I have uploaded a couple of images of SY PER in V and B. VPHOT seems not to be able to plate solve them regardless of the variable star being not far from the center of the frame. I have manually entered the variable and all comps and saved the sequence but VPHOT does not let me recall the sequences I have saved (the field in question is grey).
Thank you for your help
Have you tried to plate solve them on your own computer, e.g., pinpoint?
Could you share the two images and the sequence with me (MZK) via VPhot. I could take a look at them.
I assume that you have succesfully reduced other images in VPhot from the same CCD/telescope? Once in a very great while this just happens for no obvious reason but not often!
Hi Ken& Phil,
I have had no problem in plate solving my images with VPHOT until recently. Ken, I have shared the 2 images of SY PER with you so that you can have a look at them. Aside from plate solving images with VPHOT that appears to be no longer possible with my last images I cannot recall the sequences. I have saved the sequences for SY PER but VPHOT does not let me recall them.
Thank you for your help
Have you uploaded any new SY Per images since the two images that wouldn't plate solve? If so, did the more recent images plate solve?
Re: comp star sequence. If the image isn't plate solved, VPhot won't be able match up the positions of the sequence stars in its database with the stars in the current (unsolved) image.
I have uploaded no additional image of SY PER as I have none at the time. However I have just uploaded another target (Z UMi) and I am waiting for the image to appear in the image list. I will let you know shortly if VPHOT plate solves that one.
Same situation with Z UMI. The image I have uploaded has not been plate solved by VPHOT. It seems that any image I am uploading shows the same problem. Any ideas?
I have shared a couple of my images with you at RGN. Take a look at the fits header. I calibrate (BDF) and plate solve (Pinpoint) with Maxim before uploading. I also have my telescope parameters set up in the VPhot admin telescope tab.
I looked at the fits headers in the images you shared with me. I noticed that several fits fields that help identify plate scale are missing. Did you include that info when you uploaded these images (e.g., wizard)? I did not see the typical fits fields added by the software during pinpoint plate solving, as opposed to the line that stated it was plate solved? BTW, this line looks grayed out? I also did not notice any calibration fields that indicate that the images were calibrated.
Is the scope/ccd/software used to collect and reduce these 4 problem images (AIP4Win?) the same as used for your previous successful images uploaded to and reduced in VPhot?
I have calibrated the images with Aip4win but not plate solved them as usual. I have not uploaded the images with the wizard but I have had no problem in the past with the normal uploding with VPHOT after the calibration with Aip4win. As next step I will re-upload the images using the wizard to see if I can overcome the problem.
I am using typically Aip4Win for calibration etc., too. If I wanted to use VPhot for further processing I have used - in the past -
for plate-solving (not everybody can or wants to afford Maxim/Pinpoint etc....). Astrometry.net plate-solving is free, and I have never seen it failing.
After a successful plate-solve you can download the plate-solved image from the "results page". That image "new-image.fits" includes now the correctly filled in fits header with WCS coordinates. The VPhot wizard is happy with that info.
At least this procedure could be used as a test to pinpoint your current problem(?).
I tried submitting an astrometry plate solved image and VPHOT didn't recognize it as coming from my telescope. Also, VPHOT has given me green squares and told me that the image wasn't plate solved. I gave up and am using AIP4WIN for photometry. VPHOT IS wonderful when it works, but trying to get it to work sometimes is maddening.
Have you checked the FITS header to be sure that all the information needed plate solving is correct? See below:
FITS HEADER REQUIREMENTS
The following FITS header fields are required in order for VPhot to work properly:
- DATE-OBS TIME-OBS or UT-START
- EXPTIME or EXPOSURE
- OBJCTRA or RA (for plate solving)
- OBJCTDEC or DEC (for plate solving)
- FILTER: should be B, V, R or I. If so VPhot can automatically use the correct photometry sequence
- OBJECT: displayed in the image list to recognize images
If missing, these can be filled out during upload. Optional, but strongly recommended:
- AIRMASS: displayed in the image list, and used in reports
- EGAIN: used in SNR calculations
- CALSTAT: to display calibration status (combinations of B, D and F where B = bias, D = dark subtracted, F = flat fielded), OR BIASSUB/DARKSUB/FLATTED - to display calibration status
Also, the plate scale (and a few other things) need to be correct in (Admin>Telescope Setup). Perhaps one of these was accidentally changed. This discussion may be helpful:
I have used now the wizard to upload the image of Z UMI. VPHOT says that the following information appears to be missing in the the fits header:
- object name
- approximate RA of center of the image
- approximate DEC of center of the image
- filter used
I have entered the requested information manually and I think now the problem should be solved (I have to wait for the image to appear in the list however).
Is there any method to add those information in the fits header automatically for future images?
Adding the header info automatically clearly depends on what software you use? I know you use AIP4Win for image reduction. What about taking images and running the scope?
