CCD Width?

[jimsolt]

I see in the exif data the item CCD width. It seems to vary even with the same camera in the same post.

What does it mean? Is it of any importance to me when I'm taking a picture?

Thanks,
Jim

[lostdoggy]

Not really

[Titus213]

I see in the exif data the item CCD width. It seems to vary even with the same camera in the same post.

What does it mean? Is it of any importance to me when I'm taking a picture?

Thanks,
Jim

I must have been thinking out loud. I've looked at that same data and wondered the same thing. There has to be a logical explanation but I sure don't have it. Curious minds want to know.

[jimsolt]

I guess this is not a topic of sufficient interest. "Not really" is "not exactly" the answer I was seeking :confused:.

Jim

[MTalley]

I've used an Exif viewer to look at the information from some of my pictures, and that's not one of the fields that I see. What are you using to view the information with? I was using PapaBlues Exif Viewer 1.2 (some shareware I found on the Internet).

[lancea]

I don't even want to go into how much time I've spent this morning trying to find something that displays CCD Width :rolleyes: I eventually found a freeware command-line utility called jhead from http://www.sentex.net/~mwandel/jhead/. On the way, I came across ExifPro http://www.exifpro.com/index.html which looks really nice - but doesn't show a field called CCD Width (at least not directly, with that name).

A Google shows that CCD Width can be used to work out the 35mm-equivalent focal length of a lens http://jalbum.net/forum/thread.jspa?threadID=1223. I note that they refer to it as Image Width, so perhaps they are the same thing? I can't find the term "CCD Width" in the EXIF 2.2 spec.

Anyhow ... all my shots show CCD Width as 22.48mm. So can you please clarify what you mean by "It seems to vary even with the same camera in the same post". You've got me interested, so we can't stop now :grin:

[jimsolt]

OK, it got quite complicated trying to get all this information in my reply, so here's what I am able to send you. I tried to send a scr prt, but got a message I had to reconfigure my browser, so I didn't go that route.

The picture in the link comes from another post in this forum and is called Tayla and (name?) dog

http://i4.photobucket.com/albums/y140/skade2/Frame_IMG_3441copy.jpg

The exif info below comes from viewing on Firefox with the aid of a plugin recommended on this forum that enables one to view exif info on SOME photos,

You'll have to trust me it's different on different photos in the same post taken with the same camera. I don't mean to say necessarily THIS post, but it is true with other posts.

And it isn't in all exif data viewed with this same method, but it is pretty common.

Camera Make: Canon

Camera Model: Canon PowerShot Pro1

Image Date: 2005:06:04 08:39:16

Flash Used: Yes (Manual, red eye reduction mode)

Focal Length: 29.0mm

CCD Width: 7.48mm

Exposure Time: 0.0040 s (1/250)

Aperture: f/8.0

White Balance: Auto

Metering Mode: Matrix

[LisaMarie]

If you look at the other pictures and view the EXIF data I am sure you will see the CCD width reading remains the same as long as the same focal length is used. The CCD width information will change when the focal length changes.

Examples:
Camera model : Canon PowerShot S100
Focal length : 5.4mm (35mm equivalent: 37mm)
CCD width : 5.23mm
Aperture : f/7.1
Resolution : 650 x 488


Camera model : Canon PowerShot S100
Focal length : 7.1mm (35mm equivalent: 36mm)
CCD width : 7.06mm
Aperture : f/7.1
Resolution : 650 x 488

* with no crop seems to be a factor also. It is an attempt to show you the equivalent 35mm field of view . Note also that some of the file information I viewed in other posted images was incorrect. Must depend on the quality of the software as to consistency. Like the one post 17mm equ of 744 MM ! The overwhelming majorty of changes I viewed changed when the focal length was the only thing changed in the composition.

[jimsolt]

If you look at the other pictures and view the EXIF data I am sure you will see the CCD width reading remains the same as long as the same focal length is used. The CCD width information will change when the focal length changes.

Examples:
Camera model : Canon PowerShot S100
Focal length : 5.4mm (35mm equivalent: 37mm)
CCD width : 5.23mm
Aperture : f/7.1
Resolution : 650 x 488


Camera model : Canon PowerShot S100
Focal length : 7.1mm (35mm equivalent: 36mm)
CCD width : 7.06mm
Aperture : f/7.1
Resolution : 650 x 488

OK, LisaMarie. I think you're right. Is it just another way of expressing the focal length? I can't for the life of me see the connection, but the list of things I don't understand is a long one.
I'm thinking it probably doens't matter much, but now I'm curious.
Thanks,
Jim

[lancea]

It looks to me that CCD Width is not part of the EXIF data, but is instead calculated. If you are really interested, have a look at the program code for "jhead" at http://www.sentex.net/~mwandel/jhead/. The author has a comment that some cameras do not correctly return the information needed to calculate the width. I don't see it changing when looking at my 20D data, even with different lenses and with different focal lengths on the same lens.

[jimsolt]

It looks to me that CCD Width is not part of the EXIF data, but is instead calculated. If you are really interested, have a look at the program code for "jhead" at http://www.sentex.net/~mwandel/jhead/ (http://www.sentex.net/%7Emwandel/jhead/). The author has a comment that some cameras do not correctly return the information needed to calculate the width. I don't see it changing when looking at my 20D data, even with different lenses and with different focal lengths on the same lens.

You flatter me by suggesting I would be able to read the code. Thank you. I may just live happily ever after by ignoring that particular item in "some" of my Firefox properties readouts.

Jim

[lancea]

Well I admit that I'm not a C programmer either - but the words are English so I can figure out the plot ;) I'm glad you posed the question though as I found some useful software (especially ExifPro). An ideal activity for a rather bleak holiday Monday!

[lostdoggy]

I guess this is not a topic of sufficient interest. "Not really" is "not exactly" the answer I was seeking :confused:.

Jim

Sorry, I had a lost of words.

The intent was to Bump up the thread