Forgive me if this was already asked, i did not see it on search.

On my d90, when i use f/2.8 FF zoom lenses with build in flash the lens casts shadow at about bottom 1/3 of the image at close range. Lenses are just too big for d90. D800 also having a build in flash, yet an FF camera, hence f/2.8 lineup is intended for this camera; will it have similar problem as d90 with flash shadow?

Thanks

Yes. This is a matter of physics. If you have a big lens, and a flash mounted close to its axis, there simply is going to be a shadow. It has nothing to do with full frame or DX.

_____
Brian... a bicoastal Nikonian and Team Member

My gallery is online. Comments and critique welcomed any time!

And a good reason why so many of us get an external flash.

I was hoping that since they designed FF camera to beused with FF lenses they have adjusted the build in flash geometry as well... hoping...

It's a forlorn hope, I'm afraid. As Brian says, it's just down to geometry - it's not possible to have a built-in flash extend high enough to avoid shadows from large lenses. The D700 does it too; it's nothing to do with FX or DX.

Brian
Welsh Nikonian
Check out the Nikonians Team pages

> I was hoping that since they designed FF camera to beused with FF lenses they have adjusted the build in flash geometry as well... hoping...

How far do you want them to go? Being ridiculous, do you insist that they design a camera (of any format) so that it can avoid casting a shadow with the 6/f2.8 lens? (Hint: it's 236mm in diameter, a bit over 9" in diameter, or more than twice as tall as the D800 is.) I'm not 100% certain as I have not done detailed measurements, but to avoid the hood on the 24-120/f4 (not even the 24-70/f2.8) I think the camera would have to be about three inches taller than it is. Almost twice as high. Do you really want them to go that degree?

It has nothing to do with full frame. The D90 flash casts a shadow with the hood on the 18-200VR, too, and that's a DX camera with a DX lens.

_____
Brian... a bicoastal Nikonian and Team Member

My gallery is online. Comments and critique welcomed any time!

The built-in flash is a convenience and not really intended to replace proper external lighting. Even with the shadow, the built-in flash works very well as the Commander controlling external slave flash units in Nikon's excellent CLS wireless TTL flash system.
I have a D90 and use a lot of larger lenses with it and did not find the shade to be a problem because there was always an external flash available. The internal flash does work well with the smaller primes, and lenses all the way out to the size of the 18-108vr. The D800 will also work without shadows with those lenses. In fact, its 15mpx Dx crop mode will give new life to those small light weight lenses for travel and causal shooting.
If you do not have one now, please consider getting an external flash, your photographic options will greatly increase. Suddenly, even slow modest lenses become quite suitable for a wide range of scenes. I contend that the most bang for the buck in photography is not the lenses or camera bodies but lighting, more improvement, for less money. An SB700 for example for $300 will greatly increase the performance of both your lenses and camera.
Stan
St Petersburg Russia

Visit my Nikonians gallery.

I agree with all,

There is nothing more important than proper lighting. Lighting will effect the choice of gear and settings. I have an external flash which has no problems with big lenses, but since my d90 flash has problems with all of my f/2.8 lenses, the d90 flash is now kind of a wasted space... Since d800 will be shot 90% of the time with lenses too big for the build in flash, adding it kind of seemed stupid, unless some kind of magic was done to avoid most of the lense shadows. Perhaps internal flash with a tilt to use it as a bounce???

Get your flash off-camera and you will see why the whole product line, except for D4/3 has a built in flash. The intended customer base of D800's will probably never use the internal flash for subject illumination but will use it often as a Commander for external flashes.
A lot of people would complain if it was removed. They might be happier however if it was a infrared flash instead of visible light however.
One of the main reasons to buy into the Nikon system is the CLS wireless that the built-in flash is an important part of.
Stan
St Petersburg Russia

Visit my Nikonians gallery.

Only thing I can offer is "remember to remove your lens hood" when using the pop-up. It does moderate the problem...

Best regards, SteveK

'A camera is an instrument that teaches people how to see without a camera.' -- Dorothea Lange
My Nikonians gallery
My Nikonians Blog

Another thing that helps a lot is try not to shoot close in subjects. The lens shadow is below the frame if you zoom out.

Do you think new cameras including D800 and D4 will be compatible with older flash such as SB600 or SB800 (both mounted on camera or as part of CLS)?

They are definitely iTTL compatible, which means SB600/700/800/900/910 and SU-800/R1. And, I suppose, the SB-400 too, although I suspect that that will be a pretty rare combination.

_____
Brian... a bicoastal Nikonian and Team Member

My gallery is online. Comments and critique welcomed any time!