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Unable to Plate Solve using VPHOT

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VAastro
Unable to Plate Solve using VPHOT

I have used VPHOT for the past 3 years.

Recently, I have had problems over the past two months uploading my images for plate solving.

Only 2 images were plate solved out of 20-30 images submitted.

I have since been using astrometry.net sucessfully for plate solving.

My imaging software (Astroart 6 uses the GSC1.1 catalog) has no problem plate solving my FOV.

Any others with this issue?

 

MZK
MZK's picture
Plate-solving

Erik:

Nothing has changed in VPhot in the past two months, so let's look elsewhere.

1. Do you have a telescope setup in VPhot with all the settings included, such as image scale? Have you recently started binning differently? Is the Telescop header included with the correct name?

2. Have you ever thought about using AstroArt to plate-solve all your images before you upload them? VPhot uses PinPoint and 3 catalogs, as needed. BTW, I choose to batch plate-solve all my maxim images before I upload them. Not necessary, but it does speed up the process on the VPhot end. (This does not answer your question, but it does work.)

3. Did anything change in your image processing scheme in the past two months? No matter how small.

4.Could you share a few images with me? I could take a look. Perhaps you could also share a few previous older succesful images as well?

Ken (MZK)

 

VAastro
Plate-solving

Hi Ken,

Question 1   Telescope setup has not changed except Transform Coefficients

Question 3   I  have not changed process to my knowledge

Question 4

I am sharing 2 image files with you.

MQ Cas taken 2 days ago

and DG Aur taken in March

Thanks

Erik

VAastro
Plate-solving

Hi Ken,

I am still having a problem with VPHOT plate solving.

Have you looked at my 2 .fit fales?

Thanks

Erik

VAastro
Plate-solving

Hi Ken,

I found the problem.

In telescope setup I had my telescope plate scale set at 0.694 acrseconds/ pixel (had not been changed for the last 2 years)

I change it to 0.69 arcsecond/ pixel and Plate-solving now works

Erik

MZK
MZK's picture
Great! BUT!

Hi Erik:

Glad you checked the plate scale in your VPhot telescope setup. That was item 1 in my first response!  ;-)

PinPoint, which VPhot uses, gets confused if the plate scale is more than 25% from the expected value.

HOWEVER, did you really mean that you changed it from 0.694 to 0.69?  That is not really enough to make any difference. If that was all it took, something else was the problem?

Note that your imaging software does NOT put the imagescale fits header into your image so VPhot assumes a default value of 2"/pix. That is obviously much different than 0.69"/pix and would never work. Thus, the plate solve failed.

Ken

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