See if you can find photos of previous years’ parade to get a sense of how the event will go and how other photographers approached the challenge.

Newer lenses need to somehow improve on their predecessors/competitors to make them marketable, and the trend has been on improving their optical performance (sharpness, aberrations, etc).

In the past, aberrations and lack of sharpness was embraced as “character” for lenses, or at least accepted tradeoffs for ultra-large aperture lenses. Heck, intentionally soft images were in vogue for a while. However, the current trend in the digital age has been toward edge-to-edge optical perfection wide open, with secondary consideration for things like bokeh quality, autofocus speed, handling. With that said, it has always been Leica-M’s aesthetic to feature small lenses to go with their small cameras, and so they are willing to sacrifice some optical performance for that.

And finally, things likely have been helped by modern technology. I’m sure that having access to more computational power since the 70s has made it easier to create these more complex optical designs.

I wonder if it’s some type of buying strategy to try to influence you to lower your price, similar to negging. They ask about things your lens doesn’t have or is not suited for as a way to subtly influence you into thinking your lens is not as good as it is, that there is lower demand for the lens, that it won’t sell well, to get you to lower the price or be willing to negotiate on the price.

The time a flash is emitting light can be very short, shorter than 1/100s. For example, the Godox V1 reports a flash duration of 1/300-1/20,000s.

If you look at high speed video of camera shutters, you can see that the camera has two curtains, the first one opens, exposing the sensor to light and then the second one follows it, blocking light again. At slower shutter speeds, there are periods of time where the entire sensor is visible. However, once you get to a certain fast shutter speed, only part of the sensor will be exposed at any one time with both curtains moving at the same time. Because the flash duration is so short, if it goes off during these faster shutter speeds, only the small slit that is exposed will see the flash, resulting in the black areas you see in your images. You can see that as the shutter speed gets faster, the amount of black you see should increase.

So the fastest shutter speed where the entire sensor is visible is your flash x-sync speed which you can find in the camera specs/manual. The alternative is to use a High Sync Speed (HSS) flash mode, where the flash will go off multiple times to extend the duration the flash is emitting light.

My old CCD-based DSLR would start showing noticeable noise at ISO 800, and a smaller sensor could be worse. Sunrise/sunset can be deceptively dark; I would check the files’ EXIF info to see what the ISO was. If you’re on Windows, the file property should have a Details tab that lists the major EXIF data. You could take a couple pics, some with noticeable noise, some without, and see if there is a correlation with ISO values, and see if there is an ISO value threshold.

I have local backups on internal and external hard drives. For offsite backups, I use Amazon Photos, which offers unlimited storage with Amazon Prime.