hubble v bresser

not that comparison is the correct term but...

m16 using a bresser telescope

cost: €400

m16 using the hubble space telescope

cost: €20 000 000 000

twenty billion times better



Stars at both ends of their lives. Birth: still low but had another go at getting the Hubble Pillars. A bit better with m16 coming up to the meridian. Death: easier with the second target which was approaching the zenith.
nebula m16 in saggitarius
700d with ar152s 24 x 120s @ ISO 1600

planetary nebula m27 in vulpecula
canon + ar152s  24 x 120s @ ISO 800

And a rare chance to see the object in both APT and PHD2


the crescent

4 minute snaps and too many stars for comfort. That's The Swan for you.
ngc6888 in cygnus
imagining: canon 700d and ar152s
guiding: zwo 120 and ar80
25 x 240s @ ISO 1600


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



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


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