Once you calibrate the focus in the camcorder to frame the ground glass the focus is the same in camcorder. So after this calibration the focus is done in the 35mm lens. The Tamron lens have two rings, one for focus and other for zoom, so when you do zoom in or out in the Tamron the focus stays the same.

aha, so its possible to do the trick with a normal camera of zooming in, geting focus then zoom out for everything around that focus point to be in focus? ty btw and nice video too!

Yes, it depends on the 35mm lens in use.

I used from f1.2 to f8 no grain.

Thanks.

I really do not know a wide angle zoom lens cheaper than this Tamron. You can get it in ebay. This Tamron lens does not have constant aperture. It is 2.8 at 17mm and 4 at 35mm. The light changes a little when zooming and you need to zoom slowly, so the camcorder compensates the changing in light. There is the Nikon 17-35 with constant aperture at 2.8 but it is very expensive.

You can search ebay to a Sigma 17-35 f2.8-4 but in my opinion the Tamron is better.

I really appreciate your help; I am favouring zoom lenses at the moment to prime lenses due to the amount of focal distances I can achieve. I think you have convinced me about the Tamron 17-35, and the Vivitar 70-150. I can't seem to get hold of any Asanuma zoom lenses at the moment. I might go for a cannon fd 35-105 depending on its quality compared to the Asanuma, just for the convenience so I can get a cannon mount. Thank you very much for your help apefos!

The Tamron 17-35 is a rectilinear wide angle and shows a small amount of vignetting. You can see in the other apefos videos no vignetting with prime nikon lenses. I sell the apefos in Brazil and to other countries too. Untill now there are 16 apefos sold around the world. Thanks.