News Flash! Wider Graphics Scanning.

[mixedgas]

After much study of lenses, I found, a combination of commercial lenses that doubles scan angle while maintaining beam diameter at ONE wavelength at a time. So you can get 16' of scan angle at 30+ K while using a pair of standard scanners at 8'. The bad news is that color correcting it is not going to be easy, red, green, and blue in tests are focused but displaced relative to each other.

(Thank you Dr Lava for use of your RGB and wall)

So you can have 16' 30 to 60 K graphics with this combination in bright green.

The bad news. The cost is not cheap. even though I only paid about 75$ for my pair on ebay, a 50mm F-theta is on one end and something nonstandard on the other. I have three more of the non standard part, which can be cloned. The F-Theta makes this expensive.

To the best of my knowledge, F-Thetas have only been color corrected for two wavelengths at a time. I have something else on order that might replace the F-Theta and be color corrected , but at the cost of needing geo correction in software.

The special lens predates the AVI wide patent, and uses standard glass, not the exotic high index stuff that would be in the AVI Minolta lens. For the record, I know they were made by Minolta, but I don't know the part number, nor do I care.

PS, I just checked with my supplier, a dozen or so of the main lens are still available.

Steve

[-bart-]

Just curious, could there be something like an F-Theta ánd grin lens ?

[weartronics]

lenses that doubles scan angle while maintaining beam diameter

Hey Steve, could you elaborate on this magic? I don't understand how it's possible... Best regards, weartronics

[mixedgas]

So somebody wanted a 22" diagonal screen in a 8" depth with several thousand intensity levels, from starlight to daylight in full color. They also wanted it done using standard glass instead of a lanthi or thori high index exotic. They wanted hundreds of units with 40 each of these screens.

That means we win.

Understand it not, I do. I don't even think Yoda understands high order ray tracing, but I knew roughly what to look for from looking at the wide angle single lens full dome flight simulator patents, although some of them have 30-40 element lenses with aspherics and other weird things, although they do get almost 180' angles.

I've tried about 25 commercial lenses over the past three years, spent a lot of money and was about to give up.

The main lens has 7 elements, only one of which looks nonstandard, I used the F Theta lens backwards, which means I might just need a achromat with a horribly distorted field, and those are easy to get.
The F theta typically has 4 elements, although one of them has a radius that looks like it got gouged out by a ice cream scoop.



Some PLers with strong optical skills have PMed me already.

Its really only good for graphics anyways.

Stay tuned, pictures in a day or two

Steve

[mixedgas]

[QUOTE=-bart-;99036]Just curious, could there be something like an F-Theta ánd grin lens ? end quote.

more like F theta and a lens that has a .5 mm focal length on one end and 80 mm on the other. So yes, if there was a imaging grin, it would come close, but I dont think you'll find a grin with a 15 mm diameter to set in front of the scanners.

Sort of like a projection TV lens, but without the field flatteners inside.

Steve