Years ago the photo camper had an easy time. A selenium cell light meter or just plain old exposure calculation charts that were frequently memorized, a few rolls of film and a mechanical camera. Though heavier, mechanical cameras never suffered from the cold. Indeed the Leica M4 could work down to -20F (-29C).
These days the worry is always of battery depletion. Running out of film now is highly unlikely since memory cards are so small, light and easy to pack. Whereas a film photographer with a mechanical camera could shoot until she ran out of film, the digital photographer does not have this luxury. Typically with a compact digital camera such as an Olympus PM1 (cited as I own one), the battery will last maybe 300 photos. That means carrying multiple batteries and of course multiple memory cards and hoping that they will remain charged.
There is, however, another option. While a film photographer could carry a bag containing fifty rolls of film or 2,000 exposures, the digital photographer can carry a lightweight solar panel. The two below are both 10W flexible solar panels. The one on the left can be found on Aliexpress sold as a 20W solar panel and the one on the right can be found on eBay sold as a 20W/30W/50W/60W solar panel. Don't believe the figures - they're both really 10W.
Of course, solar panels on their own are no good to man nor beast. To go with them since both have USB fittings on the back, you'd need a USB cable. In fact I'd recommend several since the micro USB connectors seem to be particularly fragile.
Many phones, cameras and laptops or tablets can be charged straight off USB. That's good on the down days when one is just sitting around camp doing laundry etc. For the go getting photographer I do recommend another approach.
This is a nifty little charger that will run off a USB charging source. It charges just about any battery in common usage including 18650 lithium batteries. It will charge NiMh, NiCad and LIon batteries in a wide variety of sizes. It also has another trick up its sleeve - it can also be used as a power bank. Taking the micro USB end of the cable out of the micro USB socket and putting the standard USB end into the standard USB socket on the back, the micro USB end can be used to charge devices.
With all the batteries for the photographer's devices charged, the solar panel can be left in the sun charging 18650 batteries so when the photographer gets back to camp at the end of a long gruelling day the 18650s are charged and it's possible to charge camera, phone, etc.
Speaking of camera battery charging there is another option. There are plenty USB powered camera battery chargers. Apologies for the lack of clarity and focus on the photos of the camera battery charger. I took these with my interim cell phone. More on that, later.
So, everything a photographer needs to carry can be charged from a simple lightweight solar panel. The caveat is that there has to be sufficient sun and that the solar panel cannot be damaged.
Now, a quick calculation. I got 11W out of that panel at midday on a good day with no clouds. How much will that generate on an average day? Assuming 50% capacity over 8 hours then that's going to be 80WH or about 6AH. So there should be plenty to charge one camera battery in a day or all four 18650 cells or a cell phone or a compact laptop/tablet. To be a real power hog, more panels would be needed but they're not expensive.
Typically a 10W flexible solar panel is mis-sold as a 20W/30W/50W/60W and it absolutely is not. Go for the lowest priced flexible panel and it'll likely be 10W. The tell-tale sign is the photo of the back of the panel which will demonstrate clearly that it has no sticker.
As can be seen, neither panel has a sticker advising the capacity or any other technical details. Once the panel is purchased and the capacity verified as being less than advertised, it's possible to take out a claim against the seller on eBay or AliExpress and get a refund. It'll cost the seller more to get the panel shipped back on top of the refund so basically, that's how to get a free solar panel. Both of those were free because the seller lied about capacity. If one buys something and it is not as advertised, under law one deserves redress. The Aliexpress panel I had to chase through the bank for a chargeback as AliExpress seems to be crooked. I don't advise AliExpress. eBay is much more straightforward. I've heard some pretty rough things about BangGood too but haven't used them so can't give an opinion.
As for the AliExpress and eBay sellers, I urge everybody to buy mis-advertised solar panels and then to make a claim against the seller via AliExpress and eBay. That was the bad actors can be wiped off the face of the planet. There is no room in this world for dishonesty and if you get a free solar panel out of it, that's a sheer bonus. For myself, I have two flexible 10W panels that really aren't that much use for anything bar camping which is an activity I don't pursue. Sold used, I'd probably not get as much money as it would cost to post them to a buyer so they're sitting taking up not very much space in my attic.
Now, why the blurry images of the camera battery charger? Well, for a long time, Straight Talk was the carrier of choice for my phone. It became pretty darned good. It was possible to use Verizon or AT&T or any of the other also-ran networks. Thus my phone was on Verizon through Straight Talk. At the beginning $45 got 3GB data plus the phone could be used as a hotspot. That in fact is exactly what I used the phone for and the only reason I had a phone. Then the service improved to 4GB and $45 then 5GB and $45 then in came a lower priced plan $35 for 4GB then $35 for 5GB. Then suddenly the use of my phone as a hotspot was blocked. I paid for my data and didn't use it all every month yet the hotspot feature was blocked. That led to an investigation when I discovered that I'd been paying for a service that I was not getting. Clearly no amount of arguing against a mindless corporate entity would have any effect on a commercial decision affecting not just me but others too. I voted with my feet and went for a straight AT&T prepay phone. Currently that's 2GB data for $35 but a new plan is coming with 8GB a month for a $99 payment that covers 3 months. Effectively that's 3GB more data per month than Straight Talk for $2 less per month.
The most annoying thing about changing providers like that was that I'd not long bought an iPhone on Straight Talk. I liked my iPhone but could not put up with zero service. So, I have an interim phone that works well enough but takes lousy pictures. That was the route chosen just in case AT&T didn't work out. It seems to be working out so perhaps the next step will be to get a better Android or an iPhone.
