I have a Nikon d3400 with kit lens 18-55 mm af-p DX. What is the right camera settings for northern lights photography?
A friend has been kind enough to lend me a DSLR for a few months.  It's my first foray into DSLR photography, or indeed any kind of photography beyond simply aiming my Canon IXUS at something and clicking the button.    Over the last few weeks, I've been busy studying, practising and trying to learn as much as possible ahead of a planned trip to Norway where I hope to see, and get some photos of, the Aurora Borealis.  I currently have:   Canon Rebel Xsi (450D) Canon 50mm f/1.4 L  Canon 18-55m kit lens Aluminium full height tripod with ball head Cable release Spare battery &amp; memory cards   I'm prepared to spend the night wrapped up outdoors, in the hope that they will make an appearance. I'd like some advice on how to get the most out of this kit for the trip:   How should I go about setting up to get pics of the Aurora?  How might I achieve optimum focus? From what I've read, I'll need to use the tripod and cable release, with IS turned off, on continuous shooting mode with long exposure times. But I'd like some more specific tips in terms of which aperture and ISO settings might work best? Should I use one of the lenses above, or would it be worthwhile renting a better, wide angle lens; if so, which would you recommend?
Comparison between bootstrap percentiles confidence interval and BCa confidence interval? I have generated a nonparametric percentiles bootstrap confidence interval ($32.27143, 51.08571$), and a BCA confidence interval ($33.26, 53.49$) with an initial sample size of $n=7$.  Evidently, the BCA interval is larger than the percentiles interval. Shouldn't the BCA interval be better than the percentiles interval (and by "better" I mean "smaller")? I noticed also that when the sample size is larger, for example $n=40$, BCa confidence interval decreases. Localisation is isomorphic to a quotient of polynomial ring Is "shined" correct? If so, is "he shined X on the tree" also correct? Recently, I overhead a former professor of mine use the word shined, a word that makes me grammatically uncomfortable.  She used it as following: "Then, after we shined a light on the other ball, what happened?..."  My first question is: Is using shined mainstream, over what sounds better to my ear, shone?  If so, is there any historical flip-flopping between the two usages?  Secondly, if shined is in fact legit, can it be used transitively?  Saying something like,      The light shined all throughout the night.   while odd, doesn't sound as bad to my ear as,     He shined the light on the ball throughout the night.   The latter sounds quite bad to my ear.  Indeed, à propos the original question, can shone &mdash; the better sounding alternative to my ear &mdash; be used transitively? Creating a .desktop file for a new application Google Chrome is my favorite browser, and I can't imagine going on without it. Suddenly (without closing and re-opening) the browser; chrome has been reading characters upside down, very weird:    Chrome version:    I tried restarting my browser and my MAC (running OS X Yosemite 10.10), but the error keeps on coming. How do I run a program with commandline arguments using GDB within a Bash script? The no. of all possible matrices of order $3\times 3$ with each entry $0$ and $1$ and $ -1$. What's the application extension? (aka .exe, .app, etc.) I'm new to Ubuntu. What's the application extension for development reasons? I know Windows is mainly .exe and Mac is .dmg or .app. Does Linux have an unique one? I use the following table:  \documentclass[a4paper,              12pt,                                        bibliography=totoc,              index=totoc,             abstracton,              headsepline,             ]{scrreprt}  \usepackage{booktabs}    \begin{document}   \begin{table}[H]\hspace*{-1cm} \centering \begin{tabular}{lcclll} \toprule  Company&amp; \multicolumn{2}{c}{exceedances (empirical)}&amp;exeedances (expected)&amp;no. of obs.