Drift allingment

[icpass]

Hi,im sure this must have been asked a 1000 times but i need to k now.

How do i drift alling scope,I have downlaoded wcs software and i hope to give it ago as soon as the sky clears.

Has any one used this method and what was the procedure,I have reasonably good polar alingment but i would like it near to perfect for imaging.

What does it mean and how do you find out the declination of stars is there an easier method of drift allinging

My trouble is i hate to read things and understand how it works before i mess.

thanks

Ian:confused:

[ncjunk]

oohh I used that software and it is quite good. The explanation on the website is perfect though and you really should read through it.

I skipped a bit and ended up having to re-do it.

The good thing is you select a star and it follows it for 5 minutes and then shows you on the screen where you need to move the star to by manually adjusting the RA or DEC (it shows green parralel lines and red ones...if I remember correctly you move the star over to the red ones).

I hate manuals as well but in this case I would say read the site as the explanation is the best I have come accross and it is easy.

Neil C

[Sam]

Hi Ian,

I don't use WCS but I do drift align so I can tell you what I do to see if that'll help you. I use a programme called Guidemaster which is kind of like PHD (in fact I autoguide with PHD rather than Guidemaster but use guidemaster to drift align). Guidemaster has a useful drift alignment function on it. All I do is stick my telescope mount aligned roughly to the celestial pole and then point the telescope south (just a wee bit East though, not too much). I then find a star and click advanced/dirft align/ and press start. After a while it'll tell you how far off you are so I adjust the az bolts accordingly (it can be a bit confusing at first to determine which way but you'll soon work it out as only one way will make the error smaller).

The altitude is important as well so you have to swing the telescope to the East (as low as you can) and then adjust the altitude bolts accordingly (in guidemaster you'll have to tick a box so the app knows you're doing the altitude. Eventually the error will be very small and you'll be very well aligned!..... hopefully!

Sam

[ncjunk]

Sam,

WCS does basically the same. You select a Star and then move it from one grid to another to calculate the movement drift across the CCD. Then you select the star as you say and it runs for 5 mins (you can run it for as long as you like). It then calculates the error and puts up some lines on the screen and you adjust the mount to centre the star within the lines.

Sounds to me like I might try guidemaster as well just to see if it is any better.

Neil C

usefull link Understanding Drift Alignment with diagrams for southern hemisphere for drift align pics

[icpass]

Sam,

thanks for that,not being stupid but do you do this with the mount tracking or is it done whilst turned off.

Ian

[icpass]

The only problem i have with guidemaster is that it does not support any of my cams.

I have atik 16ic meade dsi,and dmk.

Ian

[ncjunk]

with tracking going. I used my DSI with WCS just downloaded the DSI version of WCS.

NC

[Sam]

The only problem i have with guidemaster is that it does not support any of my cams.

I have atik 16ic meade dsi,and dmk.

Ian

looks like you'll have to stick with WCS then:)

Sam

[icpass]

Ok guys I have downloaded dsi version and i have read the short tutorial ,next prob is that i cant see very low to my east,is this a problem,and also how do i know the declination of the star im using in the south.

Ian

[roundycat]

It is well worth remembering that you do not need a computer or any software at all to successfully drift align. Just a reticle eyepiece.

Dennis

[icpass]

Dennis

Whats the procedure for manual drift allingment.

Ian

[SteveP]

This link has a very good explanation of Drift Alignment and also a built in simulator!

Unfortunately you will have to read it! I don't know of any shortcut ... but it will help you in the longer term if you understand what is going on when your are aligning manually.

Classic Astrophotography - Photographing the Cosmos with ordinary film

Alternatively just do a google and you'll find a load of diifferent explanations. The underlying technique is universal but some explain it differently and indeed better than others.

Steve

[barkis]

I second the "No need for fancy software or tools" other than an illuminated reticule and the need for lots of patience.

It is a job that requires the will to get it right, and a must if your setup is a permanent one. The least work your autoguider has to do the better.

Ron.

[roundycat]

my prefered method requires a diagonal and a reticle eyepiece. Point your scope to somewhere near the meridian/equator and find a small star. With tracking on watch the star and it will probably move away from the centre or where ever you originally set it. Don't concern yourself with movement from side to side, you are only interested in up and down or Declination. The basic mantra is simple;

If the star drifts South you are too far East.

If the star drifts North you are too far West.

All you need to remember is that the diagonal gives you a right way up but laterally inverted image. Also the bit about being too far East, for example, means the MOUNT is pointing too far East when you view it from the south side looking at the pole. You need to adjust the mount azimuth control to move the mount only, forget about the scope. Re-center your star, or another one, and re-iterate.

After a few minutes getting your head around what is going on you will be able to do a quick check on PA using the drift align method in just five minutes.

Your telescope will be pointing to the south throughout this exercise, your mount RA axis is pointing north and it is that you are adjusting, not the scope.

Dennis

[ncjunk]

I understand completely the "no need for fancy software" comment and it is 100% correct....but I like using software for me it is fun.

And the software wasn´t too hard to configure and set up...but I will try the manual method during the winter honest!

Neil C

[barkis]

I may have posted this way back when, bu I have included it again in the hope it may help someone.

It is from Issue 8 of Astronomy,. back in 1982.

It was written by the great man himself, Robert Burnham of the Celestial Handbooks Fame.

It more or less coincides with what Dennis explained, But here it is in print anyway.

Ron.

[icpass]

Guys

I have given WCS my best shot,spent 2 hours using it tweeked it this way and that ,moved it up and down then!!!!!!! It blumming clouded over:(

Ian

[Tim]

Ian,

Take a look at this website too, it explains some of the foibles of DA in an easy way.

Its what I use for aligning. My mount is left outside, and the planetarium software can put my target centre screen without doing an alignment run each setup. I routinely do 30 min exposures, and just recently tried 60mins. That should be plenty eh?

Classic Astrophotography - Photographing the Cosmos with ordinary film there is even a simulator to help. If you can get to 15 mins with neglible drift, that should be fine. If you cant use an eastern star, what about a western one? The website explains how.

HTH

TJ

You can also DA using your GOTO if you have one, but you'd have to google that method, I dont have a link.

[Tim]

ooops, beaten to it, but its a double recommendation