LisaList2
General Category => LisaList2 => Topic started by: pl212 on October 05, 2024, 06:36:38 pm
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Do we know if anyone has scanned or photographed the "Alignment Graticule" for the CRT? I would guess this is a piece of transparent plastic with a crosshatch grid on it. Part number is 077-8043-A...
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"Alignment Graticule" for the CRT?
I've been looking for the graticule P/N 077-8043-A aka P/N 652-3520 for a long time and no sign of it yet.
If you want to make your own, my theory is that the outside dimensions of the 720 x 364 raster should be about 9.000" x 6.067" with each pixel being 0.0167"H x 0.0125"W
edit: had pixel HxW backwards
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A bit more sleuthing... I did find two different part numbers -- unsure why these would be split for the Lisa 2, unless they are talking about the square pixel mod:
077-8043 A Video Align Graticule, Lisa
077-8169 A Video Align Graticule for Mac XL/Lisa 2.0
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It's probably due to the different shape of the Twiggy vs. Sony front bezel?
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I had one listed on eBay a while back and P/N 077-8043-A is on the original LISA Alignment Graticule.
Another theory might be the part number change may have been done by what seems like a catalog wash and rename of the LISA 1 exclusive images/items.
As for their scarcity, they are very (very) hard to find in their original condition, particularly because the graticule was washed away after use.
In either case, they are unusually difficult to find item.
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I had one listed on eBay a while back and P/N 077-8043-A is on the original LISA Alignment Graticule.
First pic of the graticule that I know of -- thank you!
Is the graticule (the portion that is a transparency with markings) actually attached to that glare filter, or is it packed with a Lisa glare filter for protection/alignment?
How is it the graticule was single-use / washed away... is it some kind of transfer rather than an overlay or ... ?
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How is it the graticule was single-use / washed away... is it some kind of transfer rather than an overlay or ... ?
yep, one-time use and washed away (hot water) which explains why we don't see them much.
If memory serves me correctly, a LISA 1 manual discussed installing the glare screen, and how to align the image from inside the LISA, if needed. (so it must have been a tech manual).
Either way, should I relist it, it probably is best to include a second (regular) glare screen (for installation) to preserve this unique artifact.
<yeah, I say artifact because as L1s become available, their value will probably be critiqued by having period-correct components and accessories with them.>
Anyway, glad that helped alleviate guessing what they look like.
Take care.
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... glad that helped alleviate guessing what they look like.
If you can still find it (or run across another one), please measure the height and width of the two rectangles that bound the outline of the raster so we can determine the range --
One of the motivations for locating an original graticule is to resolve the confusion regarding the aspect ratio of the pixels.
Most references say the aspect ratio of the pixels is 2:3, but by drawing a rectangle of (720 x 2) by (364 x 3) it is clear it does not match the proportions of what we see on a Lisa screen. A theory is that the 2x3 ratio only applies to the full raster on the 12" CRT (ie. 6"x9"), and so a pixel aspect ratio of 3:4 is more likely correct.
But having seen the graticule pic, I now wonder if the aspect ratio is not defined as a whole number, but rather the size of the 720x364 raster was defined to fit nicely in the bezel and the pixel aspect ratio ends up as an arbitrary number that happens to be close to 3:4.
Thanks very much for your contributions!
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If you can still find it (or run across another one), please measure the height and width of the two rectangles that bound the outline of the raster so we can determine the range --
I was able to measure it using a grid overlay.
The dimensions are noted in the attached image.
If the numbers aren't exact they are damn close.
Anyway, hope that helps.
NOTE: replaced PNG with letter sized PDF
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hope that helps.
Yes, it sure does!
If one selects the out edge of the raster to be near the middle of the inner/outer limits, that gives a width of 8.6" and a height of 6.4", and so 720x364 pixels are then 0.011944" Wide x 0.017582" High; a ratio of 1.472.
That's closer to 3:2 than 4:3.
Still, drawing a rectangle on a square pixel screen of 720x2 by 364x3 does not look right (to me)... I speculate that this may be because adjusting to the graticule dimensions will fill the vertical size of the viewable area of the CRT, but leave substantial unused margins at the sides.
ie. although the viewable real estate of the CRT in the bezel is close to 9" x 6" (more precisely 9.49" x 6.73"), once adjusted to the graticule, the ratio of the 8.6" x 6.4" raster is perceivably different at 1.3438.
The Lisa included so many great innovations, but the Mac's WYSIWYG display is arguably insanely great.
Many thanks for the measurements & drawing!