M50ii + EF-S 55-250mm STM + Kenko SHQ 1.5x Teleconverter

As for the Kenko adapter, taking the chip out so it would work with the lens proved to be fun and games but in the end everything came together and works with not problems. Of course the information about the lens F stop and focal length is not correct but that does not bother me

I use the Kenko "1.4x Teleplus HD DGX" extender, released in 2015, which has a simple optical design (3 elements in 2 groups) but is mechanically compatible with EF-S and has no problems with EXIF or AF.

Larry, and I presume everyone else, uses the older Kenko "1.5X Teleplus AF SHQ" extender, perhaps released at the end of 1990s, which has more complex optical design (5 elements in 4 groups), but requires modifying EF-S lenses and removing the chip to get AF to work. The more complex optical design might well give better sharpness, especially towards the field edge.

There is also a Kenko "1.4x Teleplus HD Pro DGX" extender — note the additional "Pro". This again uses a more complex design (5 elements in 4 groups) and will require modifying EF-S lenses. My understanding is that the "DGX" refers to the electronics. So, I wonder if the EXIF and AF will work without remove the chip, as it does in my DGX adapter, and perhaps give better results because of the more complex optical design? Unfortunately, the extender costs about $250.

I further note that there are other Kenko extenders after the SHQ but before the latest versions which are cheaper but which also appear to have the DGX brand, such as the "TELEPLUS Pro 300 DGX" (unknown optics) and "TELEPLUS MC4 DGX " (4 elements in 4 groups), both for about $70 used at KEH. I wonder if these might be a good compromise?

Regards,

Alan