American Association of Variable Star Observers (AAVSO)
Fri, 02/03/2023 - 17:53

Súper newbie here,

and here I am, another Astroimager taking the plunge; and looking for some low hanging fruit.

Please don’t judge!

Can I use Nina , in  any extent for capturing data?

They came up with a new plug-in regarding EXO planets that can come up with variable and comparable stars.

Can I use Pixinsight, on any extent, to process, calibrate, and maybe even measure a curve?

my equipment

2 TOA150eat with an ASA 6200 MM with Narrowband and broadband filters.

2  high precision , Mounts, 10 µm GM 2000, and astrophysics 1100 AE GMT

I also have an extra ASI 2600 MM, which I intend to build an image in train specifically for photometry .

Any and all bones anyone can throw my way, will be greatly appreciated.

I have emailed requesting a mentor, but I have not heard anything back….

Would be willing to pay for anyone’s time  that’s available to help me… if need be.


Astro art?

We're all learning! No…

We're all learning! No worries. So ask away!!

First: Those are two awesome systems you have.

Regarding Nina: I don't use it myself, but looking at their website its clear Nina can be used for imaging and calibration. You'll need to take darks, bias and flat-field images as well as the scientific images. Take a look at the AAVSO CMOS/CCD photometry guide from our website, that'll go into the details. Be aware NOT to shoot JPG format images, image in FITS format. JPG compresses, or alters, the data, so basically ruins it for measurement.

PixInsight can also be used, but costs $$.

Ideally you'd use photometric filters, not standard imaging filters. Chroma and Baader offer these. If you're dipping your toes in, buy a V (green) filter, if diving in, add B, I and R filters. Purchase "Bessel" curve filters, not flat-topped filters.  

I honestly don't qualify as a mentor, I've only been doing photometry for less than 4 years. But I'm happy to offer opinions. I have many and they pretty often change! But I'll pass on your mentor request.

For general questions and filter questions, I suggest you post on the Instrument and Equipment forum. There have been many filter threads there.

Don't be a stranger!





American Association of Variable Star Observers (AAVSO)
NINA, PI and other software


I use NINA exclusively for automating remote imaging in my observatory and it works very well for time series photometry. It's very flexible. 

I am/was a very early adopter of PixInsight.  It works wonderfully for image processing regular astrophotography.  I've found it lacking in things astrometric and so haven't even bothered to try their photometric processes or attempts at science processing of data.  12 years later there's still little useful documentation internal to the application.

I use PixInsight at the moment to do image calibration, but that's the only thing I use it for....and I find it mostly annoying with their insistence on saving all intermediate files in their proprietary .XISF format.  The fact that I have to take an extra step to convert it back to a .FITS format to make photometric measurements is an annoyance to me, especially when it gives me the warning that .FITS is a deprecated file format.  I'm working on developing my own Python based calibration pipeline to automate the Bias/Dark/Flat calibration and eliminate PI entirely from my photometric workflow.  

For photometric data processing I started with VPhot.  It was an excellent way to learn basic photometry and you can't beat the price.  Because I also do a lot of minor planet work, I use TychoTracker for all of my astrometric and photometric observations.  It's inexpensive, well supported and constantly undergoing continued development of new features.  It offers photometry with download of stars from AAVSO charts, will apply transformations, and you can submit AAVSO observations directly from the application.  

I'm a relative newcomer to photometry and variable star observing, but not new to astronomy or remote imaging.  I have tons more to learn, but it's a fun ride.  



American Association of Variable Star Observers (AAVSO)
Rafa:I encourage you to…

I encourage you to check out the AAVSO's CCD/CMOS photometry guide ( There are sections of the Guide that talk about setting up your camera for photometry and about the choice of software that you use. PixInsight can be troublesome because it isn't always explicit about whether a given method is purely linear (needed for photometry) or introduces nonlinearity in order to reduce noise (a common part of astrophotography). The Guide encourages you to choose software that's been specifically written to support photometry and that won't tempt you with buttons that make your images look better while messing up your measurements.

- Mark

Vereniging Voor Sterrenkunde, Werkgroep Veranderlijke Sterren (Belgium) (VVS)

NINA is perfect as capture software. I use it for all my photometry and occasional deepsky. For processing you can use ASTAP. It is free and works good. 

In the link you can find a tutorial for photometry with ASTAP

Capture Software and Stuff


I too am a newbie at all of this, though I was active back in the early 2000's with a 10" LX200 and an SBIG ST-7 CCD Camera.

I re-entered only 6 months ago..... 

My present equipment is a Redcat51, a ASI533MC-PRO and a ASIAIR which captures my images to a Memory Stick.

I have used Nina, a little bit but, that requires me to be outside and wired to the equipment..... and I hope to develop the setup to a roll-off roof observatory.

I see no problems with NINA ... in fact any capture software that allows images to be saved as .fit files seems to work. 

As I use the ASIAIR I have some issues with what is written to the FITS Header, which prevents me getting images to upload to VPHOT (AAVSO's online Photometry tool). I haven't figured out how to solve that yet!

Pixinsight, which I use for "pretty pictures"..... is excellent for that!. I like the way the batch processing works, but they have a strange .xisf extension. It's not .fit, but I don't know what the difference is.

ASTAP works well for me. I can put the Lights, Darks, Flats and Dark Flats in and get out a Calibrated Image. Then I can extract the Green channel, which is what I'm after with the OSC ASI533MC-P.

In your case with the ASI2600 and ASI6200 being Mono you wouldn't need this final step.

Have a look at AIP4WIN by Richard Berry and AstroImageJ which is very good but takes a while and is used as well for Exoplanets.

As far as Narrowband and Broadband Filters...... here it gets tricky. None of them "may be" of use. Narrowband and Broadband filters are aimed at pictures.

Photometry is done in UBVRI with V being the most active. Johnson Cousins are the original, de-facto, go too filters. But then Johnson and Cousins filters were based on the original Johnson filters made in the 1950's. They were made for one scope, for a particular reason.  Every set of filters made since then are trying to match the passband, width and transmission level's of these original filters. 

Various different companies have produced Filters and everyone of them appears different to me. I'm cynical here.... they do it to make money.

I have a set of Photometric UBVRI filters which I recently purchased from a German supplier which are made by BAADER which are of Bessel design and I hope to use them with a Mono Camera, when I decide which one to get!

They are not readily available, they are relatively expensive and in my experience, which is low,  I expect they will all work BUT they do need a correction added to get you to the baseline of the JC system.

You can take an image of a Star Field in different filters where expert work has been done, which can then be compared which will give you a correction to your photometry and bring you as close as you can get to the baseline. You Transform your data. There is a Transform Generator (TG version 6.8) on the AAVSO site which can be used.

You will get a reply from the Mentor system, it might take a few weeks. Stick with it, they do it in their spare time and for free!

As far as what to image...... what stars too watch, I can only recommend you try anything and everything.

I have watched a few Eclipsing Binaries.... a few Dwarf Novae... a few Miras. It will take a while to figure out what you like..... I don't know yet what I will do!

SS Cyg is one.... GK Per.... try them all, you will find there is not enough time to do them all.

It takes a while to build up a Library of charts, figure out where to get data, what you see in the image, whether you pixels scale is good enough etc etc... it never ends.

Spend time on the AAVSO website, check out the various Observing Sections, read the Forums..... though I find it can be confusing. I reckon there are a lot more people lurking on them trying to learn from the experts! Like me!

Take a course.... Ed Wiley has a CCD Photometry Course open for Enrollment..... I have enrolled.

You have some nice equipment, get going, ask questions..... AND ENJOY the frustration.