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b******y
发帖数: 107 | 2 Hi all,
I have some questions about the phase distortion of filter.
For a linear phase filter, if it has phase response phi =-k* omega where
omega is the frequency . Its group delay (the neg derivitive of phi to omega
)and phase delay (the neg of phi divided by omega) are both k. There is no
phase distortion among frequencies.
If phi = -k*omega +c. The group delay is still k and it is still called
linear phase filter. However its phase delay is not a constant. Will it has
phase distortion among |
|
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l****z
发帖数: 29846 | 4 Barney Frank continues distorting the truth on his role in the financial
crisis
By Peter J. Wallison
December 29, 2011, 11:03 am
Soon-to-be former Congressman Barney Frank continues to try to defend his
record on Fannie and Freddie by distorting, or simply reversing, the truth.
Here he is in the TheAtlantic.com today on his history as he hopes we will
remember it:
In 2004, the administration of President George W. Bush began a
conscious plan of trying to increase levels of homeownership as p... 阅读全帖 |
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w*****e
发帖数: 2419 | 5 看了photozone和digital picture的数据，感觉21-24mm端就基本是distortion free，
真实情况是这样么？corner基本看不到distortion？上图吧。 |
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a***y
发帖数: 19743 | 6 http://blogs.computerworld.com/17750/opinion_google_beats_apple
Google spent millions lobbying Washington last year -- more than Apple,
Yahoo and Facebook combined.
Google's no angel
Briefly, I cannot believe that one of the world's biggest corporations is as
pure as its public image suggests. I don't even believe that of Apple, and
I'm an Apple-holic. Why would I -- or anyone -- believe that any corporation
is inherently "good"?
Some may recall Consumer Reports. That title launched a tirade of ... 阅读全帖 |
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i*******m
发帖数: 580 | 7 今天去配眼镜，眼镜店里面的人说，
我现在戴的是 High Index 的眼镜，
换成 Polycarbornate 会造成 DISTORTATION。
有道理吗？ 会一直这样，还是一段时间后DISTORTATION
会消失 |
|
w*******y
发帖数: 60932 | 8 Marshall Guv-nor 2 distortion effects pedal for electric guitar $20 shipped.:
http://www.samash.com/p/Marshall_The Guvnor Distortion Pedal_-49979421
What more can I say? Happy y'all.
|
|
m****e
发帖数: 118 | 9 【 以下文字转载自 Military 讨论区 】
发信人: mylife (mylife), 信区: Military
标 题: Media Distortion: 英文主流和非英文媒体对对看
发信站: BBS 未名空间站 (Sat Nov 14 22:14:43 2009, 美东)
1) 例子一
"Briton victim after street attack in Switzerland"
原始新闻是swedish
a) original Swiss source: "Der 23-j?hrige Mann aus Tibet hat inzwischen
ein Gest?ndnis abgelegt"
http://www.zisch.ch/navigation/top_main_nav/nachrichten/zentralschweiz/luzer
n/detail.htm?client_request_className=NewsItem&client_request_contentOID=297
680
放狗翻译成英文意思是：
"The 23-ye |
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m**********n
发帖数: 27535 | 10 http://news.yahoo.com/dalai-lama-west-distorting-protests-tarni
China has ruled what it calls the Tibet Autonomous Region since Communist
troops marched in in 1950. It rejects criticism that it is eroding Tibetan
culture and faith, saying its rule has ended serfdom and brought development
to a backward region. |
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W*******n
发帖数: 4140 | 11 The Evil Distorts Almost Everything, Even Library Account Records
01/17/2017
Limin Wang
Some humanscum was manipulating the record of my library account. I clearly
renewed the items on time, and today I found out those items were shown as
overdues for two whole weeks and got fined.
