Originally posted by ScooterMaxi Jim Goudge makes a good point overall regarding nodal point and other variables, but the last point regarding the "advantage" of close up lenses offering brighter images is pretty much like saying the light from a nearby atomic bomb detonation is brighter than anything you've seen previously - or quite obviously ever again. The compromises of sticking a simple magnifying glass in front of a good lens are much greater than the other compromises related to adapting a non-macro lens.
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Note, I am not promoting one version over another, and all of the devices mentioned are in the majority of cases devices applied to non macro lenses, but for most people starting out, a set of close up lenses is usually the first thing they try, and a bright viewfinder is a big advantage. But it is not everything, I agree.
I highlighted this point because it is the one distinguishing factor of a close up lens compared to all other methods.
---------- Post added 05-04-2017 at 06:48 AM ----------
Originally posted by ScooterMaxi Jim Every lens design responds differently, based on issues related to diaphragm placement, nodal point, other overall optical design considerations, and coatings. For some lenses, reversing is a good option, but not often. Use of a quality TC is often a good compromise, especially for standard lenses in the 50 to 85mm range. Possibly the best overall "compromise" is the extending TC, such as the Vivitar 2x macro. I have the better green numerical version (confusingly designated P/K-A R-P/K but does not have the Ricoh pin problem): optically very good as a continuously variable extender - and not bad as a TC. Short of going for a dedicated macro lens, it probably qualifies as the most versatile and simple solution to yield good results.
The vivitar macro TC is a good option for what it does, but these are getting somewhat rare and are not always cheap. I have one and like the versatility of the focusing helix, but note my initial intent was not to recommend any one solution but to explain the technical differences, which no one had gotten right to this point in the thread.
I have tried virtually every macro form available, including an enlarger lens mounted on a bellows, extension tubes used with and without focusing helix, macro lenses, (50, 90, and 100mm) close up lenses, and even an oddball sigma 135 mm close focus lens with 2 focusing rings, one on the whole group, and one just to move the front element for close focus.
Each has uses, and drawbacks, and if you play on the used market, macro lenses are plentiful in manual focus, but depending on what you are actually doing, a close up lens is smaller lighter and pretty good for casual use, or if you want capability just in case.