Registax LIMIT - Do it automatically or choose/make a ref frame?

[bus_ter]

A basic guide to Registax shows that you just choose a number of frames (or percentage etc) and click next and move onto the next step.

How does Registax know what a good frame is? Does it just use the 1st frame of the video as a reference?

I've seen detailed lunar stacking guides where an artificial pre sharpened (in PS/GIMP) is then inserted back into Registax and used as the reference frame for LIMIT.

Anyone do this with video stacking? and if so, what's your basic workflow to produce the reference frame?

[Caelus]

How does Registax know what a good frame is? Does it just use the 1st frame of the video as a reference?

I've seen detailed lunar stacking guides where an artificial pre sharpened (in PS/GIMP) is then inserted back into Registax and used as the reference frame for LIMIT.

Anyone do this with video stacking? and if so, what's your basic workflow to produce the reference frame?

If you haven't already checked it out, try the guide at http://stargazerslounge.com/topic/72142-registax51-dbk21-or-colour-cam-tutorial/

Following it took me a bit of re-reading, but basically when you load a video clip, you choose a frame with plenty of detail that you like the look of to set your initial alignment. When that has been done, you can make a reference frame by stacking and sharpening a small number of the better frames.

You can then go back and re-align using your new reference frame.

Without knowing the specifics of how, I presume that registax matches frames on a pattern recognition or pixel grouping basis to those which most closely match the original frame or reference frame for the alignment.

[Caelus]

Eech, please disregard my last post, I didn't see that you mentioned specifically making a reference in photoshop or gimp - I realise I've probably just told granny how to suck eggs!

[bus_ter]

Hi Caelus,

That helped! I didn't necessarily mean using PS or whatever. I'm just thinking that a lot of people just hit LIMIT and NEXT and move onto the next step. Is registax then just limiting based on the first frame of the video? Which is probably just an average frame, so you're not really accomplishing anything unless the first frame is above average. Or does registax know to look through the video and find a sharp frame and then use that as a reference for the Limit process?

Making a reference frame by stacking and sharpening a small number of frames seems like a better idea that will accomplish something useful with the Limit function.

[Bizibilder]

I do it by using the bottom slider (the one that goes all the way across the screen under the main window) to run through my video to find a "good" frame to use as reference. As you move the slider you get a frame count (eg 123/1000 for a 1000 frame .avi) showing under the main window. When I get a "good" frame I note its number and then input that number into the frame counter at the bottom left of the window - you can then change that number one frame at a time (up or down tiny arrow next to the number) until you are sure you have the "best" frame. Then click "Align" and Registax will align using your chosen frame as reference. When it is done you will get a frame count at the bottom of the screen eg 23/1000 - this says Registax wants to stack 23 out of your 1000 frames. You can then use the Quality Settings "lowest quality" number box to adjust the quality/number of frames stacked. It increments in 5% units if you use the arrows or you can input the %age value manually. Try and keep the %age above 80% or you will be including some "rough" frames in your stack! Then click "Limit" and Registax will quickly come back with the "Optimise" and "Stack" options - for general work I use "Optimise and Stack" with default settings - it seems to work OK. Hope this helps.

[Freddie]

You could always give AS!2 a go for stacking and then Registax for wavelets. AS!2 is quicker than Regi and usually generates a better stacked image.

[bus_ter]

You could always give AS!2 a go for stacking and then Registax for wavelets. AS!2 is quicker than Regi and usually generates a better stacked image.

Have you got a link or the full name for this? AS!2 in google doesn't bring up anything?

[Bizibilder]

Astrostakkert2!! http://www.autostakkert.com/

[Freddie]

Thanks Roger, beat me to it !!

[Bizibilder]

You've got to be quick around here!!