Think about what the evil can not do to hurt people. |
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j******t
发帖数: 65 | 12 怎么那么厉害？
刚入的D90 + 18-105套头, 又入了个35G 1.8
昨晚对比了一下，35G distortion control居然连套头的不如。。。 |
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w*****e
发帖数: 2419 | 13 大家看看这个24mm边角distortion如何？ |
|
w*****e
发帖数: 2419 | 14 难道这种不算distortion？如果把人放到这些位置一样还是变形了。 |
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g********9
发帖数: 339 | 15 我用50 1.4,发现还是有distortion 的。 |
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f*******e
发帖数: 4531 | 16 看了几篇肯大嘴的镜头review，发现很多著名的头都有不同程度的distortion，24-105
尤其厉害，这个问题大家是怎么处理的，需不需要每副照片都要用Photoshop处理一下？
另外，看了不少头，现在对炮厂15-85感兴趣，请大家评论一下，什么价位比较合适？
谢谢 |
|
f*******e
发帖数: 4531 | 17 确实考虑过以后升级的可能性，从这点看24-105确实不错，就是对于distortion问题有
些纠结，所以来请教一下。 |
|
f******l
发帖数: 70 | 18 COLORADO SPRINGS, Colo. - As Barack Obama broadens his outreach to evangelic
al voters, one of the movement's biggest names, James Dobson, accuses the li
kely Democratic presidential nominee of distorting the Bible and pushing a "
fruitcake interpretation" of the Constitution.
The conservative Christian group provided The Associated Press with an advan
ce copy of the pre-taped radio segment, which runs 18 minutes and highlights
excerpts of a speech Obama gave in June 2006 to the liberal Christia |
|
H*******n
发帖数: 5 | 19 真是要命，要用有限元软件包计算一块薄板由于温度不均匀引起的thermal distortions,
但是我几乎没有什么材料力学的背景，只知道计算温度场要用laplace equation. 在网上
google了半天，查到The equations of thermal diffusion and plane strain need to
be solved simultaneously to give the thermally-induced stress and deformation.
请问计算stress和deformation的公式的具体名称和形式，另外我的问题是不是可以简化
为
2维的问题（z方向的stress和deformation可以忽略）？如果大侠能告知应该参考哪些参
考书，那就愈加不胜感激了！ |
|
h******l
发帖数: 112 | 20 thermal stress is the addition to the normal stress, you can check the
elasticity book
distortions,
网上
to
deformation.
简化
些参 |
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r****n
发帖数: 163 | 21 i remember that plain stress simplification and plane strain simplification
could not be adopted simultaneously.
anyway, i guess you should check the linear elasticity book.
distortions,
上
to
deformation.
化
参 |
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c*m
发帖数: 40 | 22 恐怕不能说多薄就可以简化为平面应力问题。而是看其他两维上的长度和厚度相比有多少
倍。比如，10倍应该足够大了。
其实计算这个问题不需要知道许多理论公式，因为你是用软件包来计算的。以ABAQUS为例
，只要把网格建好，把传热过程和应力过程模拟出来就可以了。
这个问题包括两个过程(process), which are thermal process and mechanical
process. 如果两个过程分开算，就叫decoupled，合在一起算就叫coupled。coupled算起
来麻烦，一般跟decoupled也差不了多少，所以多数人都是用 decoupled model.
估计你是学heat transfer的，那么模拟thermal 过程应该没问题。模拟mechanical过程
也很简单，就事用同样的网格，把温度场当作一种load输进去就可以了。当然要注意定义
好它的材料参数，最好是 temperature dependent 的，否则算的可能差别很大。
凑巧我就是做类似东西的。有不明白的可以再问。
distortions,
网上
to
deformation.
简化
些 |
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s*********9
发帖数: 56 | 23 谁能给推荐一下有关cognition distortion 方面的心理书?
一时找不到合适的心理医生，想找一下有关这方面的书先自我治疗，哪位专家能给推荐
一下?谢了。 |
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c**r
发帖数: 10001 | 24 the feeling good handbook前面一两章都是讲distorted thoughts的，后面是一些
更具体的应用。 |
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D**********s
发帖数: 3139 | 25 音量控制对音质的影响，以前有一篇note写得不错，我找了半天才找到，其实还有用变
压器的方法，不过dac这块最保真的方法就是保持位深和标准输出电平，音量控制交给
前级和功放去管就好了，终究绕不过模拟放大这一关的。
Volume Control Technologies
Newsletter Edition:
July 2009 Issue
With the introduction of Benchmark’s HDR-VC™ (High Dynamic Range
Volume Control), many audio enthusiasts are taking another look at volume
control methods. What are the differences between the different volume
control topologies? Is one sonically superior, and why?
