For those who haven't heard about the white oval colliding with the GRS: http://www.skyandtelescope.com/news/news.shtml#Jupiterband Make sure the entire link is all on one line, or it may not work with some browsers. If it still isn't active, re-type it by hand. C. __________________________________________________ Do You Yahoo!? Great stuff seeking new owners in Yahoo! Auctions! http://auctions.yahoo.com
Thanks Chuck. ...very interesting article. I'll be watching Jupiter with renewed interest. ----- Original Message ----- From: "Chuck Hards" <chuckhards@yahoo.com> To: "Utah-Astro" <utah-astronomy@mailman.xmission.com> Sent: Monday, January 28, 2002 12:25 PM Subject: [Utah-astronomy] Jupiter activity
I took the opportunity to set up the 8 inch before the Mirror Grinding Class last evening and looked at the planets. What a glorious sight! I only had a 16.8 mm orthoscopic with me, so I was limited at 161X. I wish I had had more. The evening certainly would have supported it. The seeing was very steady, and the transparency excellent. Jupiter, aside from being very bright, yielded a view of spectacular detail. The shadow of (I assume) Io was a round, black blot against the detailed cloud tops. Jupiter didn't hold much back, as the GRS showed a vivid pink center surrounded by a bright vortex of clouds. If I'd had a higher power eyepiece I may have been able to see the white oval nearby, but the brightness was too great. There were other white ovals elsewhere on the surface, however. Saturn was a tan, three dimensional globe with more cloud bands than I can recently remember seeing. Cassini's Division was visible all the way around the ring, except for 5 or 10 degrees where it was hidden by the disk of the planet. The Crepe ring was stunning, and even Enke's Division was there. I did not see any spokes, however. The differences in the several rings was very obvious. Overall, it was a great night of observing! I'll have to get the scope out more often. Brent __________________________________________________ Do You Yahoo!? Great stuff seeking new owners in Yahoo! Auctions! http://auctions.yahoo.com
Great report, Brent. Thanks! I'd like to emphasize that Brent used only 8" of aperture for these spectacular views. I've had similar views with my 6". You don't need a huge aperture for great planetary viewing. Chuck __________________________________________________ Do You Yahoo!? Great stuff seeking new owners in Yahoo! Auctions! http://auctions.yahoo.com
I would be interested (as a person not owning any filters yet) in knowing what the experienced planetary observers on the list recommend as far as color filters go for planetary viewing; what color(s) seem to work best for Jupiter? How about the other planets? -Rich --- Chuck Hards <chuckhards@yahoo.com> wrote:
Great report, Brent. Thanks!
I'd like to emphasize that Brent used only 8" of aperture for these spectacular views. I've had similar views with my 6". You don't need a huge aperture for great planetary viewing.
Chuck
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Use the filter that has a color "opposite" to the color of the feature you want to examine. For example, a red/orange/pinkish feature, such as the GRS, may best be seen using a mild blue filter. Same with Mars. Using the "opposite" color will increase the contrast of the detail with respect to it's surroundings. A red filter sometimes makes bluish festoons stand out better. I'd say I use my medium and light blue filters the most. BTW, a broadband LPR filter can increase contrast on Jupiter noticeably. Sometimes a violet filter will enhance cloud features on Mars, especially near the limb, by supressing the overall reddish cast of the planet. Without recalling the Wratten numbers off the top of my head, I'd suggest getting a medium blue, medium red, medium yellow or yellow-green as one's first filters. A dark violet or ND "moon" filter works wonders on Venus, where the brightness is so overwhelming it can be hard to even see the phase easily. Chuck --- Richard Tenney <retenney@yahoo.com> wrote:
I would be interested (as a person not owning any filters yet) in knowing what the experienced planetary observers on the list recommend as far as color filters go for planetary viewing; what color(s) seem to work best for Jupiter? How about the other planets? -Rich
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Rich, My experience is a bit different than most. I find filters degrade the seeing unless you have paid top dollar for them. My 8" (refractor) has a minus violet filter in it. I don't use anything elso, because they seem to confuste the image too much. Brent --- Richard Tenney <retenney@yahoo.com> wrote:
I would be interested (as a person not owning any filters yet) in knowing what the experienced planetary observers on the list recommend as far as color filters go for planetary viewing; what color(s) seem to work best for Jupiter? How about the other planets? -Rich
--- Chuck Hards <chuckhards@yahoo.com> wrote:
Great report, Brent. Thanks!
