground, that's it. And they come with momentary switches because it only takes a second to get on target. The other night I'm trying to look straight up and I can't contort my body to look through the finderscope, luckily, I have a laser.
I think the reason why they are banned or heavily regulated in many places is because they are unfortunately also very easy to use unsafely, whether by accident or intentionally.
Accidents happen and one butterfingers moment could have even a person of sound mind pointing the laser at a passer by, a car driving by, someones house across the field or an airplane that they did not notice somewhere in the distance. Or just accidentally point it at your own face and if its some cheap ebay laser that was supposed to be 5mw but was in fact 50mw, well now you have permanent eye damage!
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You could try running banding reduction in Siril on the calibrated subs before stacking to help with the banding, although im not so sure where the diagonal lines are coming from. Could it be some processing issue if you have removed gradient from the images already? (looks like it)
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The data is probably just monochrome FITS files. Or i hope it is so existing tools could work with it (cant see why change the format to another).
I am very interested in seeing how they process the colours when they start presenting data to the public. I cant think of a way to make it look "realistic" since the wavelenghts are beyond human vision so mapping to RGB will probably look odd. Ill guess that the final images will have a similar colour palette as some narrowband shots aka the hubble palette.
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Something to think about when figuring out the cost difference would be the things other than the simple amp meter itself. These cheap plastic trinkets are far from weatherproof, tugproof on a mount, accidental bump proof and you need to wire them yourself so if you're a clutz with the process you brick the mount. Obviously a DIY man can build a casing for the ebay meter and wire it properly to go between the mount and the powersupply but its no longer obviously much cheaper. Okay its still a lot cheaper if you buy some obscure ebay components for everything or crack out the saw and do some woodwork for the casing but anyway its not for everyone.
The AC plug meter is quite convenient looking though. Shame i dont use AC to power the kit so cant really use that. Think im going to order the Prologic one unless i find some easy solution that i could plug into my existing kit.
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33 minutes ago, david_taurus83 said:
Best thing I've done with it so far. Guiding has been great. I used to always get messages saying dithering settle timeout. Everything just works properly now.
That does look good, almost too good 🤣.
Mine looks like this, although so far i have not had the pleasure of using the mount in completely windless conditions so there are some little temper tantrums here and there and its a bit difficult to tell what is guiding related and what is external, but at least from the calibration result its easy to see that there are some mechanical issues since the impulses are bunched up in pairs.
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On 28/05/2022 at 22:36, david_taurus83 said:
Have a look through the mount. The outer race is obscured by the mount casting so you'd probably just smash through the nylon cage! On 3 of mine, there maybe just, and I mean just enough of the outer race available on the inside to 'grab' with the flange on a blind bearing puller (those hammer type ones). If I was really determined I'd probably just pry the nylon cage out and the pins with a screwdriver and remove the outer race on its own. You destroy the bearings this way but you are replacing them anyway. Of course, you probably have fsr more experience than me at this sort of thing anyway!
I see what you mean, there is almost no metal edge to strike on for the bearings in the cage. I dont see a way to take them out without smashing them to pieces and also probably damaging the casing so better to leave them in place since they are not really in need of changing right now anyway.
On another note i found some real gremlins inside the mount like pre stripped philips head screws so i dont have to strip them myself. How kind of Skywatcher to do it for me 🤣. Also found that the cage bearings were underlubricated while the roller bearings were grossly overlubricated in the DEC axis while OK in the RA. Seems like someone assembling these puts more or less a random amount of grease in the bearings... Some rough to the touch surfaces too but these are under the roller bearing steel washers so shouldn't cause friction but better to clean it out properly anyway. Disappointing workmanship at display but the mount is quite cheap so i guess its a given.
I will be surprised if performance doesn't improve after this (provided i dont fumble anything).
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2 hours ago, Astro Noodles said:
Just been doing some internet browsing and it seems that the cost of a SpaceX low orbit launch is less than $3000 per KG, compared to more than $50,000 per KG for the Space Shuttle. Mr Musk is saying that when Starship is operational the costs will drop to the tens of dollars per KG.