The important qualities to consider with respect to volum... 阅读全帖 |
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f**d
发帖数: 768 | 26 这是一本计算神经科学的优秀著作，全文拷贝这里（图和公式缺），有兴趣的同学可以
阅读
如需要，我可以分享PDF文件（－－仅供个人学习，无商业用途）
From Computer to Brain
William W. Lytton
From Computer to Brain
Foundations of Computational Neuroscience
Springer
William W. Lytton, M.D.
Associate Professor, State University of New York, Downstato, Brooklyn, NY
Visiting Associate Professor, University of Wisconsin, Madison
Visiting Associate Professor, Polytechnic University, Brooklyn, NY
Staff Neurologist., Kings County Hospital, Brooklyn, NY
In From Computer to Brain: ... 阅读全帖 |
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g*********r
发帖数: 9366 | 27 ☆─────────────────────────────────────☆
Synix (坚持到底) 于 (Fri Apr 15 12:37:15 2011, 美东) 提到:
在交易成本很低的时候，民主也就是政治权利归属私人，可以通过交易协商来达到均衡，这样社会效益最大。民主有用的critical前提就是交易成本足够低，这个需要用法律制度来保障,这套制度用最小干涉原则，只设置必要规范。美国300年的民主实践建立了一套不错的法律制度，而
篮竦牡卦嫡翁跫脖Ｕ狭苏馓字贫炔换岜煌饫戳α克蚱啤Ｋ悦裰髟诿拦某晒κ羌浜奔奶乩枰奶跫腥觯.几百年的制度建设。2.相对独立的地缘政治条件。前者保证了较低的交易成本，而后者保障了交易的内部化，即利益集团不太会和外部力量进行交易，因为br />
益不受内部制度管制，所以和外部的交易容易导致系统崩溃。
中国的情况首先不满足第二条，即无法阻止和外部利益的交易，第一条则需要第二条先满足，然后长期的制度建设加强内部均衡。两者都不满足的前提下，政治权利归属个人会造成社会最优解无法实现，从而发生灾难性后果，在交易成本极大的时候根本不会有均衡，而是连绵不断的战
... 阅读全帖 |
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x****c
发帖数: 25662 | 28
For distortion, I don't think N+ is better.
For 24-70G
At 24 mm the lens shows a significant amount of barrel distortion
reaching almost 3 %. The distortion flips over to the pincushion type at
40 mm and with roughly 1 % can be an issue with certain subjects. At 70
mm the pincushion distortion is down to 0.5%, which can be considered
distortion-free for most photographic applications.
for 24-70L
The distortion characteristic is above average for a lens in this class.
Th lens produces a pronounc... 阅读全帖 |
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l****z
发帖数: 29846 | 29 Senate Liberals Narrowly Lose Bid to Reverse SCOTUS Religious Freedom
Victory
via Breitbart Feed
Senate liberals--a mix of almost all Democrats and a few Republicans--missed
by a hair last week in a bid to overturn the Supreme Court’s Hobby Lobby
decision, which ruled unconstitutional the Obama administration’s heavy-
handed requirement that business owners provide abortion services for
employees, even in violation of their constitutionally protected religious
beliefs.
As reported by Politico:
... 阅读全帖 |
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c********r
发帖数: 562 | 30 From Keith Fitz-Gerald who recommended the stock:
How to Handle a Short Attack on a Stock You Own
Keith Fitz-Gerald Jun 03, 2015
An anonymous individual writing under the name “The Pump Stopper” launched
a vicious attack on Ekso Bionics Holdings Inc. (OTC:EKSO) yesterday that
immediately pressured the stock and caused it to drop 24.28% to close at $1.
36 a share on heavy volume. Understandably, that makes a lot of people
nervous.
Here’s the thing, though.
