Can you convert the typical 80mm triplet from Lumenlab into a varifocal in an effort to focus the corners? I recall somewhere that someone had a modified lens (unfortunately i dont recall where and the person could've lied/ripped off pictures from somehwere) and the corners were focused. Would it be worth the effort of trying to make this triplet into a varifocal? Will it compromise something that we want in the lens?
yes it will be worse
The lens spacing is an important part of the triplet design. If you change the spacing of a fixed triplet, the performance will decrease. You will see much more distortion and aberrations.
Varifocals give optimal performance at one setting (probably in the middle of the adjustment range). At the extremes they are not as good. I think the lumenlab 80 mm triplet has very small air spaces, so all you could do is make it worse by increasing the spaces. But maybe "worse" would still be good enough for watching video.
The lens spacing is an important part of the triplet design. If you change the spacing of a fixed triplet, the performance will decrease. You will see much more distortion and aberrations.
Varifocals give optimal performance at one setting (probably in the middle of the adjustment range). At the extremes they are not as good. I think the lumenlab 80 mm triplet has very small air spaces, so all you could do is make it worse by increasing the spaces. But maybe "worse" would still be good enough for watching video.
Hey Guy,
So that's what that is...hah Family Guy. Even if you only adjusted the last objective in the lens assembly (closest to the screen)? I doubt this would work but you think it's worth ripping apart the 30 dollar setup 🙂. I just don't want to do it if nothing good will happen. I know you have a good amount of experience with lenses (and oslo) and your guidance is much appreciated.
So that's what that is...hah Family Guy. Even if you only adjusted the last objective in the lens assembly (closest to the screen)? I doubt this would work but you think it's worth ripping apart the 30 dollar setup 🙂. I just don't want to do it if nothing good will happen. I know you have a good amount of experience with lenses (and oslo) and your guidance is much appreciated.
This IS DIY!
I never want to discourage anybody from running a real experiment! If it only costs you $30 to learn something, then that is worth it. You might get adequate performance for your needs by adjusting the space between the lenses, or by replacing the last lens with one a bit stronger or weaker.
Even if you did not find a better combination, you could always mount the original lenses back in a tube with the original spacing.
Go for it! (And then post your results.)
I never want to discourage anybody from running a real experiment! If it only costs you $30 to learn something, then that is worth it. You might get adequate performance for your needs by adjusting the space between the lenses, or by replacing the last lens with one a bit stronger or weaker.
Even if you did not find a better combination, you could always mount the original lenses back in a tube with the original spacing.
Go for it! (And then post your results.)
I plan to DIMyself when my projector is setup and will most definitely post results. Thank you for your input, before and after the question at hand (your post from the past helped so much). As soon as my bigger fresnels get in and I cut em down, I'll finish my proj.
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