Server Bug Fix: is live view or mirrorless suitable for telephoto shots of moving subjects?

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I have been experimenting with Live View of my camera (Nikon D5100) to get a feel for what a mirrorless camera would be like, and also because I am wanting to shoot video clips of distant moving objects such as planes and birds. I realize that video on this camera is really not ideal, but at the moment it’s the only thing I have with the level of zoom required to get close enough to such objects.

But in doing so I have noticed that I find it almost impossible to actually use live view for either planes or (especially) birds, because I can’t actually get the camera aimed the right direction for them to show up. With a plane it’s a bit easier as it’s not moving as fast relative to me, so I can quickly locate it through the lens, then switch to live move. It’s still a bit tricky, and in the process of moving the lens away from my eye the camera still moves and I can lose the aircraft I’m trying to track. For moving birds it has proved impossible – I can get off a few shots through the lens, but if I try to live view instead by the time I have live view on the bird is gone. Trying to hunt for either object directly in live view without first looking through the viewfinder seems too time consuming.

At first I thought maybe it was the size or brightness of the display, but I turned the brightness to maximum and it didn’t help, and I am not sure how a bigger display would help me point the camera in the right direction.

Is using live view or correspondingly a mirrorless camera suitable for telephotos shots of moving subjects? I am wondering if there is some trick doing this or if maybe it’s just me. My on-axis hand-eye coordination seems to be great – I have never had any problem photographing moving subjects through the lens; but off axis (not looking through the lens), will it improve with lots of practice or am I just wasting my time?

The suitability of live-view and mirrorless camera options for use with long telephoto lenses comes down to ergonomics, practice, and context.

The biggest factor is likely how you’re viewing, sighting, and stabilizing the camera, vs what you are photographing.

Viewing a non-tilting rear mount screen is probably the worst option in nearly any context.

  • You give up stabilization to hold it out from your body enough to view the screen.
  • You leave the camera ‘floating’ in front of you more, reducing your bio-mechanical feedback with where the glass is actually pointing, and reduce your ability to reliably sight ‘over the barrel’ to approximate your aim before locking in on target.
  • Increased risk of issues such as screen glare making it difficult to see.

An eye level viewfinder is typically the most favourable option for the majority of use cases.

  • You gain stability by bringing the camera close into the body.
  • You gain bio-mechanical feedback by typically using the same ‘contact points’ with your body, as your hand and eye consistently align while you swing the camera.

*However, there are scenarios where one may benefit from using a rear screen, especially when tilt options come into play. [These may also apply to electronic viewfinders that can be viewed independently of the camera, such as ‘google mount’ options.]

  • Positioning the camera lower than a traditional viewfinder allows
  • Working in hazardous situations where gluing your eye to the back of the camera may make it more difficult to notice a danger in time to react.

All that said, getting a long lens to hold on target is a skill, and it demands practice.

But if photographers can learn to track moving subjects with a waist level finder on an old medium format camera [where the view is flipped left to right], then odds are good that you can learn to adapt to a given setup.

[I know we’re straying into the world of video here, but I feel it’s still relevant]

Why is live view harder than “TTL”?
because you are not using the senses you were born with – that your eye & hands are easily co-ordinated to match direction, distance, speed & focus [of attention, not sharpness of image].
Catch a ball. No maths required, you just do it.
Catch a ball whilst watching your live view… maybe not.

Will you improve over time?
Yes, otherwise the entire movie industry would be full of missed shots. Almost no cinematographer has his eye right through the lens these days, there’s always some remote aspect to it – in effect, live view. Watch a steadicam operator, gazing towards his feet, where his monitor is, whilst his camera is pointed firmly at the action in front of him.
There’s a dual purpose in that, he can see what he’s shooting whilst not falling over anything.
Many pro video cameras have the same as DSLR or mirrorless cameras, a TTL & separate moveable screen(s) for remote viewing. The use of the eyepiece is becoming much more rare, the remote ‘live view’ is more common.

So, for stills what does it mean?
Mirrorless cameras currently still have both options.
The “TTL” viewfinder is a teeny TV screen, but it’s still really “through the lens”, with your face pressed against the camera, the same as ever..
The live view you’ll still have to train towards, just like every ‘movie’ cameraman working today.

