Wed, 12/20/2017 - 16:48
Is there a way to run the photometry in Maxim DL in the background? Meaning not having the images open. We had problems with an older computer and I just bought a new Dell XPS with 16G of Ram and 1T storage. The program won't load more than 40-50 images to do the photometry. I was hoping there was a way that it could just take a folder and do it in the backgrond for maybe 200 images. Sorry if this is a repeated question.
Thanks,
(edit: this is "bad" advice - I forgot that V6 of MaxIm allowed photometry sequences to be done on a list of files, not just loaded images, which it will still do - DJL)
There is no way to do what you want to do in MaxIm. The best way for large image sets (in MaxIm) is to use its scripting interface, but that requires programming skills.
In my own case, I have developed an application called Abbey Ridge Auto Pilot that runs my observatory but also automates the photometry (using MaxIm) given raw images and input data on the star positions and comp magnitudes with the output being an aavso extended file.
Maxim DL is great for general photometry done with some images, but when have used large series, from what I have tested, AIP4Win is still the best.
Someone has a better idea?
JBD
Hi, Tim (et al):
AIP4Win is great (plus the "Handbook" is also a wonderful reference).
An alternative is MPO Canopus, that has a neat variable-star photometry tool that can handle any number of images. Plus, it does a plate-solve on each image (to identify target and comp stars), so if you have image rotation or pointing drift, it handles that seemlessly. (see http://www.minorplanetobserver.com/)
Cheers,
Bob B.
I now use VPHOT mostly as it has lots of information to make sure that the results are proper. I also like the fact that it saves the sequences so you use the same comp stars without an input. Before that, I used Maxim to do my PT. I like VPHOT for AAVSO PT better.
Gary
Assuming that all of your images are of the same field,, you don't have to read all the images into memory in order process them.
I regulary process time series of up to 1200 images with 16G of memory. As I remember the only image that is in memory is the image it is processing.
You don't want to load the images into memory, you want to open the photometry tool and use the Select tab to select the images you want processed. Then the Indentify tab to select the target, comps and check stars. Click on the Graph tab and have a cup of coffee while MaxIm goes about it's business.
I'm glad to see that jji chimed in about how to open a virtual stack in the MDL photometry tab.
While I agree with Gary that VPhot has some excellent features that really help streamline the process, I still use MDL for things like CV observations, editing the AAVSO report to read "CV" as the filter. I have not found a way to do this in VPhot, but if there's a way, I'm all ears.
I will only add that from the MDL photometry tool's selection box, I change it to "Select Folder", which will create a virtual stack that is very light on your computer resources. I believe these features were added in MDL version 6 (I'm using 6.13).
This is also a great way to do 2-color photometry, too, as MDL will read the FITS headers and sort the files by filter. I'll attach an example of B & V photometry of XX Cyg. I have not tried processing a 4-color time series, but I think it would work fine. I have some BVRI series I could try, but have never done that. That feature alone convinced me to upgrade to MDL-6 once it was out and relatively bug-free.
Clear skies,
Brad Vietje, VBPA
Newbury, VT
www.nkaf.org
Brad,
I believe you can make the change in the VPhot Available Images screen by checking the image box(es) and clicking on the Rename menu at the top of the screen. A new screen pops up and at the bottom is the filter change drop down. I see a C filter choice.
Hope that works for you,
Mike
Brad; Mike:
Creating an AAVSO format report for a time series of C filter images is straightforward. You should not use the "rename" function since you want to report your image magnitudes as CV not V.
Just run your time series of images taken with a C filter as you do for any other time series (e.g., V filter), but when you get to the Time Series results page use the sequence pull down box and select V if that is the reference mag you want to use. Refresh and the magnitude results are recalculated as V magnitudes rather than the C instrumental magnitudes.
Finally, select "Create AAVSO Report" and save the report as usual. When you open this report, you will see that the filter is reported as CV.
I assume this is what you want to see and it is what should be reported to the AID.
Ken (MZK)
Ken.
I'm still confused. I'm not sure when these filter name changes should occur. When I have uploaded images taken through the Luminance filter ("Lum" in my FITS headers), I haven't found a way to perform any photometry on them, as when I attempt to call up variable stars, the filter type is not recognized, and I get an error message. Thus, I have never been able to get started with measurements, much less generating a report.
Do I need to edit anything before uploading the images? Do I change the filter type on the images screen in VPhot?
Thanks for your advice,
Brad Vietje, VBPA
Brad,
In VPhot's Admin>Telescope Setup there is a Filter Mapping section where you can specify that the fits header FILTER value "Lum" should be changed to "C". I haven't used this options myself so I can't say how well it works.
Phil , SPP
Hi Brad:
Now I understand your issue. Yes, VPhot cannot automatically insert aavso comps onto a C (or Lum or also currently Sloan) filter image. That is for a thought-out reason. It prevents one from applying a V magnitude to an image taken with another filter that does not have the V filter bandpass. Yes, we do use V comps on C filter images BUT make sure to save as a CV filter in the report.
However, as with other photometry software, there are more manual alternatives to obtain V comps. For example, you can use "Load Simbad Data" to identify other comps and select some of those for your own sequence. There are other catalogs that you can use to identify comps. You could even "show the AAVSO chart/sequence" from the catalog pull done and manually transfer those mags to your own sequence.
BTW, yes there is a way to change the filter designation in the image fits headers during "upload" of a time series but I am reluctant to promote it since it makes an invalid change of filter designation. Look at the first quick upload page and try what you think might work. It is not that obscure. But understand that this is a work-around that is not advised for your no comp issue. I recommend that you make your own sequence as I described above. It is more involved than just the normal automatic comp selection step but you only need to do it once. This then allows you to save the report with CV in the filter field (without editing) as is desired and I described in my previous post.
HTH, email off-line if desired?
Ken
Everyone,
Thank you for all the advice. I think I'll try most of what people wrote to some degree. I have a student working on variable stars and extrasolar transiting planets, so yes the fields are the same. I relpy back after the holiday and attending a conference.
Thanks again and happy holidays.
Tim
Hi,
I am using LesvePhotometry (LP) from Pierre de Ponthiere and it is simply the best photometry program, period.
The only drawback is that you need the full version of Pinpoint which is comercially available.
Otherwise LP runs on a database where variables and comp stars are put and you do not need to remember what comp stars you used last time you did observe e.g. ASASSN-17xy or any other variable. It created AAVSO compatible files and gives you and EXCEL file with all info and a drawing of the light curve. You can also rund a series of different stars in once as the database and a naming convention of the file names takes care of the different variables. I get nightly about 700 images of 35 stars and those can be run through the photometry in one shot.
I use it since several years after I met Pierre and saw his program at an SAS/AAVSO meeeting in Big Bear in 2009.
I have processed about 2 million images so far with it.
Regards,
Josch