Newbie dome port question

Is the camera taking a photo of the image displayed to it on the inside of the dome?

If that's the case, is a zoom basically cropping the shot?

Oh, and can macro be done with a 8" port?

Thanks

Jason

There is a great piece in the 'Articles' section about dome port theory. I believe the dome creates a 'virtual image' that appears closer than the subject really is, but it's not 2-D like a tv. This is why diopters are used - to balance the lens' focusing range with that of the virtual image.

As for zooming = cropping, the simple answer is no. Cropping removes resolution, optical zooming does not.

I'm sure you could do macro with a dome, but you really wouldn't want to. Domes exist to exploit wide angle lenses, flat ports are simpler and sharper (i think....). I'm sure someone will corect me if i'm wrong.

Also many flat ports are designed to be close to the front of the macro lens allowing the short subject to lens distance required for 1:1 macro.

Depending on the dome, the lens will not allow you this short distance and you may not be able to get 1:1.

Paul C

If you are focused on the dome's virtual image with a 1:1 macro lens you will get 1:1. The flat port may give you better than 1:1 magnification with the same lens. Part of the reason a lot of shooters prefer a flat port for macro. Some prefer a dome for macro as you get less chromatic and lenticular aberrations (a sharper picture).