I recently came across an old camera that I took around Asia back in 2013. It still had a few shots from time in Assam and especially Nagaland, which I uploaded and fixed up a bit (Flickr album here). And it reminded me much I hated that camera, which I’d bought after a few minutes of cursory googling – terrible in low-light because of a tiny sensor and unreliable autofocus, especially at the long telephoto end. The Nagaland photos show it at its best, since it was bright and sunny and the ISO was kept nice and low, but the sunniness created the problem of blown highlights and thus lost details in the sky. I’ve always regretted taking it, rather than something better, on research trips in India, Thailand, Myanmar, and Singapore during that year. Taking photos in dim libraries/archives was a disaster, with illegible photos and endless autofocus hunting and weird distracting/embarrassing whirring noises.
So what should someone heading out to do some kind of fieldwork buy? I’m assuming this is a grad student (or possibly aid worker, Peace Corps, etc) who wants to capture their experiences, but also possibly to take lots of photos of documents, maps, etc in dimly-lit archives, have survey teams use it in their activities, etc. Thus the parameters are 1) decent image quality, better than a smartphone, 2) very small size that is highly portable (so no RX10 III or most DSLRs), and 3) a tight budget, ideally in the $200-600 range used (so no Leica M Monochrom).
There are four basic categories I would recommend.
1-inch sensor compacts. I think they are the best bets for most – solid image quality in low light, useful zoom ranges (though much shorter than the cheaper, smaller sensor compacts), reasonably responsive, and very very small. The Sony RX100 series, which ranges massively in specification and price from models I through V, pioneered this category (here’s a nice summary from DPreview). The Panasonic LX15 and, with a longer zoom but slower lens, ZS100, and the Canon G7X II are other excellent options. A DPreview overview of this category recently came out.
Large-sensor compacts. These are probably outside the budget of the average grad student, but used options may be affordable. These tend to have a single focal length, equivalent to either 28mm or 35mm, and a larger sensor. The Fuji X100 series and X70, Ricoh GR/GR II (though beware dust on sensor), and Nikon Coolpix A are the standard possibilities. The Panasonic LX100 is an exception in this category – an “in-between” sensor size plus a zoom. There are real trade-offs with these – can you afford them, do you need a large sensor, and can you live with a fixed or limited focal length?
Interchangeable mirrorless cameras (with small lenses). I’m leaving aside classic DSLRs here, like the Canon Rebels, Nikon D3400, etc for size reasons. Instead, for people needing high levels of portability, the newer breed of mirrorless cameras makes sense. They are excellent – very good 4/3 or APS-C sensors, fast and accurate autofocus, and a wide range of lenses. Olympus E-M10/II and E-PLs, Panasonic GX850/GX85, Sony a5100/6000, Fuji X-A3, and Canon M6 are plausible options here, plus various other used options in the Fuji X, Sony E-mount, Canon M, and Olympus/Panasonic Micro Four-Thirds systems. There are small, if not always very good, collapsible zoom lenses for Sony, Panasonic, and Olympus that can make the body + lens package extremely compact.
The downside is that often there are few small lenses, and once the lenses grow larger, portability decreases. The kit zooms that come with these cameras are sometimes not great and on their own might undermine the advantage of such a camera over a smaller sensored compact with a faster, sharper lens. Buying new lenses blows the budget, so a lot hinges on money and the likelihood of/interest in expanding one’s lenses collection over time.
Specialist cameras. For people going to very challenging physical environments, an Olympus TG-4 Tough camera might be good – not great image quality, but built to withstand sand, rain, snow, freezing weather, extreme heat, etc. For large “full frame” digital sensors, we’re way beyond budget, but a Sony A7/A7 II might be a good option. If you want a film camera, a good condition Olympus XA/XA2 is a nice highly portable possibility.
Tips. For figuring out portability, the Compact Camera Meter lets you compare the size and weight of cameras and camera/lens combinations. Buying used is best through KEH, Adorama, B&H, and highly rated, frequent sellers on Ebay, Etsy, and Amazon (especially if Amazon fulfillment allows returns). Best Buy also has some great Open Box deals on their website and their Ebay Outlet store to check out; I’ve seen RX100 I’s under $300 there. Proceed with great caution on Craiglist, most Ebay sellers, etc. Reviews from DPreview, Wirecutter, Imaging Resource, and numerous other sites and blogs can be very helpful.