>From: "C.H.Ling" <chling@xxxxxxxxxxxxx>
>
>- ----- Original Message -----
>From: "Jan Steinman" <Jan@xxxxxxxxxxxxxx>
>
>> >I think 36db is a wrong value, most agree slide has D-Range of roughly
>4.0,
>> >which is 10000:1 and 80db.
>>
>> Might you be confusing voltage (or current) ratio with power ratio? Light
>intensity is always expressed as a power ratio.
>
>Are you sure? seems that I have seen the video cam quote much more than 34db
>SN ratio, they are better than slide?
Interesting. They may be playing specmanship. Or they may be expressing a
voltage ratio.
Or they could really be doing an honest 34db, which would be about 10 stops, I
think.
> > Good drum scanners can see a Drange of 4.0, but in my experience, Velvia
>doesn't stretch nearly that far. On my ColorGetter Falcon, 4"x5" RVP
>(Velvia) seems to run from 0.16 to 3.4 or so.
>
>Really? I just think Velvia provided the deepest color of all slides, if 3.4
>is good enough then why people make the dmax 4.0 scanner?
Specmanship? :-)
I have not scanned ANY film that would approach the full range of my drum. The
only way to read the whole range is a piece of black tape measured against the
bare drum, which shows up as 0.0 to 4.0. Even horribly over-exposed film base
measures about 0.16, and totally unexposed film covered by the film holder
reads about 3.6 - 3.8 or so.
--
: Jan Steinman -- nature Transography(TM): <http://www.Bytesmiths.com>
: Bytesmiths -- artists' services: <http://www.Bytesmiths.com/Services>
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