I have bought a Pentax Optio A30 to use as my aerial camera. It is similar to a number of the latest generation of sub-compact 10Mpixel cameras and has good reviews, especially in terms of its image quality. It weighs about 160gm with battery and SD memory card and at 58mm, has one of the smallest widths I have found – important for fitting into the Cularis body.
The highest resolution image is quoted as 3648 x 2736 pixels. Based on the handbook, a 4Gbyte SD memory card at the best quality jpeg setting, should give about 1200 images. The camera has a continuous mode where images are taken and downloaded to the SD card as fast as possible as long as the shutter is pressed. One option for using the camera in the UAV, is to set it running in continuous mode and then select 1 in n of the images produced to make the photo-composite.
With a fully charged battery, I tested the camera in continuous mode while photographing a clock. The camera managed to capture 1613 images at full resolution in high quality mode in 23 minutes before filling the 4Gbyte SD card. The battery indicator showed about half full at the end of the run. Although the average interval was about 1.2 seconds, there were some gaps between images of up to 8 seconds and in other cases, 2 sequential images showed the same time. Both results suggest that the timing is not constant, but is a function of the amount of data that needs to be stored on the card. The review also states that the file size varies a lot depending upon the image content, so this make matters worse.
I then tried taking photos at timed intervals. I could get down to about a 4 second interval with only an occasional missed image, although this may have been finger trouble. So if I want images taken at regular, known intervals, I will have to use a servo driven IR interface such as the PRISM.
Now to look at flying the camera. There are two limiting scenarios.
Comments and Questions.