If you’ve been in this game long enough,... 阅读全帖 |
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O*******e
发帖数: 6055 | 31 据说好像是 麦克抗压大 = 录音不容易过载，可能我理解有误哈。
俺的理解，就是指麦克的振膜能承受的最大强度的声源冲击而不导致录音失真。比如说
录鼓啥的。这里强调的是振膜物理上的handle能力，不是指录音的输入音量。
而且，SPL值一般在130 - 150之间，这个是人声根本不可能达到的。
虽然超过了这个SPL值也会导致削顶，但这个是指音源的音量超过振膜能力导致的，和
输入音量高导致的过载不是一回事。
所以，SPL貌似和录音是否过载木有关系哇？尤其是录人声的时候，怕过载也只能是调
低输入音量了。
“The maximum SPL the microphone can accept is measured for particular
values of total harmonic distortion (THD), typically 0.5%. This amount of
distortion is generally inaudible[citation needed], so one can safely use
the microphone at this SPL with... 阅读全帖 |
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w*********g
发帖数: 30882 | 32 美国所谓的制造业回流与复苏原来又是吹出来的泡泡
来源: nWAY 于 2012-02-01 23:13:54 [档案] [博客] 旧帖] [转至博客] [给我悄悄话
] 本文已被阅读：433次
字体：调大/调小/重置 | 加入书签 | 打印 | 所有跟帖 | 加跟贴 | 查看当前最热讨
论主题
http://ablog.typepad.com/keytrendsinglobalisation/2012/01/myth.
The myth of US industrial revival
by John Ross, 31 January 2012
Currently a number of attempts are being made to claim a major revival of US
industry is taking place. For example Harold L. Sirkin, of the Boston
Consulting Group, writes: ‘A resurgence of U.S. manufacturing seems to be
in ... 阅读全帖 |
|
|
B*V
发帖数: 3365 | 34 美国所谓的制造业回流与复苏原来又是吹出来的泡泡
来源: nWAY 于 2012-02-01 23:13:54 [档案] [博客] 旧帖] [转至博客] [给我悄悄话
] 本文已被阅读：433次
字体：调大/调小/重置 | 加入书签 | 打印 | 所有跟帖 | 加跟贴 | 查看当前最热讨
论主题
http://ablog.typepad.com/keytrendsinglobalisation/2012/01/myth.
The myth of US industrial revival
by John Ross, 31 January 2012
Currently a number of attempts are being made to claim a major revival of US
industry is taking place. For example Harold L. Sirkin, of the Boston
Consulting Group, writes: ‘A resurgence of U.S. manufacturing seems to be
in ... 阅读全帖 |
|
B*Z
发帖数: 7062 | 35 THD = Total harmonic distortion
The total harmonic distortion, or THD, of a signal is a measurement of the h
armonic distortion present and is defined as the ratio of the sum of the pow
ers of all harmonic components to the power of the fundamental frequency. TH
D is used to characterize the linearity of audio systems and the power quali
ty of electric power systems.
In audio systems, lower distortion means the components in a loudspeaker, am
plifier or microphone or other equipment produce a mo... 阅读全帖 |
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a***a
发帖数: 40617 | 36 夜读春秋
对比了ZM和G头的MTF，失光，distortion，简单发言几句
（先说句废话，蔡司就是蔡司，所有镜头的说明书和官方网站都提供了mtf
失光，还有distortion，特别是distortion，这个在其他厂商的data sheet中是比较少
看到的。可见蔡司是多么自信。。。试问如果这些东西都不优秀的话，它敢腆着脸皮
贴吗。。。）
1。大部分ZM头的resolution比对应的G头优秀，但是优秀程度有限（因为G已经非常好
了）
这一点，ZM的设计者曾经非常牛x的说过，不要怀疑ZM头的分辨率，他们自信已经超过了
现有的所有胶片
2。大部分G头对distortion的控制好于ZM头，有的很悬殊，如G16 pk ZM15，前者0％，
后者最多将近4％
有的不算太悬殊，如一些1％ vs 2%的，但是总的来说，G头好于ZM
3。相比之下，大部分都打平手了，综合来看。但是，有一个头ZM完胜了G头，就是ZM35
其实，也是biogon pk planar的结果，biogon果然在distortion上完胜，同时无论是
f/2还是f/4的分辨率都有比较大的提高。基本上ZM35是我看来两个系 |
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t*******f
发帖数: 2634 | 37 狗头 does not worth much, but convenient and light weight for casual
shooting. Sometimes I only take D60+35G and 18-55 in the notebook
bag to go with me everywhere. Before D60, I usually carried N70+
50/1.8D and 35-80.
35/1.8G large distortion but sharper.
35/2.0D less distortion + FX, but not as sharp
50/1.8D almost distortion free, want to keep.
