I did do some playing with AUTOdev yesterday and then trying stuff like deringing in the shrink module with 1 iteration... it helped a little but it looks like the star appearance in the main I am trying to avoid appears even from the initial stretch which makes me think it might be inherent to ST approach and my preferred star appearance may be impossible?
Anyway will keep trying. I also subscribe to Itelescope and have access to datasets from there as well but haven't really used them much as yet.
cheers, rob
Mike in Rancho wrote: ↑Wed Feb 23, 2022 5:55 am Hi Rob,
Yeah that's the thing about ST. The fairly friendly interface, available step-by-step workflow (as Ivo would say, reveal from large to fine scales in that order), and that beginners can often get a decent result just by walking through the defaults, tend to get it tagged as a simplistic processing software. But there's a ton of power under the hood, and along with that comes a decent learning curve. Which I am still very much on, by the way.
It does take time and practice, which you will build up by going through many different datasets. To help with that, in addition to your own, you might also try out user uploads and available top-notch data, all to get a feel for how things react and look.
On the blob stars, I am hesitant to recommend it, but you can always try FilmDev as your stretch after Wipe. This will not be an optimal stretch for dynamic range, however, like you can achieve with AutoDev. In fact, if you think about it, if your stars are blobs, your structural detail may very well end up that way also, and as to both stars and target, you are missing out on one of ST's advantages. A resolved star should be a point source, surrounded by diffraction. Or so I think I am coming to understand. Ivo would have more knowledgeable advice on this subject.
Wipe is just to set the field evenly and look for, plus fix if possible, flaws. So, as you say, vignetting (hopefully taken care of by flats). Gradients. Look for LP gradients and edges, and raise aggressiveness to try to even those out. For NB, you can start with the NB preset and go from there. Raise DAF if needed for cold pixels, or color blotches. It gets a lot more complex. Perusing the online module descriptions, user notes here on the forums, and pdf unofficial manual, can all be of help.
Wipe also handles color casts, and sets up your data to go into the color module later. As Jochen noted, dynamic range freed up can then be used in your stretch. As such, it is not optional and must be part of the workflow, though if you have no gradients or other such issues that you believe need addressing, you can pretty much zero out all the settings.
Don't use Wipe to attack noise. What you are looking for is an even field (though because Wipe hyperstretches the data, it will often "look" quite noisy - not to worry).
The AutoDev, with or without ROI (and other settings) takes practice to get a feel for. But you can always go back and amend your AutoDev stretch at any time while still in tracking. As with any AP processing, too much global stretch can raise noise that you may have difficulty stomping out later, even though there are a lot of opportunities to do so (Contrast module shadow linearity, and several of the SuperStructure presets to name a couple) in conjunction with ST's own noise tracking, which get implemented at the very end.
Well that's probably enough to chew on for now, eh, and no need to get into SVD? A lot of the rest you've probably got a bit more of a handle on anyway based on your use history (those as I am learning, all the modules are more complex than one ever thinks in the beginning). And it's not uncommon for Wipe and AutoDev to remain somewhat perplexing even with a moderate bit of ST time under the belt. For sure was that way with me, before I started getting more comfortable with them.