Ruby Rod wrote:A hood is to shield the elements/filters from direct light and maybe somewhat from diffuse light but I can't imagine how a slight leak from the mounting area could affect anything. How does the light get reflected back towards the lens?The 14-24 doesn't have a filter thread, so filters have to screw into a thread on the lens hood. The light is reflecting off the back of the filter and into the lens

Ah, OK, that makes more sense!

I would get consistent space/light and test it.  Your photos, particularlylong exposures, it can introduce lens interior reflections, distant headlight/s (even diffused) can cause a havoc on the image, etc etc.  Your photos were taken 8 min apart and that too can change light....and it's visible in the clouds.  So what I'm saying that consistency can be compromised by several issues.

Karl-FR wrote:I tried quickly to show you where is the area affected by the light leak.The area affected by light leak.I now understand what your concern is.The issue is likely strong backlight getting through the gap where the lens hood attaches to the lens, then reflecting off the inner surface of the lens hood, and into the lens via the front element.Not often widely appreciated is that multi-coating on a lens element only works close to perpendicular to a lens element surfaceThe light reaching your front element may be as much is it 75° here from perpendicular –meaning even the best multi-coating in the world is unlikely to work as well as some presumeApart from the using a "proper" lens hood issue, light leaking through the rear eyepiece of a DSLR can cause an exposure problem with strong backlighting.If the camera was on a tripod and the rear of the camera was not shaded from the direct sunlight by your body your problem was likely to be exacerbated.Thank you about the dust spot. I saw it too. I hope that one day Nikon will close the shutter while swapping lenses like other brand..I understand Sony has the same "dust" issue as lower priced Nikon Z bodies.The Z9 has for me an extremely effective dust shield - with my usage no dust on my Z9 sensor in 8 months of use.Hopefully the next generation of lower price Z bodies will have a similar dust shield.Nikon feedback - only Nikon can explain why the default Z9 menu setting for the blind is open not closed on camera shut down. The vast majority of Z9 owners seem to prefer the shutter closed on camera shut down option.

Karl-FR wrote:Thank you James for your time and answer.It's a leak between the lens hood and the lens itself.I have put a flash and it's visible.Maybe it's a user error and I will be glad to have any tips.As you probably know, even the slightest light leak that would normally go unseen, will cause problems when doing long exposures.I choose kase filter for magnetic, it's handy but the leak doesn't come from here.