View Full Version here: : Why is saturn so dim???? 31st Dec
davidpretorius
31-12-2007, 05:38 AM
Paul was telling me the other night how dim was saturn was and so I decided to give it try this morning.
I could only capture at 7.5 fps and with the clear filter.......the histogram may have topped out at 140 max i reckon.
Anyway, the bands are viewable.......it may be a good excuse to go a 16" mirror :D
h0ughy
31-12-2007, 07:12 AM
yes it sound to me as though you may indeed have to go to a 16" David:whistle:;)
would it be because the rings are moving to edge on:shrug:
iceman
31-12-2007, 08:44 AM
That's a massive image scale, David! Is it enlarged?
I know what you mean about it being dim - very difficult to capture.
You've done a great job to start the season, I love it.
John K
31-12-2007, 09:06 AM
Nice going Dave, yep, due to the tilt of the rings I suspect. Massive scale there!
davidpretorius
31-12-2007, 09:40 AM
you might be right there houghy...........i do need a 16"......seriously, the rings may not be reflecting as much light our way.
Mike and John, i used the 100mm extension tube, which i think gave me 7.7x.......i better check birds calculator.
I then did a 1.5 upscale using ninox
Wow nice image scale David, even taking into account the x1.5 upscale.
Surely it must be dimmer due to the shallow ring angle.
OneOfOne
31-12-2007, 10:33 AM
I would expect the angle will reduce the brightness overall, making it appear dimmer to the eye, but the brightness of the planet itself should remain the same.
Nice scale there DP. Your image scale pretty much matches with mine for the saturn data I grabbed this morning, I'm also using a 3/2 resample before processing.
Here's my capture settings:
Image scale: 14m focal length, pixel size 7.4u
Red channel: 17fps max gain
Green channel: 17fps max gain
Blue channel: 15fps max gain
camera: PGR dragonfly2
The image is very dim at this scale, so the 12-bit data from the camera is likely to be 10 or 11 bit, not too much of a loss and the seeing has been bad enough around here to want the higher fps. Just means I have to capture 2x as much data :-)
Saturn will get a bit brighter and larger near opposition.
cheers, Bird
vBulletin® v3.8.7, Copyright ©2000-2024, vBulletin Solutions, Inc.