Accuracy Determination - TimeStamp Camera App for iPhone
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  1. #1
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    Accuracy Determination - TimeStamp Camera App for iPhone

    Does anyone use the iPhone TimeStamp Camera app to determine the accuracy of their quartz\HAQ watches? If you pay $4.99 for the premium app, it will provide video and photo timestamps that are to the thousandth of second (I’m fine with the hundredths-of-second precision)! This is what I use to determine the accuracy of my mechanical, quartz, and digital quartz watches.

    I believe the reference time on the iPhone is pretty darn good. In fact, when I use the Emerald app, it seems like it’s almost always within 50 milliseconds, and often it’s within 10 of NIST. For analog watches (especially mechanicals), I just use a photo, but for digitals, I use the video and find the precise moment when the second forms solid numbers on the LCD.

    I don’t think there is an easier or quicker way to get the job done. Who else uses this app?
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    Re: Accuracy Determination - TimeStamp Camera App for iPhone

    Quote Originally Posted by bmp3141 View Post
    Does anyone use the iPhone TimeStamp Camera app to determine the accuracy of their quartz\HAQ watches? If you pay $4.99 for the premium app, it will provide video and photo timestamps that are to the thousandth of second (I’m fine with the hundredths-of-second precision)! This is what I use to determine the accuracy of my mechanical, quartz, and digital quartz watches.

    I believe the reference time on the iPhone is pretty darn good. In fact, when I use the Emerald app, it seems like it’s almost always within 50 milliseconds, and often it’s within 10 of NIST. For analog watches (especially mechanicals), I just use a photo, but for digitals, I use the video and find the precise moment when the second forms solid numbers on the LCD.

    I don’t think there is an easier or quicker way to get the job done. Who else uses this app?
    What frame rate are you using on the iPhone when using the App?

    TIA
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    Re: Accuracy Determination - TimeStamp Camera App for iPhone

    I have the video set to 720P 30fps. I'm going to change it to 720P 60 fps and see if I get better results.

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    Re: Accuracy Determination - TimeStamp Camera App for iPhone

    Quote Originally Posted by bmp3141 View Post
    I have the video set to 720P 30fps. I'm going to change it to 60 fps and see if I get better results.
    No matter what the time stamp is showing, the resolution @ 30fps is only 0.033 seconds and @ 60fps 0.017 seconds. After shooting the video, does the App allow you to review it frame by frame?
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    Re: Accuracy Determination - TimeStamp Camera App for iPhone

    Yes. At 60 fps, I can look at the resulting video in 0.02 sec increments, and of course the reference time could be off by as much as 20 milliseconds. This doesn't seem that bad to me. COSC accuracy is 70 milliseconds per day. I was able to regulate my Elektronika 53 pretty well using this app.

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    Re: Accuracy Determination - TimeStamp Camera App for iPhone

    Quote Originally Posted by bmp3141 View Post
    Yes. At 60 fps, I can look at the resulting video in 0.02 sec increments, and of course the reference time could be off by as much as 20 milliseconds. This doesn't seem that bad to me. COSC accuracy is 70 milliseconds per day. I was able to regulate my Elektronika 53 pretty well using this app.
    And HAQ accuracy is 27 milliseconds per day and requires a thermocompensated movement.
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    Re: Accuracy Determination - TimeStamp Camera App for iPhone

    This wouldn't be a method to determine a HAQ watch's accuracy after just a day or two. But I think the precision and accuracy are pretty good given that you can do it quickly and with no other equipment than your phone.

    I don't think HAQ has a standardized definition, and I think that's a good thing. COSC is 70 milliseconds per day (25.55 spy). You can get HAQ without a thermocompensated movement: there are some high-frequency movements (like the Casio SP-400 4 MHz) with no TC that can get within 10 spy. And there are some thermocompensated movements like the Rolex OysterQuartz (accuracy: 60 spy) that don't perform within the rather generous COSC specs.

    Also, at least anecdotally, many have reported regulating a standard quartz movement within HAQ accuracy. I'm told that this "doesn't count," but to me, the proof is in the pudding. If a well-regulated quartz movement can consistently come within 25.55 spy (COSC accuracy) under normal wear conditions, who is to say that it's not "high accuracy"?

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    Re: Accuracy Determination - TimeStamp Camera App for iPhone

    Quote Originally Posted by bmp3141 View Post
    I don't think HAQ has a standardized definition, and I think that's a good thing.
    The Moderator of this forum disagrees: https://forums.watchuseek.com/f9/wha...t-5039357.html

    HTH
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    The 10 seconds per year metric for HAQ is like the pirate code. It’s more of a guideline than an actual rule.

  11. #10
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    Re: Accuracy Determination - TimeStamp Camera App for iPhone

    Quote Originally Posted by bmp3141 View Post
    The 10 seconds per year metric for HAQ is like the pirate code. It’s more of a guideline than an actual rule.
    Mr. Moderator recommends you stick to the topic of timing

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