Please anyone?? I need help with Aligning RGB images??

[PARTY MARTY]

I've finally managed to image last night with 3 hours of dark skies, And I thought it would be a good idea to try my new QHY 9 Mono CCD with the filter wheel and LRGB filters. since I've not used it for months. Well managed to scoop the M57 Ring Nebula as easy target to begin with, quite impressed with high defintion of detail from the QHY 9.

However image processing and stacking is a real pain, in fact it's more complicated, it's taken me ages to figure out that you need to stack the Lumi, Red, Blue and Green seprately and you need to combine the images again into Photo shop, It's not easy at all and the thing is that my final image, doesn't come together right the colours don't match up right, it seems that I need to align the images properly, which I still don't know how to do this?? Again Mono imaging is not straight forward as colour CCD imaging, in fact it's not that enjoyable to say at least??? With Colour once your rig is set-up properly, you just power the CCD and your away collecting light photons. I've tried to Mono and to be honest I'm not liking it not one bit?? on a serious note that Colour CCDs seem to be the way for me, Mono is too time consuming and seriously too program orintated??? It's not easy at all what some people think it is??? So here's my latest image with just 20 of LRGB light frames of 75 seconds with the QHY 9 and 80mm Lunt ED Apo, See what you think guys n girls, please comment at will?? At moment I apprieciate any advice from anyone who's done mono imaging and any help of this aligning the combime images together properly??

I've tried to align the image up by re-stacking the serprate RGB images together in DSS which seem to work a bit, bit it still looks misaligned a bit, Is there any other programs which are freeware which can help to align the images together, Or is Photoshop CG2 (which I use) can align the image some way???

[cfpendock]

Others will be more expert than me (I). I open the separate stacked images in photoshop. Then choose a "master" to align the other images to, usually red. Then copy the green onto the red, set opacity at 50% (or however you can best see both images). Then enlarge the image as much as possible (ctrl+ lots of times) Then move the copied channel until it is precisely on top of the master channel. Then move opacity back to 100%, flaten the image and save it as green al, ie to let me know that this is the green channel now aligned with the red. I do the same with blue and any other channels I want aligned. Then I reopen the aligned channels again in photoshop (inluding the master), and they will merge perfectly aligned.

Hope this helps - it's what I do - probably there are more elegant ways of achieving the same thing but it works a treat for me.

Chris

[PARTY MARTY]

Thanks Chris! I'll try it if works?? I have Photo shop CS 2 will this proces work??

[cfpendock]

Don't know. It should do - copying and pasting images is a pretty basic function for almost any image processing software....

chris

[dmahon]

As you use DSS, align the images to the same frame when stacking (assuming same resolution).

Right click on your best luminance image and set it as the default image to align to (master I think it's called). When you stack R,G and B still use the same luminance frame as the one to align to (but uncheck it, so it does not get stacked).

[Gina]

I use Registar to align my images - great software though not free but worth the money IMO.

[cfpendock]

Thanks Dmahon - I always thought there must be an easier way - I just tried it and it worked!

Gina - I have thought about this - sometimes I take images with different lenses and if I remember correctly, Registar will scale the images as well as stack them?

Chris

[PARTY MARTY]

Thanks dmahon! You're a star!!! I've tried it in DSS and it worked!! Top class advice!! I'll can I re-pay you!!!

[ollypenrice]

Others will be more expert than me (I). I open the separate stacked images in photoshop. Then choose a "master" to align the other images to, usually red. Then copy the green onto the red, set opacity at 50% (or however you can best see both images). Then enlarge the image as much as possible (ctrl+ lots of times) Then move the copied channel until it is precisely on top of the master channel. Then move opacity back to 100%, flaten the image and save it as green al, ie to let me know that this is the green channel now aligned with the red. I do the same with blue and any other channels I want aligned. Then I reopen the aligned channels again in photoshop (inluding the master), and they will merge perfectly aligned.

Hope this helps - it's what I do - probably there are more elegant ways of achieving the same thing but it works a treat for me.

Chris

This is not entirely adequate as a method because it uses only x-y movements to align the images. In reality polar misalignment (which is almost impossible to eliminate) will require you to rotate the images as well.

The longer your run of subs and the larger your chip the more this will be an issue. On short runs from the same night you can often get away with it but on longer runs I have never found x-y alignment satisfactory.

