Focus on Travel Cameras
Over the years I've used several camera systems for my travels and the search for perfection will likely continue. Traveling on a motorcycle is similar to backpacking in that space is limited, and the quest for smaller, lighter and better never ends.
My career as an advertising photographer required lots of gear, but for adventure riding I wanted to be unencumbered. High end pocket cameras got great results, within their limitations. For me, that usually meant lens range.
On the North America expedition - specifically the U.S., Canada and Alaska - I carried a Lumix GM-5 System that worked well and was miniscule. It reigns as the smallest ILC camera with viewfinder in the Micro 4/3 format and sported a 16 mp image. The body is the size of a deck of cards and in the M4/3 system there are a couple hundred lenses or more that work with the body. IQ was very good for such a small system. My only complaints are that the tiny viewfinder made hitting critical focus difficult when in a rush. Otherwise very happy.
Lumix GM-5 and GF-7 with two kit zooms
For the three month stint in Mexico I debated carrying my beloved Fujifilm system, but needed a bit smaller profile. I'd had early experience with the Sony Nex system, and other than limited lens choices at the time, I felt it gave great image quality in a really small package that wasn't "too" small. Time passed and Sony improved their lens range with several pro level lenses. I jumped back into the E-Mount system with two older A6000 bodies and some mint condition used Sony/Zeiss glass. I took more gear than I really needed, but the system is small enough that it's still really reasonable for size and weight.
In Guanajuato, I had a street vendor make a leather carry bag to my specs that fits the gear perfectly and, more importantly is low profile on the streets. Nothing like waving a flag that says "Steal Me" with an obvious camera bag.
Currently I'm taking 2 Sony A6000 bodies with 6 lenses - 16-70 Zeiss, 55 1.8 Zeiss, 85 1.8 Sony, 55-210 Sony, 30mm Sigma 1.4 and 12mm Rokinon. Two bodies were chosen, mainly for a backup on such a long trip, but also to carry a second mounted lens for shooting. Amazing that 2 bodies and 6 lenses fit in the 3" x 10" x 12" leather bag. That's a complete pro location system.
In Use: On the bike, the tank bag carries one body with 16-70 zoom attached, a 55-210 lens and batteries. The two zooms give a range of 24mm to 315mm equivalent for any situation I come upon and are close at hand. The leather bag with second body and other lenses reside in a locked case. Having a split system leaves me some gear in case the tank bag kit gets stolen.
On the streets, I carry a body w 16-70 over my shoulder and tucked under my arm. The 55-210 in a cargo pants pocket on short walkies.
Exploration days, I carry the entire kit in the leather bag, One body in the bag with lens mounted and the other tucked under my arm or in hand.
16-70, 55-210 and 55 1.8 are mainstays. Least used are the 30 1.4 and 12mm 2, both of which are razor sharp btw - as are the 16-70 and 55 1.8. The Sony 55-210 is a mixed bag - sometimes very sharp at some length/aperture combos and at other times just average. I've never figured out the "sweet spots" of the lens, but the size and range are perfect for travel. All other E-mount zooms in a similar focal range are massively larger. I suspect that the 85 1.8 and 16-70 will be my main walkabout lenses.
I've never found the perfect system or way to carry, so it's a variation of all the above - sometimes all in the bag, sometimes just a body and lens, lenses in pockets, etc.
Other Options: I think a high end pocket camera such as the Lumix LX series, Sony RX100 and similar in a coat pocket is a great way to go and would allow one to dismiss a tank bag completely. All my old ride reports were done exclusively with the LX3, LX5 and LX7 series, but the short zoom range was frustrating. For any trips less than this one, I'd be perfectly fine with the GM5 or a pocket camera as mentioned.
Two A6000 bodies with six lens kit in 3 x 10 x 12" bag vs GM-5 four lens kit in 6" wide bag
Images captured with the GM5 system are as good as with the Sony, save the 16 mp vs 24 mp image size. The quicker autofocus and larger viewfinder of the Sony are pluses.
I'd love to have the GM5 and the two primes with me to complement the Sony. The GM5 and a couple of lenses are easy to slip in a pocket, and so small they don't draw any attention. But then again, if I had the room I'd also like to carry a drone. And an Italian espresso machine.