s**********s
发帖数: 7387 | 1 你确定？
entrance/exit pupil和aperture不是一回事。
.对 |
|
s**********s
发帖数: 7387 | 2 什么时候你把那个文章找出来再说吧。
收缩光圈，image circle只有增大断无减少之理，要简单说"照不照得到"显然是站不住
脚的。
你要说入射光线角度不对还差不多。我估计其实也就是个裂像黑掉的问题，光圈小了，
exit pupil太小，导致入射角变化范围很小，满足了一侧棱镜另外一侧就会黑，也就无
法对焦了。 |
|
b*********n
发帖数: 5846 | 3 这个sounds reasonable, 也就是说镜头里光圈叶片的位置不同造成exit pupil的位置
不同引起入射光线角度不同，影响了能否最终触发F4的sensors？
a
的v |
|
x****c
发帖数: 25662 | 4 目前我只能这样理解
不同f4镜头exit pupil位置不一样，所以某些可以让光到达f4的line sensors，有些f4
到不了，或者说即使可以，但光量少，vignetting严重，无法触发f4的line sensors |
|
d*****0
发帖数: 68029 | 5 默认前提当然是放大率相同的情况了。刚才打错了，应该是f^2/光圈/crop系数，所以你的20饼干弥散圆直径会更小。
http://photo.net/learn/optics/lensTutorial
If we frame an object the same way with two different lenses, i.e. M is the same both situations, the shorter focal length lens will have less front depth of field and more rear depth of field at the same effective f-stop. (To a first approximation, the depth of field is the same in both cases.)
Another important consideration when choosing a lens focal length is how a distant background point wi... 阅读全帖 |
|
a***e
发帖数: 27968 | 6 pupil dilated too much?
that girl must be a real knockout |
|
t***e
发帖数: 2138 | 7 Red eye flash works with a series of pre-flashes before the actual main
flash. These small flashes lead to a contraction of the pupil and therefore
less reflexion from the retina. In general, the red eye problem is less
pronounced with accessory flash due to the greater distance to the lens.
The anti red eye flash feature is set on the camera, but not every
speedlight is supporting the mode due to the rapid sequence of pre-flashes
used and communication required. The SB-600 is certainly compatib... 阅读全帖 |
|
n**b
发帖数: 13203 | 8 咋解释也没用，反正就是个杯具
"One of my good sources explained why the new Zeiss 24mm f/1.8 lens is so
large: “The large lenses have optics that are usable, with minimal
modification, with SLT cameras. NEX-7 is a high quality photographic tool.
Shorter size lenses would have very short distance of the rear lens element
to the film plane. With small exit lens on wide lenses there would be too
much light fallout. That is why a high quality WA lens needs to be bigger.
The problems with NEsystem. Very short flang... 阅读全帖 |
|
b*****g
发帖数: 2727 | 9 谁用谁知道。
exit pupil 太小，眼睛必须贴得很近，稍微偏一点取景就被遮了。 |
|
b*******t
发帖数: 33714 | 10 入瞳 出瞳 是entrance/exit pupil吗？渐晕是什么？ |
|
t****g
发帖数: 35582 | 11 其实我做的东西挺土的。
先弄个paraxial的模型出来，focal length，pupil之类的搞对了。
