'Better' can easily mean that a lens reaches a typical design spec at a lower price, rather than simply having more lp/mm.
Paulr
when i asked an optical engineer about it, his first question was "better
how?" ... pointing out that my idea of better, which was more sharpness
across the image circle, was just one of many things their customers
wanted. among others were things that matter little to me, like higher
speed, better performance at high magnifications, and lighter weight--all
of which are major design parameters that require compromises to achieve.
OK - I am an optical ignoramus but coming from a Number 8 fence wire mentality where by the assumption is that if some has done it ( build the lens ) it ( the built lens ) can be improved. Some what similar to your road car engine and converting it to a racing engine. The two above statements suggest to me that if I were sufficiently knowledgeable to disassemble, grind, polish or whatever and reassemble a lens with the correct alignments and spacing I could finish up with a lens tailored to my particular needs. Which leads to the question just how difficult would that be ? Does anyone supply a “KIT” of bits - glues – alignment tools – surface shape gauges etc ? OK this might require some time and effort on behalf of the lens owner but if money can’t buy what can be built and you know what you need, then the “ best “ would actually be available ? For the poor like myself, time and work would produce lenses I could not afford. Just how difficult is it to check a lens for correct alignment ?
I hope that this not a completely stupid question ! but it seems to me putting together a kit or kits of different levels of advancement would be far more saleable than putting another camera on the market as suggested in another thread.
"Which leads to the question just how difficult would that be ? "
Rob, i think it's a great question. but sadly, based on what's been explained to me, it would probably be one of the most dificult things imaginable.
the design part might might not be too bad ... these days, with the software that's available, and with so many specialized lens designs already in existence, it might not be too hard to borrow from some old ones and do a little tweaking. i'd have no idea where to begin, but with some help and some studying you might get somewhere.
fabrication is another story. one of the guys at schneider said that that each surface of each element requires 24 hours of computer-controlled polishing. centering is done on a lathe that's guided by a laser, with everything calibrated to fractions of a micron. all kinds of interferometry is done along the way for quality control, and at the end, final qc is done by specially trained engineers who judge projected test patterns by eye. this is to say nothing of the coating process, and the machining of the barrel and all that. the level of precision is outrageous. all the top lens manufacturers probably do it in more or less the same way.
probably the best bet for a DIY project is to work with a designer and have a lensmaker build it for you. that's what they did at the gigapixel project ... http://www.gigapxl.org/technology-lens.htm (this is an example of someone needing an unusual design ... something with extreme sharpness and coverage, but able to sacrifice speed, size, and weight).
or you could work with someone like schneider who designs custom and semi custom OEM lenses for people all the time ... http://www.schneideroptics.com/oem/custom_solutions/
no matter what, you'd need some deep pockets. i think off the shelf lenses are pricey enough!
or, if you just want to play, you can do what a photographer i knew in rhode island used to do. he'd buy broken lenses and mix and match elements, and see what kinds of trippy results he could get. there was no engineering going on ... just fun. the results looked like toy camera work, but much more out there.
I understand the temptation to buy mojo. I'm in the middle of a major lens feeding frenzy. But doesn't killer mojo come from hunting (or stumbling upon) great light?
Hmmmm. Thanks for your illuminating response. It seems that fine tuning a lens is more Formula 1 than hot rodding a short block Chev.
I can see that the precision required calls for lathes of some substance ( with the attendant costs ) rather than a jig that might be attached to a mono rail camera. It looks like your MTFs curves or Chris and Kerry’s best of breed testing or both are for the present the practical solution.
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