Archived posting to the Leica Users Group, 2010/09/11

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: [Leica] not sure - but here goes
From: hopsternew at gmail.com (Geoff Hopkinson)
Date: Sat, 11 Sep 2010 21:10:20 +1000
References: <C8B09604.32B4%mark@rabinergroup.com> <8199DF19-732E-4893-8E0B-4FACA96A8DBD@btinternet.com> <AANLkTi=_N4YPCcBtSWyWvT4q0vTnoAt0k5LaJfEHe3TY@mail.gmail.com> <446608.28585.qm@web86703.mail.ird.yahoo.com>

Well silicone (the polymer) contains silicon (our metalloid chemical
friend) and we knew exactly what you were helpfully discussing, Franke!
Besides I can think of some silicone applications that REALLY would not work
well if made only from silicon. Ask Pamela Anderson.

Cheers
Geoff
http://www.pbase.com/hoppyman
NO ARCHIVE


On 11 September 2010 20:02, FRANK DERNIE <frank.dernie at 
btinternet.com>wrote:

> More crap spelling than wandering mind I fear...
>
>
> ----- Original Message ----
> From: "piers at hemy.org" <piers.hemy at gmail.com>
> To: Leica Users Group <lug at leica-users.org>
>  Sent: Saturday, 11 September, 2010 9:37:52
> Subject: Re: [Leica] not sure - but here goes
>
>  Spot on, Frank, of course. But you mean silicon - perhaps your mind
> was wandering?
>
> On 9/11/10, Frank Dernie <Frank.Dernie at btinternet.com> wrote:
> > Hi Mark,
> > on the off chance your question is not rhetorical here are a few reasons
> for
> > the difference in price between small and large sensors being much bigger
> > than thet between 35mm and 120 film.
> > Firstly the film is the same stuff, just a different shaped layer of
> plastic
> > coated with the same light sensitive stuff.
> > In the case of sensors they are made on a wafer of silicone. The crystal
> > structure of the silicone wafer has imperfections on it, and any chip
> etched
> > onto a part of the silicone wafer with an imperfection won't work, so it
> is
> > scrap. If, for example there is a defect every 2 inches, -all- 2 inch or
> > bigger chips will be scrap, so that is the biggest sensor which can be
> made
> > will be less than 2". Depending on how the layout of random faults and
> the
> > sensor layout fall on a wafer, there will be a high scrap rate even on
> > sensors less than 2". The scrap rate only comes down to negligible when
> the
> > sensors are -very- much less than 2".
> > This means big sensors are expensive since very few few of those produced
> > work. They are also expensive since the economy of scale is not there.
> Some
> > are made by joining 2 smaller sensors together with software to "fix" the
> > image at the join...
> > The technology for making the wafers is developing, so prices will come
> down
> > eventually, but never to the film ratio.
> >
> > Luckily, the sensor design of small and big chips is -not- the same,
> unlike
> > film. With film, going larger format increases the potential quality by
> the
> > increase in film area less the reduction in lens quality due to the
> larger
> > image circle. Going smaller with digital the loss is -much- less than
> with
> > film since the smaller sensors are -much- finer resolution than large
> > sensors so the loss of quality is not nearly as much as it used to be
> with
> > film.
> > cheers,
> > Frank
> >
> > On 11 Sep, 2010, at 07:12, Mark Rabiner wrote:
> >
> >> Brownie film does not cost that much more than 35mm film. Why should
> >> digital? Well it does. Bummer.
> >
> >
> > _______________________________________________
> > Leica Users Group.
> > See http://leica-users.org/mailman/listinfo/lug for more information
> >
>
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information
>
>
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information
>


In reply to: Message from mark at rabinergroup.com (Mark Rabiner) ([Leica] not sure - but here goes)
Message from Frank.Dernie at btinternet.com (Frank Dernie) ([Leica] not sure - but here goes)
Message from piers.hemy at gmail.com (piers@hemy.org) ([Leica] not sure - but here goes)
Message from frank.dernie at btinternet.com (FRANK DERNIE) ([Leica] not sure - but here goes)