I have a question to photographers who use zoom lenses and teleconverters,  do you obtain high quality photos equal to higher zoom lenses or the quality is less?

I have 70-300mm nikon lens i used it with ftz mount to use it with my Nikon Z5 camera, so can I have an appropriate Nikon Z TC x1.4 or x2 or it won't work?

Hi Asmaa all I can do is give you my experience when using using high quality Canon L lenes - I can use my 1.4 teleconverter on my Prime 300 L lens with great results - but when used on my 70 - 200 L lens good but not so good as the prime lens  - If I use the 2.0 converter the same way not as good as the 1.4... hope this helps..

For me the same, I'm using a 1.4x on sigma 70-200mm F/2.8. The only downside is the aperture goes up to minimum f/4. But I use the teleconverter to compress landscapes, shot in f/11 to f/16 anyhow. For people, I use f/2,8-f/5 most of the time, and the equivalent of 280mm is not needed. 

In your case, please regard that 600mm is very sensitive to camera shaking. You probably have to shoot high ISO when handheld all the time.

Thank you so much for you help.

Thank you Mike, I  got what you mean and I think I have to give it a try before buying. 

I have Nikon Z7 ftz adapter AF-S Teleconverter TC-14EII 1.4 x and I use it with the 200-500 mm zoom lens, the quality of the phtos are as good as without the converter but I did not try with the 70-300 which I have such lens but I think the result woulb be similar. You have to check on Nikon web site if the convrerter you have will support the lens.

I used both Nikon Z TC x1.4 and TC x2 on Nikon Z 70-200. The lens itself is great for the time, with the teleconverters I rather see the contrast worsened, but it is not that important. Of course, the TC 1.4 setup is optically better, but TC 2.0 is also usable.