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I had a hunt online to try and work out what the sensor was in the camera, but to no avail. Hopefully someone else will be able to track down the sensor then it should be easier to find the QE… maybe.
James
Gary, I think you’ve nailed it. With the eye of faith I can see an inner circular halo in Sue’s photo. Looking in Stellarium the Sun would have been 52.5 degrees above the horizon. I’ve made an animated gif to show roughly where I think the true solar halo is:
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Chris Hooker emailed about something else and mentioned this. He strongly suggest I try some flats. I’ve found this video so will try some form of cereal bag flats later in the week; I probably won’t use a cereal bag, but something along those lines.
https://youtu.be/M7rSOXWQDZM?si=A6BESGiqf-UoXE5V
Thanks for the replies. I am feeling hopeful again.
James
Paul, I’m pleased I’m not the only nutter who likes collections like this 🙂 Are there any editions you are missing as I will rummage through the piles of books I have in my garage.
James
Grant, thanks. It may be that tilt here is reducing evenness of focus, but no end of playing with tilt does nothing to the unevenness of illumination. It isn’t even as though there is predictable gradient across the FoV, it seems there are areas of the FoV which have minimal gradient but these areas are not big enough to take the whole disc of the Sun and I’m not using a Barlow. I’ve just been looking and the B1200 is over £1000. Looking at Chris Hookers images in Ha with his newly acquired Acuter Pheonic 40 solarscope (https://britastro.org/observations/observation.php?id=20250509_220342_3acfea1c341b631f) he has no gradient, and I’d suggest potentially even better contrast than I can achieve. I am having to stop myself just clicking buy now Rother Valley Optic’s website (£999).
James
This is from today. The gradient in brightness is not a natural feature, it is artefact.
I’ve not. Invariably this scope is set up outside so tracking is usually awful. I just feel there is somethign fundamentally wrong and I’d like to resolve it one way or another.
Thanks.
James
Yes an absolutely brilliant weekend. I was exhausted when I got home last night. I’ve come away with lots of ideas of things to do to improve my own observing techniques and new things to have a go at. Also great to speak to people who I only ever encounter online. The BAA at its finest. Thanks for all who organised and ran the show, especially Tony, Ann and Alan, but also the helpers on the BAA stand, registration desk etc. Brilliant.
I got up early yesterday (9.4.25) before work and managed to get the attached. Pretty disappointing, and the tail very faint compared to other observations I’d seen online. Askkar 120 with 0.8x reducer and Canon 6D, this is about 12 minutes in total of the best subs captured between 03:17 (UT) and 03:54 (UT); there were lots of bad subs. 30 seconds each, ISO 400. Desaturated and inverted to allow me to see the tail.
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Martin, thanks for that link. It is interesting, depending where you look, the transmission data varies… Surely the colour IMX585 should have a near identical transmission profile whatever camera it is in? Here are three plots, one from your link, one from the ZWO website (https://www.zwoastro.com/product/asi585mc-mm-pro/) and one from the PlayerOne website (https://player-one-astronomy.com/product/uranus-c-usb3-0-color-camera-imx585/).
James
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Martin, thank you.
Yes, poor Chris Hooker has been helping me, dragging me along really as I’m not that bright when it comes to solar physics, magnetospheres, energy states, wavelengths etc…! But good fun for me anyway. I’ve just seen there is a 585 mono camera which appears to have a QE of just under 90% at 589nm. I may have to do some overtime. The binning is an interesting idea I’d not thought of.
Regards
James
We are going to try and live stream from Nottingham too in white light, and Ha if the clouds permit. Live stream should go live just before 10am.
https://youtube.com/@nottinghamastronomicalsociety?si=niCKwEgSv8w_qnWi
James Dawson
Nottingham Astronomical SocietyWe got it in Nottingham too on the all sky camera and both meteor cameras:
