Gianfranco47 wrote:
most probably this argument has been deeply discussed but once again is not bad , i have a Nikon D800 and one D3 and i need a wide angle lens wider than 14/24 mm , i want to buy the Nikon 10/20 AF-P DX refurbished for $239.95 by Nikon what will be the problems connected with this combination ?
If you have other alternative at same price pls tell me
regards
It will work, but there's no "free lunch".
Using a DX lens on your FX camera will essentially mean throwing away all the "full frame goodness" of the camera.
Instead of a 36MP FX camera, you'll have approx. 15MP DX camera. That's considerably less resolution than the current and recent DX cameras (21MP and 24MP). You'll lose this resolution regardless whether you set the camera to DX mode where it will crop the image to DX format in-camera or leave the camera in FX mode and get heavily vignetted images that you end up cropping later in post-processing. Either way, you end up with the same greatly reduced resolution.
Also, that's an "AF-P" lens. As such, your older Nikon camera's firmware will need to be updated to work with this newer type of lens and even then it won't be fully compatible. If I recall correctly, you won't be able to switch the lens to manual focus or to turn VR off. With AF-P lenses those things are done in the camera's menu... and even updated the D800 doesn't include them.
You would be much better off saving up and getting an actual FX wide angle.
About the least expensive super wide FX lenses are the Rokinon/Samyang 14mm f/2.8 for around $275. Those are manual focus, manual aperture lenses... but depth of field is so great with an ultrawide like these that manual focus isn't very difficult with them. There also are Rokinon/Samyang 12mm in FX, but they are about $100 more expensive and they are fisheye lenses. For a little more money, there are Rokinon 20mm, IRIX 15mm and Venus Optics Laowa 14mm. Again, all these are manual focus, manual aperture lenses.
The least expensive autofocus wide angle zoom for Nikon FX is the Tokina 17-35mm f/4 for around $450 new.
You might find some of the above for a bit less used (for example, I see that B&H Photo has that Tokina zoom avail. used for $372).
EDIT: Just reread and notice you already have the 14-24mm Nikkor. That being the case, you have limited options for anything wider. The IRIX 11mm f/4 at about $535 is probably your best bet.