17.7.16

dither scale

Understood dither to have a go after realising that what I was doing previously was far too small a pixel value. Yeah, I know. It sounds as if I know what I'm talking about. So, with the lasers from the band lighting the sky, helped by the 3-days-to-full moon, here's dithering which seems to have worked.

The default dither setting in APT doesn't produce a big enough movement, so together with the sgl and phd2 guys I worked out this for my combination of zwo120 and 700d guide and imaging cameras respectively.
m13 in hercules full frame

APT dither: 5
PHD2 dither scale: 1.0

ZWO pixels: 1.93
Canon pixels: 1.17

therefore dither on the Canon is 1.93/1.17 x 5 = 8.24 pixels






pixel scale summary
courtesy of the pixel scale calculator with the Canon 700D which has 4.3 micron pixels

focal length pixel scale
  760           1.17
  600           1.48
  400           2.22
crop of m13
canon 700D on bresser 152s 36 x 120s @ ISO 800 stacked with kappa-sigma in DSS
and goodbye dark frames

16.7.16

sadr

Near Sadr in Cygnus. A little less turbulence. Managed 3 minute exposures tonight.
γ cyg region
14 x 180s @ ISO 800

13.7.16

vía láctea

milky way in cygnus
An exercise in how to deal with star fields. Poor visibility tonight with the humid easterlies but I had a go anyway. According to CDC we were here so probably best to rotate the camera next time
from top: clusters ngc6871 biur 2 ngc6888
8 x 120s @ ISO 800

11.7.16

looking back

nostalgia
looking north 2016
 looking north 1998

cygnus

less light pollution but fainter.
ngc7000 in cygnus
12 exposures 2 minutes each
This next one's really faint. Gonna need more time on this. I should have done 4 minutes frames. And yes, I know. I must get those colours balanced.
the veil in cygnus
canon 700d with bresser 102s 12 x 120s @ ISO 800

wide fov

a new wide field toy
gas clouds m8 right and m20 in sagittarius
canon 700d on a bresser 102s 8 x 120s @ iso 800 
Then a bit below it and so looking through the La Nucía skyglow and on toward the galactic centre
cluster and dark bits  M24
4 X 120s @ iso 800

7.7.16

cúmulos de verano

Against the star fields of our own galaxy. The well known
globular cluster m22 in sagittarius
10 x 120s @ ISO 800

open cluster m11 the wild duck in scutum
10 x 120s @ ISO 800

and the neglected
globular cluster m56 in lyra
12 x 120s @ ISO 800