Hi, but the camera has to choose the exposure time for the shot and therefore everything is fixed after the exposure. Setting an ISO in a digital camera is just another word for under- or overexposure. So I think what you discribe is just not possible - but a nice imagination!
Best regards, Hans. -------- Original-Nachricht -------- Datum: Fri, 15 Sep 2006 08:45:01 +0300 Von: "Antti-Pekka Virjonen" <[EMAIL PROTECTED]> An: "Pentax-Discuss Mail List" <pdml@pdml.net> Betreff: It is ingenious! Was: Does this mean what I think it means? > Hi, > > I was thinking about the 22 bit A/D converter and about the ISO > setting last night. > > Then it struck me, right into the back of my head... :-) > > It is simply ingenious (if this is what Pentax has done): > > 1) By utilizing a 22 bit A/D you get a wide dynamic range > > 2) When you have a wide dynamic range on the A/D converter, you don't > have to > use a high gain amplifier stage (to get high ISO sensitivity) but you > can use > a constant (lower) gain low noise (optimized) amplifier. > > 3) This way you can "choose" the ISO setting after exposure, before > storing > the image into the raw (or converting to jpg). You can analyze the data > and > then decide "how to actually expose". I think this is what Pentax may be > doing > with the "automatic ISO setting". It's like having all the different ISO > > negative films in your camera the same time. > > (Of course you can have a variable gain amp if you wish to get > "standard" > DSLR behaviour...) > > 5) With a relatively low gain amplifier and 22 bit A/D (and both having > low > noise) you will get a really wide exposure latitude. The K10D differs > >from the competition in this respect. It is like how negative film > differs from > slide film. > > In theory you will get a very nice package. We'll see how it will > perform > in reality, but I am sure it will do quite nicely. Pentax wouldn't have > used a 22 bits A/D if there wasn't a good reason. > > Antti-Pekka > > ________________________________________ > > Antti-Pekka Virjonen > > Computec Oy > R&D Turku > Fiskarsinkatu 7 D > FIN-20750 Turku Finland > > Puh. +358 20 7908 300 > GSM +358 500 789 753 > Telefax +358 20 7908 319 > > Y-tunnus 1974184-5 > Kotipaikka Helsinki > > www.computec.fi > > > -- > PDML Pentax-Discuss Mail List > PDML@pdml.net > http://pdml.net/mailman/listinfo/pdml_pdml.net -- "Feel free" - 10 GB Mailbox, 100 FreeSMS/Monat ... Jetzt GMX TopMail testen: http://www.gmx.net/de/go/topmail -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
