Newbie here, trying to learn thought with my equipment I could possible do this. However, the more I read of these threads its seems that owners/users of OSC CMOS sensors need not apply. ???
I have a good or very good setup for astro imaging - as long as you're not stuck in the monochrome/filter wheel need only apply mindset. Fairly fast good quality refractor (Skywatcher Esprit 100ED f5.5), APS-C sized imaging sensor with a ZWO ASI2600MC-P which is an OSC CMOS. Since slight defocusing seems to be a thing to do, even the additional sharpness / detail that a monochrome imager (CMOS or CCD) can provide seem to be not needed or beneficial.
After joining the organization and browsing the forum, trying out some of the tools, I'm beginning to feel that this was a mistake, or least not productive for me/my equipment. To summarize my perceptions after following several threads/discussions, if you don't have a CCD monochrome sensor and filter wheel, the tools don't support (or at least not very easily) the newer devices/imaging technologies without a lot of tedious manual transformation which may/or may not give reliable/repeatable results. Frankly if that is the only answer and there isn't a perceived need or associated effort to bring the tools current with current technology, joining was an error on my part.
It seems given the information now embedded in FITS files from the imaging sensor, even for OSC sensors the only thing that is needed is information on the OTA to allow software to fully characterize the imaging train and extract a specific channel from the debayer data for consistent magnitude measurements. ???
I admit that there could a resource(s) out there that would address the use of dedicated cooled CMOS astro imaging equipment, OSC and monochrome. So much information about the imaging sensor is embedded in FITS these days that the only real addition needed is information on the OTA to be able to fully characterize the optical train.
If I sound frustrated, it is because I am. I don't feel a desire or a need to spend $$$ for another imaging camera, filter wheel, filters when the problem is begging for a software solution (if DSLR/OSC data can be manipulated manually to get useable information, then software should be doing it to provide more consistent, repeatable results).IMO.
YMMV
I'm a relative noob as well so can't offer useful technical advice. But I can point you to AAVSO's mentor program. On the main page click on Getting Started then on Find a Mentor. Perhaps one of these more experienced people can help.
BTW: I look at OSC cameras as being basically DSLRs, maybe with cooling, and I do see posts from DSLR users and have seen data produced by DSLRs in data I've seen, so I think you can use OSC.
Peter
BPEC
I see no problem in using a OSC color camera. I use a Asi 533 cooled color camera. This lightcurve of KP Lyn was made with that camera and a 60 mm refractor.
/sites/default/files/users/user56485/KP%20Lyn.png
George,
You have not made a mistake. As far as I can tell you have a very good camera, claimed to have a native 16 bit sensor.
The AAVSO has made a big investment in time in colour CMOS photometry, with its programmes for DSLR photometry. You have a cooled colour CMOS sensor, which should run rings around 14 bit DSLR cameras with uncooled sensors. Apart from that, the only difference between your images and those from DSLR cameras is that yours are saved as FITS files, and those from DSLR cameras are RAW files, proprietary for the make of camera used.
I'm not sure that I fully understand the reasons for your frustration. Monochrome cameras used for determining transformed magnitudes of variable stars require images to be taken through two filters, for example B and V. Images from OSC cameras used for determining transformed magnitudes require de-Bayering, conversion to greyscale, and separation of colour channels. Thus blue- and green-filtered images are still the result. Not only that, but you do not have to go through the process of converting RAW to FITS files.
Another advantage of OSC cameras, particularly for time series photometry involving many images taken though the night to study stars with short periods, is that blue and green channel data are captured simultaneously. That is not possible for owners of monochrome CCD or CMOS astronomical cameras and filter wheels. I have one (monochrome CMOS), and for time series photometry decided simply to use only the Johnson V filter and determine non-transformed magnitudes.
Therefore, I do not know why you cannot apply any software available to users of monochrome CCD or CMOS cameras and filter wheels, because like them you will get to the point where you have FITS files taken through green and blue filters (red also, if you wish).
Perhaps I misunderstand your problem. If so, tell us what the misunderstanding is.
By the way, I have done a lot of transformed magnitude determinations with DSLR photometry over quite a few years.
Roy
See: https://www.aavso.org/2021-webinars-schedule-january-march
March Abstracts
Dr. Barbara Harris, "How to Do Variable Star Photometry With Your DSLR" Many astronomers have a DSLR and use it for general photography and astrophotography. I would like to encourage you to use your DSLR to contribute to science by measuring the brightness of variable stars.
Sorry for the delay, in…
Roy,
Sorry for the delay, in responding.
I guess when I tried to get some initial test images uploaded to learn the process, I couldn't find a way or instructions to get "there from here". I haven't gone back to it since April/May as there simply was no observing weather here (very unusual) until August and even then it has been limited.
The references I read at the time seemed to indicate that it was either extremely difficult or just not possible to get an accurate magnitude measurement that would correlate to those in the reference database. For some reason, all my searches kept bringing up discussions/documents that were VERY CCD centric and seemed more focused on why CMOS wasn't as good and OSC was great for pretty pictures and not much else. Hence my frustration.
What I'm looking for is a set of instructions/example that walks a person through OSC post processing steps/needed results to have an image or set of images to submit to the AAVSO database and what you have to 'tell' the file uploader to get it to accept the OSC generated data files that is focused on cooled AstroImagers. I've not looked again, but that is what I surprised to be unable to find previously.
George,
Send me a private message. I'll try to help offline.
Roy