I use CCDAutopilot / Maxim DL / Sky X to schedule the run / take the image / run the scope. It inputs most header info automatically but did initially require a small modification to a few check boxes and info values to ensure it was all input.
What do you use? Have you tried a google search for adding header info in this software?
At the beginning of this conversation you mentioned that you had previously uploaded images that were successfully plate solved. What software did you use control the camera and the telescope for those images?
I use TheSky6 to control my mount and CCDSoft5 to control my camera. With these most of the information is entered automatically. I do have to edit the header slightly "manually". CCDSoft will not allow a single letter, such as "V", to be used for the filter, so I set the filter name to "Johnson V", then edit out the "Johnson" after the image is calibrated (with AIP).
I also have to add the Keyword "CALSTAT" with a value of "BDF" for VPhot to recognize the image as having been calibrated.
Depending on which image processing program you use for calibration, you may be able to edit the header at that stage. The last time I checked, there was a Fits header editor tool in AIP 2.4.x, but it didn't work. I use fv (from NASA) to edit the headers with my Mac.
It may be easier to just use the VPhot upload wizard, but it could get tedious if you have to enter the RA,Dec for every image you upload.
We may be using slightly difference versions of CCDSoft5. When I name my filters in CCDSoft (when setting up the camera and filter wheel), any single letter is automatically changed. When I try to use "V", the software changes it to "Violet"(?). "B" becomes "Blue", etc. It's not a big problem since I have to edit the header to insert the CALSTAT keyword in any case. If you have a work-around for this I'd love to know about it.
If you got your camera from SBIG, try using CCD Ops. I can't imaging the nightmare of changing 250 or more image headers per night just to use VPHOT. Gives me the willies.
I have forgotten to mention that I have always used Maxim DL 5.18 for acquiring all images and I have had no problems at all with VPHOT until recently. No modifications were made to my usual setting but VPHOT now is asking for name of the star, RA and DEC of center image and filter used. Any thoughts?
I've only been using VPhot for slightly less than one year, but I think all of the items you mentioned have been required since I started using VPhot.
If you have been successfully using VPhot I can only guess that MaximDL was providing that information and that something changed with your copy of Maxim so that these header items were not being included when you started having problems.
I suggest you go back to the images that you previously submitted to VPhot and look at the headers. If these were plate solved (by VPhot) I think you will find all those items in the header. If they were plate solved by Maxim before uploading to VPhot they my have worked without that information, but I would expect that VPhot would have asked for them either way.
I think the fact that VPhot "now is asking" for object name, RA, DEC, filter is due to the fact that you used the upload wizard as opposed to quick upload yesterday? The quick upload assumes you have the necesary info and will not prompt you.
You should look at the fits headers of a few of your images that were previously uploaded and worked correctly and compare them to those presenting this "new" issue. Look for the green or red boxes under WCS and Cal. Are they different for successes and failures? I hope so! Look at these selected images in VPhot and check their headers to see what VPhot really sees. Are they different in any way? Then, look at the headers in the original images on your computer. Again, any difference? Any different or extra lines?
I use Maxim as well and have not had any recent problems with VPhot. BTW, have you tried to use it to plate solve with pinpoint even before you upload to VPhot? (Sorry, more $$ for pinpoint license?) Have you had "any" recent computer/software issues with your setup that caused you to need to reboot the computer or reinstall software? You indicate that is not the case but I suspect something may have changed? Obviously, you're the only person who can confirm that.
You could share a few of your VPhot images that worked properly and a few that did not for a second pair of eyes to check? I did get the ones that failed that you shared before but send a different set this time.
After looking at the fits header of previously uploaded images I think I have identified the cause of the issue with VPHOT. The missing infomation is just coming from a lack of connection between my goto system, filter wheel and Maxim DL as I have had little spare time recently so to save up some time I just used the keypad for centering the stars and no filter wheel. When everything is properly connected all information is registered in the fits header and VPHOT is able to do the plate solving.
Thank you all for your helping me solve this issue.
I have heard of this happening occasionally without any apparent reason, but as Ken said, I think it's rare.
I had a somewhat similar problem recently. VPhot thought it had done a plate solution (the WCS box was green), but when I called up the VSX variables for that image VPhot said there weren't any variables in the field, a variable star field I had uploaded dozens of times previously. The RA and Dec indicated by the curser were wrong. I reloaded the image several times, same problem.
I even did as Ken suggested: I did my own plate solution with AIP without any diffiulty. I reloaded the image with the plate solution parameters already in the header. ... same problem. The next time I observed that star everything worked fine.
It seems there is a bug somewhere, but since the probelm is so rare I decided it just wasn't worth the effort trying to track it down.
As Grandfather said to Dustin Hofman in Little Big Man, "Sometimes the magic does not work."
I have had this problem when I had changed the Binning and had not thought to update the VPHOT telescope settings. Creating a new scope setting for the correct Binning Image Scale solved my problem