Zinc compounds - zinc molecular

 2024-10-14 09:58:32

Not really unfortunately, I've already seen any video I could find about that, but with no use, the thing is its possible that my collimator is faulty, so idk really if its just me and its the collimator, or both...

Drift alignment is your friend. There's loads of tutorials on the web. If you use PHD2 then it has a drift alignment tool built in.

Now rotate the collimator again but aim to get the dot at the top of the circle, and choose a screw the same way and loosen it.

I guess I'm just going to need to experiment and see if my southern view is adequate enough to try and perform these methods, there doesn't seem to be any information on if they become unreliable at a certain angle over the horizon.

In terms of the trees themselves, I'm hoping a conversation with Rail Track might get me somewhere, as they are not a standard neighbour and have no personal attachment to the trees and neither like / dislike or care about them it will boil down to cost for them as a company. By offering to pay the cost of the tree surgeons I might be able to get some work done on them, even if it's just to cut back the areas around Polaris.

I place the collimator in a v-block (anything that supports it in a fixed orientation is fine) aimed at a wall about 16 feet away.

You just need to have the laser spin evenly around the polo mark so irrelevant how far the laser is out of collimation .

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This may seem long and drawn out but you always move towards a better setting and will get on point faster. Doing large adjustments is actually slower in the end.

Rotate the collimator and the dot describes a circle. Get the dot at the bottom of the circle. If a screw is more or less at the top, tighten by half a turn. If a pair of screws are either side of the top, turn one of them to the top and tighten by half a turn.

The laser unit is held in the machined housing with a rubber "O" ring type thing at one end and three grub screws that go through the housing press against the laser unit at the other end of it. On some models you need to remove a label to reveal the grub screws I believe. You might need to loosen one grub screw a little to allow adjustment to another. You need to remove the screw on battery cover section and spring from the end of the collimator to allow the last unit inside to be free to move as well.

Do you have any examples anywhere? The PHD2 instructions show standard drift align techniques of pointing south for declination and then east / west for altitude, and closer to the horizon the better, which is an issue in every direction for me.

Yes an AZEQ6, do you know how is works, does this involve slewing to pairs of stars? These sorts of things like alignmaster normally present a pair of stars where I can't see 1 or both of the stars as they are blocked by trees / house.

I don't have the facility to film it I'm afraid. You turn the laser collimator slowly around 360 degrees, stopping every 90 degrees and marking the position of the laser dot on a piece of paper taped up around 30 feet from the laser unit. The V-block and laser unit must stay completely still in one place of course during this rotation. That shows you how far out the unit currently is. Then you pick a grub screw, hold the laser collimator in place in the V block (and the V-block exactly where it was as well) and make an adjustment to the screw noting which way the laser dot moves - hopefully towards a spot at or near the centre of your 4 90 degree marks. The repeat the rotation, mark accordingly and adjust again as necessary. It is a bit trial and error I'm afraid.

i get this topic here which will be very helpfull to me.my laser collimator is also not steady its red spot in constent position.i hope this advice will work for me.

Another factor is securing the laser in your focuser. A single screw will knock the laser off centre. For this reason I prefer the Hotech with it’s expansion rings which keep the laser centered. My HoTech came perfectly collimated and when used it’s in perfect agreement with my Cheshire and cap.

Any thoughts or ideas would be very gratefully received, as I really don't want to have to give up as I can no longer polar align my mount .

Well the problem is no matter what I try its just not really working, the screws are not going to the direction they should.

The circle should keep getting smaller. As you it gets really smell reduce the amount you turn to a quarter turn or less.

I need a southern view to drift align, which is blocked, mostly, by my house, up to about 75/80 degrees from the horizon.

Hello, I purchased a laser colliator but unfortunately I'm facing a problem, I knew that I need to collimate the laser before I purchsed it, and I got something just for that at home, so I thought it wouldn't be a problem, but for a reason I don't seem to be able to collimate the laser, at first the laser was a bit off, so I tried playing with the screws, but it just didn't really worked, no matter when I did the laser was just not going to the direction I needed it to.

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The pic doesn't show the ground, and it is a stitched panorama so the perspective is a little flattened. The left hand to right hand side of the pic is almost 90 degrees.

Fortunately I have a lathe which makes collimating your collimator easy. Mount the collimator in the chuck, tape a piece of paper on the far wall and slowly rotate the chuck. Word of warning though: many modern 3 jaw chucks do not run true, so you may have to use a 4 jaw & dial it in.

So I'm very soon likely to lose my view of Polaris to polar align my mount (which is a non permanent set up). The picture below is a stitch of my NE - N - NW view from my imaging location, and I've marked the position of Polaris.

Wire grid polarizer theory

So if you insert the laser in the focus tube and spin it, how vast the gap should be? Do you mind filming a really short video showing that when you're free?

So if I chose Vega for example, I can then pick any other star in the list? Or does it have a predetermined partner I must then slew to?

What is polarizer in Physics

Sound's like there are some options to try out there, Sharpcap and drift align at even quite a high altitude to the south.

