Can't Plate Solve (ANSVR)


I know many or all of you believe ANSVR is not the best way to do plate solving. But it has always worked for me except for tonight.

Tonight I have my Nikkor 70-200mm F/2.8 lens mounted on a ZWO ASI 1600 camera and I am just playing around with it. The scale is 3.92 arc-sec/pixel.

I am at home and have access to both remote and local ASNVR and both fail. This is the first time I am using a DSLR lens for astro and I wonder if there is something else I need to be checking.

One place I was suspecting was if I had downloaded sufficient data to cover the scale I am using. But then when I use the remote ANSVR that should not be a problem, so I have a haunch something else is wrong.

Does anyone have any ideas on what could be going on?


If Astrometry.Net can’t solve your image then the problem is probably something about your image. I’ve found it to be ultra reliable, but not fast, and a local version almost as reliable.

I’d try longer exposures.

I tried up to 3-minutes and it would still not resolve.

Upload one of your images to nova astrometry and look at which index file it used.

You may find the index tou need is in their “wide field” section on the main website.

I did upload two pictures to and tried plate solving and they
both failed.

Can you paste the link of the results webpage here. The results page is a shareable link you can share it anywhere.


Too many stars (and noise). Try using shorter exposition durations.

Your lens should much more luminous (f/2.8) than your usual devices.

I don’t know what you mean by your last statement but I did try lower
exposures and there were dots and they could not be resolved.

Can you show us a new sample that can’t still solve online?

Concerning my last statement, I mean that if you change your optical part, it is changing the aperture i.e. the amount of light hitting your sensor per surface unit. As for the first time, you are using a DSLR lens, I suspect its aperture (f/2.8) is much larger than the one of your usual device(s). What is(are) your usual device(s)? Because of the larger aperture (and much more light on the sensor), much more stars are detected and is lost.