Hello, I recently tried making my first timelapse using the Auto Holy Grail feature in DslrDashboard. I used a Canon 6D paired to an iPhone 6, with a Polaroid intervalometer set to take a picture every 7 seconds. I set slowest shutter speed to 2" to allow plenty of time for previews to load. Everything went fine until as it got dark, shutter speed increased to 1". At this point, images continued to be captured, but without compensation for light changes by the application. I thought that my SD card was not fast enough, so I got a 65 GB card and retested, but found the same problem. Finally, tonight I tried again using the DslrDashboard internal intervalometer and did not have any issues. It seems that when I use the Polaroid intervalometer, as the exposure time increases, this is not accounted for by the intervalometer, which continues telling the camera to take a photo every 7 seconds, regardless of whether the camera is still processing a capture. Has anyone else encountered this problem, and if so, are there any suggestions of how to fix this without relying only on the internal intervalometer? Thanks very much

This post was last modified: 2016-01-07, 10:29 by Gunther.

It's unfortunately quite common with some intervalometers, that the "block" the AF signal all the time, this will prevent the camera from transmitting the image. This even happens with the original ones from canon and nikon.
So either you cut the AF-Signal cable or you buy a Pixel Timer that is known to work as expected: http://amzn.to/1NNajzU

Update: here is an article from me about that issue with intervalometers: http://lrtimelapse.com/news/intervalometer-hack/

Excellent, thanks!

So I tried recording another sequence, this time using the internal intervalometer in DslrDashboard. All other settings were similar to what I described previously. This time everything seemed to work well, up until the shutter speed reached 2.5 sec. At this point the camera continued taking photos, but the images would not show up in the DslrDashboard app, and as it became darker there was no compensation for changing light levels. 

Furthermore, before it stopped working, there were several instances when intervals randomly deviated from what I had set (7 sec). What's going on here?

Thank you,
Zach

I assume, the darktime (difference between shutter time and interval) was too short for the transmission of the preview then.
The minimum darktime depends on your setup. With my D750 internal Wifi I can get as short as 2-3 seconds - but with other setups I know that it can take longer.
Try setting the jpg size and quailty as low as possible (on nikon you can only control the quality, on canon the size too).
Let us know a bit more about your setup: camera, tablet, connection between both etc...

Here is an article explaining, how to fix the annoyances with external intervalometers to get the best performance: http://lrtimelapse.com/news/intervalometer-hack/

Hi Gunther, thanks for sharing that article, I will check it out! I am using a Canon 6D paired with an iPhone6 using the cameras internal wifi, and internal intervalometer in DslrDashboard. JPG size and quality are both set to lowest possible settings.  I set the interval at 7", with longest exposure of 4". I think these settings are the same as what you used in your tutorial video, so I am confused as to why the darktime would be too short. (unless using a tablet allows for shorter darktime than iphone?) I tried turning off mirror lock-up to see if that would help, but still, when shutter speed reaches 4", interval doubles from 7" to 14".

This post was last modified: 2016-01-07, 17:41 by Gunther.

iPhone might not be the fastest. I know of setups with Canon and iOS where 3 seconds are not enough. Just keep experimenting with different setups. Using a TPLink router might help too.
But I guess an external intervalometer (I mostly don't use the internal timer in qDDB) will do the trick.