The transit of Mercury is a quite rare event, which occurs every 3,5 and 13 years. In the last decade, we were fortunate to witness two celestial events such as this, in 2016 and 2019. Unlike the transit of Venus, the transit of Mercury cannot be seen with an unaided eye through the filter. We need at least basic optical zoom to detect the "black spot" on the solar disk. In both cases, I used the equivalent of 12x optical zoom. In the shots below you can see the difference. As both were cropped, this difference arises out of resolution. The left image was taken by Canon Powershot SX130 IS with 12MP resolution only and a 1/2.3" sensor, whereas the image on the right was taken by Nikon D5300 with the Nikkor 55-300mm mount. The resolution here was 24MP by the CMOS sensor. In both cases Mercury is visible.
Read more about the observations here:
https://astro-geo-gis.com/transit-of-mercury-9-may-2016/ and here:
https://astro-geo-gis.com/mercury-transit-on-november-11-2019/