Jack Douglas has alerted us to Art Morris switching to Nikon
“As many have surmised, I am — after 34 1/2 years of using Canon gear, after about 18 years as a Canon Explorer of Light (not many know that I was fired from that role about four years ago), and after 17 years of using Canon digital gear, switching to Nikon. If you do lots of flight photography, you should switch too. If not, I far prefer my Canon gear. Some of the AF stuff with Nikon — such as switching the AF patterns — is horrifically designed. But if you want sharp images of birds in flight then you should/will switch to Nikon. The funny thing is that I recently figured out — with help from Arash Hazeghi — how to make the most of the AF systems of my 5D Mark IV bodies and especially with my newly replaced EOS-1DX II. But for birds in flight Nikon is light years ahead. After 30 seconds of working with the Nikon AF-S NIKKOR 200-500mm f/5.6E ED VR lens and the blazingly fast professional digital camera body, the Nikon D5 DSLR camera body with dual XQD slots), I was pretty sure that I was gonna switch even before I saw the images. To make sure that I not was crazy, I had Patrick Sparkman try out the Nikon rig. After one bird flew by he said, “I am switching.””
http://www.birdsasart-blog.com/2018/01/23/this-just-in-internet-experts-state-that-the-nikon-200-500-1-4x-tc-14e-iii-d5-combo-is-not-sharp/
The new Nikon D850 and D500 are awesome. The problem is having a hand-held telephoto to go with them. Art, however, goes overboard in praise of the Nikkor 200-500mm f/5.6. I took a keen interest in the 200-500mm and have read dozens of reviews. The consensus is that the lens is tack sharp close up but softer at long distances and it is slow focusing. It’s on a par with the old Tamron 150-600mm. You can read comments on Art’s blog about the distance fall off of sharpness and the focusing.speed.
A really in-depth review that sums up the consensus is in https://photographylife.com/nikon-200-500mm-vs-tamron-150-600mm-vs-sigma-150-600mm-c
“Niki is razor sharp at 500 mm and near minimum focusing distance. “…“At infinity, it’s another story altogether with Niki showing noticeable softness, especially in the corners at all focal lengths but more so at longer focal lengths.”
“When it comes to sharpness, Sigi had good center sharpness from near to far and through the range of focal lengths. Corners are noticeably soft in long distance shots at all focal lengths."
“Of the three lenses I feel Tami has the best balance of near to far and corner-to-corner sharpness at all focal lengths.”
“When it comes to AF speed, Tami and Sigi are both quick and in the field I can’t distinguish a difference when they are focusing on a static subject. Racking focus from 10 feet to infinity takes the same amount of time. Niki is noticeably slower than both Tami and Sigi. I give Tami the slight edge over Niki in AF performance on static subjects just because Tami is a bit faster.”
Other reviewers also recommend the Tamron over the Nikkor. And the new G2 Tamron is an improvement over the old 150-600mm.
I am not migrating to Nikon if the best lens available is a Tamron 150-600mm or its near-equivalent! My 400mm f/4 DO II has blazingly fast and accurate focus on the 5DIV, as well as being tack sharp corner to corner, and has given me consistently good birds in flight photos. If Nikkor could bring out a similar lens, then maybe I would consider it. By that time, however, Canon should have leapfrogged Nikon. In any case, for shots in good light, the Canon lenses on the 5DSR are difficult to beat for IQ.
“As many have surmised, I am — after 34 1/2 years of using Canon gear, after about 18 years as a Canon Explorer of Light (not many know that I was fired from that role about four years ago), and after 17 years of using Canon digital gear, switching to Nikon. If you do lots of flight photography, you should switch too. If not, I far prefer my Canon gear. Some of the AF stuff with Nikon — such as switching the AF patterns — is horrifically designed. But if you want sharp images of birds in flight then you should/will switch to Nikon. The funny thing is that I recently figured out — with help from Arash Hazeghi — how to make the most of the AF systems of my 5D Mark IV bodies and especially with my newly replaced EOS-1DX II. But for birds in flight Nikon is light years ahead. After 30 seconds of working with the Nikon AF-S NIKKOR 200-500mm f/5.6E ED VR lens and the blazingly fast professional digital camera body, the Nikon D5 DSLR camera body with dual XQD slots), I was pretty sure that I was gonna switch even before I saw the images. To make sure that I not was crazy, I had Patrick Sparkman try out the Nikon rig. After one bird flew by he said, “I am switching.””
http://www.birdsasart-blog.com/2018/01/23/this-just-in-internet-experts-state-that-the-nikon-200-500-1-4x-tc-14e-iii-d5-combo-is-not-sharp/
The new Nikon D850 and D500 are awesome. The problem is having a hand-held telephoto to go with them. Art, however, goes overboard in praise of the Nikkor 200-500mm f/5.6. I took a keen interest in the 200-500mm and have read dozens of reviews. The consensus is that the lens is tack sharp close up but softer at long distances and it is slow focusing. It’s on a par with the old Tamron 150-600mm. You can read comments on Art’s blog about the distance fall off of sharpness and the focusing.speed.
A really in-depth review that sums up the consensus is in https://photographylife.com/nikon-200-500mm-vs-tamron-150-600mm-vs-sigma-150-600mm-c
“Niki is razor sharp at 500 mm and near minimum focusing distance. “…“At infinity, it’s another story altogether with Niki showing noticeable softness, especially in the corners at all focal lengths but more so at longer focal lengths.”
“When it comes to sharpness, Sigi had good center sharpness from near to far and through the range of focal lengths. Corners are noticeably soft in long distance shots at all focal lengths."
“Of the three lenses I feel Tami has the best balance of near to far and corner-to-corner sharpness at all focal lengths.”
“When it comes to AF speed, Tami and Sigi are both quick and in the field I can’t distinguish a difference when they are focusing on a static subject. Racking focus from 10 feet to infinity takes the same amount of time. Niki is noticeably slower than both Tami and Sigi. I give Tami the slight edge over Niki in AF performance on static subjects just because Tami is a bit faster.”
Other reviewers also recommend the Tamron over the Nikkor. And the new G2 Tamron is an improvement over the old 150-600mm.
I am not migrating to Nikon if the best lens available is a Tamron 150-600mm or its near-equivalent! My 400mm f/4 DO II has blazingly fast and accurate focus on the 5DIV, as well as being tack sharp corner to corner, and has given me consistently good birds in flight photos. If Nikkor could bring out a similar lens, then maybe I would consider it. By that time, however, Canon should have leapfrogged Nikon. In any case, for shots in good light, the Canon lenses on the 5DSR are difficult to beat for IQ.