Mirror v Zoom lenses
I have taken a series of photos with both of my Tamron Mirror Lenses.
Both these lenses are quite elderly at this stage and are completely manual focus. The have a fixed aperture, the 350mm is f5.6 and the 500mm is f8. Thus means they will not operate the metering system on my Nikon D5300, so I had to take a series of pictures at different shutter speeds and look at the screen on the camera to determine which ones have the best exposures. The ISO was set at 100 and this could be increased if necessary.
A big advantage of these mirror lenses is that they are quite short in comparison with a standard telephoto of the same focal length. They are based on the same plan as an astronomical reflector telescope, where the light is "bounced" around inside the lens, instead of going straight through as in a refractor telescope. The 350mm body length is only 70mm while the 500mm is only 80mm long. The 350mm has the facility to fit rear counted filters, UV, Red, Orange etc. The 500mm does not have this facility.
Likewise, they are quite light, the 350mm weighing only 732 grams and the 500mm is only 593 grams. Consequently in reasonable light you can hand hold the 350mm but a tripod is best for the 500mm (because of the extra magnification shake is a problem, even if you haven't been drinking!!).
Both lenses have a comparatively close focus when compared to their conventional lenses equivalent. The 350mm focuses down to 38 inches (97 cms), while the 500mm gets as close as 60 inches (152 cms).
One disadvantage of mirror lenses is that bright out of focus items can appear as bright doughnuts, called circles of confusion, which can detract from the main image. Sunlight on waves on the water are notorious for this.
Read MoreBoth these lenses are quite elderly at this stage and are completely manual focus. The have a fixed aperture, the 350mm is f5.6 and the 500mm is f8. Thus means they will not operate the metering system on my Nikon D5300, so I had to take a series of pictures at different shutter speeds and look at the screen on the camera to determine which ones have the best exposures. The ISO was set at 100 and this could be increased if necessary.
A big advantage of these mirror lenses is that they are quite short in comparison with a standard telephoto of the same focal length. They are based on the same plan as an astronomical reflector telescope, where the light is "bounced" around inside the lens, instead of going straight through as in a refractor telescope. The 350mm body length is only 70mm while the 500mm is only 80mm long. The 350mm has the facility to fit rear counted filters, UV, Red, Orange etc. The 500mm does not have this facility.
Likewise, they are quite light, the 350mm weighing only 732 grams and the 500mm is only 593 grams. Consequently in reasonable light you can hand hold the 350mm but a tripod is best for the 500mm (because of the extra magnification shake is a problem, even if you haven't been drinking!!).
Both lenses have a comparatively close focus when compared to their conventional lenses equivalent. The 350mm focuses down to 38 inches (97 cms), while the 500mm gets as close as 60 inches (152 cms).
One disadvantage of mirror lenses is that bright out of focus items can appear as bright doughnuts, called circles of confusion, which can detract from the main image. Sunlight on waves on the water are notorious for this.
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