INTANE OPTICS BLOG

Scientists in a US university have developed a special coating that increases the energy efficiency of solar cells by about one-and-a-half times.

A Northwestern University research team found that energy from sunlight falling only on a patch of the Mojave Desert is enough to power all of the US - if it is tapped efficiently.

The operative word, however, is “efficiently”. At present, solar cell technologies are not only inefficient but are also too costly and cumbersome for large-scale commercial and industrial applications.

The researchers seem to have come up with a way to partially overcome this problem.

They have developed an anode coating that boosts efficiency of solar energy power conversion from 3-4 to 5.2-5.6 percent.

This breakthrough promises to bring researchers and developers worldwide closer to the goal of producing cheaper solar cells. It will reduce the dependence on fossil fuels and cut down on carbon emissions.

A paper, focussing on “engineering” organic material-electrode interfaces in bulk-heterojunction organic solar cells, has been published online in Proceedings of the National Academy of Sciences.

The Northwestern researchers employed a laser deposition technique that coats the anode with a nano-thick layer of nickel oxide. The oxide coating is cheap, electrically homogeneous and non-corrosive.

In the case of model bulk-heterojunction cells, the team has increased the cell voltage by 40 percent and the power conversion efficiency from approximately three and four percent to 5.2 to 5.6 percent.

The researchers are currently fine-tuning the anode coating technique for increased efficiency. (IANS)

为了满足爱好者们对摄影的爱好，英田光学最新出品的T 照相机转接环（2” 通用型）可以适用于任何天文望远镜/观景望远镜的2” 接管和M42*1螺牙的照相机T型环。

• 铝制材质，表面采用黑色（哑光）电镀处理。

• 内部采用防反射螺纹设计以降低杂散光，能有效提高影像对比。

• 内有螺纹可接M48 滤镜。

• 还必须使用与您的照相机相配的T型环来连接您的相机

零售价：130元/个 （不含快运费）

The next total solar eclipse will occur on the first of August in 2008. Much of the eclipse path crosses areas of the Earth that are not inhabited or are difficult to reach. Starting near the northeastern tip of Canada the path moves northeast into the Arctic Circle over northern Greenland. It then passes over the Arctic Ocean to northern Russia moving south east into Siberia. Novosibirsk is one major city that the path covers before passing over the Altai mountains into China near the Mongolian border. The eclipse path ends in the middle of northern China.

The weather plays an important part in viewing this eclipse. In early August the ice prevents most ships from going into the regions of northern Greenland plus the weather is extremely variable. The only sure thing is to board an aircraft and get above the clouds. (Check out Glenn Schneider’s web site for details) Northern Siberia does not present a better weather picture however as the path enters the farming regions surrounding Novosibirsk the climate begins to improve quickly for eclipse chasing. One of the better locations is south of Novosibirsk near the northern edges of the Altai mountain range. The mountains themselves present all sorts of difficulties in regard to climate plus travel conditions. The climate improves along the Chinese-Mongolian border with 50% and better chances however travel can be difficult in that region. As the eclipse path ends in China the cloud cover percentages indicate a rapidly decreasing chance of seeing the eclipse.

Analysis of the eclipse path shows that the best locations for land based observation will be along the Chinese-Mongolian border and south of Novosibirsk, Siberia.

The Olympics will be taking place in Beijing, away from the eclipse path. As a result the Olympics should not pose a problem for eclipse chasers traveling to China. The timing works well since the eclipse will be over before the Olympic crowds are expected to start arriving in force.

Welcome to come to China, and welcome to enjoy with us.