The alignment of colour images is a one click affair if you have the right software. It is crazy to let it become an issue or to do it by hand. So where can you find this?

I'm not sure but can't DSS do alignment and colour combining? Doubtless someone will come along and say. It's free.

Pixinsight, Maxim, Nebulosity and AstroArt 5.0 all do it. I like AstroArt 5.0. It is good value and logical to use. One click (3 images open) on Align All, Star Pattern, Traslation and Rotation and your images are aligned. Go to Trichromy, put the right coloured image in the right box, choose Auto White Balance and Auto Colour Balance and you have a colour image.

Now I'm a bit picky and I find that AA5 does not always align the colours as perfectly as I'd like. Since I have Registar for other reasons as well, notably for mosaics and the combination of low and high res images, I use that. It is ultra precise but would be an expensive solution because that is all it does. It doesn't colour combine. I believe Pixinsight is also ultra-accurate but is not easy to fathom.

It is very obvious that LRGB is faster than OSC. While you are shooting L you are collecting 3x as much light as when shooting through colour filters. These can be in a Bayer matrix (OSC) or filterwheel (mono). That makes no difference. But L is about 3x faster than colour. So if you do five hours in OSC or RGB you have five hours with 2/3 of the light blocked all the time. If you shoot LRGB for five hours you have one of those hours working 3x faster. If you bin the colour you can work about 1.5 to 2x faster in each colour, as well.) Of course, the frustrations of not getting a data set finished are another matter. I'd agree with you there. Cycling your capture in LRGB, LRGB, etc, can mitigate this but really only with an electric filterwheel.

Just sort out the right software for colour aligning and combining and you'll be laughing. Like many other imagers on here I've found that processing OSC to a high standard can be harder than processing LRGB to the same standard. You just need to suss out the right software for you. For me it's AstroArt 5.

Olly

Oops, beaten to it! Good to see that DSS does indeed do this job for free. I guessed it would.

[PARTY MARTY]

Thanks Olly! Some very interesting points there, Mono imaging is very complex matter, it's quite difficult for me at the moment! OSC is nothing really, it's more plug n play! But Mono in LRGB is a bit tricky! I'll try to keep things simple I stick to 1x1 Bining images for now, But Olly do I need to collect more Luminance lights than colour lights! My basic approach to image my first LRGB image of M57 I used 4x 75 secs in red, green, blue and lumiance to complete a 20 lights in total. Ok it's not much light frames, but I needed to keep things simple, so that I can get my head round!!

I use EZCAP as my main imaging capture software, than I use DSS to stack the images, here I use Photoshop CS 2 to convert all the gray scale images into one RGB colour image, than I use the RGB alignment with DSS whilst using a master Luminance image as a default image which is not stacked in , which I've seen Pixinsight which I'm going to look into this,( I'm currently download a free trial at the moment) than for final processing using Paint shop PRO X5. That's my current plan so far, which I know is a bit chip shop for some people but it seems to work for me!!!

So what you're saying Olly is collect more lumanice, that's the more important one for the images than coloured images??

[martin_h]

Luminance is where the detail is held. I always collect my luminance then the colour in the order of red, blue green, that way if I dont get time for the green I can always make one using software.

[kirkster501]

The Preprocessing script in Pixinsight can do the whole calibration, registration and integration shebang with a few mouse clicks, and makes a terriffic job of it too. If only I could get some data with my new Atik - in Midlands UK it is permanently cloudy!

[JamesF]

I was in the same position with trying to stack RGB frames the other day and asked here:

http://stargazerslounge.com/topic/191651-aligning-stacked-lrgb-frames/

Freddie's answer was really helpful.

James

[PARTY MARTY]

I've finally completed the stacking and aligning the RGB with a Luminance frame set as a marker in DSS, and wow I finally glad that the images have finally aligned properly! I will like thank all the guy's on SGL for helping me out!!

So far the image needs more work and light frames, but I'm delighted as my first LRGB paided off in the end, it's not much but it's a great start!!!

[ollypenrice]

If you collect equal quantities of LRG and B, processing will be easy. Once you stert to get crafty you can get away with more L and less RGB. Don't run before you can walk... There's a lot to learn.

Olly

[cfpendock]

Thanks Olly - of course it's obvious when you think about it - my images have generally been a small number of short (5min exposures) so I hadn't noticed the field rotation. But having tried some test images, I shall give DSS a shot following the instructions given by dmahon above.

Chris