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Warm VS Cool Tone Eyepieces

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#1 NorthWolf

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Posted 29 December 2012 - 11:54 PM

I remember reading this "Warm and cool tones suggest a couple of things. If you're observing a planet
which reveals color, for example Jupiter and Mars, you will get more color fidelity by observing with a
warmer glass. If you are observing more pale or opaque objects, for example the Moon and Saturn, do to
the haze of ammonia ice crystals in its upper atmosphere, then you would probably be better suited
observing with a cooler glass to achieve the best transparency at higher magnifications since there isn't
all that much color to lose anyway depending on the aperture of your telescope." Link: http://www.cloudynig...ryeyepieces.pdf

And was thinking how my Pentax XW 5 used to give amazing cool white visuals of the moon and saturn. I just wanted to know which popular eyepieces these days are considered warm toned (Which are great too of course) and which are considered cool toned?

#2 GlennLeDrew

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Posted 30 December 2012 - 07:43 PM

Unless the color cast is rather notable, I don't see how it should impact the image to any meaningful degree.

To anyone who has a sufficiently vast collection of eyepieces for comparison, I'd like to see a photo of the coolest and warmest of the bunch. The image should have them side by side, looking through them toward a white target. The focus should be set for the reduced, inverted images, and include the white target in the background (which can be quite out of focus.) The inclusion of very subtly tinted blue and yellow filters would be even more instructive.

Other than the pronounced outliers, most eyepieces deliver a sufficiently neutral color cast as to be if no concern. The small differences cannot amount to what would be considered color filtration. The atmospheric transparency, and the concomitant reddening, can be of greater magnitude.

#3 Sarkikos

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Posted 02 January 2013 - 01:32 PM

FWIW - you decide - here are the list of my eyepices for which I've read comments concerning color tone and that I've verified for myself:

XO 2.5, 5.1 - cool
XW 3.5, 7 - neutral
Radian 4 - neutral-warm (haven't verified for myself yet)
LVW 8 - warm
UO Abbe Ortho (entire line) - neutral
ES 82 4.7mm - warm
BGO (entire line) - neutral
TV Plossls - warm
Brandon 6 to 32 - neutral-cool
Sterling Plossls - neutral
RKEs - neutral
Ultrascopic 35 - neutral

YMMV

Mike

#4 Tank

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Posted 02 January 2013 - 01:52 PM

I thinks its more your cup of tea thing.
As for me i find the so called warm view there is better color saturation to the image than using a cool tone EP.
Best example find a nice open cluster with some rich Carbon Stars(red) have a peak in a EP with the Warm tone and then the cool tone EP you should see a significant difference.
Cool tone the Carbon stars will look pale and the the Warm EP the stars will look vibrant.
Planetary is similar i find the Warm tone EPs tend to bring out the major features on the planets surface while the cool tone does a bit better on the subtle detail.
But bottom line is the quality of the EP.

Speaking of tones i have a few scopes and been thru a few scopes and testing and looked thru many also and i feal the scopes dictates alot as to what tone your getting.
I never seen a cooler tone than thru my 180 MAK and a Intes mak that my friend Mike owns has a really warm warm tone.
I dont have any issue with either warm or cool view i actually like both.

#5 BillP

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Posted 02 January 2013 - 02:05 PM

I'd like to see a photo of the coolest and warmest of the bunch. The image should have them side by side, looking through them toward a white target.


Glenn,

Unfortunately, what a camera sensor will record is a far cry from what an individual will "see". We all have different sensitivities to various colors...and a camera sensor does not in the 1st place even record how the average "normal" human eye sees anyway. As example, an observing friend of mine thinks Saturn looks like a "white" star naked eye. To my eye it's very yellow-orange. So we are all very different.

