Hi

Iâ€™ve been doing some experimenting with my book scanner rig last night using my A1400s; thanks to waterwingz for helping me crack the problem of zoom-induced crashes.

I have a couple of other queries from the images I took last night; Iâ€™d be grateful for any advice on these issues.

The first is variable shutter speeds when taking images. The first image represents what I would call a useable exposure for post-processing. The shutter speed was 1/20.

The second image, for me, is too dark. Shutter speed was 1/80.

What is confusing me, is that all other variables with the cameras were identical. ISO 10, f/4, identical lighting conditions. So I am guessing that the variation in speed is either due to a difference between the two cameras, or, what was being photographed, eg a large white (brighter) subject, and a more text-heavy (darker) subject.

I may be answering my own question here, but is the way to ensure a uniform shutter speed to change >Disable Overrides, and go into >Override Shutter Speeds and enter the required values?

The other issue concerns focus; I have mentioned setting manual focus before. I have worked out how to disable autofocus. Will setting the subject distance in chdk override the AF Frame Mode set on the A1400? I am guessing that Iâ€™ll also need to fiddle with aperture settings?

Sorry for these long, endless enquiries. I have a basic knowledge of photography, and it can be confusing working out how chdk and the native A1400 firmware interact with each other.