I'd like to emphasize that Brent used only 8" of aperture for these spectacular views. I've had similar views with my 6". You don't need a huge aperture for great planetary viewing.
Chuck
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It is important to know that filters don't improve the image wholesale- they just bring out details that are otherwise lost, mostly due to "irradiation"; that is, the tendency for low-contrast details to bleed into one another. If you are expecting something spectacular when using a filter, you will probably be disappointed. There have been times when details invisible with no filter have become obvious with it- but much of the rest of the planet actually suffers. That's the point-removing colors that would otherwise mask a particular detail. Filters are for the details only, not a general enhancer. I use Orion's color filters, not the cheapest on the market, but hardly "top-dollar" either. Brent, one of these days let's get together, maybe I can change your mind on filters. BTW, as our eyes age, our corneas tend to yellow (that's why old ladies sometimes have blue hair- it doesn't look blue to them, but silver) so we eventually get a filter FREE! (Hey, look on the bright side!) Chuck --- Brent Watson <brentjwatson@yahoo.com> wrote:
My experience is a bit different than most. I find filters degrade the seeing unless you have paid top dollar for them. My 8" (refractor) has a minus violet filter in it. I don't use anything elso, because they seem to confuste the image too much.
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Chuck, I must admit that I am interested in sharp, contrasty images. A filter tends to scatter light, and so degrades the sharpness and overall contrast of the image. Some individual details do become more aparent (contrasty) but at the expense of the rest of the image. That's what I don't particularly like. Cross polarizers on the Moon, or anything else, ruin the image for me. So, I don't use them. I also have not had alot of success in bringing out significantly more detail. The detail is supressed, although the contrast may be increased. I just have never liked what I see through filters. Yes, let's try it again. I'm always open to try again. Brent --- Chuck Hards <chuckhards@yahoo.com> wrote:
It is important to know that filters don't improve the image wholesale- they just bring out details that are otherwise lost, mostly due to "irradiation"; that is, the tendency for low-contrast details to bleed into one another. If you are expecting something spectacular when using a filter, you will probably be disappointed. There have been times when details invisible with no filter have become obvious with it- but much of the rest of the planet actually suffers. That's the point-removing colors that would otherwise mask a particular detail. Filters are for the details only, not a general enhancer. I use Orion's color filters, not the cheapest on the market, but hardly "top-dollar" either. Brent, one of these days let's get together, maybe I can change your mind on filters. BTW, as our eyes age, our corneas tend to yellow (that's why old ladies sometimes have blue hair- it doesn't look blue to them, but silver) so we eventually get a filter FREE! (Hey, look on the bright side!)
Chuck
--- Brent Watson <brentjwatson@yahoo.com> wrote:
My experience is a bit different than most. I find filters degrade the seeing unless you have paid top dollar for them. My 8" (refractor) has a minus violet filter in it. I don't use anything elso, because they seem to confuste the image too much.
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--- Brent Watson <brentjwatson@yahoo.com> wrote:
Some individual details do become more aparent (contrasty) but at the expense of the rest of the image. That's what I don't particularly like.
Well, that's the purpose of filters.
The detail is supressed, although the contrast may be increased.
I don't understand this statement, Brent. Increasing contrast tends to increase visibility for the kind of details I typically use filters for.
Yes, let's try it again. I'm always open to try again.
Great! When the temperature is a bit higher, OK? Chuck __________________________________________________ Do You Yahoo!? Great stuff seeking new owners in Yahoo! Auctions! http://auctions.yahoo.com
It sounds like so far the consensus is, Orion filters work well; are Lumicon generally considered better? I think I heard Lumicon will be here for ALCon this summer -- do the items they bring for sale usually end up being "seconds"? Anyway, thanks guys for your input! Rich --- Chuck Hards <chuckhards@yahoo.com> wrote:
It is important to know that filters don't improve the image wholesale- they just bring out details that are otherwise lost, mostly due to "irradiation"; that is, the tendency for low-contrast details to bleed into one another. If you are expecting something spectacular when using a filter, you will probably be disappointed. There have been times when details invisible with no filter have become obvious with it- but much of the rest of the planet actually suffers. That's the point-removing colors that would otherwise mask a particular detail. Filters are for the details only, not a general enhancer. I use Orion's color filters, not the cheapest on the market, but hardly "top-dollar" either. Brent, one of these days let's get together, maybe I can change your mind on filters. BTW, as our eyes age, our corneas tend to yellow (that's why old ladies sometimes have blue hair- it doesn't look blue to them, but silver) so we eventually get a filter FREE! (Hey, look on the bright side!)
