MLPT within NINA is here!

Very pleasing! Thank you to everyone working on this. Best regards

What is MLPT?

MLPT stands for Multi Local Point Tracking. It was a proprietary ASA feature only available when using ASA Sequence for imaging. This is how it works;

• Let’s say you choose a target and plan to capture 5 × 10min subs.

• Sequence will look at the amount of time this takes inc AF, readout etc. Let’s say that amounts to 40min total.

• Sequence will initially perform a local sync to confirm the target position. It will then take multiple images along the path the capture will take and plate solve.

• The images will reveal the current tracking and PA error at each point. Sequence will make corrections to the drive on both axis so the residual error is 0 arc sec. This ‘local model’ is then sent to Autoslew. If you look in Autoslew you will see an icon on the top right called LPT (LPT came before MLPT). When MLPT tracking is active, this icon goes orange.

MLPT is predictive guiding as opposed to reactive. It is more accurate and far more predictable than normal guiding. It has limits and normally I would suggest each MLPT track is no longer than 45min. It can be capable of more but it’s a simple task to break up your imaging into a series of runs. i.e. instead of a single run of 50 images, you do 10x runs of 5, each with a new MLPT.

MLPT is only really possible with a Direct Drive Mount and probably only an ASA one due to the way an ASA constantly monitors itself. Once you use MLPT I can’t see why you would ever use anything else. Prior to this NINA development it relied upon Sequence, which needed both Maxim and Pinpoint.

Any mechanical system has limits. There will always be an element of free play in the gears. You cannot engineer that out. A mechanical system is also not able to react that fast. Of course the best mechancial mounts are capable of unguided images for short durations but its not really gauranteed. Different users have different experiences.

Unguided imaging with a mechanical mount is at best due to the mount maintaining a constant tracking variable rate instigated by the model.

Direct Drive mounts are able to react instantly to external influences like wind etc if the drive system is self monitoring. They can stiffen and relax on demand. This behaviour also allows them to effectively have a drive that is variable in nature so it can compensate. MLPT makes use of this. An ASA mount has good torque so it is not fazed by gusts of wind etc. Conversley a Planewave DD mount likes to showcase it can do 50°/sec which is trading torque for speed. In my experience I have seen these affected quite easily by wind.

Direct Drive mounts are preferred for Exo Planet research where targets need to remain on target to within a pixel.

DD Mounts can also be very fast and are the first choice for LEO satellite tracking. They can also guide on a satellite.

A DD mount has caveats. It needs to be perfectly balanced and the motors tuned. It is much less tolerent of balance than a mechanical. The technology does, however allow a manufacturer to leverage it to allow for new solutions. MLPT is one of those.

I’m not familiar with the AP option but there is whats called a ‘sidereal track’ option within NINA for 10M, which I assume is a sort of MLPT. The fundamental difference is a mechanical mount cannot be as accurate as a DDM. With less FL you might not see the errors but they are still there and still influence the image. The fact is the best images relay on attention to detail. Optimum tracking and focus etc. The better the fundamentals are, the better the end result.

Rupert Smith · Sep 30, 2025, 11:24 AM

The ball was set rolling after a chat with Wolfgang at ASA and as a result MLPT is now supported within NINA! Currently this is just for users of the latest generation of mounts as a new version of Autoslew is required…but wait

……support for legacy mounts (DDM60, 85, 160) is coming very soon!

Rupert Smith · Sep 30, 2025, 02:37 PM

To my knowledge while 7.2.5.0 supports MLPT via NINA with the latest DDM’s, its not going to be the release version for Legacy.

Rupert Smith · Sep 30, 2025, 02:37 PM

When the release version of Autoslew 7 is available, it will require a new licence. The suggestion so far is that this will be chargeable for users of legacy mounts.

Hi @Rupert Smith,

First of all, thank you for all the effort, it really gives hope to older DDM mount users.

From your reply, ASA will release a new version of AutoSlew7 (higher than 7.2.5.0) and Sequence that supports the older DDM mount like DDM85 and DDM60, and that older mount users will also be able to use MLTP in NINA with the new AutoSlew 7 ?

cs

xlong