Processing Smart Telescope Images: Seestar, Dwarf and Vespera

A Seestar S50, a Dwarf 3 or a Vespera gives you a finished JPEG on your phone after twenty minutes, so it is fair to wonder why you would process anything yourself.

The reason is that the JPEG is not everything the telescope collected. It is a live stack, made on a small computer under time pressure, with conservative decisions so the preview on your phone never looks broken. The frames underneath are better than the preview suggests, and on a good night much better.

What the built-in stack does and does not do

The live stack does real work. It aligns each new frame onto the last, rejects the obviously bad ones, and adds to a running average. Most of what a desktop processing run does, it does not.

It cannot get back frames it has already thrown away. A live stack decides in real time. A desktop run sees the whole session at once and can grade every frame against the session’s own norm rather than a fixed threshold.

Its gradient handling is limited. Light pollution gradients change through the night as the target moves, and modeling that properly means looking at the whole session.

Its color is approximate. Proper color calibration matches the stars in your field against a catalog of measured star colors and fits the white balance to what those stars are. That needs a plate solve and a star catalog.

Its stretch is conservative. The preview has to look acceptable straight away, so the curve is safe rather than optimal.

None of this is a criticism. Doing those things live, on battery, on a phone-class processor, is not what these telescopes were designed for.

Getting the frames out

Seestar S50 writes individual sub-exposures as FITS files when you enable them. On the telescope’s storage there is a folder per target with the subs alongside the stacked result. Copy the whole folder. There is a detailed guide to the Seestar’s FITS output, including what its headers do and do not record.

Dwarf 3 also writes FITS subs per session, plus its own stacked output.

Vespera exports FITS when you ask it to. By default it saves only the processed result.

In every case you want the folder of individual frames, not the single stacked file. The stacked file is already averaged and there is much less you can do with it.

What changes when you process them properly

It depends on how many frames you have and how good the night was.

On a short session in poor conditions, careful processing of the subs may gain very little over the live stack. The sky was the limit, not the telescope.

On a long session in decent conditions the difference is usually obvious: more faint structure, a flatter background, and color that looks like the object rather than the sensor. A hundred ten-second Seestar subs of a bright nebula carry a lot more than the live preview shows.

The thing that improves most reliably is the background. Live stacks tend to sit on an uneven, slightly colored sky, and modeling that across the whole session is the biggest visible change.

Doing it without learning a whole new skill

The obstacle is the software rather than the telescope. Desktop astrophotography software assumes you already know the sequence (calibrate, register, integrate, gradient, color, stretch, denoise), the order, and the settings.

Siril is free, very capable and cross-platform, and it will do all of this if you are willing to learn which script matches your data.

Akastroid is the program we make. You point it at the folder of subs, and it measures them, decides what your data needs, and shows you the numbers behind each decision. Seestar and Dwarf FITS files open directly without conversion. It is free to try, and nothing is uploaded; the frames stay on your computer.

Download Akastroid · The Seestar FITS guide · The DWARF 3 FITS guide · The Vespera FITS guide

If you have no computer

Quite a few smart telescope owners do not own a laptop at all, which is partly why they bought one. We are building a cloud version for that case, and there is a waitlist.