I'm just someone who enjoys photography, but I'm not a photographer. I don't know a lot, so please try and keep things simple.  I've been using a Fujifilm Finepix S9200, a bridge camera with a 24-1200mm lens (50x zoom), but only a 1/2.3" sensor. It's too cumbersome for travel, so I'm looking for something lightweight, most likely a point and shoot. Some of what I enjoy photographing are faces: children, statuary, etc. I've never needed to go to the end of my lens, but I've easily used 3/4 of my lens capability.    If I get a camera with a 35x zoom, will that be sufficient for what I want to shoot?
I need to purchase my first ever lens. So far I've only used lenses that were built into a camera. This specific lens is for the BlackMagic Deign Pocket Cinema Camera (a video only camera, but one that uses photography lenses). I would prefer this to be a prime lens.  I have tried to find the exact way to calculate the focal length of the lens I need but I have not been able to find a good resource to make this simple enough for my limited optics knowledge. Can you please explain a simple way to calculate the focal length of a lens given the following inputs as an example:    I would prefer a simplified mathematical explanation so that I may use it to make similar determinations in the future using a "" method.  I have . Using that method, I came up with:  Required lens focal length = 7.02mm sensor height x (77in / 36in) = 15mm   Is that correct?
In the book , at page 27 we find the exercise asserting that       Exercise I.XXXVI.   The underlying space of a zero-dimensional scheme is discrete; if the scheme is Noetherian, it is finite.     Thoughts I thought that a zero-dimensional scheme is one such that, in every local ring $\mathscr O_{X,p}$, the only prime ideal is its unique maximal ideal $\mathfrak m_{X,p}.$ Hence, supposing that $X=\operatorname{Spec} R$ is affine, we deduce that every prime ideal is maximal, so each ponit in $X$ is closed. But how does this imply the discreteness? It only implies the Hausdorff-ness of $X$, right? Furthermore, I cannot perceive what the "Noetherianity" has to do with the finiteness claimed here. In the affine case, it seems to be claiming that there are only a finite number of prime ideals in a Noetherian ring, if its scheme is zero-dimensional? For example, $\mathbb Z$ is a Dedekind domain, hence its scheme is zero-dimensional, but it has infinitely many primes: does this contradict the statement?    Thanks in advance for any reference or hint, and point out any inappropriate point if any is presented. Edit I see why my example cannot work now: it is one-dimensinoal: don't forget the pirme $(0)$. But I am still wondering why the statement is true... Delete all lines in Notepad++ except lines containing a word I need? Recreate plot when data file changes Is it possible to use the TikZ/external library and have pgfplots recreate a figure when a data file that is plotted changes? Say I have something like the following:  file.tex:  \documentclass{article}  \usepackage{tikz,pgfplots} \usetikzlibrary{external} \pgfplotsset{compat=newest} \tikzexternalize \newcommand{\figFilename}{}  \begin{document}   \begin{figure}[t]     \centering     \renewcommand{\figFilename}{thePlot}     \tikzpicturedependsonfile{\figFilename.tikz}     \tikzsetnextfilename{\figFilename}     \input{\figFilename.tikz}     \caption{The caption.}   \end{figure} \end{document}   thePlot.tikz:  \begin{tikzpicture}   \begin{axis}[     xlabel={$x$},     ylabel={$y$},]     \addplot+[only marks,mark=x]       table[x=x,y=y] {data.dat};   \end{axis} \end{tikzpicture}%   data.dat:  x y 0 20.44 1 20.06 2 19.76 3 19.54 4 19.40 5 19.34   If I change thePlot.tikz, the external library will detect that the figure is no longer up-to-date and recreate it. Is it possible to have the same effect when any of the plotted data files changes as well? I tried something along the lines of \tikzpicturedependsonfile{data.dat}, and it doesn't work. That wouldn't be an ideal solution anyway, as most times I use many data files in each plot and listing all dependent files manually would be more pain than gain.  So is there an easy, automated way for the external library to check all data files included in a tikzpicture and recreate the plot if at least one of them has changed? How many $6$-integer subsets of $\{1, 2, 3, \ldots, 20\}$ have no consecutive integers? I have to determine how many six-integer subsets of $\{1, 2, 3, \ldots, 20\}$ are possible if no two consecutive integers are in a set. How can timelapse sequences be shot without in-camera support? How can timelapse sequences be shot without having in-camera support for it?  Which third-party tools are recommended? my circuit is shown on the picture. the problem is the output of the mosfet does't work as desired. For example, If I use Vin=100V and the duty cycle is 50%, the output is Vout=19V.  Anyway, the output is not even near to the desired value. can you help, please? Core Data - Storing Images (iPhone) It is a win7 ultimate x64 machine. The machine was in a domain where it got those group policy settings. Now it has left the domain but it still receives the settings from the group policy. For example, the power options. I set a certain power option but soon it will be reset to another power option which is endorsed by the domain.  Is there a way to remove the settings? Write access without read access Is it possible for a user to have a write access to a file and not be able to read it? How is it possible?   