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To drift align you only need to be within about 20 degrees or so of the celestial equator, meridian or horizon as appropriate. If you can't get even that close you can still drift align but it takes longer as you iterate the alt and az adjustments.

If you have an RA motor on your mount with settable slew rates, you cna use your camera to preform drift alignment in just a few minutes. Photographic drift alignment takes just over one minute per measurement. The procedure is: 1. set your slew rate to 1x sidereal 2. set your exposure time to 70 seconds (assumes computer control of the camera) 3. point your scope at the drift measurement location (ie celestial equator near the meridian) 4. Make sure your mount is tracking 5. Start the exposure. Track for 5 seconds, slew E for 30 seconds then slew W for 35 seconds Examine your image. You should see each star as a bright point with a V shaped tail that passes through or by the star. If you're perfectly polar aligned, the V collapses into a line that passes through the center of the star. The width of the V at the star is a measure of drift in pixels over one minute. Adjust the mount in one direction (azimuth) and see if the V gets wider or narrower. If wider, you need to adjust in the other direction. If the V moves to the other side of the star, you moved the mount too far. Once aligned at the first measurement point, point the mount to the second drift alignment point, the celestial equator around 30 degrees above the E or W horizon and repeat the measurement adjusting the altitude of the mount. After doing this alignment point, repeat the process for both alignment points to refine the alignment and check that doing the second point didn't change the first one.

You just need to have the laser spin evenly around the polo mark so irrelevant how far the laser is out of collimation .

I can't seem to get the perspective right with this picture. Your position of Polaris looks about 20 degrees in Altitude to me, not the 52 degrees I would expect, what am I missing?

Polarizer film

It needs to be at least that I feel. The further the laser dot is projected, the easier it is to see where it varies as you rotate the laser around it's axis and the more accurate the collimation is, when you achieve it. I try and get around 30 feet and when adjusting, try and get the laser dot to stay within a 10mm circle, or better if possible.

I can't seem to get the perspective right with this picture. Your position of Polaris looks about 20 degrees in Altitude to me, not the 52 degrees I would expect, what am I missing?

The second one a friend well more advanced than me collimated it for me but he even said done the best he could and it is only slightly out, I know you won't like this but I then check with a Cheshire/ sight tube.

Yes, when the leaves drop it's easy, but here in tropical Sevenoaks that's the end of November and they're back by the end of March! 4 months of imaging from 12 doesn't make me happy!

I'm going from memory here, but I am pretty sure that you can change the alignment stars that the Synscan initially selects.

My attempts to have Network Rail lower the heights of these trees has been totally unsuccessful, they outright refuse to consider anything not overhanging my property, and they are not! The trees are over double the size of my house, and although look a distance away in the stitched pic, aren't in reality.

Edit: Even with my laser collimated I mostly use a sight tube to collimate the secondary mirror, with the laser just to check/tweak. To collimate the primary mirror I use the barlowed laser method (just put a barlow between the focuser and laser). This turns the laser into a torch which illuminates the central part of the mirror and the centre spot. You then collimate the primary by centring the shadow of the primary spot on the collimator face. This method reduces the effects of inaccuracies in the collimation of your laser and secondary mirror.

As I'm expecting to lose my view of Polaris to those trees in the very near future, what are my options? Software alignment usually requires pairs of stars in different parts of the sky to slew to, and these trees, along with the house to the south block almost every pair of stars. Drift align needs a clear view south (that's blocked by my house!)! So I'm in a pickle!

I place the collimator in a v-block (anything that supports it in a fixed orientation is fine) aimed at a wall about 16 feet away.

Now rotate the collimator again but aim to get the dot at the top of the circle, and choose a screw the same way and loosen it.

A well-collimated laser collimator when rotated on itself, will generate a 10 mm circle on a wall when at a distance of 30 feet (9.144 meters). Adopting this criterion it's clear that the collimator has a deviation angle from the centerline (circle's center) equal to alfa, where alfa = 1.8 arc-minutes. So: A well-collimated collimator must have a deviation < 1.8 arc-minutes. Let's simplify and assume a maximum tolerance of 2 arc-minutes of deviation for any laser collimator. In that case, the deviation r [mm] at a distance L [mm] will be: r [mm] = L [mm] x tan ( 2 arc-minute) = L [mm] x tan (1/30) = L [mm] / 1719 r [mm] = L [mm] / 1719 Therefore, on a collimator with alfa < 2 arc-minutes at 30 ft (9144 mm) from a wall, we are considering it generates a circle with a diameter < 10.6 mm. A 10 or 11-mm circle is quite small so we need to increase the distance by at least 20 meters to have a circle of 23 mm, which has enough room for the laser dot and will let us draw the circle easily on paper and center it to make the proper corrections! Regards Andy

John, try Alignmaster, I've used this before when I've had trouble with a mobile set-up. There's a nice video on Astronomy Shed as well on how to use it. You just need to stars well apart and it gives you menus with a big list to choose from. The PA is usually very good with this software.http://www.alignmaster.de/

This may seem long and drawn out but you always move towards a better setting and will get on point faster. Doing large adjustments is actually slower in the end.

