What is the FOV (field of view) of the Lumen Lab 320mm focal length lens, costing 29$? What is the aperture limited (light circle) one and the good image one, so it can still separate .264mm on a say 5X magnification projection?
Also do you know the exact aperture value, ie related to back focal length, not the approximate f/4, from 320/80.
TIA
Simply put, does it cover decently 17'' panels, or merely 15'' at 5-6X?
I understood this and the pro 450mm LL objective are about the only options, except more expensive photographic lenses, or undocumented surplus copy lenses.
Also do you know the exact aperture value, ie related to back focal length, not the approximate f/4, from 320/80.
TIA
Simply put, does it cover decently 17'' panels, or merely 15'' at 5-6X?
I understood this and the pro 450mm LL objective are about the only options, except more expensive photographic lenses, or undocumented surplus copy lenses.
I don´t know the lumenlab's standar triplet's STATED FOV. But the F number is somewhere F=5. (320 mm focal & 62mm aperture?)
The other one (coming soon) is the 500mm focal and 100mm aperture triplet. F=5 again.
There are more factors than FOV as well to determine the max circle (LCD size) such as throw. The FOV is a setip tependent circle but the FOV angle is constant. Personally I prefer to use the FOV angle, rather than FOV circle in milimeters.
The other one (coming soon) is the 500mm focal and 100mm aperture triplet. F=5 again.
There are more factors than FOV as well to determine the max circle (LCD size) such as throw. The FOV is a setip tependent circle but the FOV angle is constant. Personally I prefer to use the FOV angle, rather than FOV circle in milimeters.
Ooops, I was hoping for a better F/D given the 80mm value. Even old dia projector objectives have 1:2.8 and 60degrees angles, with huge resolutions. But they're too small for my coverage needs.
Yes, I prefer the FOV angle too, but any would do since we can convert between them. The angle isn't precisely constant too, as it may vary with the object distance.
I don't need to cover more than 17'', regardless of angle or focal length. So I need 2*arctg(17/F) angle with as good F/D as possible, but only modest resolution vs photographic applications.
Yes, I prefer the FOV angle too, but any would do since we can convert between them. The angle isn't precisely constant too, as it may vary with the object distance.
I don't need to cover more than 17'', regardless of angle or focal length. So I need 2*arctg(17/F) angle with as good F/D as possible, but only modest resolution vs photographic applications.
Yeah, the FOV angle and the FOV circle are directly related. You can't have one without the other. The 80mm has been said to not perform well with a 17" LCD. Even the 135mm has fuzzy corners. The new 500mm Pro lens from LL is supposed to resolve these issues with 17" LCDs. It also costs $200 and isn't available until after January. But, if it proves to work flawlessly with a 17" LCD, it would be your best choice (without considering price). If price is an issue, you'll have to try your luck on e-bay for an opaque projector lens or a copy lens for a large format camera. I've heard that 22" FL (559mm) opaque projection lenses can handle 17" LCDs.
'The 80mm has been said to not perform well with a 17" LCD.'
Then perhaps it still covers all corners, meaning the image isn't cut, despite unclarity. That would be good to hear, because 200$ is pretty steep for a project now, with commercial prices falling and LED projectors around the corner (they're announced in January 2006).
But I can part much easier with 29$ for the sake of experimenting and DIY 😉
Then perhaps it still covers all corners, meaning the image isn't cut, despite unclarity. That would be good to hear, because 200$ is pretty steep for a project now, with commercial prices falling and LED projectors around the corner (they're announced in January 2006).
But I can part much easier with 29$ for the sake of experimenting and DIY 😉
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