I personally find there is a warm/cool relationship for some eyepieces...and Barlows as well. Yes it is subtle and no where near what a color filter produces. However, even though subtle the impacts are there if one looks in the right places. On Lunar observing I find there being a very very slight advantage to warmer toned eyepieces as they deepen and darken some of the subtle maria features, however they also color the white ejects very slightly which I find a disadvantage aesthetically. On planetary I find it more of an issue as the warmer toned eyepieces mask many of the subtle colors and color/hue changes in the polar regions of Jupiter and Saturn, which I particularly enjoy observing. Similarly on Mars, I find the warmer toned eyepieces mask the limb haze and make it less pronounced. Yes these are all subtle things and not something most newbies would even care about. But for long-time observers who might enjoy more technical observing it can matter.

I also think however, that subtle trasmission differences might fool one into thinking one eyepiece may be warmer as well. So the "tone" may not be tone in some instances. An example of where I feel this was happening was using a 6mm UO Volcano and a 6mm UO HD side-by-side observing the Moon and some planets. The NOT fully multicoated UO Volcano always gave the impression of a warmer tone compared to the HD. I spent a lot of time critically examining all the places this happened and after evenings of ferreting it out, I was pretty much convinced that the Volcano was showing a very slightly less bright image, and concluded this was the likely driver vs any tone difference. At any rate, over time I have noted how slight brightness differences can fool the perceptions into thinking warmer tone is happening.

An interesting experiment I did with Mars one evening was to use the same eyepiece to ensure that at least that was leveled, then used two different premium 2-element Barlows. I validated with a bench test that both Barlows were producing the exact same magnification factor with the eyepiece to eliminate any possible image brightness difference due to that (actually had to offset the seating of the eyepiece in one of them to achieve equivalence). Then observed Mars with that one eyepiece using 2 different Barlows. Was amazed at how much tonal difference there was to see between just the Barlows!!

#6 t.r.

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Posted 02 January 2013 - 02:26 PM

If you're observing a planet
which reveals color, for example Jupiter and Mars, you will get more color fidelity by observing with a
warmer glass.


No. Fidelity's definition in short is "true or faithful". Warmer tone eyepieces donot show truer colors. They darken the colors artificially, making it appear more saturated and more "colorful" and warmer. But it is false. The view may very well be enjoyable and I like it too, but it is not natural planetary lighting. Neutral tone eyepieces tend to show true natural "white light" colors unaltered. This would be the choice for a fidelity eyepiece. Cool tone eyepieces will favor the blue end of the spectrum slightly, making objects appear cooler or slightly bluer.

Now each eyepiece tone will have its merits and you've got the uses above correct. Mars and Jupiter details are enhanced by warmer eyepieces to a degree, but NO additional details will be present, jusst presented in a warmer, different manner. Some people prefer the sterile white views that neutral or cool tone eyepieces provide as being faithful to what is really there...hence, presented in fidelity! Keep in mind, these differences are subtle and many cannot see any differences at all due to eye physiology!

#7 Sarkikos

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Posted 02 January 2013 - 02:27 PM

Tony,

As for me i find the so called warm view there is better color saturation to the image than using a cool tone EP.
Best example find a nice open cluster with some rich Carbon Stars(red) have a peak in a EP with the Warm tone and then the cool tone EP you should see a significant difference.
Cool tone the Carbon stars will look pale and the the Warm EP the stars will look vibrant.


I've seen that effect with my LVW 8 (warm toned).

Mike

#8 Sarkikos

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Posted 02 January 2013 - 02:32 PM

Bill,

On Lunar observing I find there being a very very slight advantage to warmer toned eyepieces as they deepen and darken some of the subtle maria features, however they also color the white ejects very slightly which I find a disadvantage aesthetically.


I'm starting to think that for lunar maybe a warm eyepiece is better for albedo features, but a neutral-cool eyepiece is best for stark white-black contrasts, such as near the terminator.

Most observers who comment on it tend to prefer neutral-cool eyepieces for lunar. Maybe that's because most lunar observers spend most of their time observing close to the terminator? :thinking:

Mike

#9 t.r.

