二手定焦鏡

Canon EF 35mm f/2 IS USM is a compact full-frame EF prime lens with f/2 maximum aperture, 4-stop image stabilization, and ring-type ultrasonic autofocus.

• Minimum focus distance: 0.24 m
• Filter size: 67 mm
• Weight: 335 g

On APS-C bodies, the field of view is roughly like a 56mm lens, so it behaves more like a normal prime.

搭配 Canon EOS 1500D，這是非常實用的日常街拍與低光人像鏡頭組合。

Full Frame 50mm 的特點可以說是攝影界的「萬用標準鏡」，它的視角接近人眼自然視角。

Set the camera to manual focus, choose your aperture, then rotate the focus ring until the infinity mark lines up with the aperture mark on the depth-of-field scale. The matching mark on the other side then tells you the nearest distance that should stay acceptably sharp, so you get a zone from that distance to infinity.

Because the 1500D is an APS-C EOS camera, the hyperfocal distance calculation uses the APS-C circle-of-confusion value rather than full-frame. Canon’s guidance specifically notes that the distance scale is the simplest way to set hyperfocal distance when the lens has one, and manual focus is the best option for doing it accurately.

The scale is only an approximation, so it is worth checking the result with a test shot and magnified review, especially at wider apertures where depth of field is thinner. If you are shooting landscapes, f/8 or f/11 is usually easier to work with than very wide apertures.

Aperture	Hyperfocal distance	Approx. focus range
f/4	15 m	7.5 m to infinity
f/5.6	11 m	5.5 m to infinity
f/8	7.7 m	3.9 m to infinity
f/11	5.6 m	2.8 m to infinity

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超焦距指相機對焦於那個距離時，能把可接受的清晰範圍最大化，使其由該距離的一半延伸至無限遠。它常被應用於風景拍攝，因多數風景照都需要較闊的清晰範圍。利用超焦距的物理特性， 攝影師便可獲得最大的景深。

www.imagejoy.com/article/675

The focus index is the fixed line in the middle; the distance markings and aperture marks move against it.

The lens has a distance scale in a window and a depth-of-field scale with marks like f/11 and f/22. When the infinity mark is aligned with one side of the DOF scale, the opposite mark shows the near limit of acceptable focus.

If you set the lens to f/11 and align infinity with the f/11 mark, the focus index helps you see the corresponding near distance on the other side of the scale. That gives you a hyperfocal setup, so everything from that near distance to infinity should be acceptably sharp.

For this lens, the red dot is for infrared focus, not for normal hyperfocal use.

www.perplexity.ai

Brain and emotions

attuned: familiar with somebody/something so that you can understand or recognize them or it and act in an appropriate way

undermine: to make something, especially somebody’s confidence or authority, gradually weaker or less effective

Endorphins are natural, opioid-like chemicals produced by the central nervous system and pituitary gland. Acting as the body’s natural painkillers, they block pain signals and trigger feelings of pleasure, well-being, and relaxation.

as though: ​in a way that suggests something

It sounds as though you had a good time.

wreck: a person who is in a bad physical or mental condition

Emotions are a vital part of decision-making and there are very few decisions we make in life that are not accompanied by some form of emotion.

情緒是決策的重要成分，會影響我們對資訊的重視、風險與回報的評估，以及行動的動機。大多數人生決定（例如工作選擇、感情關係、消費行為）都伴隨某種情緒，即使只是微弱的喜好或不安。情緒能提供快速的直覺與價值判斷，但也可能造成偏誤，因此理性與情感應互相補充。

overwhelm: IPA[ˌəʊvəˈwelm]

dreadful: very bad or unpleasant

sarcasm: a way of using words that are the opposite of what you mean in order to be unpleasant to somebody or to make fun of them

Emotions can influence how we retrieve memories, leading to biases in how we recall information, which can skew our perception of events.

