The Sony a77 has an electronic level gauge in the display which shows how much the camera is tilted sideways and forward/backward. Sort of like an attitude indicator / artificial horizon in an aircraft. When the camera is level, the color of the pointers will be green.
I wonder if the angles measured by this level gauge are recorded in exif? Knowing the tilt angle would be very useful when straightening a tilted image in post processing.
I can take some test photos and send the exif, but I am a little uncertain how to do it in a way which makes the information easy to find. Of course I can take one photo tilted both ways, one photo with green confirmation on sideways level, one photo with green confirmation on forward level and one photo with green confirmation on both. But that will probably only help to find the confirmation info and not the actual angle info.
Hi Allan,
This sounds good. I decoded this information for my Pentax K-5, and it is useful.
I can measure the roll angle from the image if your subject has a horizontal or vertical line. The pitch angle is harder to measure, but probably encoded the same was as the roll angle. If you send me 10 pictures, 5 with the pitch level and different roll angles, and 5 with the roll level and different pitch angles, I should be able to figure this out. Set the camera to the smallest JPEG image format, and email the pictures to philharvey66 at gmail.com. Thanks.
- Phil
I took the requested 10 photos in landscape, then another 10 in portrait as I assume that you will need that too. And finally a single photo with both axes off.
I have tried to keep one of the axes green all the time, and the extreme angles were approximately at the "end stops" in the level gauge on screen.
That made a total of 51 MB, even with the lowest quality and image size. So instead of mailing them, I uploaded them in a .zip file here:
http://www.myupload.dk/showfile/1koWGiX_2.zip (http://www.myupload.dk/showfile/1koWGiX_2.zip)
As most other upload/download services, they make the real download link really difficult to find and instead use a large download button to generate clicks to some advertized tool. So do NOT press the green download button. The download link is a text link labelled "Download now", right below the commercial at the bottom, .
Thanks. I'll let you know if I can find anything.
- Phil
Thanks for the samples.
Wow. Sony doesn't make this easy. As far as I can tell, if the level gauge information exists it must be in one of the large binary data blocks in the maker notes. I have sifted through all of this data now, looking for patterns to match the sample images you took (good set of samples, btw), but unfortunately haven't found anything yet. So if it exists I must have missed it. I haven't given up hope, but it's not looking too good at the moment.
- Phil
I will keep my fingers crossed. But I can imagine that it must be really difficult to find this kind of data with an almost infinite number of states.