Well the beta is out on a 30-day trial and I downloaded the beta this afternoon to do a little testing. I first tried it with my current test subject – an AVI from a night of good seeing. I fired up RegiStax v5 and selected 64×64 alignment boxes and then let it pick how many and where to place the boxes. The area of the Moon was near Walter so there were many features to choose from. RegiStax decided to put down 230 alignment points and distributed them pretty uniformly. It also avoided the area beyond the terminator. It took 24 minutes for the initial alignment, 1 minute to make a reference from the 50 best frames, 2 minutes to optimize, and 1 minute to stack the best 200 out of 1300 frames in the AVI. Total run time 30 minutes for 230 alignment points. Not Bad. I had just run the same AVI through AviStack on the same machine the night before with 2500 alignment points. That took 36 minutes. I reran the AVI through AviStack using only 230 alignment points ( I had to manually delete nearly 160 points because I could not get AviStack’s auto placement routine to lay down fewer than 390 points). AviStack ran through that case in 20.5 minutes. So, RegiStax is faster than AviStack except when you force AviStack to use the same number of points. When I looked at the RS version compared to the AviStack result using 2500 alignment points – after wavelet enhancement (using the same tool), I could easily tell where the RS processing could have used more alignment points. The problem boils down to this – when you use 10 times as many alignment points, the distance between points is 3 times smaller. This results in 3 times less distortion (on average) from seeing within any single stacking polygon. If your skies are like mine this will make a noticeable difference in the result. The quality of the final image with RegiStax v5 is still not as uniform as with AviStack. One other thing to know about RegiStax. It aligns and stacks to sub-pixel accuracy and so if your images are not properly sampled you will lose some resolution.

My next test was my old test AVI of the region near Aristarchus. This was an AVI where RegiStax had a tough time tracking some features in the darker areas of the Mare. I could not get v5 to complete the optimize step. The program would simply crash. I did not, however, try some of the new settings – this is after all a Quick Peek of the Beta on the day of release. It also decided that only 32 alignment points were needed. I’m going to have to spend some more time on this test case and learn some of the new controls that are supposed to help in these situations.

Here are a few problems I noticed in the beta which I assume are going to be easy to fix in the final release:

The status bar along the bottom has a place where RS reports Time Used and Time Left. For some reason that line is split in two – one above the other – but the single line height of the status bar cuts the top off of the top line and the bottom off of the bottom line.

I was running RS on Win XP under Parallels in coherence mode on my Mac. The first time I ran RS, it kicked Parallels out of coherence mode into a small window with scroll bars. It had apparently changed the screen resolution from 1920×1200 to 1900×1182!!! After restoring everything back to the way it was, RS did not repeat this the next time I ran it.

Here is one thing that I think is going to remain a problem:

One of the problems the previous versions of RegiStax had was that the reference created after setting the Limit frame count still had slight geometric distortions which only really became apparent when you tried to build a mosaic from multiple AVIs. I compared the RS result to the AviStack result using the difference mode in PhotoShop. AviStack reported that the seeing in this AVI was never greater than 2-pixels of relative shift – so this is a very quiescent sky I was imaging through. The comparison between the two results showed that only one alignment point had a slight relative shift. It was an area of sharp contrast around a 40×40 pixel crater. Not a definitive test, but given the problem I had around Aristarchus I suspect RS is still going to have problems with astrometric accuracy.

So, my quick peek tells me the following. RSv5 is faster than v4. There are more features to learn that should help with problem AVIs. If you are fortunate to live in a place where your sky provides excellent seeing or you are shooting at shorter focal lengths – you are going to like RegiStax v5 and can use most of the automated features. If you are like me with a sky that rarely cooperates – the jury is still out. I will learn the new features and report back here within a week.

DISCLAIMER: I am now contributing some post processing code to the AviStack program. You may feel that this limits my ability to remain objective. Fair enough. Try these tests out for yourself and report your results here. I’d love to hear from you.