然后针对各个paraxial lens去thor, newport，。。。。找接近的。
把真lens装进去，一算，差了10万八千里。然后去掉一个最差劲的stock lens，换
custom design的。再算，还是不行再去一个。
最后把custom design的solidworks画个图，送工厂。其他的去thor下单。 |
|
G**Y
发帖数: 33224 | 12 Patent of the image plane phase difference AF not to degrade the image
quality Canon [semiconductor electronics technology] [edit]
キヤノンが像面位相差AFを用いても、画質が劣化しない撮像素子に関する特許を出願
中です。 Canon patents pending on the imaging device may be used to image
plane phase difference AF, image quality does not deteriorate. この技術なら
、既存のレンズ資産の利用と高速AFを可能としつつも画質の劣化がほぼありませんか
ら、後発であっても他社に負けないミラーレスを出せますね。 If this technology,
since almost no degradation of image quality while still enabling high-
speed AF lens and the use of... 阅读全帖 |
|
b*******t
发帖数: 33714 | 13 变的是pupil function，啥叫光圈没多大关系 |
|
w****g
发帖数: 727 | 14 物理孔径(diameter of the entrance pupil/aperture)
是怎么定义的？ |
|
e*f
发帖数: 1709 | 15 Steiner 7x50 Marine Binocular ------$289.98 from Amazon.com
The amplification 7X is at the upper end of a casual user who won't feel the
shake of his hands. The X50 gives you large exit pupil
50/7=7mm which makes aiming (your eyes to the lens) and viewing (no black
background) very pleasant. |
|
j****c
发帖数: 19908 | 16 这个exit pupil只有4mm啊，年轻时候瞳孔可以张到7mm，上了年纪后只能到5mm
整个7x50的，看起来亮 |
|
e**n
发帖数: 5876 | 17 上面第二张图没贴上. 可以看到新版屁股的镜片直径, exit pupil, 明显比旧版的大
42 |
|
p**o
发帖数: 3409 | 18 跟微距镜比锐度，是不公平的
90mm这个焦段，我倒是对xpan的90mm头转接有兴趣，
中幅像场，exit pupil又远，至少边角应该无敌
等adapter到了我可以测一下 |
|
i*****y
发帖数: 3449 | 19 原来不止一个人被烫伤
Microwave ovens should display prominent warnings about the dangers of
exploding eggs, says a team of opthalmologists in the UK.
The opthalmologists made the appeal in a letter to the British Medical
Journal. The letter described the case of a nine-year-old girl who reheated
a boiled egg in a microwave for 40 seconds. About 30 seconds later, when she
was carrying the egg, the egg exploded, hitting her in the right eye and
face.
The shrapnel from the scalding egg tore open her cornea, ... 阅读全帖 |
|
d**********2
发帖数: 684 | 20 你要是连宋美龄讲演的最后那一句都理解不了，我看还是不要浪费时间了。
MITBBS关于宋的谑误太多。
为了忠于历史，我特意上传英文原版影音和英文稿。请注意这个稿子是宋亲自准备的，
是历史上第二个女性有机会在美国国会演讲，也是第一个中国人这样做。这个讲演有重
要的史学意义. 请别忘了，她当时是代表整个中国来作这个讲演的。在抗战的早期，她
多次去前线劳军，冒生命危险,死里逃生，数次受伤。她和努力和民国政府给当代的
PRC留下了许多历史遗产如：联合国发起国，联合国安理会常任理事国，许多世界一流
的科学家和艺术家，包括两弹元勋等。这些历史贡献是超越意识形态的。
这个演讲应该编入所有华人学校的英文教科书。
我个人最喜欢的一句宋美龄语录：We write our destiny; we become what we do.
片断:
录音全版：
2-1:
2-2:
讲演原文(全)
Addresses to the House of Representatives and to the Senate, February 18,
1943.