情緒會影響我們從腦中取出過去經驗的方式，讓某些細節更容易被想起或被遺忘。這種情緒導向的記憶偏誤會扭曲我們對事件的整體感受與判斷。

skew: to change or influence something with the result that it is not accurate, fair, normal, etc.

fiasco: disaster

chuckle: an act of laughing quietly

Nicole Vignola "Rewire"

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oxfordlearnersdictionaries.com

Google AI overview

Explanation by Microsoft Copilot

Hobbies

By engaging in hobbies, we immense ourselves in something else so that our mind doesn't think about these stresses and it has a chance to regulate in that time of distraction.

subside: to become calmer, quieter or less intense

pastime: ​something that you enjoy doing when you are not working

embark on: to start to do something new or difficult

profound: very great; felt or experienced very strongly

Hobbies make us feel good after we've engaged in them because they stimulate various regions of the brain that challenge us, and this causes a rise in BDNF. BDNF is released through activities like exercise, learning and creative pursuits associated with hobbies.

從事嗜好能把注意力投入其他事物，暫時不去想壓力來源，讓大腦有時間在這段分心期間調節。嗜好讓人感覺良好，因為它們刺激大腦不同區域並帶來挑戰，進而促使腦源性神經營養因子 BDNF 上升。像運動、學習和創作等活動都會促進 BDNF 釋放，對神經健康與學習能力有幫助。

Explained by Microsoft Copilot

Brain-derived neurotrophic factor (BDNF) is a vital neuropeptide that promotes the survival, growth, and maintenance of neurons. Acting primarily in the brain and spinal cord, it is essential for synaptic plasticity—the brain's ability to adapt, learn, and form long-term memories.

pursuit: the act of looking for or trying to get something

dampen: to make something such as a feeling or a reaction less strong

Allostatic load is the cumulative "wear and tear" on the body and brain caused by prolonged, chronic exposure to stress. Over time, this constant activation of stress hormones (like cortisol and adrenaline) alters the body's natural balance, significantly increasing the risk of cardiovascular disease, diabetes, and mood disorders.

Nicole Vignola "Rewire"

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dictionary.cambridge.org

Google AI overview

Exercise of Python Learning

「除數」（divisor）是在除法算式中，用來「除」另一個數字（被除數）的數字。以 12 ÷ 4 = 3 為例，被除數是 12，除數是 4，商是 3。若指整數的整除關係，除數在中文也常被稱為「因數」（factor）。

def allPrimesUpTo(num):

    primes = [2]

    for number in range(3, num):

        sqrtNum = number**0.5

        for factor in primes:

            if number % factor == 0:

                break

            if factor > sqrtNum:

                primes.append(number)

                break

    return primes

print(allPrimesUpTo(20))

Function definition

Creates a function that will return all prime numbers less than num.

Initialize list of primes

Starts with [2] because 2 is the first prime number.

This list will grow as new primes are found.

Loop through candidate numbers

Tests every integer from 3 up to num - 1.

Compute square root

Finds the square root of the candidate number.

Check divisibility against known primes

for factor in primes:

Loops through all primes found so far.

This is efficient: instead of checking every integer, you only check prime factors.

Case 1: divisible by a prime

if number % factor == 0:

    break

If number is divisible by any prime factor, it’s not prime.

break exits the loop immediately.

Case 2: factor exceeds square root

if factor > sqrtNum:

    primes.append(number)

    break

If you’ve checked all prime factors up to the square root and none divided evenly, then number must be prime.

Append it to the list of primes.

break stops checking further factors (no need).

Example trace (num = 20)

• Start: primes = [2]

• number = 3 → factors checked: 2 (not divisible, 2 > √3) → add 3 → [2, 3]

• number = 4 → divisible by 2 → skip

• number = 5 → factors: 2 (not divisible), 3 (3 > √5) → add 5 → [2, 3, 5]

• number = 6 → divisible by 2 → skip

• number = 7 → factors: 2 (not divisible), 3 (3 > √7) → add 7 → [2, 3, 5, 7]

• number = 8 → divisible by 2 → skip

• number = 9 → divisible by 3 → skip

• number = 11 → factors: 2 (not divisible), 3 (not divisible), 5 (5 > √11) → add 11 → [2, 3, 5, 7, 11]

• … continues until 19.

Microsoft Copilot

A Public Letter

Currier House is one of twelve undergraduate residential Houses of Harvard College.

