View Full Version here: : no telescope
poider
24-04-2016, 06:36 PM
If I want to get some cloud bands in Jupiter is it possible without a telescope?
I have a Nikon D7000, a good Tripod and
Sigma 10 - 20mm f/3.5
Nikon 50mm f/1.8
Tamron 90mm f/2.8
Nikon 18 - 105mm f/3.5 - 5.6
Nikon 55 - 300mm f/3.5 - 5.6
Nikon 18 - 300mm f/3.5 - 5.6
Sigma 150 - 500mm f5.6 - 6.3
I find it very hard to get stars etc in proper focus, is there a sure way, I try to get good focus on the moon then use that focus for stars planets etc, off course that means the moon is spoiling my skies but I don't see another way.
Peter
PS should I use a polarizing filter?
raymo
24-04-2016, 06:57 PM
Your longest lens would show the bands[but very small], you could of course crop the image.
Does your Nikon have "Live View"? if it does just magnify a bright star 10x
and focus until the star is as small as possible.
raymo
janoskiss
24-04-2016, 07:06 PM
Short answer: Live View centred on bright star, max display zoom, manual focus.
With a point source like a star, the optimal focus point is usually obvious, because that's where you get the tightest smallest dot on the display. If too bright or unclear, reduce aperture, or pick a not-quite-so-bright star. (Worth double checking anyway till you're confident in your method.) Focussing on the Moon is not very reliable.
skysurfer
24-04-2016, 07:35 PM
With Canon, AF does work when I focus my 200/2,8L (70mm aperture) on a bright star. I tested on Alpha Centauri and Alpha Crucis.
Probably with Nikon it works as well. AF-ing on Jupiter should work even better.
But Jupiter ?
Well, Jupiter is angular 40" wide. A 150-600 at 600 is 2 degrees wide.
7200" / 4928 pixels (long size of a D7000 frame) = 1.46" per pixel, so Jupiter's sphere is displayed as a circle of 27 pixels, so when focused properly, the bands should be visible.
poider
24-04-2016, 08:35 PM
Yes I do have live view and do focus that way, but even then the focus ring is too sensitive and i can never seem to get it that well, i will have to keep trying,not gonna happen tonight though as we have the "oh so predictable (peter's getting camera out we had better stir up some clouds) night"
Thank you for help
Peter
raymo
24-04-2016, 09:00 PM
There are a couple of members who advertise in the classifieds here, who
will quite cheaply make you a bahtinov mask for your lens, which allows
quick and accurate focusing.
raymo
I have used autofocus with Nikon on 300mm on stars. Not sure about 600mm but it should work. At the moment you also have the Moon out so you could focus on it and then recompose to Jupiter.
poider
25-04-2016, 04:06 AM
I took jupiter with sigma 150 - 600 f6.3 on many different settings, focused on live view with my reading glasses and a magnifying glass to get it as small as i could get it and after much trial and tribulation with exposures etc, I had about 20 shots ranging from being too bright right down to where i can barely make out the moons and i can not see any details even after playing with contrast and brightness in photoshop.
I must be doing something wrong
Peter
doppler
25-04-2016, 08:36 AM
While it may be possible with your equipment it is not an easy task, even with a longer focal length scope and tracking it's hard to get a reasonable pic with a DSLR. Keep the iso low and shutter speed fast. Atmospheric conditions need to be good, if you can't see the bands at 10x live view you wont be able to photograph them.
poider
30-04-2016, 05:06 PM
Sorry I have misled you all., I have a sigma 150 -500mm, not the 150 - 600 as i previously stated, i was confused between what i have and what i want, but last night after many attempts at different exposures etc i got some banding with a little post processing
Peter
vBulletin® v3.8.7, Copyright ©2000-2025, vBulletin Solutions, Inc.