It seems that the age of the amateur space telescope may be closer than thought.
This cost is probably derived from a full payload launch, so there would have to be an awful lot of amateur scopes going up to fill the entire rocket! Remember the cost of the rocket with nothing sitting in the payload fairing is pretty much the same as launching the thing with a max payload. Ride sharing with a bigger launch is more likely, but i doubt this will get anywhere close to the theoretical price either.
Many things need to be ensured for a space telescope to work at all and this price will easily be more than the launch cost. It will need a propulsion system for orbital maneuvers, that is if you dont want the scope to re-enter the atmosphere and become a cloud of plasma and a puff of smoke. Also some kind of high resolution pointing system, with probably reaction wheels and gyroscopes. Will also need power, communications and epic thermal design. In orbit the temperatures can range from -100c to 100c so you just cant have any old scope and throw it into orbit and expect it to work. Realistically the scope needs to be kept cool both passively and actively when on the sunlit side and still be built from very low thermal expansion materials = Basically entirely carbon fiber.
But for lets say 1 million $ one could probably get a small private space telescope up with the rideshare option. Its pipedream money for most, but not all people so i think this may qualify as an "amateur" space telescope then?
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A= Not sufficient. Not even close really, and if someone guides like this they will definitely lose resolution to poor guiding and so shooting at this resolution is a pointless waste of SNR.
B= Definitely good enough and i doubt there would be a very noticeable difference with better guiding at this resolution.
I think a guiding error of 50% of your imaging scale is where things start going to the nitpick and diminishing returns category.
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35 minutes ago, Astro Noodles said:
I'm trying to run my 294mc from a Celestron power tank.
It should be enough shouldn't it?
Celestron Lithium 7.2 Ah LiFePO4 Powertank | First Light Optics
I had a terrible experience with this powertank so wouldnt recommend it. I see that some others have not so terrible experiences so mine might be from a monday morning batch of units but anyways.
This powertank has a DC port and 2 USB ports, but only one of these can be used at any one time, so you dont really have 3 ports to use if you planned to use the USB ports while the DC port is running too. The DC port is also a "smart" port so you cannot choose to supply power or not, the powertank will choose for you. If the power consumption is too low the powertank goes to sleep and you lose power, also if its too large, and by too large i mean anything that is greater than 3A by even a little bit for 1/10th of a second, the powertank shuts power off. For instance using this to power an equatorial mount will mean that during every go-to the powertank shuts power off because probably for a fraction of a second there is a current spike. Terrible design and not one i cant not recommend when given the chance!
That being said, i doubt there are many current spikes when powering a camera as its more or less constant power required rather than 1 moment no power and another moment full power with 2 motors.
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The distance is not that strict in mine. I have tried 54, 55 and 56mm with my maxfield and saw no obvious difference in any of them. So with my 8'' F4.4 scope it didn't really matter that much whether it is accurate to some or the other claim.
Your mileage may vary of course, but that's how it was for mine.
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6 minutes ago, Sarek said:
Thanks. Magic Lantern certainly looks like an option. Have you tried it?
Have used it a bunch before i hooked my 550D to a mini-PC and controlled the exposures with NINA. Simple changes like the intervalometer work great with no issues. There are also some not quite flawless settings that can make the firmware crash but the camera warns you of those before hand (video related mostly).
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My 550D can only shoot continuously, so exposures back to back, and only up to 30s.
However you could install https://magiclantern.fm/ to get many 3rd party features, like a proper in-camera intervalometer where the 30s limit and only continuous shooting rules dont apply. You can also set a delay between shots if you are worried about mirror shaking affecting the shots.
