ASTRO: Gamma Cygni region in RGB

this was taken using a 6x7 format Pentax SMC 300mm f/4 lens with an FLI
PL39000C one shot color camera.

this is 39megapixels in RGB. total exposure was 11 x 15 minutes = 2h45m

the stars have pretty bad haloes. I would imagine that is from the lens:
there's a reason Pentax sold a very expensive APO lens in that same focal
length/ratio

http://www.narrowbandimaging.com/gam...pl39k_page.htm

in the full resolution version, the sheer number of stars is staggering

Richard Crisp wrote:
this was taken using a 6x7 format Pentax SMC 300mm f/4 lens with an FLI
PL39000C one shot color camera.

this is 39megapixels in RGB. total exposure was 11 x 15 minutes = 2h45m

the stars have pretty bad haloes. I would imagine that is from the lens:
there's a reason Pentax sold a very expensive APO lens in that same focal
length/ratio

http://www.narrowbandimaging.com/gam...pl39k_page.htm

in the full resolution version, the sheer number of stars is staggering


Looks like the red is a bit out of focus compared to the other two
colors. Did you refocus the individual filters with the black and white
camera?

Could you blur the other two channels to match the red or deconvolve the
red to match the other two?

Rick


--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

"Rick Johnson" wrote in message
ster.com...
Richard Crisp wrote:
this was taken using a 6x7 format Pentax SMC 300mm f/4 lens with an FLI
PL39000C one shot color camera.

this is 39megapixels in RGB. total exposure was 11 x 15 minutes = 2h45m

the stars have pretty bad haloes. I would imagine that is from the lens:
there's a reason Pentax sold a very expensive APO lens in that same focal
length/ratio

http://www.narrowbandimaging.com/gam...pl39k_page.htm

in the full resolution version, the sheer number of stars is staggering


Looks like the red is a bit out of focus compared to the other two colors.
Did you refocus the individual filters with the black and white camera?

no, it is a one shot color camera..... i think stopping it down is the best
path forward

i think that is lateral chromatic aberration and if so stopping down the
aperture will improve it. live and learn.






Could you blur the other two channels to match the red or deconvolve the
red to match the other two?

i might try some of those ideas. I just did a quickie standard process on
the data and posted it.

didn't do much in the way of tricky things on it yet




Rick


--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

Beautiful image Richard.
At least in the version you posted the halos around stars don't look bad,
don't know if they were more prominent in the raw pictures.

Stefan

"Richard Crisp" schrieb im Newsbeitrag
m...
this was taken using a 6x7 format Pentax SMC 300mm f/4 lens with an FLI
PL39000C one shot color camera.

this is 39megapixels in RGB. total exposure was 11 x 15 minutes = 2h45m

the stars have pretty bad haloes. I would imagine that is from the lens:
there's a reason Pentax sold a very expensive APO lens in that same focal
length/ratio

http://www.narrowbandimaging.com/gam...pl39k_page.htm

in the full resolution version, the sheer number of stars is staggering