Polarizing Filter for phone

from sharpcap: " SharpCap's plate solving only works within 5 degrees of the pole though (N or S) " The polar alignment works by analyzing two pictures taken of the area near the pole."

I need a southern view to drift align, which is blocked, mostly, by my house, up to about 75/80 degrees from the horizon.

Just one more thing, I know the long debate about laser vs cheshire, please spare replies such as "get a cheshire" or "you should've bought a cheshire" and so on, maybe its true, maybe I learned it the hard way, but its still not helping my situation, so thats just it, thanks a lot

I honestly can't remember John....it's a while since I had a Synscan mount. I know that you can definitely select from a list when selecting the first star, but i can't remember if you can do the same when selecting the second and third stars. Perhaps someone with more recent experience of Synscan can advise?

I don't have the facility to film it I'm afraid. You turn the laser collimator slowly around 360 degrees, stopping every 90 degrees and marking the position of the laser dot on a piece of paper taped up around 30 feet from the laser unit. That shows you how far out the unit currently is. Then you pick a grub screw, hold the laser collimator in place in the V block and make an adjustment to the screw noting which way the laser dot moves - hopefully towards a spot at or near the centre of your 4 90 degree marks. The repeat the rotation, mark accordingly and adjust again as necessary. It is a bit trial and error I'm afraid.

Polarizer and analyser

Thanks, one important question, the laser doesn't need to be "10 feet away" to do it right? I'm not failing to do it because of the distance I'm trying I assume?..

Indeed, but they are on Network Rail land, above a railway line, I really don't want to break the law, kill myself or a train full of people.

Right, Mike! 👍🤜🤛🔭 Your description of how to proceed is excellent! I just wanted to give some numbers and the general formula so our colleagues would understand why it's essential to put a reasonable distance between the laser and the wall, I'd like to use 10 to 20 meters. I forgot to mention narrowing the laser beam even more! 1st - Regulate the laser lens to have the point focused at the calibration distance. 2nd - Open the collimator and under the 45º diagonal, just in front of the laser exit (internal) glue an aluminum foil, press your finger on it so the central hole appears, and with a needle, punch a small hole at its center. This will reduce considerably the laser dot diameter, which is not a dot because the solid-state laser beam is generated at a rectilinear junction. The laser point should have an internal diaphragm, which has not. So we make one at the exit. This mod really improves the laser collimator performance making the dot smaller! Regards and clear skies for us all!🙏🔭 Andy

Now bottom and tighten, followed by top and loosen. If at any point the screw feels tight, don't force it but do a top/loosen cycle twice instead. If it a screw feels loose, retighten it and do one or two bottom/tighten cycles

So if you insert the laser in the focus tube and spin it, how vast the gap should be? Do you mind filming a really short video showing that when you're free?

Polarizer Sheet

You need a view of the Polaris area for this to work though. Doesn't Astrotortilla have some sort of polar alignment routine?

So if you insert the laser in the focus tube and spin it, how vast the gap should be? Do you mind filming a really short video showing that when you're free?

Some of the China made budget lasers and cheshires are a bit naff imo and are just not made well enough to be totally accurate out of the box. I ended up buying a Baader and it was spot on. The reason Howie Glatter and Hotech kit is so expensive is because they manufacture high quality, precision made devices.

Thanks, one important question, the laser doesn't need to be "10 feet away" to do it right? I'm not failing to do it because of the distance I'm trying I assume?..

Spin the laser in the focuser so the red laser spins around the polo mark on the mirror then adjust secondary so laser spins evenly around polo mark , does it that make sense

Drift alignment is your friend. There's loads of tutorials on the web. If you use PHD2 then it has a drift alignment tool built in.

Absolutely. IMO this bit really isn't optional if you want to ensure good collimation. An unbarlowed laser can be useful for rough alignment of the secondary, but that's about it in my view. On its own, I'd rather use a basic collimation cap than a laser.

I agree with you, bosun21! A very important point you mention by the way! Indeed this is a problem with many drawtube's eyepiece holders...😢 Laser collimators and Cheshires will show this off-centering when we tighten the retention screw... A partial solution is to make the collimator body fit more tightly (a scotch tape around usually will do), being the recommendation not to tighten the screw when we achieve a tight fit using this method.

You need a view of the Polaris area for this to work though. Doesn't Astrotortilla have some sort of polar alignment routine?

A bigger problem is that after about 30 minutes of trying to collimate the laser, the screws worn out and it was just unusable, so I just used regular screws instead, it should work in theory, after all its only laser with screws that push it to whatever direction you need, the weird this is, when 1 specific screw is not screwed at all, the laser circle(when you spin the laser to check if its collimated) is not so big, but after screwing the screw(is that how you supposed to write it? o: the gap is widening, eventually, no matter really what I try, I just can't seem to manage to collimate it. Maybe I'm doing something wrong possibly? Hopefully someone will be able to help me and give me some advices.

The circle should keep getting smaller. As you it gets really smell reduce the amount you turn to a quarter turn or less.

So if I chose Vega for example, I can then pick any other star in the list? Or does it have a predetermined partner I must then slew to?