A simple solution would be to connect the panel to the input of a 1 amp 7809 voltage regulator,
and the output to a 6 AA holder.
Remove the batteries from the camera and place them in the holder. Point the panel toward the sun.
This would allow a slight overcharge of 0.05v for each battery, I wouldn't worry about it myself, unless the batteries were left charging for days at a time.
To ensure no overcharge, a 2.5 ohm resistor could be placed in series between the batteries and 7809, but this will slow the charging considerably.
Another way to ensure no overcharge is to use the first example, but use a 7808. However, this will result in never reaching a full charge.
It will take more than a day of good sun to get them full.
Most 7800 type voltage regulators will try to keep the voltage as high as they can up to their rating. A 7809 will try to stay at 9 volts (7808 is 8 volts). If it can't reach 9 volts (because the panel can't make enough current to instantly get the battery to 9 volts) it will do what it can, say 7 volts. This is good anyway, because you don't want the batteries getting so much current they instantly go up to 9 volts.
The wrong regulator. Some 7809's will stay at 9v if they can, but if they can't maintain 9v they shut off. You don't want this kind. The problem is you can't tell which is which, or at least I can't.
It would be wise to use a heat sink on the regulator.
I find TO-220 style regulator easier to use for something like this.
Don't go less than 1 amp rating for the regulator.
The regulators call for 2 capacitors, but I never needed them for this type of use, so I don't use them.
It's rare I get the 'wrong' type of regulator, so what ever one they have usually works for this.
Give it a try. Cheap and easy. The regulator has 3 wires, one to the panel positive, one to the battery positive, and one to both negatives.
G-