I tried the following commands:  debianbox@debian:~/posix/io$ touch filetest debianbox@debian:~/posix/io$ ls -l filetest -rw-r--r-- 1 debianbox debianbox 0 14 oct.  03:10 filetest  debianbox@debian:~/posix/io$ echo "Hello World" &gt; filetest debianbox@debian:~/posix/io$ cat filetest Hello World  debianbox@debian:~/posix/io$ chmod u-r filetest debianbox@debian:~/posix/io$ cat filetest cat: filetest: Permission forbidden  debianbox@debian:~/posix/io$   As you can see here, I have write but not read access on this file. How can this be possible? Is this considered as a bug? If not, in what situation would this be useful? *.xhtml url-pattern causes java.lang.NullPointerException at com.sun.faces.context.flash.ELFlash.loggingGetPhaseMapForReading How to get class object's name as a string in Javascript? Polynomial contrasts for regression The Bash Manual says   { list; }        Placing a list of commands between curly braces causes the list to be executed in the current shell context. No subshell is   created. The semicolon (or newline) following list is required.      The braces are reserved words, so they must be separated from the list   by blanks or other shell metacharacters.       The parentheses are operators, and are recognized as separate tokens   by the shell even if they are not separated from the list by   whitespace.   If I remove the semicolon, like this:  $ { date } &gt;    Why does it expect stdin input? A metacharacter is a character that separates words.  The semicolon and whitespace are both "shell metacharacters". Why can't whitespace separate words date and }? Why do we need a semicolon instead of a whitespace for separating the words? How do the likely/unlikely macros in the Linux kernel work and what is their benefit? Cropping Shapefiles in QGIS? Support for OpenID ended on July 25, 2018 NOTE: Signing up or Logging in via OpenID is no longer officially supported from any of our sites. Currently,  is still on the internet, but we are in the process of completely removing it.    Stack Overflow was an early and strong supporter of . We built our sign up/log in flow around it. We were idealistic and had , but these hopes weren't realized. Over the years people have wondered if  is . We've had to remove support as OpenID providers  or .  The time has come to part ways. The reality is OpenID support has created a ton of complexity in our codebase and the number of users actively using OpenID simply don't justify that cost. Users have spoken with their actions. You prefer Google, Facebook and Stack Exchange (aka email/PW) based account auth.     Of our 9,813,747 accounts around one-tenth of a percent are actively using OpenID (defined as having visited a site in the past 12 months). If you include all the inactive accounts it is still less than 2.9% of all accounts.  So, what is the plan?   DONE - Remove the ability to create a new account with most OpenID providers DONE - Add the ability to  DONE - Convert Launchpad (used on  ) to OAuth DONE - Remove creating new accounts with Steam from  (Steam removed support for OAuth. Only 454 accounts that use Steam have visited Arqade in the past 6 months.) DONE - We will email all users that rely on deprecated OpenID credentials and request that they  DONE - Run an announcement banner for any user who signs in with deprecated OpenID credentials urging them to  DONE - End support for logging in via OpenID  In progress - Remove  (note: only 0.2% of authorized sites in the last year have been non-Stack Exchange sites.)   Obviously, if your account relies on OpenID, then make life easy and go now and .   If you've forgotten what you credentials you use to login, then  to refresh your memory. If you don't see one of the three account types shown in the image below (Google, Facebook or Stack Exchange) then click the "add more logins" button to add one of them to your account.    Remember, SE OpenID accounts are really email/pw accounts handled through complicated OpenID code path. They will be migrated to a simpler email/pw only code path as a part of this change. No extra work required on your part. I am running the latest version of Linux Mint with Cinnamon. I'm trying to map Caps Lock to Ctrl, but I cannot figure out how to do it. All web searches I've done have led me to older versions of Linux Mint (there is no keyboard layout option in my settings). How can I do this? What is a word for getting an award in a competition or being one of the top three? I am writing about a competition I won in which I got third place. I want to say that I am the first out of my school to get an award in this competition, with a third place award but that sounds a little bulky. What would be a short phrase or word to describe this. I am thinking maybe I can say "I placed in the competition" but I am not sure that will work. I have an Samsung Galaxy S3 Neo.  Bus 002 Device 042: ID 04e8:6860 Samsung Electronics Co., Ltd GT-I9100 Phone [Galaxy S II], GT-I9300 Phone [Galaxy S III], GT-P7500 [Galaxy Tab 10.1]   The keyboard &amp; language setting is português.  I today installed Android Device Manager and to test it's functionality I locked the phone with the password: "abcd" (4 letters were required).  After entering the password and confirming with the "OK" button of my keyboard, the phone showed me that the password is wrong. "Senha incorreta".  I reset the password after some tries to "123456" and the phone reloaded the lock screen. Again the password showed up to be wrong. I also tried the alphabetic password: "abcdefg" - same error.  I changed the language of my Google account from German to Portuguese and reset the password to "123456" again and I tried to really reboot my phone and unlock the SIM card again. But anyways I can not get through my lock of the Android Device Manager.  I tried to enter the password 35 times wrong with hope to get a chance to authenticate with my Google Account login.  I also tried to connect the phone with adb but it does not show up in this state with:  adb devices   So what can I do to get access to my phone again? persist port routing from 80 to 8080 I use amazon EC2 instance which works via ubuntu. By default according security restrictions I can't bin my application to port 80, so I just bind it port 8080 and then set routing redirect from port 80 to 8080 via the following command:  iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to 8080   But I found that when I reboot the server this settings no longer active untill I invoke this command again.  So my question is how to enable port's redirect work even if system was rebooted?