Noooo... ASA - doubleing the values means halving the shutter time - a numeric/linear scale. DIN is a logarithmic scale - 3 DIN means twice or half as much light. It's true that Scheiner and Weston are 1/3 stops apart. http://home6.inet.tele.dk/haagen/ei.htm
This table does not mention BSI. Jens Bladt http://www.jensbladt.dk +45 56 63 77 11 +45 23 43 85 77 Skype: jensbladt248 -----Oprindelig meddelelse----- Fra: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] vegne af P. J. Alling Sendt: 19. oktober 2006 19:34 Til: Pentax-Discuss Mail List Emne: Re: BSI - film speed system etc Yes but they don't bother telling you that ASA = BSI = ISO and that ISO is just the combination of the ASA value and the DIN value in a single notation, (and most people just leave off the DIN value). Bob W wrote: >BSI and ASA apparently used the same numbering system, according to >this web page: >http://www.photographytips.com/page.cfm/1591 > >BSI was obviously superior in all other respects, of course. > >That looks like a nice camera. I'd like one of those sometime. > >-- >Cheers, > Bob > > > >>-----Original Message----- >>From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On >>Behalf Of Jens Bladt >>Sent: 18 October 2006 21:56 >>To: Pentax-Discuss Mail List >>Subject: OT: BSI - film speed system etc >> >>Is this fairly the same as ASA/ISO? >>I recently got this 1955 Agifold camera. The extinction >>meter/calculator has >>SCH (Scheiner-Grad) and BSI (Brittish Standard Institute) >>film speed scale. >>I wonder if BSI is equal to ASA? >>Please take a look: >>http://www.flickr.com/photos/bladt/273145251/ >> >>Does anyone here have experiences with Ensign 820 (6x9) or >>Ensign Autorange/ >>Ensifn 16-20 (645), please? >>Thanx >>Regards >> >>Jens Bladt >>http://www.jensbladt.dk >> >>-- >>No virus found in this outgoing message. >>Checked by AVG Free Edition. >>Version: 7.1.408 / Virus Database: 268.13.5/482 - Release >>Date: 10/18/2006 >> >> >>-- >>PDML Pentax-Discuss Mail List >>[email protected] >>http://pdml.net/mailman/listinfo/pdml_pdml.net >> >> >> >> > > > > -- Things should be made as simple as possible -- but no simpler. --Albert Einstein -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.408 / Virus Database: 268.13.7/488 - Release Date: 10/19/2006 -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.408 / Virus Database: 268.13.8/489 - Release Date: 10/20/2006 -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