50/1.4D large aperture
50/1.8G sharp, but relative large distortions
50/1,4G - do not want it for its distortions too large for 50mm. |
|
d***a
发帖数: 13752 | 38 软件纠正的是lens distortion，不是perspective distortion
用广角镜头的一个问题，是广角镜头的barrel distortion一般比较严重
perspective distortion，是不用去纠正吧
5D3相机里有纠正lens distortion的功能，不知道是不是有什么副作用
这是我想问的问题 |
|
w*******y
发帖数: 60932 | 39 Energy ESW-M8 1200 Watt Subwoofer (Black):
http://www.wwstereo.com/Energy/ESW-M8
for $249.99 + Free ShippingApply Coupon Code = POW123
Detailed Specs:8-Inch Aluminum woofer and dual 8-Inch Aluminum Passive
woofers
Patented Ribbed Elliptical surround suspensions for greater output & lower
distortion
1200 watt Dynamic custom matched amplifier for clean and deep bass down to
42hz
Rigid, low-distortion MDF enclosure with High Gloss piano black lacquer
finish
Variable Crossover and Phase Control to b... 阅读全帖 |
|
S***x
发帖数: 2382 | 40 我说了，这个问题无法用理论回答，专政用得好是维护所有人利益(这取决去对某些关键变量的设定，当然也与决策人有极大关系）。用得不好则会造成
大的distortion。当然distortion总是存在的，因为对于未来市场无法准确判断。而这个distortion和高交易成本下的民主造成的distortion谁更大，不是
理论问题，而是一个empirical问题，只能用过去的经验数据来推断。 |
|
C*****H
发帖数: 7927 | 41 ☆─────────────────────────────────────☆
dumbCoder (HumbleCoder) 于 (Tue Jan 15 13:53:47 2013, 美东) 提到:
经常看到有怀疑古希腊文明有水分的帖子
http://bbs.tianya.cn/post-no01-458848-1.shtml
我是菜鸟，请版上高人指点。
☆─────────────────────────────────────☆
yenite (燕岭悲歌) 于 (Tue Jan 15 16:11:29 2013, 美东) 提到:
呵呵，要怀疑先看看原著吧，否则会闹些特洛伊不是希腊的笑话。。。
btw，为啥国内突然兴起了一股质疑希腊罗马的风气，而且还是一帮对希腊罗马没啥了
解的人？
☆─────────────────────────────────────☆
maywind (五月风) 于 (Tue Jan 15 16:31:59 2013, 美东) 提到:
这叫两手都要硬
☆────────────────────────────────────... 阅读全帖 |
|
l****z
发帖数: 29846 | 42 Meddling Renewable Energy Standards Distort Energy Markets, Raise Prices
By Joe Nichols | August 10, 2015 | 3:06 PM EDT
Environmental groups scorn state leaders who dare question the sanctity of
renewable energy mandates, commonly known as “renewables portfolio
standards” or RPS. Such scorn is misplaced and state leaders should
continue to reconsider the wisdom and value of these mandates.
RPS laws typically require electric utilities to purchase specific
quantities of electricity from renewabl... 阅读全帖 |
|
f****i
发帖数: 20252 | 43 时钟抖动也会带来distortion，振幅量化也引起distortion，但是这两者得分开来
举个例子说，时钟抖动导致-100dB的distortion，振幅量化导致-80dB的distortion，
你总不能把这个-80dB算到时钟抖动上头吧。 |
|
l******g
发帖数: 6771 | 44 新手，最近看看音响,看看电影，唱唱卡拉OK，人笨不太会考古搜精华，所以就放狗搜
，看到这个深入浅出，转到版上分享一下，抛砖引玉。。。
http://thecreativealternative.com/best-home-theater-receiver-gu
#####################################################################
AV Receiver Guide – Home Theater
Posted on April 14, 2013 by mychaelp
Check out some of the latest models with 4K Ultra HD compatibility now
included in this AV Receiver Guide for Home Theater
The A/V Receiver… Some have referred to this device as “The “Heart of the
Home Theater”. And for good reas... 阅读全帖 |
|
t*******f
发帖数: 2634 | 45 I have had 35/1.8G since it came out. It is good
in many ways: cute design with the little hood,
sharpness, large aperture, light weight, "standard"
lens for D80. I like it very much. If I want low
weight for just one lens, I use it. For many trips,
I put it on D90 and carry them with notebook and GPS
in my notebook bag.