Your potential pitfall, for fast action, is the frequency with which your live view updates on your screen. Modern high-end cameras have truly ‘as live’ playback; no discernible delay at all. An old entry-level consumer DSLR is going to be pretty laggy by comparison.

As the other answers have hinted at, this isn’t so much about the difference between an electronic viewfinder and an optical viewfinder as it is about the different ergonomics of using an eye level viewfinder held in a constant position relative to your face and eyes versus a screen on the back of a camera held a foot or so in front of your face.

When you are using an eye level viewfinder, whether it is an optical viewfinder such as is the case with your D5100 or an electronic viewfinder as would be the case with a mirrorless camera, you hold the camera against your face. To aim the camera you don’t merely move the camera with your hands. You aim the camera by moving your face towards your target and your hands follow to keep the camera in the same position relative to your face.

When you move the camera away from your face to use a monitor screen that is not in a fixed position relative to your face, you can no longer aim the camera by simply moving your face relative to the target/subject. It’s not an insurmountable problem, but it is a different skill set that takes much practice to master. After all, you’ve been learning to bring distant objects into the center of your field of vision by moving your face towards the desired subject for your entire life! Now you’ve got to unlearn that to some extent.

It’s not easy. It is doable. It will probably never become as instinctive as using an eye level viewfinder can be, though. You’ll always have to be more consciously thinking about how to move the camera to keep it pointed in the right direction when the camera is not pressed against your eye and face.

The difficulty of pointing is a combination of both the different body position when looking at a screen and the inherent latency in a LCD display.

One option would be to mount an external viewfinder to the hot shoe on the camera. There are many models available, search for “external optical viewfinder” or “hot shoe viewfinder”.

Hot shoe viewfinder

Such a viewfinder will not show the image as it is through the lens, so the framing will be different. Typically the external viewfinder will show a wider area than your telephoto lens, which actually helps in initially finding the target but may make it a bit harder to accurately follow it.

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Ubuntu HowTo: Lagrangian for scalar field in terms of klein Gordon equation

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I am Studying Peskin and Schroeder, at page 287 , Lagrangian for scalar field is

$$L={1over 2}(partial _mu phi )^2-{1over 2}m^2 phi^2.$$

It can be rewritten as

$$L={1over 2} phi (-partial^2-m^2)phi . $$

I don’t understand how it is rewritten,
Your little helps may save my lot of time.

Let us look at the first term in your Lagrangian:

$$partial_mu phi partial^mu phi$$

Now, for a general derivative $ partial_x $ we have:

$$partial_x left(y partial_x yright) = (partial_x y)^2 + y partial^2_x y$$
$$Rightarrow (partial_x y)^2 = partial_x left(y partial_x yright) – y partial^2_x y$$

If you substitute the above for $partial_mu phi partial^mu phi$ in your Lagrangian, you get two terms, one of which is of the form $partial_mu (…)$. This term is a total derivative and does not contribute to the equations of motion. This is because in the action,

$$S = int dvec{x} dt L$$

the total derivative term will integrate out to give constant. And when we calculate equation of motion, that constant will be differentiated to zero.

The two Lagrangians are the same modulo total spacetime divergence terms. If you vary with respect to the scalar field the action constructed from the lagrangian you will obtain the Klein-Gordon equation.
People usually write the kinetic term of the scalar field as $(partial_{μ} phi)^2$. You can write it as $phi partial^2 phi$. Both these two expressions after variation will yield $partial^{2}phi$.

($phi partial^2 phi$ contains second derivatives of the dynamical variable. Be careful with Euler Lagrange equations.)

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Steam Game: Total Lockdown

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Total Lockdown is a battle royale on the top floors of a giant skyscraper. In this action shooter, the goal is to survive using any available weapons, gadgets, and tricks. Fight for fortune and fame in a battle to the death!

About This Game

Total Lockdown is a multiplayer online game. In this action shooter, the goal is to survive using any available weapons, gadgets, and tricks. Fight for survival on your own, or with friends at your side. The game takes place in a grim cyberpunk world where corporations wield all the real power and daily live broadcasts of a battle royale inside an enormous skyscraper have become the most popular form of entertainment.

