Long exposure photos on iPhone: NightCap lets you shoot in low light.

Discussion in 'iOS Apps' started by psonice, Jan 6, 2012.

  1. psonice, Jan 6, 2012
    Last edited: Jan 6, 2012

    psonice macrumors 6502a

    Jul 22, 2005
    Yep, it's finally possible, and the results can be seriously good for low light and night time photos:


    Those two photos were taken on an iPhone 4s, once with the built-in camera app and once with NightCap. No software tricks, photoshopping etc., these are the original photos, and that was the best I could get from the built-in app.

    App store link: http://itunes.apple.com/us/app/nightcap/id486414195

    NightCap is a simple camera app, the only thing it does differently from the built-in camera app is let the camera use much longer exposures - it will take up to 1 second (the camera app only goes to 1/15th). This is the first app to make this possible. It means much brighter photos in low light (like the shot above) or less grainy photos (it will use longer exposure and reduce the ISO level giving a cleaner image) in many cases.

    There's also a manual mode where you can set exposure between 1s and 1/20th (or 1/15th on iPhone 4 or 3GS). This locks the exposure, although Apple's camera controller will over-ride it if the image gets over-exposed.

    It takes full-res photos of course. It supports iPhone 3GS, 4 and 4S, plus the iPod Touch (with camera), and it needs iOS 5.

    If you try it and have any suggestions, let me know - we're writing NightCap 2 at the moment (self-timer, grid and exposure/focus/white balance lock are already on the list). If you take a cool photo with it post it up :)

    I'll post some free download codes in the promo codes forum in just a moment. In the meantime here's a couple more comparisons:

  2. psonice thread starter macrumors 6502a

    Jul 22, 2005
  3. psonice, Jan 6, 2012
    Last edited: Jan 6, 2012

    psonice thread starter macrumors 6502a

    Jul 22, 2005
    An explanation of the 'location services' thing, as it was asked in the promo codes thread:

    Because photos can contain GPS data if they're geo-tagged, so in theory the app could access locations you've visited in the past. Apple therefore requests your permission to use your location when nightcap displays a photo. All apps need this permission if they want to access the camera roll.

    If you read the message carefully when it asks this is actually what it says, but it's not exactly clear. We didn't understand it either when we came across it - we thought it was geo-tagging the photos and asking for permission to do that! Unfortunately this feature (and the message) are built into iOS so we have zero control over it. Apple should certainly make the message a bit clearer though.

    We're very much pro-privacy by the way. The app doesn't use your location at all and there's no tracking/reporting/whatever else at all in the app. There's no geo-tagging either (although we're looking to add that in the next version).

    ** Edit: Even iMovie asks for permission to use the photo library! http://forums.macrumors.com/showthread.php?p=14118745 **
  4. calb macrumors 6502

    Mar 12, 2009
    It's a useful app. I've attached some shots below, comparing the default Camera app, the NightCap app, and each shot ran through Camera+'s Clarity mode.

    The first set of four is perhaps the best example of how NightCap works versus salvaging a dark picture after the event. Much less noise but also more difficult to get a fully focused and sharp shot.

    The second set of four demonstrates the challenges and limitations. Clarity version of the default picture retains (and brings out) the detail, but with serious colour distortion on the dog's head. The NightCap picture is slightly blown out (on toy's face, white fur), although it's been left on auto. I should have taken some shots with Apple's HDR feature turned on for comparison, but my memory isn't perfect.

    NB: What are the lightish areas in the NightCap photos? (See right on dog pics, bottom on candle pics.) If you can't see the areas I mean, I'll blow them up full size and repost.


  5. psonice thread starter macrumors 6502a

    Jul 22, 2005
    Thanks, this should be useful for people - it's a pretty fair first look at the app I'd say.

    Yes, longer exposure time always means camera movement is much more likely to get caught - it's important to stay very still when taking the shot. Ideally, rest the phone against something solid so it stays stationary, or use a tripod. If you can keep the camera still the photos will be just as detailed and focused, but brighter and with less noise.

    You can use tap-to-expose to avoid blown-out highlights - in this case you would tap on the white part of the dog or maybe the brighter part of the carpet to get it balanced correctly. If you left it on fully automatic, then actually the built-in camera app would have blown the highlights too if the light was brighter because both apps use the same camera control system.

    HDR probably won't help in the camera app, and might even make it worse in low light. HDR combines a darker exposure shot and a brighter one, and the camera app can't go any brighter so you'd be mixing a dark, grainy image with an even darker, grainier one. It would have helped in the NightCap photo because that's actually a bit over exposed, but unfortunately apple don't give developers any access to the HDR functions! Maybe we can add HDR functionality in future - I'll get this added to our list of stuff to investigate.

    It looks like the camera is getting hot in that area - if the chip gets a bit too warm it can cause bright areas in part of the image. This is a well known problem with some DSLR cameras when doing long exposures, but we haven't seen it in NightCap before. Which iPhone model are you using? And had you been using the phone for a while before taking these shots? Do you still see it if the phone is left on standby for a while so it's nice and cold?

    It won't cause any harm at all, beyond being annoying in your photos! Unfortunately Camera+'s clarity feature will make it worse, because it's designed to emphasise slight differences in light and dark areas. If it turns out to be a common problem we'll add a new feature to remove it. :)
  6. UFGatorMel macrumors member

    Jan 10, 2012
    I saw a couple people trying out your app on Instagram. Nice!
  7. psonice thread starter macrumors 6502a

    Jul 22, 2005
    Hey, thanks - I wasn't aware of that! If anyone else wants to see, you need to go into your profile in instagram and then 'search instagram', then 'tags', and search for nightcap. It's mostly pictures of booze, but there are a few good examples of nightcap photos too.

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