Hi, I am curious about how you are performing & measuring timings between subsequent shots as there may also be some variability according to your method(s). For example, I found that using a Timer object there was some variability in when the task was actually run, sometime by a few hundred milliseconds. I had done some related work a while back trying to closely synchronise the cameras shutters of multiple Android devices connected via Bluetooth. This was successful to a degree but would sometimes lock up a Nexus S entirely, if the intershot delay was less than a few seconds.
Regards, the other gjs. On Wednesday, August 1, 2012 12:41:27 AM UTC+10, greg wrote: > > Thanks for the suggestions. Based on them I tried disabling all the camera > auto parameters. There is still a range of about 0.2 s in the shutter lag > time. In this application (and perhaps there are others), I'm more > concerned about the variability and not the average duration of the lag > time. I have posted a feature request to the Android issue tracker to add > an optional minimum shutter time argument in Camera.takePicture() that > would delay the shutter if it were ready before the specified minimum. If > you think you might find that extra control helpful in a future > application, "star" the feature request at > http://code.google.com/p/android/issues/detail?id=35785 > > Thanks! --Greg > > P.S., We have the same initials, and for a while a few years ago I used > those same initials as an on-line signature. Our writing styles are similar > enough that I sometimes read your posts and momentarily wonder, "Did I > write that?" :*) > > On Monday, July 30, 2012 9:02:37 PM UTC-4, gjs wrote: >> >> Hi, >> >> Set other camera parameter values to non-auto settings eg: set a specific >> white balance such as daylight, set flash to off etc. >> >> Other than that ensure there is no other non essential app's / services >> running at the same time & examine your own app to minimise or eliminate >> any garbage collection, reduce sensor use / frequency. >> >> Try a few different devices, dual cores, quad cores particularly those >> claiming zero shutter lag. Some devices let you vary the camera preview >> frame rate & preview size maybe try this as well, not sure if that would >> make a difference as I've have not tried this myself. >> >> If that is still not good enough consider triggering a remote camera >> instead, such as an SLR via bluetooth or usb. >> >> Regards >> >> On Tuesday, July 31, 2012 6:41:53 AM UTC+10, greg wrote: >>> >>> Thanks Richard. Setting the focus to >>> Camera.Parameters.FOCUS_MODE_INFINITY helped as shown in the added >>> histogram at >>> http://stackoverflow.com/questions/11727240/how-to-reduce-the-variability-in-android-camera-shutter-lag >>> >>> At the risk of sounding like an ingrate, do you have any ideas on how to >>> reduce the variability even more? (A range of 0.2 s still covers a large >>> portion of the periodic motion.) >>> >>> -- Greg >>> >>> On Monday, July 30, 2012 3:05:50 PM UTC-4, RichardC wrote: >>>> >>>> Could it be related to auto-focus? Try turning it off. >>>> >>>> On Monday, July 30, 2012 7:55:52 PM UTC+1, greg wrote: >>>>> >>>>> Given a known periodic motion (e.g., walking), I'd like to take a full >>>>> resolution snapshot at the same point in the motion (i.e., the same time >>>>> offset within different periods). However on the Nexus S (currently >>>>> running >>>>> OS 4.1.1 but the same was true of previous OS versions), I'm seeing so >>>>> much >>>>> variability in the shutter lag that I cannot accurately plan the timing >>>>> of >>>>> the snapshot. Is there anything I can do in the application to reduce >>>>> this >>>>> shutter lag variability? (In this application, the mean lag can be any >>>>> duration but the standard deviation must be small ... much smaller than >>>>> the >>>>> 0.5 s standard deviation I am seeing.) I'm hoping someone has a clever >>>>> suggestion. If I don't get any suggestions, I'll post a feature request >>>>> in >>>>> the Android bug tracker. >>>>> >>>>> I've posted the same question (and showing a histogram of camera >>>>> shutter lag times) at >>>>> >>>>> >>>>> http://stackoverflow.com/questions/11727240/how-to-reduce-the-variability-in-android-camera-shutter-lag >>>>> >>>>> Thanks! -- Greg >>>>> >>>> -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