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19 hours ago, edarter said:
Just come across this thread while researching whether the 294MC Pro is the camera for me. I had long got it on my shopping list but recently saw all the negative comments surfacing about using it with a dual or tri band filter.... something I would be interested in medium term as it seems the only clear nights in the south UK are full moon 😒
So am I right to assume from this that there should be no issue with the 294 and dual or tri band filters if the gain is upped to 200 in order to get on the linear part of its response? (for subs and calibration files)Thanks
EdIf you dont mind going for less popular brands you can have an equivalent camera to the 2600MC for a much more palatable price, have a look at these:
All are basically the same camera, but be aware that none of these will work with an ASIAIR (if you have one).
Right now it looks like the Omegon 571 is the best deal with the Rising Cam from aliexpress pretty close. The 2 others are more expensive but i just linked them anyway, since they are the same camera and still cheaper than ZWO.
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I like Ed Ting, even though i am maybe 95% imaging and he is the opposite. His presentation style is very easy to enjoy even though i am not even remotely interested in buying some 16'' dob that he is reviewing.
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The problem with the shuttle disaster(s) was that the orbiter was right next to the boosters and so there was no chance of survival in a launch failure like there is with a conventional design. It also meant that ice and debris falling off the boosters for any trivial reason will strike the fragile wings and damage them.
SRBs are sort of safe to use with normal rockets where the orbiter is on top of the stack, far away from the deathy end of the rocket. But they are most importantly cheap and powerful, hence their common use as boosters.
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13 hours ago, Captain Scarlet said:
Mirror segment hit by micrometeorite, larger than any they modelled...
https://blogs.nasa.gov/webb/2022/06/08/webb-engineered-to-endure-micrometeoroid-impacts/
From the article:
QuoteFurthermore, Webb’s capability to sense and adjust mirror positions enables partial correction for the result of impacts. By adjusting the position of the affected segment, engineers can cancel out a portion of the distortion. This minimizes the effect of any impact, although not all of the degradation can be cancelled out this way. Engineers have already performed a first such adjustment for the recently affected segment C3, and additional planned mirror adjustments will continue to fine tune this correction. These steps will be repeated when needed in response to future events as part of the monitoring and maintenance of the telescope throughout the mission.
This is what came to my mind too, the mirrors can be bent back to shape or in a worst case scenario maybe pointed completely off-axis to take the damaged segment out of play? That will produce a missing piece in the telescope and some diffraction problems but the mission will still go on without much of a problem, after all the probe could have lost both of the side wings and still have a mission left. Lets hope some 50km/s spacepebble doesn't torpedo some electrical components or something else that can ruin the mission...
Very few micrometeor impacts have been recorded for probes overall, JWST being the biggest of them will of course make them a bit more likely but its still very unlikely that a rock will turn Webb into space junk!
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I can see stellina and other smart scopes like that becoming more and more common as time goes on. Just needs to drop more than half of the pricetag to be viable for more folks but thats a question of when rather than if since the individual parts to make such a scope are nothing new or special.
I would also imagine that the same kind of tech would make its way onto visual scopes in the form of some kind of plate solving auto pointing system (like Celestron starsense?).
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Terraforming Mars into an Earthlike planet is basically a pipedream with little base in reality. Doesn't mean we couldn't live there, like in underground cities for example. But a full terraform of the surface is not gonna happen.
Human travel to other solar systems is so far into sci-fi territory with today's technology or even tomorrows imaginable technology that i dont think its reasonable to think that will happen in a long time (1000+ years at least). We will definitely destroy our own planet first and if we can fix it we can sort of start thinking about fixing other planets. If we cant fix the one planet that we have evolved to live perfectly on, we definitely cant even dream of surviving in another.
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Jumping from issue to issue sounds very familiar, and getting any kind of result in the end makes it all worth it!
I will echo the above about taking flats, that will allow you to stretch the image harder in processing without the corners going full black.
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The SLS was an antique design when it was first drawn on paper, 10 years ago! It an embarrassingly bad launch vehicle by today's standards...
It has no reusability and uses 4 of the most expensive rocket designs ever made, the RS-25, which were designed to be entirely reusable (hence the cost). Think about it, the engine was designed to be reusable with the shuttle and NASA is going to literally catapult 4 of them into the ocean every time one launches? Braindead design right there which is not excusable for an entirely new design since SpaceX has shown its actually viable to reuse big rockets time and time again.
