Hi,
I’m planning to acquire a smart telescope to get my feet wet with this kind of equipment.
In the price range of the Seestar S50 (plus EQ mount) there are interesting alternatives for doing photometry and supporting the Ascom Alpaca protocol?
I have the Seestar S50 and use it in EQ mode. You can use NINA or even SharpCap to control it and even operate it remotely. I haven’t done much photometery with it. (One of the reasons I’m taking this class) You might also look at the SeeStar S30. It seems to be be a better scope at a cheaper price. Also its weight makes it much easier to use in EQ mode.
Hi Bruce
Thanks for sharing
Did you have issues related to the weight in EQ mode?
Even though it’s considerably more expensive, the Unistellar telescopes were invented by astronomers and have made a point about their use for scientific purposes such as variables, exoplanets, etc. They had a course within the last six months about using them for this purpose. I’ve got an eVscope2 but haven’t started doing photometry yet with it.
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Hi, I know abou Unistellar products but before shelling out that amount of money I’d like to get more experience in treating images.
By the way do you know if the course you mentioned is publicly available?
I just purchased the Odyssey. Can you tell me more about this course please?
Thanks!
Wayne
Try contacting Unisteller. The course was taught jointly with the Astronomical Society of the Pacific. There might be a way to get the slides or other material.
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No issues with weight. But I am at 32 degrees Lat so the scope is not that far off center. I do make sure that one leg of the tripod is under the scope. Sort of standard EQ set up where one leg points north. I sometimes attach a counter weight to the tripod if there is any wind just to be safe.
I have both a SeeStar 50 and a Unistellar EQ2. The SeeStar is much easier to use in my opinion.
I’m doing V-band photometry of long period variables, RCB-stars, dwarfnovae, symbiotic stars, HADS-stars and even ons supernova (SN 2026fvx) since March. I’ve purchased a 50 mm V-band filter, I’ve printed a holder for that and I am using a sturdy tripod. I use ASCOM/ASTAP/N.I.N.A. (with the plugin Target Scheduler) on my laptop, and my SeeStar S50 in station mode. I reduce my observations in Phoranso. Make sure that you use a FITS-header editor to change the filter from clear or IR to V (Phoranse does this for me). I can get to the 15th magnitude, sometimes even fainter. Though the error increases significantly with these faint stars.
Clear skies, Erwin
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Hi, thanks for the details, I’d like to set up a similar workflow,
have you done some testing with other filters?
Using only V transformation is not possible as far as I know
If you are using a smart telescope with an RGB sensor, standard practice is to transform RGB to BVR (scientific) and not use an additional photometric filter. The principle is the same as that applied to DSLR photometry.
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Hi Gianluca, I’ve only used V-filter, nothing else.
Hi Roy,
I will study the DSLR manual to see how those transforms are done. Although it is (apparently) not standard, is it wrong to use a V-filter and doing only V-band photometry?
Hi Erwin,
It is not wrong to do only V-band photometry. A lot of useful photometry can be done that way (for the right targets). However, if I understand you correctly, you have a smart telescope with an RGB colour sensor and you plan to place a Johnson V filter in the light path. Instead, you should not use a V filter but extract the G (green) channel data from your images. It would be correct to use a V filter if you had a monochrome sensor.
I don’t use a smart telescope, thus cannot advise on workflow. That’s what the smart telescope working group is working toward.
The issues with G-band only photometry performed on RGB images are twofold. First, only half of the pixels are green, therefore you are using only 50% of the light that falls on your sensor. Second, the spectral transmission of the green channel will not be identical to that of a V filter, hence the need for transformation coefficients.
For observers starting out, reading the DSLR Photometry Manual and the Guide to CCD/CMOS Photometry (for mono cameras) about transformation coefficients is a lot to take in. However, a good understanding of transformation coefficients is an extremely useful knowledge set.
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I have been EvScope user for four years now and am one happy user to be sure. Excellent science application, well supported. A couple of references as co-author to date. OK to start here as you will end up spending plenty anyway.
Contact the Astronomical Society of the Pacific. They ran the course.