Bokeh with D3 vs D300 at f2.8

I have been diving more and more into Macro photography and while working with a longer focus distance of my Sigma 150mm f2.8 on my D300 (225mm 35 equiv) I still find I don't always get the clean background I desire when working with things such as very tiny short flowers. Stuff like 1/8th wide flowers with 2 inch stems etc.

I've read that the larger FX 36mm sensor of a D3 or the new D700 should provide better bokeh @ f2.8 then the same lens with the same settings on the D300 with the DX sensor.

So my questions are:

#1: Is this correct? Any experience you owners of both the D3 and D300

#2: How much of a difference does this make in your opinion to your images? Example images would be awesome.

If its true I'm tempted by the D700 as I continue photographing Colorado Wildflowers for a new field guide.

You will get exactly the same depth of focus when the shot is taken from the same distance with the same lens at the same f/stop. The only difference is that the D300 image will be cropped tighter than the D3 image.

If you move back with the D300 to where you have the same field of view as the D3, then, because you are farther from the subject, your depth of field will be greater.

Hope this helps.

Boken should look better with a D700 Vs a D300 with the same subject if you keep the subject size the same. Chris is correct it is more of a distance issue and not DOF.

This factor is easy to understand when you realize that 1:1 repro ratio with your Sigma 150 on a DX sensor body is the same 1:1 on an FX body. People think that 1:1 on a FX will be 1:1.5 on a DX camera. This is not the case. They will both have a 1:1 ratio. You will just have a bigger field of view on the FX and a tighter drop on the D700. DOF and Repro are exactly the same.

Robert

Thanks for the clear up.

I had read something on sensor size, and how that might influence the dof, then the circle of confusion was brought up and my eyes crossed and I'm pretty sure I blacked out a bit.