mate
Just subtract 11 hours from your local time when you captured the image. That will give you UT.
It'll be minus 10 once daylight savings ends, if Tas is currently operating on EDST????
If you took that at 5 this morning and tas is on daylight saving time, that's be 1800 UT, I think???
You then express the time on your pix in UT... without reference to local time since UT is Universal and understood as a time relative to one location - the old GMT
There are also sites you can visit which give UT. Just don't know what they are, sorry