Nikon P310 - Infinity Focus and Flash

Question

I have a Nikon P310 point and shoot which I intend to use for a very specific application. I want to use infinity focus setting. However, when selecting infinity focus the camera disables the flash. So, a two part question:

1. Why would Nikon do such a thing? I assume there is a reason behind this.
2. Is there something I can do to force the P310 to use the flash? I have a workaround but it is not optimal. The workaround is to place the camera in manual focus mode and set it to infinity that way. This would be acceptable accept the camera does not remember the manual focus setting after powering the camera off which is quite a pain in my application.

Any thoughts?

Answer 1

I can guess about question 1. You say this is a point and shoot, so it is dumbed down for the masses. Past some distance, the built in flash won't do anything but run down the battery. There won't be enough light from the flash hitting the subject. Light intensity falls off with the square of the distance from the source. Another way to think of that is that the flash looses 2 f-stops every time the distance is doubled. Eventually, and that's probably only a few 10s of feet at best, the flash no longer does anything useful. Because this camera is aimed at people who don't understand all that, Nikon probably figured disabling the flash at far focus distances would keep people from complaining about excessive battery drain, or complaining that their flash shots didn't work. Sounds like a reasonable feature to me given the intended market.

It always amazes me when I see people using flash just because the light is low even when the subject is far. For example, consider how often you see a flash go off in the stands at sporting events. There is no way any of those flashes in the stands are going to add measurable illumination to anything on the field. Just last week I saw people taking pictures of fireworks with flash on. Not only are they too far away, they are self-lit and illuminating them externally would only make the picture worse. There is a reason fireworks displays are after dark.

Answer 2

Responding following Jason's clarification of what he's doing: I'm afraid point and shoot cameras aren't really usually designed to be used with external flash units of any kind. Some cheap bridge and mirrorless cameras support wireless flash out of the box, including the Olympus E-PL1, which sells new (body only) at Amazon for $150. From the Amazon description:

"The camera is also compatible with a range of optional external flashes, including the Olympus FL-36R and FL-50R, which can be controlled wirelessly by the E-PL1 so you can dynamically control lighting as your photography skills grow."

The Nikon P310 actually costs more new so you may be able to make the upgrade with no net loss. I think this is better than trying to hack your P310. It's also a much better camera all around, with a micro 4/3s sensor, interchangeable lens support, full manual controls, etc.