Why is Saturn white in my scope??

[launchpad67]

I realize that most photos seen are false color but why is Saturn white when viewed from my telescope? What is the scientific explanation?

 

[little_star]

It's a conspiracy.

 

[igorsboss]

The light is fine... The problem is with your eyes!<br /><br />Human eyes have two kinds of photorecoeptors: rods and cones. The rods pick up intensity without color, like a black and white camera. Each of the cones pick up one of 3 colorss. Rods are more sensitive to low light levels.<br /><br />There isn't enough light coming through the small telescope to activate the cones. The rods can determine Saturn's shape and grey-level, but not the color.<br /><br />Have you ever noticed that it is very difficult to see colors in moonlight? This is exactly the same effect. We evolved this way because it was important to sense danger at night and pick ripe fruit by day.<br /><br />You can see color through a larger telescope because there is enough light gathered by the telescope for your cones to start working.<br /><br />The fovea, the very center of your vision, is jam-packed with cones, and has few rods. Since the cones aren't being activated by the low light level, it is hard to look at Saturn through the telescope if you look directly at it. However, if you move your eyes very slightly, so that you are looking directly at the black sky NEXT TO Saturn, you might find it easier to see. This technique is called "averted vision".<br /><br />Cameras can see color in telescopes because the longer the sensor (film, CCD) stares at the target, the more photons are counted on the image. Eyes don't work that way. You won't be able to see the color, no matter how long you stare.

 

[bbk1]

Even when one uses a camera to record Saturn, it still appears white. I used a SONY Handycam to record video clips of Saturn but the image still appears white. The reason, as you indicated, might be due to the size of the scope. I'm using 4.5" Aperture scope with a maxmimum magnification of 675 with a Barlow of 3X. Without the Barlow I have a magnification of 225 which I used for my recording.

 

[wisefool]

One of the reasons for going with maximum aperture is the ability to see color in more objects. The cones need enough intensity to work, and a small aperture boosted to high powers does not provide the brilliance. <br /><br />I see Saturn as a creamy object, with different colored bands (subtle), and a darkened southern area around the pole. I also see lots of different colored stars, even ones around 10th magnitude. And even bright asteroids take on interesting colors. But, alas, I am using a 16.25" Dob to get this effect. So, whenever you can, join with your astronomer friends and borrow some views of objects that can be somewhat colorful.

 

[CalliArcale]

I'm told that filters can also help, and I'm thinking of getting some filters for my telescope. Does anybody have some advice for what filters would be good for bringing out detail in the gas giants? I do not have a very big 'scope -- 130mm. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[tfwthom]

Don't bother with color filters, if I remember you have a 130mm Orion. You need all the light that you can get. Now a UHC or and OIII would be alright, and a V-block would help but for color filters really need 8" or more aperture to work well. <div class="Discussion_UserSignature"> <font size="1" color="#3366ff">www.siriuslookers.org</font> </div>

 

[CalliArcale]

Cool! Thanks for the advice. <img src="/images/icons/wink.gif" /> I'll hold off on filter acquisition (apart from my solar filter, of course) until I've gotten a bigger scope, which will probably not happen until Ada is old enough to start appreciating astronomy by my side. <img src="/images/icons/cool.gif" /> <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>