Well, I got convinced. I bought the Fringer Pro canon lens to Fuji X mount adapter. As I understand, it does allow for auto shooting.

I would like to carry ONE camera instead of TWO when I have to walk a bit to get to the spot to take pictures or I go on a ferry ride. Switching between cameras is not only awkward, it makes me feel like I am being pretentious. ONE is simpler and weighs less than two. At 74 yrs old - and a hobbyist rather than professional photographer - those are important factors to me. When my picture taking spot is convenient, I will definitely take one or both of my Fujis.

Thanks for all the advice from everyone who responded!

No, I sold my Olympus gear. I now have an X-T4 with a 100-400mm and an X-T3 with an 18-135mm. My hobby is taking pictures of ships & boats - often over long distances - and posting them on marinetraffic.com. Sometimes I have to walk a ways to take a picture, and I may have to take both cameras as some vessels are close and require the 18-135mm while others are distant and require the 100-400.

The Fringer adapter is an option to consider and the Tamron lens is on the campatibility list. But I must admit an aversion to changing lenses on my cameras. Thanks for the suggestion.

I have excellent Fujifilm camera equipment, but I want to additionally get the new Tamron 18-400mm lens. Unfortunately, it only works with a Canon or Nikon camera. I need a recommedation to pair an APS-C camera with this lens based on 2 major factors: weight and price. I want a fairly recent camera with at least a 18 megapixel sensor. It should produce nice pictures but I am not concerned about bells and whistles as my targets are fairly stationary and I most frequently shoot on auto mode then tweek post-processing. I only shoot jpeg. The variable I play wuth most is exposure compensation. I am thinking Canon EOS 850D but is there a better low price/weight Canon or Nikon that might pair up well with this Tamron lens?

Please don't give me advice on buying other lenses or shooting RAW. That is not what I am asking.

Well, depends on whether you are looking to have professional pictures or just very good vacation pictures. If the latter, then I would heartily endorse the earlier opinion of something like the Sony RX10 IV. It has a 1" sensor and great for both closeups and telephoto. If you want to be able to just relax and take good pictures, that would be the way I would go. Simple. Lightweight. Unobstrusive. Easier packing with less worry over damage. Shoots RAW and JPEG. If you want best quality, then I would also recomment bigger telephoto even if you just rent/borrow it. Those grizzly bears and sheep can be awful far away on land trips and same with sea otters and whales on cruise ships. If you are leaving from Seattle, wave as you go by my house on Whidbey Island.

Seattle and Tacoma are pretty much off limits legally for drones. And my best spot is next door to a Coast Guard facility - definitely no fly area. I thought about drones because another photographer uses them extensively to take pictures of ships going up the Columbia River. But he is in a more rural area.

I remember being barely in sight of Hong Kong on a cruise ship a few years back and suddenly seeing a drone fly close by. It took a moment for my brain to register what it was. I looked around and saw no boats close by. That was a bit jarring at first, being under surveillance from an unknown source in the open ocean. That drone had a big range.

Of course I would get back further if I could! I don't need a book or course to understand that. I am talking about tight situations where I am very constrictive for space to take a picture - like a a sliver of a waterfront park to see ships go in narrow channels to dock or undock. There are times where moving back is just not possible (an still get an unobstructed picture).

Well, the "solution" that most appeals to me to try is taking a wider angle picture and NOT cropping. I am a hobbyist so the results have to please only me. I want to keep things simple as this is not a common scenario for me. My 100-400mm telephoto gets the bulk of my usage.

But I appreciate all the thoughtful replies. Thanks!

Thanks to all who replied. Sounds like a consensus (not always easy on this forum) that a wider lens is not a solution. I guess I will need to live with the issue. Getting further back is usually not feasible as I can often only find tiny spots along the waterfront to take pictures of docked/docking/undocking ships.

Again, thanks to all.

I shoot with a Fuji X-T4 and my hobby is taking pictures of ships. My two lenses are 100-400 and 18-135. They are all I need for most of my needs.But occasionally I get very close to a very large ship. 18mm or thereabouts is sufficient to get the entire ship in frame but the resulting picture is often not pleasing. It just looks wrongly proportioned. I do not want to stitch. If I got a 10 or 14mm shot and then cropped it to larger size, would the ship appear more normal looking?

Jay, thank you for an excellent summary of your experience with the two lenses. Exactly what I was hoping to get.

I do photography of ships & tugs that may be close or may be very far off. They may be relatively small or enormous in size. If I have to walk to a vantage point, I prefer to only have to carry one camera/lens. That is why the 18-300 appeals to me. I prefer my 100-400mm Fujinon on most occasions, but if I get too close or the vessel is too big, then I can't capture its entirety with the 100--400mm. The 100-400mm Fujinon is the best lens of its telephoto reach that I have ever used (never used a prime though). The 18-135 is good but not outstanding in my opinion.

Yes, I am familiar with the general rule, and it makes sense. But you end by saying "Assuming all other things are equal the Fuji may be a better lens optically." Are all other things equal? That is what I am hoping to find out from those who have used both.