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A fellow collector once asked me whether I have any suitable short-throw projection lens for his Eiki projector. Sure I didn't have, and buying the specifically made lens would be outrageous expensive for his casual use. So the story seemed to end here...
But later I came up with a weird idea - using a readily available manual CCTV lens found from any online source instead.๐คจ Better yet, I happened to already have a 25mm 1:1.4 lens sat unused in my attic. I then asked if he's interested in making this irreversible modification experiment?
To my surprise he agreed with this idea, so I accepted the challenge.๐
In essence - I stripped down the lens until literally being bare-bone, only the glass and its core body remains. Then after some measurements I've made a sketch for the adaptor sleeve to be made and sent that to a local machine shop. A few weeks later I've got this back from that shop.
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Alright, mediocre finish & fit, and not ISCO glass quality for sure. But this should give me something.
And here's the moment of truth...
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As a reference, here's what the standard 50mm lens would give you.
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And here's my Frankenstein's lens. A considerable improvement in terms of pic size, of course.
To my understanding these kind of lens are made to work with 1/3-1/2 type image sensor, or to cover only around 6-8mm image circle size, while 16mm frame size would be close to 12mm. No wonder it's probably not up to the task for any serious work (VERY noticeable softness around the edge, as expected). But it's more than good enough for his casual/personal use.
And since the lens itself is only $12, plus $25 for machining the adaptor sleeve. Therefore he'd happily paid some extra $$ for my R&D work - not a too bad deal I can say.
In the end since he's very pleased with the result. So I called this a win-win deal.๐
But later I came up with a weird idea - using a readily available manual CCTV lens found from any online source instead.๐คจ Better yet, I happened to already have a 25mm 1:1.4 lens sat unused in my attic. I then asked if he's interested in making this irreversible modification experiment?
To my surprise he agreed with this idea, so I accepted the challenge.๐
In essence - I stripped down the lens until literally being bare-bone, only the glass and its core body remains. Then after some measurements I've made a sketch for the adaptor sleeve to be made and sent that to a local machine shop. A few weeks later I've got this back from that shop.
โโโAlright, mediocre finish & fit, and not ISCO glass quality for sure. But this should give me something.
And here's the moment of truth...
โโAs a reference, here's what the standard 50mm lens would give you.
โโโAnd here's my Frankenstein's lens. A considerable improvement in terms of pic size, of course.
To my understanding these kind of lens are made to work with 1/3-1/2 type image sensor, or to cover only around 6-8mm image circle size, while 16mm frame size would be close to 12mm. No wonder it's probably not up to the task for any serious work (VERY noticeable softness around the edge, as expected). But it's more than good enough for his casual/personal use.
And since the lens itself is only $12, plus $25 for machining the adaptor sleeve. Therefore he'd happily paid some extra $$ for my R&D work - not a too bad deal I can say.
In the end since he's very pleased with the result. So I called this a win-win deal.๐
Trying to fix it at the moment.
Seems to worth the attempt, at least this met my fellow's level of expectations.
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