Giant sunspot, AR3664. EOS R7 and RF 200-800mm lens.

[Dennis]

On Friday 10th May 2024, I managed to play hide-and-seek with the intermittent cloud cover and record this giant sunspot, AR3664 which has been classified as a 'Carrington-class' sunspot.

The Carrington Event was a large solar storm that took place at the beginning of September 1859, just a few months before the solar maximum of 1860.

I used the Canon EOS R7, RF 200-800mm and RF Extender x1.4 mounted on the Tak EM 200 Temma II to grab 75 frames which I then Aligned/Stacked in Autostakkert!4, deconvolved in Wavesharp and then finished in PS CC.

1120mm, 1/1,000 sec, F16, ISO400.

Here are a couple of examples showing the effects of the poor seeing due to the jet stream. One of the better frames and one of the more seeing-affected frames.

They are single, full-res crops (Raw SOC) taken at the same settings but 17 seconds apart.

I also fitted the RF x2 Extender to give 1600mm, but the seeing was so poor that all the images were very soft and lacking detail.

Dennis.

[RichardJ]

Lovely full disc Dennis. If only the weather cooperated…

Richard.

[Dennis]

Thanks Richard, I guess I can’t really complain about the seeing conditions as I was fortunate enough to find some clear patches to shoot through.:)

Here is an example of one of the better frames vs one taken under poor seeing, taken some 17 seconds apart with the same gear and settings.

Dennis

[Derek Klepp]

Good effort on the quick grab Dennis I was in Tassie but unfortunately came home the day before the event.All clouds and showers here at Yelgun.
Cheers Derek

[Dennis]

Thanks Derek, the Canon RF 200-800mm zoom is useful in that you can locate the target at the 200mm end and then zoom in all the way to 800mm.

Cheers

Dennis

[Derek Klepp]

Dennis I have recently got the OM 150 -400 mainly for Telemacro of insects but was thinking of using it in a similar way just have to find my baader Solar film I have put in a safe place.Still cloudy here this morning though.Also Steve Massey actuall got the top of the Aurora from Hervey Bay so definitely a powerful flare.
Derek

[Dennis]

Yes, these modern lenses, sensors and processing software make it so much easier to record fairly decent images using a quick, basic, back garden set up.

I just plonk the Tak EM200 Temma II tripod down on its 3 pads in the grass on the back garden, fit the camera/lens and this has me rough polar aligned which is all I need.

No complicated set up or software routines required, making it more appealing when you spot half an opportunity with the clouds and weather conditions.:)

Does that lens come with the built-in x1.25 Extender?

Dennis

[Derek Klepp]

Yes Dennis that’s the one .Although mine is a second production line one and is made in OMs Vietnamese factory had about a 2 month wait.After lugging around heavy Canon gear over the years these smaller OM setups are good for travel but I do notice the slight noise increase.

[Dennis]

Thanks Derek, I had a Pentax KM 35mm SLR back in the 70's and coveted the Olympus OM-1 SLR when it came out, it was so much smaller and lighter than the big SLRs of the day.

Cheers.

Dennis