| M45 |
The Pleaides, also known as Subaru, or the "Seven Sister" is a cluster of young stars ( less than 100
million yrs old), and associated reflection nebula, located just over 400 lyr away, in the constellation
Taurus.
Photo detail: The photo consists of two frames, each using 5hrs of exposure, made with the H9 through
the TV FL/RD on the 80ED @ f/6. Each LRGB frame uses the following exposures:
L - 40X3m, R - 24X2 1/2m, G - 28X2m, B - 24X2 1/2m
million yrs old), and associated reflection nebula, located just over 400 lyr away, in the constellation
Taurus.
Photo detail: The photo consists of two frames, each using 5hrs of exposure, made with the H9 through
the TV FL/RD on the 80ED @ f/6. Each LRGB frame uses the following exposures:
L - 40X3m, R - 24X2 1/2m, G - 28X2m, B - 24X2 1/2m
The following is a quick test of the Nikon D2Xs (unmodified), through the TV X0.8 FL/RD on the 80ED. The photo, of
M45, consists of three 10min exposures @ iso800, using "mode 3". Six darks, six flats were used in the cal process.
The photo is a 6Mpix central crop from the 12Mpix frame (I would need to spend some time optimizing the FL/RD to
sensor distance, or get a different FL to fix field curvature issues on the 80ED).
Clearly, at least eight or ten times as many light exposures would be needed, as well as two, or three times the
number of darks and flats (flat darks should have also been acquired, they weren't), if I wanted the background to
approach that obtained with the cooled CCD.
The "2" series Nikon DSLRs aren't really ready for life at night. They're still too noisy. In order to escape the built-in
median filter, one must use the (absurd) "mode 3" (physically turn-off the power switch while the "long exposure NR"
frame is being processed).
Maybe the "3" series Nikons have improved, but the median filter is still there, and until it goes away, and noise is
significantly reduced relative to the "2" series, I would leave my Nikons in the house after dark.
I love my Nikons, and the Nikon glass, for wildlife and nature work, but they just aren't worth using on astro subjects.
M45, consists of three 10min exposures @ iso800, using "mode 3". Six darks, six flats were used in the cal process.
The photo is a 6Mpix central crop from the 12Mpix frame (I would need to spend some time optimizing the FL/RD to
sensor distance, or get a different FL to fix field curvature issues on the 80ED).
Clearly, at least eight or ten times as many light exposures would be needed, as well as two, or three times the
number of darks and flats (flat darks should have also been acquired, they weren't), if I wanted the background to
approach that obtained with the cooled CCD.
The "2" series Nikon DSLRs aren't really ready for life at night. They're still too noisy. In order to escape the built-in
median filter, one must use the (absurd) "mode 3" (physically turn-off the power switch while the "long exposure NR"
frame is being processed).
Maybe the "3" series Nikons have improved, but the median filter is still there, and until it goes away, and noise is
significantly reduced relative to the "2" series, I would leave my Nikons in the house after dark.
I love my Nikons, and the Nikon glass, for wildlife and nature work, but they just aren't worth using on astro subjects.