Longtime Exposure

 

Long Time Pro Exposure Calculator

Longtime Exposure:

ND Filter
In photography, a neutral density filter or ND filter is a filter that reduces or modifies the intensity of all wavelengths orcolors of light equally, giving no changes in hue of color rendition. It can be a colorless (clear) or grey filter. The purpose of a standard photographic neutral-density filter is to reduce the amount of light entering the lens. Doing so allows the photographer to select combinations of aperture, exposure time and sensor sensitivity which would otherwise produce overexposed pictures. This is done to achieve effects such as a shallower depth of field and/or motion blur of a subject in a wider range of situations and atmospheric conditions.

For example, one might wish to photograph a waterfall at a slow shutter speed to create a deliberate motion blur effect. The photographer might determine that to obtain the desired effect a shutter speed of ten seconds was needed. On a very bright day, there might be so much light that even at minimum film speed and a minimum aperture, the ten-second shutter speed would let in too much light and the photo would be overexposed. In this situation, applying an appropriate neutral-density filter is the equivalent of stopping down one or more additional stops, allowing for the slower shutter speed and the desired motion-blur effect. http://en.wikipedia.org/wiki/Neutral_density_filter

Longtime Longtime  will help you to calculate long exposure times automatically when using ND Filters instead of reading exposure tables or calculate exposure times in mind.

UsageFind a suitable position for your composition as you would do for any shot. Note it’s vital to use a tripod with these shots due to the long exposures. Once you have the shot composed the next step is to work out what exposure will be needed. Provide Longtime with your desired ND filter and the mettered shutter speed by your camera. Adjust the shutter speed of your camera to the calculated exposure time. Set your camera to „Bulb“ or „B“ if shutter speed ist more than 30 seconds.

Für die Langzeitbelichtung verwenden viele Fotographen Filter vom Typ ND (Neutral Density) um die Belichtungszeiten bei Tageslicht deutlich zu verlängern. Beliebt ist der Filter B+W ND1000 welcher die Belichtungszeit um 10 Blendenstufen verlängert. Für die Berechnung der verlängerten Belichtungszeit soll die App „Longtime Exposure“ dem Fotografen eine Hilfestellung geben.

download at the App-Store

Coming soon: LongTime 2

  • improved user interface
  • Apple Watch integration
  • calculation for multiple filters attached

15 Responses

  1. Bossley
    Bossley · April 6, 2015 at 13:18:51 ·

    The Timer stop with all Iphone… It’s time to find a solution…

  2. Bossley
    Bossley · November 14, 2014 at 10:09:50 ·

    Thank you for your answer, but IOS does not stop its own timer during a stand by…
    I wait your solution, Best regards.

    1. Bossley
      Bossley · April 6, 2015 at 13:15:32 ·

      I’m looking for a solution…..

      SO DO YOU HAVE THE SOLUTION ????????? The pro application is not neccessary don’t you think ?…

  3. Bossley
    Bossley · November 14, 2014 at 09:58:19 ·

    Do you have solution ?
    Thak you very much !

  4. Bossley
    Bossley · November 13, 2014 at 15:23:19 ·

    The timer stop when your Iphone is in stand-by during the Time exposure…

    1. Tom
      Tom · November 14, 2014 at 10:04:19 ·

      Hello Bossley,
      thanks a lot for your hint. iOS stops any timer or process from applications when the phone goes in stand-by. I’m looking for a solution.

  5. Astrid
    Astrid · Oktober 14, 2014 at 11:19:42 ·

    Hello. Is there a version of this application for Android phones or is this just available for iphones? I would so love to have it on my phone but its an Android. I have found a calculator for Android but it does not include a timer with it. Thanks. Astrid.

  6. 5 handige fotografie-apps voor smartphones - Dolfilms
    5 handige fotografie-apps voor smartphones – Dolfilms · September 24, 2014 at 21:02:04 ·

    […] fotografie-apps die de moeite van het proberen waard zijn. LongTime Exposure Calculator: http://muc365.wordpress.com/longtime-exposure/ (Apple) f/8 DoF Calculator: http://www.bitwerkz.ch/f8.html (Apple) Pocket Light […]

  7. Jo Backa
    Jo Backa · August 10, 2014 at 21:47:24 ·

    Hallo,
    ist die Entwicklung eines solchen Tools auch für andere Plattformen außerhalb iOS denkbar ?

    1. Tom
      Tom · August 20, 2014 at 19:05:59 ·

      Ich habe mich bis jetzt noch nicht mit Android befasst aber möglicherweise an langen Herbst- und Winterabenden.

  8. LML
    LML · September 13, 2013 at 11:30:37 ·

    What is the difference between Longtime Exposure and Longtime Pro?

    1. Tom
      Tom · September 26, 2013 at 12:35:56 ·

      Longtime Pro has an improved interface. The main difference is the ability to set a timer for the calculated exposure time.

  9. Longtime Pro iOS Mobile App ID 618478580
    Longtime Pro iOS Mobile App ID 618478580 · Juli 28, 2013 at 13:41:15 ·

    […] (App ID 618478580)Genre or Category: Photo & VideoPrice: $0.99Version: 1.0Developer: Thomas Penn at http://muc365.wordpress.com/longtime-exposure/Rating: out of 5, by usersContent Rating: 4+File Size: 2.37MRelease Date: March 22, 2013Release […]

  10. Tom
    Tom · April 5, 2013 at 07:14:24 ·

    Hello Didier,
    first of all, many thanks for buying „LongTimePro“. I hope this tool helps you with creating your long time exposures.

    ND filters are quantified by their optical density or equivalently their f-stop reduction. Hoya do a 9 stop ND filter which they call the ND400, based on the table below it ought more logically to be called an ND512 flter. The ND400 is more inbetween. In the App (as a single filter) I gave it a 8 2/3 stop.
    Stops………..Filter Designation…………….Remaining Light
    1………………ND2……………………………half
    2………………ND4……………………………quarter
    3………………ND8……………………………1/8th
    4………………ND16………………………….1/16th
    .
    .
    .
    9………………ND512…………………………1/512th
    10…………….ND1024………………………..1/1024th (actually rounded down to 1/1000)

    Resuming:
    CPL – 1-2 stops (depending on brand daw)
    ND400 – 9 stops
    ND4 – 2 stops
    ND8 – 3 stops

    ND400 + ND4 = how many stops? 11
    ND400 + ND8 = how many stops? 12
    ND400 + CPL = how many stops? (possibly same as ND400 +ND4?) 10-11

    In your combination of a ND400 + ND8 you can work with 12 stops.

  11. Didier
    Didier · April 5, 2013 at 06:31:10 ·

    Hello,
    I just bought LongTimePro application, but I have questions:
    I use two filters mounted together (ND400 + ND8), I settle on anything in your application?
    5 stop; 7 stop, stop 9, 10, 11, 14, 15, 16, 17, 18 …….. this corresponds to what …?

    Thank you in advance for your answer

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