On Mon, 19 Feb 2007 13:18:00 -0500, John Francis wrote > On Mon, Feb 19, 2007 at 09:40:01AM -0700, Joseph Tainter wrote: > > Is there any advantage in using the .PEF file format other than reduced > > size on the SD card? Such as better lens info in the EXIF etc. Apologies > > if this has been asked before. Currently I'm using .DNG and I'm not > > getting lenses like Tamron 28-75 and Sigma 70-200 in EXIF, I'm sure > > somebody mentioned them appearing. > > > > It's a long shot but, will perceived exposure be affected? > > > > Regards, > > > > John > > > > ----- > > > > John, recognizing lenses depends on (a) the lens's chip properly > > transmitting the information, and (b) the camera's firmware recognizing > > what the lens transmits. Apparently for many (all?) third-party lenses, > > this doesn't happen. Camera Raw can't address that. > > I don't think John is talking about the well-known problem where many > Sigma lenses mis-identify themselves to the camera, using lens codes > assigned to certain Pentax lenses. I believe he's wondering whether > there is any difference between what information is stored in a DNG > and what is stored in a PEF.
Correct, I should have explained myself better. > When this issue was first raised I put together a little utility to > rummage around inside K10D DNG files, and showed that everything from > the MakerNote tag in the PEF format (including, in particular, the > lens ID code) was stored in a DNG PrivateData tag. But not all image > viewers (even those that know how to display images in DNG format) > know how to get this information from K10D DNG files. That's true > even for image viewers that know how to read the Pentax private data > both from PEFs and from DNGs created by Adobe Camera Raw; there are > subtle differences between the file formats that make this tricky. > > Since then ExifTool <http://www.sno.phy.queensu.ca/~phil/exiftool/> > has been updated to understand the K10D DNG file format, so it's > easy enough for you to confirm this for yourself (particularly now > there are stand-alone ExifTool executables for Windows and for Macs). > > One final nit-pick; the camera firmware doesn't have to recognise > what the lens transmits (other than it having to be using the correct > protocol to transmit the data). It just takes the data from the lens > and stores it somewhere in the image file. As far as I know all > third party auto-focus lenses transmit *something* to the camera; > it's just that what they transmit isn't always strictly correct. Thanks for the information. I guess I'll have a rummage around and see what I can see. Regards, John ---------------------------------------------------------------------------------------------------- The information transmitted is intended only for the person to whom it is addressed and may contain confidential and/or privileged material. If you have received an email in error please notify Carmel College on [EMAIL PROTECTED] then delete all copies of it from your systems. Although Carmel College scans incoming and outgoing emails and email attachments for viruses we cannot guarantee a communication to be free of all viruses nor accept any responsibility for viruses. Although Carmel College monitors incoming and outgoing emails for inappropriate content, the college cannot be held responsible for the views or expressions of the author. The views expressed may not necessarily be those of Carmel College and Carmel College cannot be held responsible for any loss or injury resulting from the contents of a message. ---------------------------------------------------------------------------------------------------- -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
