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Plate solving vs finderscope in LP skies

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Hi all,

I am attracted by plate solving as a mean to dismiss my almost useless finderscope, under my heavily light polluted sky.

I have an idea that  real time plate solving on my capture camera screen will work as a very precise finderscope, avoiding erratic search of nearly missed objects, as it happens to me when manually pointing to a DSO by use of graduated circles.

A limitation could arise from heavy celestial coordinate files to be loaded onto my PC.  In All Sky Plate Solver freeware, they total to 168 files of a few GB each, and it seems to me that this amount will not fit my PC memory, MSI USB3.0 460 GB. In any way, I fear my PC will be severely slowed down, at least. 

A possible solution might be a capient (1-2 TB) external memory disk for hosting the coordinate files, but I don't have any idea of the resulting speed of the system.

In conclusion, given the idea of using plate solving at the main camera in place of the finder scope is correct, this method may remain a tantalizing fantasy due to system memory limitations....

What about you? Any idea/suggestion useful to put this fantasy in real use?

Thank you,


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For frustration free viewing I often use plate solving and goto to see numerous objects quickly. My refractor will have a flip mirror diagonal in it so I can slew and plate solve, when it's centred change to the eyepiece to view. I'm bortle 7 so can't really see anything at all visually (DSO) and rely on averted vision which is difficult if you're manually star hopping, my Rigel quikfinder helps with this together with a phone app for star navigation, but it doesn't beat the computer method.

Asiair makes this easy, an alternative is a raspberry pi with astroberry loaded onto it, install the astap databases (around 16gb) and then you can plate solve in ekos/kstars.

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1 hour ago, ONIKKINEN said:

Look up ASTAP platesolving, its what you are after. The H18 database is like a gigabyte, not a terabyte and i dont recall platesolving ever taking more than a couple of seconds (ignoring a few user error type situations...).

If your FOV is more than 1 degree then the H17 database should be fine, and that's only 500MB in size. 🙂


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I rely on plate-solving to aim my EVAA setup (102mm f5 achro, ASI224MC, EQ-5 Synscan).  Both ASPS and ASTAP are loaded on a laptop with 250GB of SSD memory.  The plate-solving is used to correct the aim of the GoTo, and the process is relatively quick. 

Note that if your scope has a smaller aperture, or the actual FOV is smaller than I am using, the plate-solve may not work so well. 

The finder is only required to perform an initial GoTo alignment.      

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Thank everybody for suggestions...I will put my eyes onto Astap.

My setup is as follows:

- Imaging scope: Meade semiapo ED 7” f/9 refractor on Losmandy G11, manually operated, upgraded to ST4 guiding by means of a SBIG Relay Box connected to Losmandy model 492 control unit;

- Imaging: Atik 428EX monochrome videocamera operated by Atik software Artemis. FOV 19’hx14’v;

- Guiding scope: acromatic refractor Vixen Auriga 80mm f/12;

- Guiding camera: Atik Titan;

- Guiding software: PHD2;

-Planetary camera: TIS DMK21AU618 (next to be replaced by a Player One Mars-MII USB3.0 mono camera)

- Processing/stacking: Dawn, Registax6, DSS, Autostakkert (planetary);

- Filters: RGB Baader dielectric on Baader filter slit, no luminance, Neodymium filter in front of Atik camera;

I'm aware it is millenium old, but I am so acquainted with it that any change is quite bothersome to me. I just added a QHY Polemaster for polar aligning, which works very nicely and, above all, quickly. Plate solving appears to me as another time-sparing tool....my aim is to speed up manual operations: according to my idea, once everything is speedy enough no matter to upgrade to complicate automatic devices....

Hope the ASTAP software will fit.....

Thank you


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