Chuck
--- Brent Watson <brentjwatson@yahoo.com> wrote:
My experience is a bit different than most. I find filters degrade the seeing unless you have paid top dollar for them. My 8" (refractor) has a minus violet filter in it. I don't use anything elso, because they seem to confuste the image too much.
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I bought mine from Sky Instruments in Canada. I have been happy with them. As I recall, I got one or two more than I would have from Orion for the same price. I'm not sure they have a web site, though. You'll of course pay a premium to filter those nifty two inch EPs that I envy so much... dave --- Richard Tenney <retenney@yahoo.com> wrote:
It sounds like so far the consensus is, Orion filters work well; are Lumicon generally considered better? I think I heard Lumicon will be here for ALCon this summer -- do the items they bring for sale usually end up being "seconds"?
Anyway, thanks guys for your input! Rich
--- Chuck Hards <chuckhards@yahoo.com> wrote:
It is important to know that filters don't improve the image wholesale- they just bring out details that are otherwise lost, mostly due to "irradiation"; that is, the tendency for low-contrast details to bleed into one another. If you are expecting something spectacular when using a filter, you will probably be disappointed. There have been times when details invisible with no filter have become obvious with it- but much of the rest of the planet actually suffers. That's the point-removing colors that would otherwise mask a particular detail. Filters are for the details only, not a general enhancer. I use Orion's color filters, not the cheapest on the market, but hardly "top-dollar" either. Brent, one of these days let's get together, maybe I can change your mind on filters. BTW, as our eyes age, our corneas tend to yellow (that's why old ladies sometimes have blue hair- it doesn't look blue to them, but silver) so we eventually get a filter FREE! (Hey, look on the bright side!)
Chuck
--- Brent Watson <brentjwatson@yahoo.com> wrote:
My experience is a bit different than most. I find filters degrade the seeing unless you have paid top dollar for them. My 8" (refractor) has a minus violet filter in it. I don't use anything elso, because they seem to confuste the image too much.
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===== David Moulton dmoulton@rocketmail.com Carpe Ductum __________________________________________________ Do You Yahoo!? Great stuff seeking new owners in Yahoo! Auctions! http://auctions.yahoo.com
Here's the deal: Orion filters are Japanese-made, from optical glass, dyed in-the-vat. Same manufacturer that University has been buying from for decades. Sky Instruments filters are Chinese-made, hence the lower price. I have no data or experience with these filters. They do not have a web-site, last time I checked, which was October. I buy focusers and some refractor-objective lenses and cells from them. I didn't know that Lumicon had a house-brand color filter, but I do use their LPR filters and recommend them highly. Is it possible that Lumicon's color filters are really Meade brand, since they are a Meade dealer? You do not need color filters for 2" eyepieces, in general, since planetary observations are usually made at higher powers, hence eyepieces with 1.25" barrels usually suffice. There are a few exceptions; a light green filter can serve as an ersatz LPR filter, a red filter can be used for B & W photography, acting as a LPR filter and contrast-enhancer. Sometimes comets can benefit from a color filter, though not from my personal experience. For those who haven't discovered Baader solar-filter material yet (poor lost souls), a light blue filter will suppress the orange hue of glass filters, yielding a (somewhat) more neutral hue. (but this is a band-aid. Get the Baader material. Then you can toss the glass filter into your glove compartment for quick solar-checks when on the road. Or use it for a coaster.) Likewise, an orange filter compensates for the blue cast of "standard" Mylar filters. Rich, just borrow some filters before you buy, and see if the effect is worth the expense to you. Chuck __________________________________________________ Do You Yahoo!? Great stuff seeking new owners in Yahoo! Auctions! http://auctions.yahoo.com
Brent, can you send me a quick comment about how cold it was? I'm doing a weather story for the Deseret News. thanks, Joe
Joe, It was DARN cold. When I started observing the thermometer in my truck said 15 degrees. When we put the frost covered scope away at 10 PM the temp was down to 10. I have observed before in temps down to -3. Brent --- Joe Bauman <bau@desnews.com> wrote:
Brent, can you send me a quick comment about how cold it was? I'm doing a weather story for the Deseret News. thanks, Joe
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Thanks, but I was rushed and I already had to send my story in. -- jb
participants (6)
-
Brent Watson -
Chuck Hards -
David Moulton -
Joe Bauman -
Larry Frisk -
Richard Tenney