need help with extension tubes for macro shots...?

So from the other posters you have already learned that shallow DOF is simply a fact of life in macro shots, and that you need to use a tripod and a small aperture.

Here is another thing to help you. If you have Photoshop, look up "focus stacking". It means to focus on different planes in the image, then PS combines them all into ONE image that is in focus from front to back.

First, use prime lens not zoom for decent macro, the 85mm is fine.

Second, the depth of field is a mathematical thing, for a given focal length and object distance and aperture, it is what it is. F22 is the best you can normally do, but may cause diffraction (edge haloes) so try to keep around f16 unless it is a Zeiss, Leica or Hasselblad lens.

The more you space the lens from the camera (sensor or film) the more you are asking of the original lens computation and the more light transmission you lose. Go for 22mm of spacing max, get the focus, live with the smaller image or crop it later in Photoshop or whatever you use.

Put the object so it is parallel with the camera back, presto - mostly in focus, or, just concentrate on the nearest edge at an angle. Consider a two panel or three panel picture - a triptych that's called, say the full circle flat to camera ring view on one panel, the front view on the centre 'pane', the inside inscription on the the third 'pane'. Can work well.

The way they do this in the pro world is a tilt and shift lens (one that swivels in itself and bends the light);- on a large format camera, think in thousands for each part, or, Nikon and Canon do 35mm lenses that do that same thing to a limited extent, starting at £1500 upwards (never seen one second hand). By bending the lens axis more of the ring is kept in focus, a very exacting scientific approach is needed.

For amateurs with limited dough, the dipych/triptych way is within reach and pleases many customers. Using the macro (some lenses go 1:1) with no tubes at all and cropping the result will probably be better on screen than losing the depth of field and filling the frame more.

Hey - its digital, the 'film' is almost free - try both methods, examines at 200% on screen and pick the best.

Be ultra careful with unsharp mask on the finished product, the out of depth parts can get worse, try lab sharpening much more subtle (sharpening your shot is the last step in your process, right? Hope you do it on a layer, too, so you can adjust it later non destructively if you want to).

You'll need a trial ink jet print or two if that is the finished product - oversharpen for prints, less for the screen views.

Good luck with that, much fun

Use f/22. You'll need a long exposure on a tripod.

If you want the whole image in focus, use a compact camera in macro mode with a high pixel count and crop into the image.

Try with the zoom at the closer aperture