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Posted 02 January 2013 - 02:37 PM

Interesting Mike, I do find just the opposite for myself. I prefer neutral or cool tone eyepieces to show the albedo differences on luna, whites, grays, blacks, while I prefer the warmer tones such as provided by TV plossls on Mars and Jupiter.

#10 Sarkikos

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Posted 02 January 2013 - 02:47 PM

t.r.,

Actually, your preferences closely match mine. I was refering to Bill's predilection for warm-toned eyepieces for viewing the Moon and I noted the specific lunar features he mentioned. I was trying to figure out in my mind why he would have a contrarian opinion opposed to the consensus. :grin:

I really ought to check out the possibility that warm eyepieces (TV Plossls, Radians) are better for albedo features while neutral-cool eyepieces (Brandons, BGOs) are better for white-black contrast on the Moon.

A similar experiment could be done for Jupiter, Saturn and Mars to see the possible advantage of warm vs neutral-cool eyepieces on various features of those planets.

But apparently Bill has already done the field checks.

:grin:
Mike

#11 Glen A W

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Posted 02 January 2013 - 02:53 PM

My Vixen 260 scope gives a the warmest tone I've ever seen, and it is a real killer on Jupiter, the best I've ever seen. But for the Moon or Saturn I much prefer a reflector or Apo.

Some of the cheaper eyepieces vary within apparently identical units. The 26mm Meade Plossl which was included with so many scopes was sometimes very warm, sometimes not. I have a warm one which is a favorite of mine. GW

#12 BillP

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Posted 02 January 2013 - 03:43 PM

Most observers who comment on it tend to prefer neutral-cool eyepieces for lunar. Maybe that's because most lunar observers spend most of their time observing close to the terminator? :thinking:

Mike


I also "prefer" cooler toned eyepiece for the Moon, like others. But I prefer it for aesthetic reasons. The warmer toned eyepiece bring out the maria shadings more starkly to my eye. So they are all easier to see with a warm toned eyepiece for me. But I still prefer the cooler toned eyepiece on the Moon because I like the "look" better, even though it makes some maria features more difficult to pick out. There is no logic to "liking" and "not liking", it's just the way it is. :lol:

On very high contrast starkly lit areas like the terminator, I don't find either advantageous over the other. No real subtlties that I am acustomed to viewing on the terminator, just wealths of contrasty details. For this area I find transmission has the advantage to see into the very dark features and tease out some details...and then I go to extreme magnifications for the very bright areas to dim them down to reveal things hidden in the excessive brightness.

#13 GeneT

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Posted 02 January 2013 - 06:14 PM

This is just my opinion--for me, this is a non issue. I have a variety of 'warm' and 'cool' eyepieces and I have not noticed any difference in the ability to resolve detail in either planetary or stellar images. There are some posts in this thread that detail a variety of eyepieces with the different tonal differences. Some are reporting that the Delos has among the 'whitest' images.

http://www.televue.c..._2011NovDec.pdf

http://www.televue.c...b=_rev#201112AS

#14 GeneT

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Posted 02 January 2013 - 08:05 PM

Mars and Jupiter details are enhanced by warmer eyepieces to a degree, but NO additional details will be present,


Well said.

#15 Sarkikos

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Posted 02 January 2013 - 09:45 PM

But similarly to filters, warmer eyepieces can make some details easier to see. If a specific eyepiece tone or particular filter makes a feature easier to see, it will be more obvious to the observer, even though the same feature can be seen through a neutral-cool toned eyepiece or filterless with more effort.

It is definitely not a matter of the warm-toned eyepiece or contrast/color filter increasing resolution of details. That is not what happens. In fact, that is impossible. The details are just made more obvious and easier to discern.

Mike

#16 t.r.