A defining feature of Total Lockdown is its “vertical” gameplay. As characters move between floors in a hive-like building, the scenery changes rapidly from robot assembly factories to artificial parks with waterfalls and panoramic vistas of a fascinating and heartless metropolis of the future. This approach helps make the gameplay much more dynamic and varied.

Participants will get to choose one out of several corporations. As its representatives, they’ll gain access to more lucrative quests as well as various unique weapons. During combat, special terminals will offer a wealth of unlockable upgrades. However, other players aren’t going to just sit and watch from the sidelines, so intense firefights will frequently erupt around these locations. Much to the delight of the viewers and the eventual winners.

Players can choose from over 40 different weapons and auxiliary devices, from classic firearms to such exotic pieces as the Gauss rifle, plasma shotgun, or a defender drone that’s ready to throw itself between its owner and enemy fire at any moment. Fighting has never been such fun, with different options to suit everyone’s taste.

Several game modes are available. In the popular Battle Royale mode, 100 players fight on all 24 floors of the skyscraper as they gradually fill up with poisonous gases. The survivors converge on the final safe floor, where a deadly showdown will see a winner emerge.

Those who prefer more traditional forms of entertainment might want to try the Tournament mode, in which players fight through a tournament bracket to get to the finals. Each match is held on an isolated floor of the building. The survivor will advance to the next stage, keeping all the equipment and weapons they’ve acquired.

Total Lockdown uses Unreal Engine 4, one of the best modern game engines, which ensures high performance and amazing visuals on most systems, allowing for full immersion into the game’s atmosphere.

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Steam Game: Aimbeast

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The ultimate training and warmup solution for FPS players: Aimbeast combines human-like AI and lot of useful gamemodes to make you better and destroy your enemies in the battlefield, are you ready to become an Aimbeast?

About This Game

The ultimate training and warmup solution for FPS players: Aimbeast combines human-like AI and lot of useful gamemodes to make you better and destroy your enemies in the battlefield, are you ready to become an Aimbeast?


You can explore and play a large amount of community and dev created scenarios, each scenario have a lot of options and can be customized in detail, when you upload a scenario on the workshop a leaderboard will be created and everyone will be able to play it.


Create automated routines / playlists by combining your favourite scenarios. Every time you play a routine you will see an overview of your performance and you will be able to see from the progress tracker how much you are improving.


Thanks to an advanced movement system bots can move and behave very naturally like a human, the movement system and every bot property and behavior is entirely customizable for every bot you create.


Everything in the game is easily customizable from the options menu like: crosshairs, sounds, map textures, HUD, map shading, sky type, third person settings, etc..


Every scenario available in the game has a leaderboard so you can compete with other players and get an idea of your skill level and how much you are improving over time.


Workshop is fully supported in the game and players can share, search and download: maps, scenarios, routines, bots, weapons, sounds, themes, etc..


Aimbeast offers the best and easiest tools for creating maps and scenarios thanks to a fast and easy to use map editor in which you can easily create, test your maps in real time and then share them on the workshop.


Thanks to one of the best progress trackers on the market. You can see a graph showing how much you are improving over time and you have a lot of filters at your disposal to see your statistics more in depth.


On every verified scenario you can see your current rank which is calculated from your position in the leaderboard, you will also be able to see what score you need to achieve to get to the next rank.

Make sure to join our official discord to get in touch with us and give feedback.

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Steam Game: The Waylanders

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The Waylanders is a classic party-based RPG featuring some of the top-talents who brought well-known titles within the genre like the Dragon Age, Mass Effect or Pillars of Eternity sagas.

About This Game


The first meeting between the Celts and their gods, the Tuatha de Danaan should have been a time of celebration and enlightenment. But, when the negotiations go catastrophically wrong, you find yourself near death- and untethered from time! The land has been overtaken by magickal corruptions, and the kingdom, once peaceful, has splintered into multiple factions warring for the throne. The Celtic culture- a complex tapestry of different religions, cultures, mortal and immortal human races, werewolves, druids, goblins, and monsters threatens to tear at every seam. Will you support the immature yet rightful heir, or the pragmatic general? What alliances will you forge, what friendships will you foster, what romances will you pursue, and… what will you do when you are suddenly thrust into Medieval Spain?

