Re: 15Hz to VGA converter

["Charlie" <charlieDOTd@verEYEzon.net>]

"Michael J. Mahon" <mjmahon@aol.com> wrote in message 
Q9qdnXHiQrqoTvfRnZ2dnUVZ5oednZ2d@giganews.com">news:Q9qdnXHiQrqoTvfRnZ2dnUVZ5oednZ2d@giganews.com...
> Charlie wrote:
>> "Michael J. Mahon" <mjmahon@aol.com> wrote in message 
>> M-mdnWTkifPdCfTRnZ2dnUVZ5vSdnZ2d@giganews.com">news:M-mdnWTkifPdCfTRnZ2dnUVZ5vSdnZ2d@giganews.com...
>>
>>>Charlie wrote:
>>>
>>>>>On 8/13/2010 7:02 PM, MdntTrain wrote:
>>>>>
>>>>>
>>>>>>On Aug 13, 4:06 pm, Steven Hirsch<snhir...@gmail.com>  wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>>The Highway Model 100 converter does a FAR better job on the 
>>>>>>>desktop.
>>>>>>
>>>>>>Yes.   Reposting some of my old photos, you can see the 
>>>>>>differences:
>>>>>>
>>>>>>http://www.cimmeri.com/js/download/
>>>>>>
>>>>>>RGB1-7.JPG = IIGS ->  Keene Aptus ->  Samsung 192MP
>>>>>>                    = RGB ->  RGB/YUV ->  15khz YPbPr in
>>>>>>                    = A-A-(A-D upsampled to LCD)
>>>>>>
>>>>>>    Problems seen on desktop are due to the 192's high 
>>>>>> bandwidth
>>>>>>     Component input, and its sampling rate creating aliasing 
>>>>>> effects.
>>>>>>
>>>>>>    The Samsung 910MP with SCART does NOT have this problem
>>>>>>    as the SCART input is bandwidth limited.
>>>>
>>>>
>>>>In case anyone is interested in seeing pictures of the Apple 
>>>>IIGS desktop on a Samsung SyncMaster 940MW wide screen LCD 
>>>>monitor/TV using just the IIGS to SCART cable (no converter box) 
>>>>I have included the link I posted some time ago:
>>>>
>>>>http://www.noboot.com/Charlie/a2gslcd.htm
>>>>
>>>>I have added another picture of the finder desktop with 4:3 
>>>>ratio and periwinkle blue background for comparison with others 
>>>>posted in this thread.
>>>
>>>Now *that's* lovely!  ;-)
>>>
>>
>>
>> The periwinkle blue seems to have less vertical banding effect 
>> than the gray I normally use.  You can barely see it in the 
>> picture.  A little more so on the screen but still very faint.
>>
>> The white on black 80 column text in the picture is more 
>> saturated than on the screen due to my camera having trouble 
>> getting it right. On the screen there is some variation of the 
>> 'whiteness' in parts of some letters.  Still easily readable 
>> though.
>
> Auto exposure will always get a text display wrong...  Manual 
> exposure
> is needed to expose for the (very limited area) highlights.

My camera is a cheap point and shoot that's three years old.  I 
don't even know if it has any way to manually set the exposure. 
I'll have to look into that :-)

>
> I'm betting that the horizontal strokes of the characters are 
> brighter
> than the vertical strokes, since full-white verticals (or 
> diagonals)
> require unusually high luminance bandwidth.
>

Yes, I didn't notice that before, the horizontal strokes are 
slightly brighter and/or seem thicker to my eye.  The diagonals are 
the problem strokes, they are even dimmer or less sharp than the 
verticals.  The ghosting that I have referred to previously is 
present on the text modes but is less noticeable when the text is 
white on a black background.  I believe this is causing most of the 
problems with the text.  Again though the text is still easily 
readable and I don't want to make it seem otherwise.

Charlie