Monday, February 25, 2008
NGC 2683 "Sanp shot"
This is a dim galaxy in constellation Lynx.
I managed to capture less than two hours of data before
the clouds rolled in.
There is some details visible in the core.
LX200 GPS 12" and QHY8
Guided with SXV-AO and LodeStar camera
IDAS LP filter
10 x 660s + Flats and Bias frames
IRIS Drizzle function was used to bring out some details.
(Light pollution more or les destroy this image.)
Tuesday, February 19, 2008
Horse head nebula, IC 434
I'm not happy with this image at all, but since
I finally managed to capture this nebula with some color I put it here.
Up here the maximum elevation for IC 434 is about 21 degree and when target is in its moust Southern point, the view is blocked by the buildings.
That means lots of turbulent air between target and telescope.
When I was shooting the RGB channels, target was only 10 degrees abowe horizont.
There is a way too few exposures for this relatively dimm object, only two hours of H-a.
6 x 1200s for H-alpha and 4 x 660s for RGB channels with IDAS LP filter.
Actually I shoot half of the frames between neon signs at top of the opposite building.
Telescope LX200 GPS 12" @ f6.3
Camera QHY8
Guiding SXV-AO, active optics unit.
Here is the H-alpha channel only
Friday, February 15, 2008
Second light for Canon FD 200mm f2,8 lens
Rosette nebula is located very low in the horizont at my location.
The maximum elevation is about 29 degree.
Last night I shooted one hour of exposures to RGB channels, with UHC-s
filter 6x600s.
Hevay light pollution coused strong gradient and very weak signal/noise.
Then I shooted 9x1200s for H-alpha channel, but thin upper clouds ruined 5 exposures.
Final image is composed from 6x600s RGB and 4x1200s H-alpha.
This lens is fast enough to capture a nice amount of photons in that time,
not very deeb image but tolerable.
Here is pure H-alpha version:
Thursday, February 14, 2008
First light, Canon FD 200mm f2.8 lens
Last nigh was very windy, almoust a storm. Normaly I do not shoot under that kind of
conditions. How ever, this time I wanted to test my 200mm f2.8 Canon lens under the stars.
"HARTH & SOUL"
IC 1805 & IC 1848 in H-alpha light.
Only 6x1200s, this is a fast lens. Flats and Bias, guided with LX200 and PHD-guiding.
Camera QHY8 + QHY5 guider.
I added some color, but there was problem with camera orientation, so image is clipped.
Color data: only 3x600s with UHC-s filter
I shoot California nebula as well. Elevation was very low at the end of the exposures,
only about 28 degrees.
H-alpha 4x900s, same setup.
Color version:
3x600s trough UHC-filter added.
Over all, I'm veryhappy with this lens. This is very first time to me use camera lens
for astro photography.
I was expecting severe distortion in the image edges, there is none!
I was expecting severe color aberration, there is none!!!
This lens was unexpencive, doe the old FD model, about 120€.
Here is the link for moreinformation:
http://www.mir.com.my/rb/photography/companies/canon/fdresources/fdlenses/200mm.htm
All the images are shooted with full f2.8 aperature.
The front lens aperature is 72mm.
FOCUSING Fast lenses are very difficult to focus manually, it's pure luck to reach sharp focus. 200mm f2.8 lens has about 20 microns sharp focus area! I build a simple autofocuser to my lens by using TCF-s temperature compensating focuser. I'll send real pictures about that later. Here is a picture about principle.
This system solves allso problems with focus temperature shift!
TCF-s focuser is easy to move back to the main telescope at anytime.
I was able to use FocusMax with the lens and reach sharp focus in 30 seconds.
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