by Soong May-ling
Mr. Speaker an... 阅读全帖 |
|
b***n
发帖数: 13455 | 21 Because he is 肖锤子's pupil |
|
b***n
发帖数: 13455 | 22 Because he is 肖锤子's pupil |
|
r*******g
发帖数: 380 | 23 不仅仅是在美国，在英国，华裔的基础教育表现也是非常超前的。媒体也很关注这种现
象。比如《卫报》的这篇文章http://www.guardian.co.uk/education/2011/feb/07/chinese-children-school-do-well。
华裔不仅仅是学习成绩优秀，犯罪率也很低。华裔小孩走向歧途的比例是最低的。
尤其是，在其他族群中，教育程度与家庭经济条件密切相关；而华裔儿童无论是家庭经
济条件好坏，差距几乎不大——这是华裔教育最重要的特点，即超越了家庭经济和阶层。
翻译：
标题：隐藏的老虎：为什么中国孩子在学校做得好？
（来自中国的孩子，无论贫穷还是富有，在学校都表现的令人难以置信的好，但几
乎没有任何研究能找出为什么。）
这似乎是英国教育正在研究的一个巨大现象，但杰西谭认为她有答案。
“这主要是父母。中国的父母往往倾向更多的推动自己的孩子，而且有很高的期望
。我想，也许是因为他们没有我们今天拥有的这样的机会，他们希望我们能得到更多有
利的条件。”
杰西谭，18岁，作为一个在沃特福德的文法学校获得A级的女学生，她的父亲是从
香港来到英国的，她曾被要求在英语学... 阅读全帖 |
|
M****u
发帖数: 4504 | 24 康州这场枪击案，除了禁枪的呼声，也重新引起了很多人关于对mental illness孩子的
焦虑。这篇文章在twitter上很火，转来给大家读读，明枪易躲，神经病难防。应该
identify那些potential会出问题的孩子，防止他们酿成大祸。
连接：http://thebluereview.org/i-am-adam-lanzas-mother/
I am Adam Lanza’s Mother
It's time to talk about mental illness
Friday’s horrific national tragedy—the murder of 20 children and six
adults at Sandy Hook Elementary School in New Town, Connecticut—has ignited
a new discussion on violence in America. In kitchens and coffee shops
across the country, we tearfully debate the ... 阅读全帖 |
|
k**f
发帖数: 301 | 25 http://www.huffingtonpost.com/2012/12/16/i-am-adam-lanzas-mothe
'I Am Adam Lanza's Mother': A Mom's Perspective On The Mental Illness
Conversation In America
Written by Liza Long, republished from The Blue Review
Friday’s horrific national tragedy -- the murder of 20 children and six
adults at Sandy Hook Elementary School in Newtown, Connecticut -- has
ignited a new discussion on violence in America. In kitchens and coffee
shops across the country, we tearfully debate the many faces of violence ... 阅读全帖 |
|
f**********r
发帖数: 18251 | 26 【 以下文字转载自 Military 讨论区 】
发信人: justinezeus (Justine), 信区: Military
标 题: 苏州大学浮萍新报料：孙中山抚养了我爷爷
发信站: BBS 未名空间站 (Wed Feb 13 10:05:07 2013, 美东)
http://www.guardian.co.uk/books/2013/feb/13/ping-fu-controversy
A successful US entrepreneur faces mounting questions over her widely lauded
tale of childhood torment in China's cultural revolution, as fresh
contradictions emerge and experts cast doubt on key elements of her story.
Ping Fu's rags-to-riches memoir Bend Not Break says she was torn away from
her ... 阅读全帖 |
|
m**c
发帖数: 7299 | 27 摘要的最后一句话: (男生只要自称是女就可以进入女厕所吗?)
.......use facilities consistent with his or her gender identity,
irrespective of the gender listed on the pupil’s records. |
|
h*h
发帖数: 27852 | 28 【 以下文字转载自 Medicalpractice 讨论区 】
发信人: Aplusplus (Hakuna Matata), 信区: Medicalpractice
标 题: 美国医院的经营策略
发信站: BBS 未名空间站 (Fri Sep 19 22:56:19 2014, 美东)
目前我在的医院动不动就解雇人，这跟他们的垄断地位有关，没有竞争就形成独裁。
好几个经验丰富的医生离开了，医院却从容不迫，大招新毕业生，反正他们有钱，不愁
没人来。 更可恶的是他们不管市场需求，硬招他们想要的专业，把当地的老医生挤走
。
这么做的好处是什么？
1.新医生听话，让干什么就干什么。
2.新医生经验少，什么病都收入院，入院后新手一般都大做检查，很多都是浪费，但医
院却收入大增。
上个星期看了两个瞳孔增大的病人，我问ER的新手，收这种病人的理由是什么？ 她说
不知道病因才收住院。 尼玛，每个病人都做颈动脉造影，医院放射科都高兴坏了，可
是，你看到什么stroke会引起瞳孔单侧增大的？
问她听说过Adie’s pupil吗？ 她居然说从来没听说。 她要是懂了，我估计医院要少
一半的收入。
所以说... 阅读全帖 |
|
k****m
发帖数: 4670 | 29 Tom Ammiano (born December 15, 1941) is an American politician and LGBT
rights activist from San Francisco, California.
