BobJ

I have the 23mm f2 and mine doesn't rattle. So unfortunately it does look like something is wrong.

Frankly the difference looks too small to be significant. All lenses are sharper in the image centre.

Of course, some of this is down to marketing. However, Fuji are restricted by what sensors are available to them. Fuji make or specify the filters that are positioned over the sensels but they do not make the silicon. There are very few manufacturers that do, because setting up the fabs is hugely expensive. Fuji use Sony, who are probably making the best available the moment, but that means that Fuji are bound by what Sony make. In any case the difference between 36mp and 40mp is too small to be significant. Finally, the question of resolution. Resolution is an area defined factor. To double the sensor resolution you have to have four times the number of pixels. So you can see that going from 26 to 40 makes sense. I guess that Fuji decided that their target buyers wanted more resolution. They had to do something to make the x-t5 different to the 4. Maybe Fuji could have offered a 26mp version of the x-t5, but because of differences in the electronics that would be expensive for them to do.

Wouldn't that heat shrink tubing mean that you would no longer be able to move the ring? How would you add the necessary o ring to seal the mount? How would you test it without risking it?

In the first photo the camera has focused on the nearest leaf. In the second it has focused somewhere on the background. This sort of random behaviour is definitely not a normal characteristic of the x-t5. When you take the first half pressure on the shutter button, assuming you are set for single focus, you should see a green square in the viewfinder which indicates where the focus will be. Set the focus area to single point and try another test. Personally I never use the touch screen for the reasons that others have written here.

Sorry about my dumb misunderstanding. .

Sorry, I didn't finish that comment. I don't, know what is going on but yes, try a different card. Also, always format the card in the camera. I expect you did, but I thought I would mention. There is no point in not using lossless compression by the way.

Use lossles compression.

I recently took some studio portraits using eye detection with auto eye selection. I didn't have one failure. There is either something wrong with the camera or lens, or more likely, an incorrect setting. Check all the relevant settings and test. Are you sure you didn't accidentally move the focus lever to manual? It's easily done. Or you might have left one of the special focus modes (animals etc) selected.

You can! You can save up to 7 custom settings, and you can assign a function button to cycle through them. Look out for YouTube videos on this. Or you can try and read the awful manual. The reason I don't give you the instructions here is that I don't use custom settings myself. Hopefully someone will chip in with the exact instructions.

If you are going on hikes you really don't want the f1.0 50mm or indeed any f1.0 lens. Something light weight would be better. So, if you want a 50mm because you decide to go for the 70-300, it's the f2.0. The 23mm f2.0 is a sharp lens, although it gets a little softer when focused very close. I have one and would recommend it. WR is somewhat overrated. I had the 55-200 and used it in some horrendous Scottish weather with no problems. I replaced it with the 70-300, mostly for the longer reach, but it is faster and sharper than my particular 55-200. You might want a wideangle. The 14mm is a good lens.

You should ask Sigma, but I think they are not.

The distance between the sensor and the lens flange is different for each make of mirrorless camera.

Because the sensor assembly is moved electrmagnetically. When there is no power it is essentially free moving.

Only use sensor cleaning swabs and solution made for the job. They are expensive but a lot cheaper than a new sensor. You may have to do it twice or more but my guess is that it will work.

Switch the shutter to ES to prevent any possibility of the mechanical shutter going off while cleaning. Turn on the camera and leave it on Set IS mode to off. Clean.

As far as I know the firmware is not country specific. Are you sure that the filename has not been changed ( I am told this can happen with mac os). That's the only thing I can think of.

My x-t5 does not exhibit the focusing switch behaviour as you report it, so that is very strange and indicative of a fault. It does not matter whether the flash is attached or not. Once you set the camera for your studio flash, say 1/250th at f5.6, the camera, which is showing you what you will get at that exposure without the flash, will show a black screen unless the ambient light is brighter than what you would typically get indoors. That is why, as Jerry says, you have to set preview exp/wb to off. I have set a button for this.

I don't understand at all why your histogram is not changing with exposure - it does on my cameras. There is something wrong. The little histogram that you can have in the corner of the viewfinder is of little value - it's too small. If, like on my x-t5, you can have a full histogram with all three colour channels showing, assign a button to it. The resulting histogram is accurate for the jpeg only. The right hand highlight end is fairly accurate for raw, although you may squeeze out another half stop. You cannot recover blown highlights, so make sure the right hand side is not bunched up against the limit. Also remember, that if there are specular highlights in the picture, such as sun on water or mettalic surfaces the highlight end will show a narrow peak, which in this case, will be OK. For raw you can pretty much ignore the shadow clipping as the shadows will be recoverable, unless they are really dark. The histogram is of great use when taking landscapes with a tripod. I use it frequently. It tells me when I need a separate exposure or grad filter for the sky. Of course, you wouldn't use it for street!

Mine is over a year old. No problems so far

I used to own the older Fuji 56mm. It sounds like it has not improved. It didn't focus closely enough for a tight head portrait either.

I used to own the Fuji 56mm. It has a drawback that no-one has mentioned. It doesn't focus closely enough to allow tight head shots.

Lightroom

This problem is much exaggerated and is difficult to see unless you are pixel peeping. However, if you want the ultimate quality, use X Transformer to do the initial conversion and then import the resulting dng into Lightroom. X Transformer is cheap.

A bubble in the glass will absolutely not affect the image quality in any way. Whether it will affect the resale value is hard to say. If you are concerned can you not send it back?