The first Arts were the 35/1.4 and I'm not sure wether the 24/1.4 or 50/1.4 came next. Until the 50/1.4 the Art lenses were in terms size and weight equal to their Nikon counterparts, minus the rubber gasket which is often confused with weather sealing 
From the 50/1.4 on they grew in size and weight. They never were the lightest of the pack but these days it's not easy to find heavier lenses. Except the manual focus with blue dot on it. If they now reduce weight - and the 14-24 lost 33% by becoming a DG DN type - both Sony and Panasonic appear to be more attractive to me. Canon is out of the game - great lenses, weak sensors. Sony published specs of their new sensor designs: https://www.dpreview.com/news/4477765388...yer-sensor
Nikon has light lenses but relies on software correction in a way that makes the cost of their "made in China" lenses look less attractive. I still haven't bought more than two native lenses. The 14-30 is attractive but apparently has some sample variation and relies even more on SW correction. Knowing Sigma's 14-24, which costs about the same as the Nikkor, one stop faster, 300 grams heavier, I wished to have that choice. If Sigma is smart, they disobey Z-mount and put their efforts into E- and L-mount: More existing bodies and making DN lenses for Sony always will work for their own L-mount, too.
I hope it's a good sign their DN glass gets lighter (and also a tad thinner, although not shorter). Interesting times, and meanwhile I still can have fun with the Nikon bodies - no haste to change.
From the 50/1.4 on they grew in size and weight. They never were the lightest of the pack but these days it's not easy to find heavier lenses. Except the manual focus with blue dot on it. If they now reduce weight - and the 14-24 lost 33% by becoming a DG DN type - both Sony and Panasonic appear to be more attractive to me. Canon is out of the game - great lenses, weak sensors. Sony published specs of their new sensor designs: https://www.dpreview.com/news/4477765388...yer-sensor
Nikon has light lenses but relies on software correction in a way that makes the cost of their "made in China" lenses look less attractive. I still haven't bought more than two native lenses. The 14-30 is attractive but apparently has some sample variation and relies even more on SW correction. Knowing Sigma's 14-24, which costs about the same as the Nikkor, one stop faster, 300 grams heavier, I wished to have that choice. If Sigma is smart, they disobey Z-mount and put their efforts into E- and L-mount: More existing bodies and making DN lenses for Sony always will work for their own L-mount, too.
I hope it's a good sign their DN glass gets lighter (and also a tad thinner, although not shorter). Interesting times, and meanwhile I still can have fun with the Nikon bodies - no haste to change.