Thanks Dave!
I've attached a DSS/Aladin overlay on part of my upside down image
of a similar field and scale.
The only GSC/HST/Hipparcos cataloges I can overlay with any
mag indicators are all in Jmag(Blue) and Rmag(Red) values.
Not many visual mag estimates from any of these cataloges that deep.
But the circled triangle area has some values of 18s and 19s for
blue and red filter mag estimates.
There are even deeper stars in my image but none covered by
any catalogues that I can find.
I have to remind myself sometimes that:
This all from a set of 5sec frames on a homemade GEM, with
a homemade worm gear and Bartelisation, 12" F4.5 Chinese OTA,
A home cooled $500 Meade camera.....
from suburban backyard Adelaide!
The DSS image is from a 1m Schmidt Survey camera
Steve