Ammiano authored legislation, Assembly Bill No. 1266, which was passed in
May 2013 by the State Assembly:
均来自你信任的维基百科，此议员的条目
这个和你不相关？
大家质疑的不是这个法案的表面的好的方面的用心了（极可能还有更加隐蔽的用心）
而是质疑这个法案的不严谨
这你也有意见？法律条款中，哪一条写了，你说的那种身份记录在案？
法律条款中，却说了，irrespective of the gender listed on the pupil’s
records.
是你说的records 么？是你认同的records么？
这个法律，就是防君子，不妨小人的法律
这是你认为，法律应该有的模式？ |
|
d*b
发帖数: 4184 | 30 【 以下文字转载自 Military 讨论区 】
发信人: dcb (奉钻风之命删除), 信区: Military
标 题: 英国筹建屁精学校有望刷新犯罪率记录
发信站: BBS 未名空间站 (Thu Jan 29 08:50:02 2015, 美东)
纽约哈维牛奶屁精学校的一个月内7%学生因为暴力犯罪入狱的记录有望做古！！！！
避难所？英国拟建立第一所同性恋学校(双语)
2015年01月16日11:23 新浪教育 微博 我有话说 收藏本文
a gay schoola gay school
导语：英国一组织提出建立当地第一所同性恋学校，其目的是为了庇护在学校受到
欺负的儿童，包括男/女同性恋者，双性恋者以及变性人。但有评论指出，这一举动会
损害已经建立起来的社会对同性恋者的容忍度。
A taxpayer-funded youth group has drawn upcontroversial plans for
Britain’s first school for gay, lesbian, bisexual andtransgender pupils。
由纳税人资助... 阅读全帖 |
|
b*s
发帖数: 82482 | 31 看电视跟看书不同。
when you watch it in the dark, then the problem is that that is the only
lighting in the home. This then sets the lighting level for the whole room,
and as what's on the television changes, so the level of lighting changes.
For that dark scene with them in the cupboard the room will be dark, but
when the explosion goes off (not sure what film this is... ) it's going to
be very bright. So that then means that your eyes are forced to constantly
adjust to different levels of lighting whic... 阅读全帖 |
|
a****e
发帖数: 173 | 32 But wherefore do not you a mightier way
Make war upon this bloody tyrant, Time?
And fortify yourself in your decay
With means more blessed than my barren rime?
Now stand you on the top of happy hours,
And many maiden gardens, yet unset,
With virtuous wish would bear you living flowers
Much liker than your painted counterfeit:
So should the lines of life that life repair,
Which this Time's pencil, or my pupil pen,
Neither in inward worth nor outward fair,
Can make you live yourself in eyes of men |
|
O**n
发帖数: 649 | 33 Janus v. Tarasewicz, 135 Ill.App.3d 936, 482 N.E.2d 418, 90 Ill.Dec. 599 (
Ill.App. 1 Dist. 1985) arose out of a freakish series of events that began
in the Chicago area in 1982. Adam Janus unluckily purchased a bottle of
Tylenol capsules that had been laced with cyanide by an unknown perpetrator
prior to its sale at retail. On the evening of September 29, 1982, the day
of Adam's death, his brother, Stanley Janus, and Stanley's wife, Theresa
Janus, having just returned from their honeymoon, gath... 阅读全帖 |
|
m***y
发帖数: 14763 | 34 Though it's penned by His pupiles, they all acknowledged the ideas are from
Him. They purely wrote it down :) |
|
|
|
|
x****o
发帖数: 21566 | 38 我原来喜欢说 how do you do? 还有I am a pupil .
现在都说how is going? |
|
|
x****o
发帖数: 21566 | 40 我原来喜欢说 how do you do? 还有I am a pupil .
现在都说how is going? |
|
|
w**********5
发帖数: 1741 | 42 英国黑其他国家的笑话
How do you convince Americans to get involved in a war?
