Lagoon Nebula

[desler]

Here's my attempt at the Lagoon neb.

32x 70 seconds exposures, ISO 800, Nil guiding.

1000d unmod through ED80. Stacked in DSS. RGB align, levels, curves and crop in Gimp.

Darren

[Jen]

Well done Darren

[jjjnettie (Jeanette)]

Good effort.
It's a bit dark on my screen. Maybe lighten it up a little more with Curves?

[desler]

As suggested.

[Ric]

Nice capture Darren, the central area of the lagoon looks very good.

Cheers

[jjjnettie (Jeanette)]

Ahhh that's better.

[g__day (Matthew)]

The colour is good, lots of fine details but the stars are a bit football, so tracking (or polar alignment) needs attention if you wish to do longer shots unguided.

Great effort overall

[desler]

Thanks everyone! Tips are good, advice is good, knowledge base is starting to lift from all the fun I'm having.

Matthew, Illuminated reticle arrived yesterday from Andrews.
Typically clouds and rain. Have to wait a little to try drift aligning.
I'm reading and reading about the processes, but am starting to believe that it's something I just need to do and keep doing till I get better, a bit like polar alignment!

Any easy straight forward tips on DA would be welcome!

Darren

[g__day (Matthew)]

Drift alignment - took me months to get the hang of - reading from a book or website and mistaking terms. If you can - get a friend who knows what he's doing to show you - or visit an astro party and learn there.

If you can rig a permament peir somewhere you have a HUGE advantage. You can tune your gear to be within arc seconds of the SCP - which means pointing and tracking will be excellent right off the bat.

There are alot of automated tools for polar alignment, some free, some a 30 day trial some cost. I used PEMPro and it did the job well for me.

The process - in the simplest laymans terms:

1. Get you mount set up as best guess you can level and pointing towards SCP.

2. Put in your guiding eye-piece and orientate it so RA movement takes any centred star exacly along two of the lanes precisely.

Now in all the following steps ignore RA drift - its only DEC drift (that 90 degress opposite to RA drift you are correcting for).

3. Find a star about 20 - 30 degrees above the horizon - as due East as you can. Centre it in you eyepiece.

Have a stop watch or egg timer and monitor after say 5 minutes how far it drifted in DEC only (and in which direction).

4. Drift means your elevation is wrong - one direction your above SCP, the other direct below SCP.

I cheat - guess and adjust your elevation say 1 degree. Now re-centre your star and time its drift for another 5 minutes.

It will either show alot more drift (in the same direction - meaning you guessed whether to raise or lower elevation incorrectly), less drift (meaning you guessed right - keep going but in smaller increments) or now its drifting in the other direction (you over compensated, wind it back some way).

Keep adjusting height - re-centre star and measure drift again.

5. Once you are happy there is no DEC drift for 5 - 10 minutes - simply swing the scope in RA only until your tube - weights arm is parallel to the ground. To clarify if you point the scope due East at the horizon, then swing the scope in RA only through 90 degrees - that is the best spot to check for East/West misalignment.

6. Find a star around this location - centre it and time it for 5 minutes - looking only for DEC drift.

If you get drift in DEC - you need to adjust the East/West orientation of the scope. Again guess one - if it right you'll see less drift once you re-centre the star and time it again for 5 minutes. Guess wrong and there'll be more drift.

Keep looping like step 4 until you see no DEC drift.

7. Now go back to step 4 - star above the Eastern horizon and do it again - adjusting elevation only. Once that is nailed go vertical again and nail East/West orientation. You'll find your adjustments get smaller and smaller as you bear in one the exact SCP on both axes of your mount.

Generally 2-3 iterations of the above should be sufficient to get you very close to the SCP.

* * *

An automated program checks your orientation - measures angular size for your camera and following the same procedure tells you or even shows you how far to adjust your scope and in which direction. So with PEMPro I might do a 30 minute run on either axis and look to get less than 5 arc seconds DEC drift. I will still need to guide long shots (to even out Periodic error and atomspheric seeing errors) but the guiding will be alot simpler and much less frequently - meaning it should be far easier getting great shots.

Hope this helps!

Matt

[Robbie]

Thats a nice pic but you're right the DA has let it down
Have you thought about a guidescope and PHD? If you use a guidescope DA becomes a bit less critical
You can set up guiding fairly cheaply, the guidescope can be as simple as a kmart 50 dollar kids refractor, dovetail/rings and an obsolete meade dsi 1 linked to PHD (which is free). I just found that for a portable set up spending half the night getting near perfect DA was an ultra drag.
All in all tho if I took a pic like that one when I was new to the game I would be very proud indeed nice work!

[Robbie]

Originally Posted by g__day

Drift alignment - took me months to get the hang of - reading from a book or website and mistaking terms. If you can - get a friend who knows what he's doing to show you - or visit an astro party and learn there.

If you can rig a permament peir somewhere you have a HUGE advantage. You can tune your gear to be within arc seconds of the SCP - which means pointing and tracking will be excellent right off the bat.

There are alot of automated tools for polar alignment, some free, some a 30 day trial some cost. I used PEMPro and it did the job well for me.

The process - in the simplest laymans terms:

1. Get you mount set up as best guess you can level and pointing towards SCP.

2. Put in your guiding eye-piece and orientate it so RA movement takes any centred star exacly along two of the lanes precisely.

Now in all the following steps ignore RA drift - its only DEC drift (that 90 degress opposite to RA drift you are correcting for).

3. Find a star about 20 - 30 degrees above the horizon - as due East as you can. Centre it in you eyepiece.

Have a stop watch or egg timer and monitor after say 5 minutes how far it drifted in DEC only (and in which direction).

4. Drift means your elevation is wrong - one direction your above SCP, the other direct below SCP.

I cheat - guess and adjust your elevation say 1 degree. Now re-centre your star and time its drift for another 5 minutes.

It will either show alot more drift (in the same direction - meaning you guessed whether to raise or lower elevation incorrectly), less drift (meaning you guessed right - keep going but in smaller increments) or now its drifting in the other direction (you over compensated, wind it back some way).

Keep adjusting height - re-centre star and measure drift again.

5. Once you are happy there is no DEC drift for 5 - 10 minutes - simply swing the scope in RA only until your tube - weights arm is parallel to the ground. To clarify if you point the scope due East at the horizon, then swing the scope in RA only through 90 degrees - that is the best spot to check for East/West misalignment.

6. Find a star around this location - centre it and time it for 5 minutes - looking only for DEC drift.

If you get drift in DEC - you need to adjust the East/West orientation of the scope. Again guess one - if it right you'll see less drift once you re-centre the star and time it again for 5 minutes. Guess wrong and there'll be more drift.

Keep looping like step 4 until you see no DEC drift.

7. Now go back to step 4 - star above the Eastern horizon and do it again - adjusting elevation only. Once that is nailed go vertical again and nail East/West orientation. You'll find your adjustments get smaller and smaller as you bear in one the exact SCP on both axes of your mount.

Generally 2-3 iterations of the above should be sufficient to get you very close to the SCP.

* * *

An automated program checks your orientation - measures angular size for your camera and following the same procedure tells you or even shows you how far to adjust your scope and in which direction. So with PEMPro I might do a 30 minute run on either axis and look to get less than 5 arc seconds DEC drift. I will still need to guide long shots (to even out Periodic error and atomspheric seeing errors) but the guiding will be alot simpler and much less frequently - meaning it should be far easier getting great shots.

Hope this helps!

Matt

Yeah ...what he said

[desler]

Wow Matthew, Thanks heaps for that.

Darren