1- Pending questions about the vision of Uranus banding pattern:
Our eyes are sensitive to contrast level for a given detail size.
This depends indeed from the scope in use (diameter and strehl involved) but also on
the observer itself and the sky conditions (transparency, moisture, dust, seeing).
Our ability is as it is and this is gift received, training can improve such for reaching
our ultimate abilities. We cannot do more.
CCD chipsets has also limits, largely unknown by most users, even prestigious (moreI am investigating in and more I see this).
On visual investigation, we have steps of difficulty for going ahead beyond:-Color of the disk seen: no interest except if declarations makes color still with
2D magnifications even 1D, witness to be discarded,
Vision of the planet limb darkening: a first step,
For 2013, vision of EZ and more the bright collar surrounding the polar cap, asecond level,
Vision of the banding pattern, a third level,
Vision of the banding pattern and albedo variations, a fourth level,
Vision of the brightening and spotting: depends on their own contrasts but say
from the second level and upper.

When doing this scaling, the change of the aperture by say 2 times may involve thepossibility of discovering more, not night and day effect, but substantially from thesecond step well anchored from an observer.
The contrast transfer between a 200mm versus a 400mm aperture remains thefollowing (for a 1% contrast detail on planet and 1” arc band width):-200mm: contrast 0.59% at eyepiece, needs 360x with seeing 7-8/10,
400mm: contrast 0.74% at eyepiece, needs 710x with seeing 7-8/10,
1000mm: contrast 0.88% at eyepiece, needs 1780x with seeing 7-8/10,

for keeping the optimal planet surface brightness and get only 25% more in contrast
level when involving 2 times aperture from 200mm. This may help for merging fromthe noise from an observer to another. These are evaluations but tendency remains
kept.
This is important to consider as still to-day most of people consider this difficulty level
similar to Mars kind of observations, this has nothing to do similar because thequestion wear capability to reach 1-2 % contrast levels, also and even applying toCCD imagers.
When the subject is at a margin, experience, competence and ability prevail, I think
we have to consider accordingly.

2- Expected patterns observable versus wavelengths:
Essentially on 3 spectral segments:-visual: 485 and 619nm methane rays around-NIR: 889nm methane ray around-IR: 1600nm methane ray around.
Images published in IR domain show a banding pattern with hard contrast transitionat the band limits.
Images published in NIR show a banding pattern with hard contrast transition at theband limits (some start to show albedo variation on some part of the planet).
Images published in visual domain show a banding pattern with soft contrast
transition and albedo variations on some part of the planet surface.
Albedo variations exhibited at the margin constitute nevertheless a point to beconsidered seriously.
This is not a mistake to evaluate these albedo variations for the following reason:-IR: this shows the planet status at bottom layers of the atmosphere, closer tothe rocky node of the planet,
NIR: this shows (if the imaging acquisition parameters are well mastered,remains to be proven) the layer at mid depth into atmosphere,
Visual: this shows the status of the upper layer of the atmosphere.

Therefore, albedo variations (brightening observed, soft contrast transitions) could beobserved more and more as the atmosphere layers merge to the outer surface.
This idea is nevertheless pondered anyway when considering that visual domain islead mostly by solar light reflection and atmosphere absorption, IR light is lead mostly
by the planet node emission and atmosphere absorption.
Spots or iced clouds stays at the outer surface and may come from condensation of
the aerosols of the outer atmosphere layers. The association of spots andbrightening (started to be observed visually) constitute a probable scenario.
Indeed, confirmations are needed and when some other can report similarly, can thisbe discarded?
Discussion and comments about are welcome.
Stanislas Maksymowicz.
28th.10.14