You discover, because you have been untethered from time, that you are able to travel between the Celtic and Medieval eras. Things look pretty different in Galicia under Christianity than they did under Celtic rule. Where are your immortal allies now, and what has become of the souls of your mortal friends, reincarnated? Could the corrupt magicks that interfered during your meeting with the Tuatha have led to the destruction of all the Celtic world held dear? Or was a larger force of politics and religion at fault- or, perhaps, to thank for the changes the world has experienced?


The Waylanders is an exciting fantasy RPG inspired by classics such as Dragon Age: Origins and Baldur’s Gate.

  • Unique, party-based experience that time travels between two distinct eras: Celtic and Medieval
  • Story: written by international acclaimed scriptwriters: Emily Grace Buck (Lead Writer), Chris Avellone (Writer) and Mike Laidlaw (Consultant)
  • Music by an Emmy award-winner,3 times BAFTA nominee and Fallout’s main theme composer, Inon Zur.
  • Multiple endings: choices made in one time period can have dire consequences in the other, meaning players will feel the impact of their decisions in surprising and shocking ways.
  • Strategy and innovation: gameplay features unique formations for deep, tactical combat
  • Full character customization: 6 basic and 30 advanced classes, 5 playable races based on Celtic mythology and different origins for your character
  • Companions: they are an integral part of any RPG experience, and The Waylanders offers a variety of traveling companions that can join you on your journey. The player will be able to talk to their companions in-depth, discover their past, play loyalty missions, and even experience romances with them.
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Steam Game: Don’t Fall

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Don’t Fall is a third person action multiplayer game that puts players on a floating arena that is shrinking every second. As floors vanish, the falling risk becomes higher. Pick up powerful weapons, and knock the enemies into the abyss. Become the last one who hasn’t fallen.

About This Game

Don’t Fall is a third person action multiplayer game that puts players on a floating arena that is shrinking every second. As floors fade away, the risk of falling becomes ever higher. Pick up powerful weapons, and knock the enemies into the abyss. Become the last man standing.

Strategically use special items to push the other players over the edge. Special items includes grenade, arrow, and energy.

Each play has a number above him that indicates how far he would be pushed if he was hit. The number will increase each time you are hit. Use healing energy to reduce that number, but be mindful about nearby enemies because you will be defenseless while you heal.

The Arena
The floors are disappearing fast! There is not enough room for everyone! Push your enemies off before you get pushed off!

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Steam Game: Resolutiion

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An old killer escorts a curious AI through chaotic combat, puzzling secrets, and unsettling calm. Explore a fractured future, collecting weird weapons and stories, to piece together the past.

About This Game

An old killer escorts a curious AI through chaotic combat, puzzling secrets, and unsettling calm in a dreamscape of madmen and sane animals.

Resolutiion is a fast-paced action-adventure created by two angry German brothers leading a band of vagrants who loaded it with lovely pixels, dirty jokes, deep ideas and badassemotional tunes for 20 hours of punishing combat, rewarding exploration, and layered storytelling. Will you be the player or will you be played? In the Infinite Empire nothing is as it seems.

Explore a fractured future, gathering weird weapons and stories, to piece together the past: a friend betrayed, a family broken, worlds at war.

To solve the mystery of the Cradles take on a multi-cultural-mashup of cynical gods, emotional machines, zealots, luddites, and furry critters in a world that doesn’t care if it confuses or kills you — oh hey, a kitty!


  • 20 hour playtime
  • Explore a grim cyberpunk world where nothing is as it seems
  • Experience a dark story where you might be the hero – or the villian
  • Unlock new abilities to defeat your enemies
  • Survive in brutal fights and crush gruesome bosses
  • Listen to a badassemotional cyberpunk Soundtrack

Here kitty-kitty…

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Steam Game: Deep Rock Galactic – MegaCorp Pack

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About This Content

Straight off the industrial carbon presses of the research floor! It’s time to shine up your weapons and gear with the very latest in design aesthetics – and the company-approved MegaCorp Pack is here to provide you with just that:

– The MegaCorp Framework – a set of FULL MESH RESKINS of all weapons in the game into a flashy, cyberpunky style. Like all Frameworks, it comes with a Paintjob unique to it but supports all your other Paintjobs as well.