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Posted 03 January 2013 - 08:59 AM

As Bill said, we are talking about aesthetics or more to the point, presentation. On occassion, a new detail, not seen in another tonal eyepiece may emerge...but IME it is the exception, not the rule. Most of the time, if you go back to the other eyepiece, the detail is there, just not noticed because it was not "enhanced" by the tonal qualities of said eyepiece. To me, the biggest difference seems to come from the overall quality of the eyepiece itself due to other factors...polish, coatings, glass etc. But, I certainly wouldn't be without both my warm and cool eyepieces! Just as I wouldn't be without my narrow, wide-angle and mega-wide angle eyepieces...it's all in how I want to "present" my subject for observation. But it is a luxury, not a necessity! ;)

#17 BillP

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Posted 03 January 2013 - 10:05 AM

As Bill said, we are talking about aesthetics or more to the point, presentation. On occassion, a new detail, not seen in another tonal eyepiece may emerge...but IME it is the exception, not the rule. Most of the time, if you go back to the other eyepiece, the detail is there, just not noticed because it was not "enhanced" by the tonal qualities of said eyepiece.


I agree. It is mostly a matter of presentation. The only place where I have readily seen detail there or not there has been in the colors present and the fine hue changes in the colors in the polar regions of Saturn and Mars. With a warm-toned eyepiece some of the distinct colors and variations will simply not show because they have gotten masked by the tone. Moving up in aperture may negate this, but certainly in my 4" scope they will vanish away. I think many of the differences people see, or don't see, might sometimes be a function of scope aperture as well. IME the characteristic changes in the views between two eyepieces varies depending on the aperture of the scope because the image the scope is presenting is fundamentally different (resolution, brightness, contrast).

As another point though, yes for the most part it may be a presentation issue, but that does not mean it is not vital! Afterall, I can serve you your cheesesteak with the melted cheese mostly pouring out of the roll and now on the plate, the steak pieces half in and half out of the roll, with the edge of the roll sitting sloppily against a mount of ketchup. Or it could come to you nicely presented without slop. Both are cheesesteaks, but I know which one I would rather have. btw, the the more neatly and constructed presentation one is a cool-toned cheesesteak :lol:

#18 GeneT

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Posted 03 January 2013 - 04:12 PM

To me, the biggest difference seems to come from the overall quality of the eyepiece itself due to other factors...polish, coatings, glass etc.


Agree!

#19 NorthWolf

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Posted 03 January 2013 - 11:39 PM

Very interesting answers... t.r's answer to fidelity makes good sense in many ways.
How would cool, neutral and warm ep's differ on DSO's such as: Nebulas, Double Stars, Variable Stars, Galaxies and other objects. Which ep is best in your eyes for which object and why?

#20 junomike

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Posted 04 January 2013 - 08:16 AM

Some eyepieces can make bright Stars more esthetically pleasing. I find the TV Plossl has a certain color saturation that enhances a Stars natural color.
I`ve read that the Brandon`s exhibit a similar effect.

Sometimes I prefer this and other times I prefer the neutral tone of my XW`s.

Mike

#21 BillP

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Posted 04 January 2013 - 10:10 AM

How would cool, neutral and warm ep's differ on DSO's such as: Nebulas, Double Stars, Variable Stars, Galaxies and other objects. Which ep is best in your eyes for which object and why?


I have only noticed the tone having impact on Moon, Planets, and to some degree colorful stars (either enhancing or subduing their color). On general stars, galaxies, nebula, clusters, I have not noted any impact. Of course I have not ciritically examined if there is any impact for these objects because of tone, and would not expect there to be really since the light level is so low that color vision is not operating, particularly for galaxies and nebula. But the bottom line is how it affects Person-A's eyes will not necessarily be the same on how it impacts Person-B's eyes because we all perceive colors a little differently and to different degrees. So each person really needs to assess for themselves if an eyepiece is producing any tone for their eyes. I have also found it is near impossible to determine from the eyepiece alone, and only becomes obvious when comparing two eyepieces that happen to be tonally different. This whole area is also very subtle in nature...so it is about some very subtle differences in eyepieces, that is only important IMO for those who want to get into that depth of observational nuances. Kind of like the "shaken" vs "stirred" difference for a martini...it's there, but only important for those who enjoy geting down to these subtle levels with their observing.






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