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1 hour ago, Aramcheck said:
Thanks for the comments/suggestions. @ONIKKINEN The scope is kept in a storage area which is near ambient & is only moved a small distance. I re-checked collimation yesterday but I don't have a collimated laser, so could only do so with a cheshire (& obviously without the coma corrector). I took a few pictures with the scope at different orientations, roughly mimicking the positions during the last imaging session, but there could be some focuser slop once the 2600 camera is attached. Why should tube currents create the elongation in one direction?
Warm air rises and exits from the top of an open telescope such as a newtonian so there is a preferred way for the smearing rather than a random motion.
I have this issue almost every time since i dont keep the scope in an ambient location. I delete most of the worst ones but i found an example of what it looks like when there are still a bit of tube currents left. Far from the worst but its still somewhat clear.
First image is from early in the night and second is later when the currents have settled. Notice the bottom part of the star is smearing outwards and that would be the axis that coincides with the up-down axis of the scope at that situation.
My coma corrector, a Maxfield 0.95 one, introduces tilt/collimation issues of its own so i found that i needed to collimate through the coma corrector and in the orientation that i would want to image in, so a different collimation for 0 degree and 90 degree camera orientations for example, and different for no coma corrector at all. Dont know how common this is but id say there's a good chance your MPCC has something similar. You cant know for sure unless you have a way to collimate with the corrector in place which i dont think can be done without a laser as the image is all out of focus visually.
Tilt of the focuser is very possible, id say almost likely. But that is apart of the umbrella term that is collimation, if you cant have a reproducible camera/collimation tool position you just cant have reproducible collimation. The scope is collimated when the primary mirror points to the center of the camera and all 4 corners are on the focal plane, so if the focuser is sloppy the scope is just out of collimation. Try to tape a weight onto your cheshire and see if the collimation holds. If it doesn't, it definitely wont with the camera either.
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8 hours ago, bomberbaz said:
Ok so had a little play tonight and here are my findings.
The comet rotates with the camera, one way or the other it follows the rotation.
As regards exposures, 180 seconds or 10 seconds, it is there.
Not sure if I am right here but this appears to point towards a image train/collimation issue rather than tracking!
Sure sounds like a mechanical issue with tilt or an optical one with collimation then, yes. Just by coincidence the effect happened to be along the dec axis.
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The tadpoles look a bit like tube currents inside the tube when the scope is not cooled to ambient, but in that case the tadpole looking effect would be to the same direction for all stars but in your image they are sort of not. Some stars have the tadpole going the other way which is a bit confusing and so maybe not tube currents, but that's my guess anyway.
29 minutes ago, Aramcheck said:The scope has recently been collimated.
From personal experience: Unless recently means before each imaging session, one should expect that the scope is out of collimation even if ever so slightly. Especially true if you transport the scope at all, or even take it off the mount and put it away (so in all cases other than permanent observatory).
45 minutes ago, Aramcheck said:
The cross looking stars in your bottom right here look like miscollimation for sure. Maybe collimate the scope again, preferably through the coma corrector with a laser and check that it really is collimated?
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The elongation appears to be in DEC as plate solved by astrometry.net here: https://nova.astrometry.net/user_images/5963191#grid
Do you have a guide log or just some guide statistics from the night of capture? Looks like your DEC axis is struggling, but dont know how to advice on this particular mount on how to fix. If backlash in DEC is particularly bad you may need to guide in one direction or not guide in DEC at all but would be easier to advice with some guide stats.
Using an OAG with a Newtonian
in Getting Started With Imaging
Posted
Recreating any angle takes as long as recreating 0 or 90 degrees, but it needs platesolving (yes i know you dont like it😅).
In NINA just hit a button in the platesolving tab with slew to target turned off and it reports the orientation down to 2 desimal degrees. Couple minutes at most to recreate an orientation to within a degree.