TomFama wrote:
I have a Nikon D500 and a Sigma 160-600mm Contemporary. I am considering a 1.4x teleconverter and would like any info on using a Nikon versus a Sigma TC.
It should match the lens. And a good match is not necessarily the same mfgr. I use a Kenko 300 plus 1.4x TC with a Nikon 80-200 F2.8 AF-D with excellent results. Nikon's TC requires a physical modification, and after being modified it is no better than the Kenko. There are other combinations that are awful, even though they are the same brand. Like a Nikon 1.7 TC and a Nikon 70-200 F.28 AFS VR I, though it works much better with the VR II version.
When in doubt, and when it is possible, it's always best to test the combo.
Specific to your question, the Contemporary is not a particularly sharp lens at 600mm - compared to the Tamron, it's about the same. Compared to the Sport, or the Tamron G2, it is clearly not in the same league. I can get decent results with a Sigma 1.4 TC (Mod #1401) on the Sport, but I don't have access to a Contemporary to test. However, when I purchased the Sport last September, I found the Contemporary lacking in sharpness by comparision. I would expect the TC to just make things worse. From what I have read (Link below) the Contemporary with the TC is noticeably softer).
http://www.the-digital-picture.com/Reviews/Sigma-150-600mm-f-5-6.3-DG-OS-HSM-Contemporary-Lens.aspxThis is all assuming that your camera can do autofocus with a lens that has a max aperture of F8.
If you really think you need to get a longer lens, consider that it may not be the answer.
These images were all taken with a Canon 5D Mk III - a full frame sensor, and a 400mm F5.6, hand held, with no optical stabilization.
https://untamednewyork.smugmug.com/BirdsMy guess is that you may not have fully exploited what you can do with your current setup, so getting a TC will only cost you more money and provide poorer results until you fully leverage what you have now.
Question? Have you ever tried to hand-hold a 1260mm lens, and tried to manually focus through a lens that is F8? Or put such a combo on a tripod (you'd need to spend around $1000 to $1500 to get support stable to hold that combo steady.
Focal length isn't everything. But you are free to spend your money as you wish.