\\ \cmidrule(r){2-3}\\ &amp;standard normal&amp;standardized Student's-t&amp;&amp;\\ \midrule Company1&amp;1&amp;5&amp;9&amp;13\\ Company2&amp;2&amp;6&amp;10&amp;14\\ Company3&amp;3&amp;11&amp;15\\ Company4&amp;4&amp;8&amp;12&amp;16\\ \bottomrule \multicolumn{4}{l}{\begin{footnotesize}an additional hint about a detail\end{footnotesize}} \end{tabular} \caption{Here is the caption.} \label{labelhere} \end{table}   \end{document}     Which gives    I have two problems:   The space after the \cmidrule(r){2-3} is too big, how can I change this? The table looks not that good, how can I improve it in general? Endow $S^3$ with its standard smooth structures from the stereographic projections, i.e. $$\chi_1:S^3 \setminus \{(0,0,0,1) \} \to \mathbb{R}^3, \chi(x,y,z,t) = \frac{1}{1-t}(x,y,z) $$ and $$\chi_2: S^3 \setminus \{(0,0,0,-1) \}   \to \mathbb{R}^3, \chi_2(x,y,z,t) = \frac{1}{1+t}(x,y,z).$$   Do the same for $S^2$, call the charts $\eta_1, \eta_2$ (in the same order as the ones for $S^3$). Now, consider the complex projective space $\mathbb{C} \mathbb{P}^1$ endowed with the smooth structure given by the charts $\{(U_0, \varphi_0), (U_1, \varphi_1)\},$ $$U_0 = \{[z_0:z_1] \ \mid \ z_0 \neq 0 \} \text{ and } U_1 = \{[z_0: z_1] \ \mid \ z_1 \neq 0 \},$$ where $[x:y]$ represents the complex line through the point $(x,y)$ and $0$ in $\mathbb{C}^2$, and $$\varphi_0([z_0: z_1]) = \frac{z_1}{z_0} \text{ and } \varphi_1([z_0: z_1]) = \frac{z_0}{z_1}. $$   Now define the Hopf maps: $$h: S^3 \to S^2, h(x,y,z,t) = (x^2+y^2-z^2-t^2, 2(yz-xt), 2(xz+yt)) $$ and $$H:S^3 \to \mathbb{C} \mathbb{P}^1, H(x,y,z,t) = [(x+iy):(z+it)]. $$  Is there an easier way to prove that $h$ is a well-defined smooth submersion and that $H$ is a smooth submersion (with respect to the respective smooth structures)? By this I mean we can of course compute $\eta_i \circ h \circ \chi_j^{-1}, \forall i,j \in \{1,2 \}$ and $\varphi_k \circ H \circ \chi_l^{-1}, \forall k,l \in \{1,2 \}$ and prove that they are smooth (in the classical real-analysis sense) and that they are submersions, but this is a very tedious process. So, are there easier ways to do this? Will this maybe be easier if we switch the smooth structure of the unit spheres from stereographic projections to, say, normal projections (though we increase the number of combinations of charts to verify from 4 to 48), since they induce the same smooth structure? What does the [Flags] Enum Attribute mean in C#? Unable to locate package Give a sequence such that root test works while ratio test fails There's something funky about some titles in revision histories here on Meta Stack Exchange How to execute hostapd command in cli? I always got error. When i execute hostapd command. I was changed everything in my hostapd.conf file but i got error.  hostapd_cli wps_pbc Failed to connect to hostapd - wpa_ctrl_open: No such file or directory  Can anyone help to me.? makefiles CFLAGS In the process of learning tinyos I have discovered that I am totally clueless about makefiles.  There are many optional compile time features that can be used by way of declaring preprocessor variables.  To use them you have to do things like:  CFLAGS="-DPACKET_LINK"        this enables a certain feature.  and    CFLAGS="-DPACKET_LINK" "-DLOW_POWER" enables two features.  Can someone dissect these lines for me and tell me whats going on? Not in terms of tinyos, but in terms of makefiles! What happened to Saruman after he was knifed by Grima? I went through a , but the answer was informing how to hide the monitor, but not how to disable it. I do not want any new windows to creep into the laptop display when the external display is connected. I could not find any in the Display Settings (under System Preferences). I don't want to close the lid because I think it impacts the air flow of the MacBook Pro. I don't want to close the lid because the sound quality is reduced. Newsletter open and click tracking use http. Can i configure it that it uses https with our certificate? Can this cause block bounces? Once I reach 15 reputation, will my old votes be taken into account? Users below 15 reputation can't effectively vote. It says:     Votes cast by those with less than 15 reputation are recorded, but do not change the publicly displayed post score   Does it mean that they will take effect after I reach 15 reputation or because they were cast before, they're recorded but ignored?