Tell them it's nearly finished.
如何说服美国参与一场战争？
告诉他们战争马上就要结束了！
An American walked into an English pub and asked for a pint of Budweiser.
The barman replied "You're American aren't you?"
The man says, "Yeah. Could you tell by the drink I ordered, or the accent?"
The barman replied. "Neither, you are the fattest **** I have ever seen."
一个美国人走进一个英国酒吧,点了一瓶百威
服务员问道:你是美国人吧?
美国人诧异的回答:是啊!你是怎么知道的?是我点的酒不一样,还是口音不一样?
服务员回答:都不是! 你是我见过最TM胖的!
I'v... 阅读全帖 |
|
k***r
发帖数: 13724 | 43 had sex with the pupil until the ‘early morning hours’
‘hot and heavy’
Some of the encounters were filmed on video
大叔看得鼻血直流啊。 |
|
z*********n
发帖数: 94654 | 44 获奖感言里有一段我倒是觉得说的狠有道理，美国教育系统太烂！ per pupil
investment世界第一，学生表现30个国家里排名第三十，lol
真够烂的 |
|
I*******g
发帖数: 7600 | 45 【 以下文字转载自 Military 讨论区 】
发信人: root002 (root), 信区: Military
标 题: 77年考大学的英语试卷的汉译英，索南也不见得行
发信站: BBS 未名空间站 (Tue Jun 7 16:16:15 2016, 美东)
1977年的高考英语试卷
一、写出下列单词的变化形式（每空1分）
1.hero (名词复数)
2.enemy (名词复数)
3.railway (名词复数)
4.life (名词复数)
5.sheep (名词复数)
6.woman (名词复数)
7.stop (过去式) (过去分词) (现在分词)
8.die (过去式) (过去分词) (现在分词)
9.hurry (过去式) (过去分词) (现在分词)
10.rise (过去式) (过去分词) (现在分词)
11.win (过去式) (过去分词) (现在分词)
12.catch (过去式) (过去分词) (现在分词)
二、用英语回答下列问题（每题2分）
1.Are you a student?
2.How many people are there in your fa... 阅读全帖 |
|
发帖数: 1 | 46 pupil 这个单词很久没看到啦。。。都说皇帝一言九鼎。。。九鼎干什么，九个锅煮饭
，一锅炖鱼肉，俩锅水蒸饺，。。。还剩下些什么。。。6个锅 |
|
k*****e
发帖数: 22013 | 47 【 以下文字转载自 Rainbow 讨论区 】
发信人: beikeqin (beikeqin), 信区: Rainbow
标 题: 用核磁共振研究女性性高潮 (转载)
发信站: BBS 未名空间站 (Wed Nov 10 18:12:58 2010, 美东)
发信人: cumeveryday (高每日), 信区: Biology
标 题: 用核磁共振研究女性性高潮 (转载)
发信站: BBS 未名空间站 (Wed Nov 10 17:33:25 2010, 美东)
发信人: MrGaLa (Independent Pig), 信区: Sex
标 题: 用核磁共振研究女性性高潮
发信站: BBS 未名空间站 (Wed Nov 10 16:32:16 2010, 美东)
科学家们扫描女性性高潮时的脑部变化照片发现，性高潮过程涉及逾30个不同脑区，而
且在达到高潮的每一阶段，脑部活动都会增加，不但影响脑内的回馈线路，负责理想思
考的脑区也会受影响，让痛楚感觉暂时纾减。
美国Rutgers大学脑神经科研人员利用计算机素描，首次拍摄女性在进入和达到性高潮
时的脑部活动情况。研究中，8名女... 阅读全帖 |
|
s********n
发帖数: 4346 | 48 I read a book about psychology of love on the train. It says that there is
universal standard of beauty independent of culture and time. Men usually
like two types of woman: 1 baby round face with large eyes and small nose
and small chin. 2. Sexy type with high cheek bones, full lips and widened
pupils. They say sense of beauty is "genetic".
Is that so? Are there universal beauty of lesbian girls? |
|