– Class-specific Armor Paintjobs to match your new weapons.

– A matching Paintjob for your trusty personal Pickaxe.

Important note: The contents of this Pack are cosmetic only!

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Steam Game: Deep Rock Galactic – Dark Future Pack

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About This Content

Wanna look your best, Miners? Well, then maybe the Dark Future Pack is for you! The lads down in R&D went all-out on putting together a hard-edged and tactical set of kit especially for our most discerning employees:

– 4 unique suits of Armor, one for each Class. Like all Armors, they come with Paintjobs unique to each but support all your other Paintjobs as well.

– Two matching Helmets to go with your new Armor – a light version to show off your beards, and a heavier, full-face-cover version.

– A matching Paintjob for Bosco – team up with your favorite drone in style!

Important note: The contents of this Pack are cosmetic only!

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Steam Game: Cepheus Protocol

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Find patient zero before an alien virus takes over San Francisco and the cepheus protocol is enacted. Command your squad, save civilians, and stop the Pangu virus. Kill patient zero and save the world.

About This Game

A mysterious virus of alien origin is sweeping through San Francisco. It is up to the Center for Epidemic Research and Control (CERC) to track down and find Patient Zero before it is forced to enact the Cepheus Protocol. Command your squad, save civilians, and stop the Pangu Virus before it is too late.

Main Objectives:

  • Train and level a single squad of up to 8 members as you search the city for Patient Zero.
  • Build, train defenders, and safeguard your base from the Pangu Virus’ victims as they will attempt to retake zones
  • Manage your squad as you attempt to control the spread of the virus.


  • Take command of Captain Adrian Winter as she leads an 8-member squad of elite soldiers as you attempt to stop the Pangu Virus from spreading beyond containment.
  • Choose how to spend your in-game money on important upgrading to your barracks, improving weapons, or buying new soldiers to fill your ranks. You earn in-game money by completing bounties and eliminating the infected.
  • Collect viral samples to better improve your squads’ abilities and expand your understanding of the virus before it is too late.
  • Every life matters and every soldier counts. If Captain Winter dies, it’s game over. Decide whether to leave her at the base or use her advanced skill-set to even the odds while in the field.

Pangu Meteorite

In the farthest reaches of the frozen Antarctic ice shelve, Chinese researchers discovered a 4.8 billion-year-old meteorite that had microscopic alien organisms deep within the rock. Decades later, after a Special Forces raid to retrieve a sample of the virus that had been cultivated from the discovery, Chelsey Trader is accidentally exposed to the Pangu Virus.

Becoming Patient Zero, inadvertently, she spread the virus, which infects innocent civilians which are mutated into monstrous beings under her control.

Build and Defend Your Base

  • Building: At the onset of the game, you’ll be able to build a base comprised of specialized buildings where new soldiers can be trained and research on the Pangu Virus can be conducted.
  • Defenses: As the threat from the virus grows, your base is at constant risk of being overwhelmed as random and planned encounters with the infected threaten to overrun your only means to find a way to stop the outbreak.
  • Patrolling: As the infection grows, more and more parts of the city fall to the Pangu Virus. You must send out patrols to each section of the world and destroy toxic gas towers that spread the virus at an alarming rate.

Infection System

The Pangu virus grows stronger by the minute. Complete missions and destroy infection pods throughout the map to lower its spreading rate. Be warned, each soldier under your command is equally at risk of becoming infected.

Tactics on the Battlefield – Combat Features

  • Command Captain Winter as your powerful hero character.
  • Train soldiers across various disciplines. These include assault, heavy weapons, Spec-Ops, sniper, scientist, and medical.
  • Use tactical awareness to slow downtime and get out of sticky situations!
  • Use different squad formations to give you a tactical edge over the infected.
  • Use different team dynamics by utilizing specialized units in conjunction with their counterparts for maxim effect.
  • You’ll have access to other tools such as carpet bombs, ammo drops, and more!
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