Quote:
Originally Posted by space oddity
I also think this looks like a bullet or torpedo. I wonder how this would have gone with stopping down and holding a small flash nearby. With the inverse square law, a flash held very close and fired while the shutter is open gives the potential for very stopped down apertures and thus depth of field. Even a cheapie GN 10 flash held a modest 10cm from the subject gives f/1,000 shooting conditions. In practice, you could get in to 1 cm for f/100,000 shooting, enough to compensate for the light loss from this extreme macro.Quick maths here -50x shooting = 2500 x LESS light, so the f/100,000 is equivalent to f/40 .Loose a stop or two for lack of reflections from wall etc gets down to more or less f/22 on the camera lens for iso 100 shooting.
With such a monster rig here with a lot of extension, the scheimflug principle could be used with tilting the lens to increase depth of field. Focusing this rig would be the hard part.
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An interesting idea but unfortunately it won't work with respect to microscope optics. Microscope optics are considerably more complicated than camera lenses or telescopes and have a much smaller depth of field.
The f/ratio of a microscope is related to the numerical aperture of the microscope objective not the aperture or opening of the objective. Placing a stop on the aperture won't increase the f/ratio as the numerical aperture doesn't change. The numerical aperture is determined by the refractive index of the medium in which the lenses operate and the maximum cone of light that can enter the objective. In fact the depth of field decreases with increasing magnification. The high magnifying objectives of 100X incidentally have apertures or openings not much larger than a pinhole.
Regards
Steven