Hello,
Any one had the chance to use a Zeiss AS100/1000? I am really interested how good these are (were) as they use an aspheric doublet and one low dispersion schott element.
Any views appreciated, thanks.
Ed
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Hi Ed,
I have no direct experience of the AS100/1000 but I own an AS110/1650, thus I may give you some infos (…Gerd has an AS130/1950 — luck him ! — so he may add his own views…;–)
These are *very* good (that “very good” usually spelled as “excellent”). They don’t really use low dispersion elements, rather a Steinheil design with a leading Flint (KzF2/BK7). One surface is indeed aspherized to correct a residual fifth order spherical aberration in the green part of the spectrum. These AS are conceived as “planetary” instruments, so with a global correction shifted towards the red (which is indeed perfectly focused together with the green) where the more interesting planetary wavelengths are located. This is done at the expenses of the blue part of the spectrum which is heavily undercorrected. So much that this tends to produce almost no blue halo (blue light is too much defocused, so it becomes invisible), but rather a spurious bluish hue in the black sky.
Figure is *extremely well corrected* and *extremely smooth*. These scopes do not break under any reasonable magnification… No gain by using neither a Wratten #8 or a Semi-Apo filter (with this one colors are less warm but I find an induced lessening of both contrast and resolution, not to mention light).
Using a Zeiss binovier brings of course the best views, although I have to confess that most of the times I prefer the purity of the straight-through view where, using Zeiss Orthos, you don’t quite see where the sky ends and the barrel begins…
The AS — conceived by Zeiss as “improved achromats” (what today is usually called semi-apo, whatever that means) — are supposed to have a 50% improvement in the color correction over a regular Fraunhofer BK7/F2 Achromat. In a week time I shall be putting my new AS63/840 (same design as the AS100 and AS110) against both a Telementor (C/63/840, regular Fraunhofer) and a Royal-Astro 60/1200 (idem Fraunhofer). Being f/13.3 +50% equal to f/20, I shall be able to let you know if these claims are true.
But this is just color correction. The rest of the pudding is in the overall correction and smoothness of figure. And here these AS are among the best.
Hope this helps,
Max
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Thank you, I missed a 110/1650 lens in cell recently for sale but now a 100/1000 complete is available in original condition..very tempted.
Ed
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Hi Ed and Max,
I am lucky to have some friends who give me the opportunity to observe with several Zeiss stuff,
but not with a AS 100/1000
My experiences relate to Zeiss
C50/540, E 50/540, C63/840, C80/500, AS 80/1200, C110/750, AS 110/1650, AS 130/1950, AS 150/2250.
Also APQ 100/640, APQ 130/1000, APQ 150/1200
I can show you a table from the archive of Wolfgang Rohr-Germany where you can see something interesting
about the different colour errors of the AS lenses.
Dieter Lichtenknecker, Germany describes in the sixties the colour error with a value,
the RC (Rest Chromasie) which means rest colour error at 1mm exit pupil.
The effective value RCeff is RC/Exit Pupil
In the table color error smaller than the value of 1 means Apochromat.
A value between 1 and 2 means Semi-Apochromat.
A value greater than 2 means Achromat.
A BK7/F2 110/1650 Achromat has a colour error value of 6.7 at 1mm exit pupil.
You can see how well corrected a AS lens is, also the AS 100/1000.
(Ed, your TAK TSA is much better colour corrected)
The AS lens is a invention from August Sonnefeld in 1926.
It was manufactured by Carl Zeiss Jena from 1926 until 1995.
Sorry for my bad English language.
Gerd
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Hi Gerd,
That’s quite an interesting table…!!! Thanks for sharing it…!
Would you please send a hi-res version to my private email address?
Thank you so much !
Max
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Ed,
I had a Zeiss AS100/1000 for many years. The correction and figure of the lens was first class, couldn’t ask for better. As far as the chromatic aberration, there is some. Of the Zeiss AS scopes, I have owned the AS63/840, the AS80/1200 and the AS100/1000. The AS80/1200 had virtually no CA, but the 63 and 100 showed some; conclusion - the short-flint element in the AS lens does very well at f/15. In his landmark article in the Feb. 1963 Applied Optics, entitled “Planetary Telescopes”, James G. Baker called the Zeiss AS lens a semi-aprochromat.; I don’t believe Zeiss ever claimed that. The AS100 is a great scope and you really can’t go wrong with it. The value is going up on these scopes each year and so if you later decide to sell it, you won’t loose anything.
PJ
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Thanks,
I have not been able to find much info on the web on these fine refractors so this really helps.
Ed
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