Plate Solving Engines - What are the differences?


#1

Hello together,

as I started with SGPro I also purchased a PinPoint licence, mainly because I was afraid it will be too complicate to install Astronometry.Net and I didn’t want to fight at too many places and I think my decision was ok for that time.

But in the meantime I have installed local Astronometry.net. Because I urgently needed a local fall back solution as PinPoint fails to solve if the target is too way off (and at my standard imaging place I have no internet connection).

Another drawback of PinPoint is that it is not possible to change its default time out (60s) in SGPro which makes it overall too slow. So I finally switched completly to local Astronometry.Net.

Now I am wondering, why anybody should use PinPoint (for 149$) instead e.g. Astronometry.Net or PlatSolve 2 (free) - besides easy installation? Have I overseen something? Are there some drawbacks of the free solutions?

(it’s free - whats wrong with it? :slight_smile: )

Best regards

Reinhard


#2

As a reminder to everyone, this forum is a place to discuss SGP and third party software as it relates to SGP. As such it is entirely appropriate to discuss the advantages and limitations of third party software, again as it relates to SGP. What is not appropriate is denigrating or “bashing” third party software. If there is an issue with the third party software itself, please refrain from denigrating it here but rather take it up directly with the third-party software developer.


#3

Nothing is wrong with either solver. Different people need different things which is why we support different solvers.

Each plate solver offers different benefits. As for PinPoint specifically:

  • It’s considerably faster than Astrometry.NET
  • It requires no internet connection.
  • Many people already own PinPoint
  • Setup is considerably easier than a local Astrometry.NET solution.

Pinpoint is not a blind solver. It requires somewhat accurate hints to solve quickly and effectively.

Personally I use PinPoint as my default solver and use a Local Astrometry.NET setup as the fallback. This means that 90% of my solves are done very quickly and in the rare event that PinPoint fails it falls back to Astrometry.NET. I don’t use Astrometry.NET as my main solver because those solves take in excess of 1 minute to complete. PinPoint solves those in about 4 seconds.

Hope that helps,
Jared


#4

I should also add that PinPoint allows you to use FWHM rather than our internal HFR measurement for autofocus. This may be better for some folks with central obstructions.

Jared


#5

I would appreciate hearing feedback like this directly. If people are finding ansvr difficult to install please let me know and I’ll see what I can do about making it easier.

If I could venture a guess, I think the most cumbersome part is having to copy/paste the endpoint URL into SGP. Perhaps SGP could offer an explicit “Local Astrometry.net (ansvr)” in the drop-down list?

Andy
ansvr developer


#6

Sorry Andy. I should have said that “ANSVR used to he harder to setup”.

Thanks,
Jared


#7

No problem Jared. Do you think it would make sense to add an option for Local Astrometry.net so you don’t have to copy/paste the endpoint?

Andy


#8

2.5.0.4 has a much more user friendly method of choosing the Astrometry.NET URL


#9

Thanks, Ken. That is an improvement. I just updated the ansvr instructions.

Andy


#10

I have used all the solvers mentioned here and I now use Astrometry.NET exclusively. It solves for me in around 10 seconds most of the time. I feel I more than make up any total time differences because I don’t get the first (usually very long) failure from one of the others and then Astrometry.NET gets used anyway. Maybe its a lot faster for me because of the SSD boot drive it is installed on. It just solves on the first try no matter what.

Revision: I just checked my logs from last night, and the 30 Astrometry.NET solves were mostly 5 to 7 seconds and 2 at 10 seconds. Not counting 2 that took 60 seconds, my solve time limit, which occurred when SGP took solve images of the inside of my dome. It does not seem to know when my dome is done positioning with the mount. I am changing my limit to 20 seconds. These times BTW are faster than Platesolve2 works for me.


#11

Reinhard,

I’ve used all of the plate solving methods on here minus Elbrus. Plate Solve 2 is gold. It almost never fails. I still have a local astrometry.net server installed. If it’s your first time using it, make sure you do a couple of plate solves with it to ensure you have the correct index files.

I used to really like Pinpoint, but with the introduction of Plate Solve 2, it’s just not necessary.

Good luck,
Chris


#12

Thanks to all for feedback,

my main question gets clarified: after you have managed to purchase/download, install and configure the different plate solvers, “speed” remains the single criteria for the tool of choice.

Unfortunately, I cannot effectively use PinPoint, as its speed advantage is eaten up by the cases where the target is too way off - because of the bad pointing accuracy of my mount.

As recommended I will give PlateSolve 2 a try.

Best regards

Reinhard


#13

I think one piece of gold here was the mention that Pinpoint uses FWHM and can be better for focusing with central obstructions - that is welcome news to me. I currently use Pinpoint but use HFD for focusing.


#14

You can set that in the AF tab. Please let us know how it works out for you. It may be a mixed bag. FWHM may not be as resilient to clouds and seeing but it may handle donuts better.

Jared


#15

Thanks Jared - I finally got my system up and running over the weekend and I have to say the normal HFD focusing algorithm was working well with the RCT and producing good V curves. I think (but cannot prove) that good collimation also has a significant part to play with the reliability of any autofocus algorithm.


#16

+1 for @buzz comments. I finally did a collimation on my RC12 last month and I am getting decent V curves myself. I have found it is important not to make the interval so large that there are donuts at the ends of the V.


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