NCR: National Cash Register

staggering: so great, shocking or surprising that it is difficult to believe

exclusive: only to be used by one particular person or group; only given to one particular person or group

self-referential: referring to the fact of actually being a work of literature, or to the author, or to other works that the author has written

devote: to give all of something, especially your time, effort, or love, or yourself, to something you believe in or to a person

chastise: to criticize somebody for doing something wrong

pony up: to pay money for something

royalty: a sum of money that is paid to somebody who has written a book, piece of music, etc. each time that it is sold or performed

overhead: regular costs that you have when you are running a business or an organization, such as rent, electricity, wages, etc.

break-even: to complete a piece of business, etc. without either losing money or making a profit

please: to make somebody happy

deluge: to send or give somebody/something a large number of things at the same time

grist: grist (for somebody/something) useful ideas or material

hunk: a large piece of something, especially food, that has been cut or broken from a larger piece

slam: to criticize somebody/something very strongly

irate: very angry

outrage: to make somebody very shocked and angry

diplomatic: having or showing skill in dealing with people in difficult situations

Business stationery encompasses the customized printed materials a company uses for day-to-day communication and brand representation. It includes any document or branded piece sent to clients, vendors, or the public, such as business cards, letterheads, envelopes, and presentation folders.

screed: a long piece of writing, especially one that is not very interesting

onstage: on the stage in a theatre; in front of an audience

convention:  the way in which something is done that most people in a society expect and consider to be polite or the right way to do it

confab: an informal private discussion or conversation

stunned: ​very surprised or shocked; showing this

envision something (formal) to imagine what a situation will be like in the future, especially a situation you intend to work towards

A "scrum of people" refers to a dense, chaotic crowd where individuals push and jostle against each other to get somewhere or grab something.

A mental metronome can refer to an internal cognitive skill or a specialized therapeutic tool.

hinge on: ​(of an action, a result, etc.) to depend on something completely

enigma: a person, thing or situation that is mysterious and difficult to understand

couch: ​a long comfortable seat for two or more people to sit on

PO box: a box with a number in a post office to which your letters and parcels can be sent and from which you can collect them

scribble: to write something quickly and carelessly, especially because you do not have much time

concerted: done together by more than one person, government, country, etc.

Bill Gates "Source Code"

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Google AI overview

本機算力 vs 雲端算力

把 AI 功能放在手機「先用本機算力」通常既有技術理由也有商業策略成分；廠商會根據產品定位、成本、隱私法規與使用者體驗來決定本地運算與雲端運算的比例。

廠商會優先用本機算力的原因︰

• 延遲與即時性：本地推理延遲低，適合即時互動（語音助理、相機即時增強）。

• 隱私與合規：敏感資料可留在裝置上，降低跨境或雲端傳輸的合規風險。

• 成本控制：長期看可減少雲端推理費用與頻寬成本。

• 離線可用性：無網路時仍能提供基本功能。

• 差異化賣點：以「更快、更私密、低流量」作為市場訴求。

Microsoft Copilot

漢語和人工智能

漢字結構包括象形、指事、會意、形聲，以漢語訓練出來的人工智能與西方國家創造出來的有明顯的分別嗎？

用漢語語料訓練的模型在語言表徵、文化偏向與本地化表現上通常有明顯優勢，但在核心架構與基礎能力（如推理、算力需求）上與西方模型並非本質不同，更多是「優化方向與應用生態」的差異。

語言結構影響 token 與效率：漢字每字語義密度高，對 tokenizer 與上下文窗口利用率有不同影響，可能降低推理成本或改變訓練策略。

文化與價值觀嵌入：模型會反映訓練語料的文化傾向；中文原生模型在本地文化、語域與禮貌用語上更貼近華語使用者。

技術相似但生態不同：基礎架構（Transformer、訓練技巧）全球通用，但資料來源、監管、部署速度與商業模式在中西有顯著差別。

Token 是自然語言處理中把文字切分成的最小單位，模型以 token 為基本運算單位來學習與生成語言。token 可以是字元、子詞、整詞或字節序列，取決於所用的 tokenizer。

常見 tokenizer 類型

字元型：每個字或字母為一個 token。

子詞型（例如 BPE、WordPiece）：把常見字串當作 token，能平衡詞彙覆蓋與詞表大小。

字節級（Byte-level）：對任意語言都穩定，處理未知字詞更健壯。

Modified from Microsoft Copilot