[Rover]

I think only Canon produces f/7.1 lenses, the rest stay at f/6.3 (the Tamron 150-500 has a quirk of only hitting nominal f/6.7 at 499mm or so... of course since the actual aperture is not as granular, I had to add the disclaimer of "nominal").

Frankly the trend is a little irritating even though of course high ISOs are getting better all the time. But how can they be cutting so many corners to sell us the 18-45/4.5-6.3 lens with a straight face. :-)

Ahem, I digress. Pity the original (DSLR) 60-600 was never tested here for comparison's sake...

[stoppingdown]

An insane number of elements seem to be the trend. I don't like it really. Less so because of the weight but because of the required centering accuracy.

And also flare...

https://www.lenstip.com/159.3-article-Sigma_S_60-600_mm_f_4.5-6.3_DG_DN_OS_%E2%80%93_first_impressions_Autofocus_and_some_remarks_concerning_optical_properties.html

When it comes to the performance against bright light, we feel the bar couldn't have been raised higher - in the case of the new Sigma you get as many as 27 elements positioned in 19 groups and it means as many as 38 air-to-glass surfaces where you can catch unwanted reflections. What's more, you also deal with a big front element that is not hidden inside the barrel very deep. The high zoom factor, autofocus, and image stabilization units mean it's rather cramped inside the casing; you don't get many places where apertures or ribs, helping to fight off reflections, can be installed.

It would be difficult to expect excellent performance so we are not especially surprised that we managed to catch quite a lot of light artifacts. As a kind of consolation you might add that these are present only when the sun is situated close to the frame corner and these aren't frequent situations while taking photos with this kind of equipment.

[thxbb12]

Dustin Abbottt just reviewed it in Sony E mount:
https://dustinabbott.net/2023/01/sigma-60-600mm-f4-5-6-3-dg-dn-os-sport-review/

Rather impressive given the zoom range. Its IQ is very close to Sony's 200-600 while having a larger zoom range and better close focusing capability. Compared to Sigma's own 150-600:

"Sigma’s own 150-600mm DN Sport is only very marginally smaller and is outclassed by the 60-600DN in performance in basically every metric. The 60-600mm is sharper, faster to focus, and has better optical stabilization."

[stoppingdown]

I've watched the review by Christopher Frost and the flare performance looks very different (very good) than the one by Lenstip...