• Laowa 25mm f/2.8 2.5-5X Ultra Macro vs 100mm f/2.8 2x lens

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    https://gilwizen.com/laowa-25mm-ultra-macro-lens-review/

     

     

    https://www.cameralabs.com/laowa-25mm-f2-8-2-5-5x-ultra-macro-review/

     

     

     

    • Pros:
      – Lightweight, small size for a high-magnification macro lens
      – Highest magnification lens available for non-Canon users
      – Excellent sharpness and image quality
      – Consistent working distance
      – Narrow lens barrel makes it easy to find and track subject
      – Affordable

     

    • Cons:
      – Manual, no auto aperture control
      – No filter thread (but still customizable with caution)
      – Dark viewfinder when closing aperture makes focusing difficult in poor light conditions
      – Magnification range is short 2.5-5x compared to the competition

     

    Combining a Laowa 25mm 2.5x lens with a Kenko 12mm extension tube

    To find the combined magnification when using a Laowa 25mm 2.5x lens with a 12mm Kenko extension tube, given the magnification of the lens itself, the extension tube length, and the combined setup, you can calculate the total magnification.

    First, consider the magnification of the lens itself, which is 2.5x.

    Then, to find the total magnification when the extension tube is attached, you can use the formula:

     

    Total Magnification = Magnification of the Lens + (Magnification of the Lens * Extension Tube Length / Focal Length of the Lens)

    In this case, the extension tube length is 12mm, and the focal length of the lens is 25mm. Using the values:

     

    Total Magnification with 2.5x = 2.5 + (2.5 * 12 / 25) = 2.5 + (30 / 25) = 2.5 + 1.2 = 3.7x

     

    Total Magnification with 5x    = 5 + (5 * 12 / 25)      = 5 + (60 / 25) = 5 + 2.4 = 7.4x

     

  • SourceTree vs Github Desktop – Which one to use

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    Sourcetree and GitHub Desktop are both free, GUI-based Git clients aimed at simplifying version control for developers. While they share the same core purpose—making Git more accessible—they differ in features, UI design, integration options, and target audiences.


    Installation & Setup

    • Sourcetree
      • Download: https://www.sourcetreeapp.com/
      • Supported OS: Windows 10+, macOS 10.13+
      • Prerequisites: Comes bundled with its own Git, or can be pointed to a system Git install.
      • Initial Setup: Wizard guides SSH key generation, authentication with Bitbucket/GitHub/GitLab.
    • GitHub Desktop
      • Download: https://desktop.github.com/
      • Supported OS: Windows 10+, macOS 10.15+
      • Prerequisites: Bundled Git; seamless login with GitHub.com or GitHub Enterprise.
      • Initial Setup: One-click sign-in with GitHub; auto-syncs repositories from your GitHub account.

    Feature Comparison

    FeatureSourcetreeGitHub Desktop
    Branch VisualizationDetailed graph view with drag-and-drop for rebasing/mergingLinear graph, simpler but less configurable
    Staging & CommitFile-by-file staging, inline diff viewAll-or-nothing staging, side-by-side diff
    Interactive RebaseFull support via UIBasic support via command line only
    Conflict ResolutionBuilt-in merge tool integration (DiffMerge, Beyond Compare)Contextual conflict editor with choice panels
    Submodule ManagementNative submodule supportLimited; requires CLI
    Custom Actions / HooksDefine custom actions (e.g., launch scripts)No UI for custom Git hooks
    Git Flow / Hg FlowBuilt-in supportNone
    PerformanceCan lag on very large reposGenerally snappier on medium-sized repos
    Memory FootprintHigher RAM usageLightweight
    Platform IntegrationAtlassian Bitbucket, JiraDeep GitHub.com / Enterprise integration
    Learning CurveSteeper for beginnersBeginner-friendly
    (more…)
  • Photography basics: Shutter angle and shutter speed and motion blur

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    http://www.shutterangle.com/2012/cinematic-look-frame-rate-shutter-speed/

     

    https://www.cinema5d.com/global-vs-rolling-shutter/

     

    https://www.wikihow.com/Choose-a-Camera-Shutter-Speed

     

    https://www.provideocoalition.com/shutter-speed-vs-shutter-angle/

     

     

    Shutter is the device that controls the amount of light through a lens. Basically in general it controls the amount of time a film is exposed.

     

    Shutter speed is how long this device is open for, which also defines motion blur… the longer it stays open the blurrier the image captured.

     

    The number refers to the amount of light actually allowed through.

     

    As a reference, shooting at 24fps, at 180 shutter angle or 1/48th of shutter speed (0.0208 exposure time) will produce motion blur which is similar to what we perceive at naked eye

     

    Talked of as in (shutter) angles, for historical reasons, as the original exposure mechanism was controlled through a pie shaped mirror in front of the lens.

     

     

    A shutter of 180 degrees is blocking/allowing light for half circle.  (half blocked, half open). 270 degrees is one quarter pie shaped, which would allow for a higher exposure time (3 quarter pie open, vs one quarter closed) 90 degrees is three quarter pie shaped, which would allow for a lower exposure (one quarter open, three quarters closed)

     

    The shutter angle can be converted back and fort with shutter speed with the following formulas:
    https://www.provideocoalition.com/shutter-speed-vs-shutter-angle/

     

    shutter angle =
    (360 * fps) * (1/shutter speed)
    or
    (360 * fps) / shutter speed

     

    shutter speed =
    (360 * fps) * (1/shutter angle)
    or
    (360 * fps) / shutter angle

     

    For example here is a chart from shutter angle to shutter speed at 24 fps:
    270 = 1/32
    180 = 1/48
    172.8 = 1/50
    144 = 1/60
    90 = 1/96
    72 = 1/120
    45 = 1/198
    22.5 = 1/348
    11 = 1/696
    8.6 = 1/1000

     

    The above is basically the relation between the way a video camera calculates shutter (fractions of a second) and the way a film camera calculates shutter (in degrees).

    Smaller shutter angles show strobing artifacts. As the camera only ever sees at least half of the time (for a typical 180 degree shutter). Due to being obscured by the shutter during that period, it doesn’t capture the scene continuously.

     

    This means that fast moving objects, and especially objects moving across the frame, will exhibit jerky movement. This is called strobing. The defect is also very noticeable during pans.  Smaller shutter angles (shorter exposure) exhibit more pronounced strobing effects.

     

    Larger shutter angles show more motion blur. As the longer exposure captures more motion.

    Note that in 3D you want to first sum the total of the shutter open and shutter close values, than compare that to the shutter angle aperture, ie:

     

    shutter open -0.0625
    shutter close 0.0625
    Total shutter = 0.0625+0.0625 = 0.125
    Shutter angle = 360*0.125 = 45

     

    shutter open -0.125
    shutter close 0.125
    Total shutter = 0.125+0.125 = 0.25
    Shutter angle = 360*0.25 = 90

     

    shutter open -0.25
    shutter close 0.25
    Total shutter = 0.25+0.25 = 0.5
    Shutter angle = 360*0.5 = 180

     

    shutter open -0.375
    shutter close 0.375
    Total shutter = 0.375+0.375 = 0.75
    Shutter angle = 360*0.75 = 270

     

     

    Faster frame rates can resolve both these issues.