However, it has pretty large geometric distortion.
But you may either correct it or do not shoot straight
lines (for example, buildings) -- well, you may feel
OK with distortion... 阅读全帖 |
|
j***y
发帖数: 5098 | 46 ☆─────────────────────────────────────☆
tulipwolf (土狼，秃尾巴狼, 秃 18 Wolfy, 图例玻列夫) 于 (Thu Jun 16 15:43:17 2011, 美东) 提到:
最近几天双脚脚跟疼，后面，不是底下。鞋应该没问题。
是不是要减跑步的运动量乐？
可是我腿上肌肉从不酸痛。所以好象还没有达到刺激肌肉
的强度。难道是我太胖，需要饿瘦十磅再说？年轻的时候
都是肌肉不顶，没有这些烂毛病。
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Mutu (Camoranesi) 于 (Thu Jun 16 15:47:29 2011, 美东) 提到:
是不是鞋磨的？
美川袜子？
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tulipwolf (土狼，秃尾巴狼, 秃 18 Wolfy, 图例玻列夫) 于 (Thu Jun 16 16:05:17 2011, 美东) 提到:
是里面，可能是肌腱。
☆────────────────────────... 阅读全帖 |
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l*******g
发帖数: 4894 | 47 在说器材前，说说我自己，我，一个宅男，对于计算机有点小热爱，对于器材有大热爱
。想想自己也近中年，不成家不立业，沉迷于音乐似乎有不对，以前堂而皇之为艺术献
身，献了好几年，艺术不要我，现在人老珠黄了，没人要了，便从了个姑娘，自此更少
和朋友们出去混了，大多数时间都交代在电影院和奔波的路上了，冷落了我家里的在艺
术道路上纳下的各房小妾。每次想到此，心中不忍，和小妾们亲热一会，每次甚密之时
必是我家姑娘生闷气欲动肝火之时，再后来要纳新妾，必先进行三省五省，再之后这事
自然提都不敢提，于是器材控只能作罢，只能过过嘴瘾，且有了下面这篇文章。
先不说琴也不说效果器，先说音色。说喜欢谁的音色，就买谁的设备，然后按照书上写
的调，再后来看了和听了若干的现场，发现基本上有人就拿了把破琴和一个破vox出来
非常好的效果，也有大牌演出每场效果都不一样。其实也不用迷信大牌，linkin park
的现场就音效不好，system of a down也乱的一塌糊涂，不过小场地演出，joe
satriani就音色超赞。总结来总结去，发现自己想找的音色其实也不固定. 从设备的角
度来说也是不固定。总体来说看看大师们... 阅读全帖 |
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k****t
发帖数: 12697 | 48 中文模糊不清.
ENGLISH的话, 就是GEOMETRIC PERSPECTIVE.没DISTORTION 说.
DISTORTION 就是BARREL DISTORTION 跟PIN CUSHION DISTORTION
这第一图17拍不出. 14 到15. |
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e**n
发帖数: 5876 | 49 才发现dxo一直在用机身矫正变形之前的数据测m43头.
according to photozone
25 1.4 矫正之前distortion 2.73%, 矫正后0.04%
30 f2, 不矫正. 1.2%
dxo的测试,
25 1.4 distortion 1.5%
30 f2. distortion 0.5%
明显dxo用的矫正之前的distortion. dxo这个测试对谁有参考价值? 对于买相机是
用来照相的人来说没意义, 但对非要在犄角旮旯里找一个不支持矫正的raw解码软件的
人有重要价值. |
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x****y
发帖数: 1853 | 50 Really? 不过 21 zm 跟24L不好比吧。 广角差一毫米差很远的。 更何况是旁轴和单反
的比较。
Ken大嘴的评价，且当笑话看看：
Distortion performance top
The Zeiss ZM 21/2.8 has no visible distortion. This is better than the LEICA
ELMARIT-M 21mm f/2.8 ASPH or Voigtländer 21mm f/4. The Voigtlä
nder has a little barrel distortion, and the LEICA ASPH has a bit of bulging
distortion in the center of its image. Even shooting brick walls, this
Zeiss ZM 21 2.8 is flat. |
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