Can I try SGP version 4 if I am using the old 3.1?

I am a long time user of SGP version 3.1. Now I am interested in testing version 4, especially the auto focus.

Can I install this version 4 as a demo and use it in parallel to version 3?

Thank you,

Well, I know that technically, I am not supposed to convince you to not buy SGPro 4, but please note that both SGPro 3 and 4 have the same version of Auto Focus. In other words, if your intent is just to get Auto Focus, SGPro 4 is not required. That said, SGPro 4 does have a lot of things that SGPro 3 does not, but AF is not one of them. To answer your question though…

Unfortunately, the answer is “probably not”, but maybe. The reason is that SGPro uses common settings and profiles for all installs and also that the structure of a sequence file is changed. Once you open a sequence in SGPro 4, that sequence will very likely no longer be usable in SGPro 3. This means that the new SGPro 4 install will use and overwrite settings and will possibly do it in a way that makes those settings no longer compatible with SGPro 3.

If you’re on the fence about SGPro 4, here is a brief tutorial on how to try it out safely. This article link below discusses a method to get SGPro starting when it refuses. That said, you can follow the process there to also backup all your SGPro settings. The only modification: Instead of renaming the folder, simply copy it and save it elsewhere. It’s quite simple, just make a copy of a folder and stash it away. If you go back to SGPro 3, you’ll simply restore it.

Then, for any sequence you want to run in SGPro 4 that you are also using in SGPro 3. Open them in SGPro 3 and then “Save As…” with something like the same name and append a _v4 to the end or something. If you intend on only running new sequences in SGPro 4, you can ignore this step.

Thank you for your very honest answer.

I am asking because I am having serious difficulties with autofocus in the tarantula nebula using Ha (Antlia 4.5nm), SGP just goes crazy with the center of the nebula and is unable to achieve focus, and no matter what exposure time I use. This is during a full moon, but this is not a problem in any other region of the sky.

The thing is that if I change filters, as Lum can focus without problems on the tarantula, the same if I try on a nearby region of the sky using the same Ha filter. But the tarantula drives the SGP autofocus crazy when using Ha. And I was thinking that maybe SGP 4 used a different focusing algorithm.

Auto Focus in SGPro is a (necessarily) complex process so, without logs, it’s difficult for me to speculate why it fails on that target. It could be a star poor region when paired with your FL or one of a dozen other issues. That fact that you noted focus is for Ha makes me believe it might be a data issue. AutoFocus with narrowband filters is fairly difficult. You’ll need to take somewhere near 60 second auto focus frames to get enough measurable data. Because of this, most choose to calculate a one time offset between their Lum filter and their Ha filter, then from that point forward, simply perform a normal Lum autofocus and have SGPro apply the focus position delta.

Thank you again.

I am trying to understand how to use the filter offsets. Let’s say Lum’s focus point is 10000 and Ha’s focus point is 10500. The difference is 500.

So, in the Filter Setup panel I should select:

Filter Name > Ha
AF Exposure > 10s
Focus with Filter > Lum
Focus pt: 500

Is this correct?

Almost. All Focus Point entries are absolute. You would literally enter the numbers 10000 and 10500. The you’ll want to, in Auto Focus settings, set the focus override filter to Lum (called “Auto focus with filter”). That’s it, but as long as your going through the trouble of calculating the filter offsets, you may as well use the “auto adjust focus position on filter change” functionality. It’s not required, but can help to minimize the number of auto focus runs required during a session.

More on Auto Focus and Filter Positions here:

More on filter settings here:

More on Auto adjust focus position on filter change here: