
I have been comparing the limits of my favourite freeware astronomy software 
Cartes Du Ciel, 
with the new astronomy add on for 
Google Earth, 

and also with another online resource namely 
Data Release 6 of SDSS 
which is approximately 16Tb of data.
And I am impressed with the results of my investigation which take me to the limit of 21 magnitude observational astronomy using these software.
So I decided to pick a special point in the sky to compare.
Starting PointStart at Pisces directly below Pegasus Square and zoom due south.

Zoom past below Seyfert Galaxy NGC7742
Zoom past towards  the Polygon asterism within Pisces denoted by stars
Gamma,Theta,Iota,Lambda,Kappa PiscesZoom towards a Skewed Rhombus denoted by stars
CGCS 5928(NW)aka 
19 Psc
HD223075 
TYCHO-2 2000 TYC 589-1671-1 
USNO-A2.0 USNO-A2 0900-20488086 
BSC 1991 HR 9004 
HIP117245 
at Visual Magnitude 5.30,
 
XZ8Q 32002(NE) aka
22 Psc
HD223719 
SAO128427 
HIPH117683 
TYCHO-2 2000 TYC 590-329-1 
USNO-A2.0 USNO-A2 0900-20511366 
BSC 1991 HR 9033 
HIP117683 
at Visual Magnitude 5.59 and distance 1087.2 light years, 
XZ8Q 32064(SW)aka 
XZ Psc aka HD224062
SAO146973
HIPH117887
at Visual Magnitude 5.78 and distance 652.3 light years, 
XZ8Q 31958(SE) aka 
21 Psc
WDS23495+0105
HD223438
SAO128401
TYCHO-2 2000 TYC 586-1293-1 
USNO-A2.0 USNO-A2 0900-20500547 
BSC 1991 HR 9022 
HIP117491 
at Visual Magnitude 5.77 and distance 271.8 light yearsThese group of 4 stars forming a skewed Rhombus point NE towards Pisces Polygon Western Side containing stars Iota and Lambda Piscium.
Zoom into the Rhombus and Zoom past a belt similar to Orion’s  Belt denoted by stars
XZ8Q 32025 aka
25 Psc                                
WDS23531+0205 
HD223855 
SAO128436 
TYCHO-2 2000 TYC 587-1273-1 
USNO-A2.0 USNO-A2 0900-20516100 
BSC 1991 HR 9042 
HIP117774 
at Visual Magnitude 6.29 and Distance 465.9 light years, 
XZ8Q 31988
aka
HD223617 
SAO128417 
TYCHO-2 2000 TYC 587-949-1 
USNO-A2.0 USNO-A2 0900-20507649 
HIPH117607   
at Visual Magnitude 6.96 and Distance 652.3 light years,
XZ8Q 31950 aka
HD223346 
WDS23488+0213 
SAO128393 
TYCHO-2 2000 TYC 586-272-1 
USNO-A2.0 USNO-A2 0900-20497891 
BSC 1991 HR 9015 
HIPH117445
at Visual Magnitude 6.47 and Distance 181.2 light years 
Zoom downwards through the Rhombus toward a group of stars similar to Orion’s Sword denoted by stars 
ASCC 1184742, ASCC 1184797 split by a galaxy NGC7783 aka Galaxy PGC72803   MCG  0-60- 58  
pointing towards the lowest point of Rhombus denoted by star 
XZ8Q 32064Zoom to the center of the triangulation of NGC7783, IC1515-17, IC5385
Zoom into this center until NGC7783, IC1515-17, IC5385 go out of view
Near this center find two Pleidaes type shining stars aligned on a diagonal denoted by stars
ASCC 1185089, ASCC 1263991Zoom past these two Pleidaes type shining stars and let them travel south of you as you travel north of them towards a another group of two shining stars on a parallel denoted by stars
ASCC 1185088 aka V_USNOB 0899-0000043 aka E_USNOA U0825 00000615
ASCC 1263996 aka V_USNOB 0899-0627221that sit between PGC 10 north and PGC 7 south
Zoom past these two shining stars on a parallel and let them travel south of you as you travel north of them and north of PGC 10
Zoom past PGC 10 and let it travel south of you as you travel north towards a another group of stars forming an Equilateral Triangle
This Equilateral Group of stars contains 
E_USNOA U0825_00000501 Bottom Right
E_USNOA U0900_00000603 Vertex
E_USNOA U0825_00000738 Bottom Left=V_USNOB 0899-0000051Zoom past these group of stars forming an Equilateral Triangle and let them travel west of you
ie let star E_USNOA U0825_00000738=V_USNOB 0899-0000051 travel to the west of you as you zoom in
ie and then let star E_USNOA U0825_00000501 travel to the west of you as you zoom in
Zoom past star V_USNOB  0900-0000004 and travel to the north west of you as you zoom in
Zoom until all stars are out of view both North, West, South, and East and stop just before you see the next stars namely
V_USNOB  0900-0618271 North East
V_USNOB  0900-0618263 North East 
V_USNOB  0899-0627211 South EastFinishing PointYou are now in a stellar void at magnitude 21
Where are you?