Attached Link: Jessica_Ten-Mono

I am having an interesting experience that Canon calls an "unexplainable phenomenon.

The story and image is in ATTACHED LINK.
(The image contains nudity)

If anyone can shed some light on this or has had a similar experience I'd like to hear from you.

I read your story, and I gotta agree with Canon on this one :) Truly an odd phenomenon. I tried a search on this, and came up with nothing concrete to help you out, but if I had to make a humble guess.... Id have to say that obviously it is the lens. The camera ccd sensor in RAW mode, is taking direct readings of your colors (as opposed to compressed lossy format), and recording this into a raw format on your media card. Im guessing here, but I reckon its a possibility that the optics in the lens is somehow causing 2 kinds of readings to be made on the sensor, and this is causing the camera to interpret it into both a colour and b+w version on the same image????? Just a guess.

I am not totally sure, but if I had to guess I'd say it's firmware. The EXIF data for the RAW and color JPEG read a Paramter 1 setting and the B/W shows being processed in the B/W parameter.

This started after the 2.0.2 firmware upgrade last year. I had the Tamaron lens about a month before the upgrade and it never did this until after the upgrade.

Canon did tell me that some EF-S lens users were getting both color and B/W images when they use a #25 red filter.

I don't mind the extra image, but it's becoming an annoyance. It takes twice the card space and the buffer is cut in half. A 4GB 80x that normally holds 465 JPEG + RAW is now 230

More reasons why I think it's firmware ... the same lens on a 5D and an XTi - no problem.

Yup you didnt mention the firmware update before, but after hearing this ~Id have to agree with you. Loss of media space can be a pain, I can understand your frustration. Goodluck though, perhaps keep pestering them, to find out when another update is due, and if theyre gonna correct this problem.

Yes have to agree with you about the extra space usage being a pain. I always shoot in raw/jpeg. But trying to remember when i did the B&W parameter if i ended up with four photos. Thought just two. Will try tomorrow to see what i come up with. I just use Canon lenses and also have Canon20D.Have a great weekend:)
Chris

How bizarre! This must be an electronic  ... I would take the lens back to Tamron and get it rechipped has to be the easiest option if you want to save space on your card... Or put the lens on ebay maybe somebody would like that feature!! Be interesting to know if the lens does the same on another 20D 

This only happens when I use that one particular lens. I only have that one Tamaron lens as the rest are Canon.

The only time I have seen this happen is in the following settings:
RAW + JPEG
Parameter 1
Using any Creative Zone

This morning I finally found a way to stop it from happening.
Turn the ISO expansion ON in the custom functions.

Quote - Yes have to agree with you about the extra space usage being a pain. I always shoot in raw/jpeg. But trying to remember when i did the B&W parameter if i ended up with four photos. Thought just two. Will try tomorrow to see what i come up with. I just use Canon lenses and also have Canon20D.Have a great weekend:)
Chris

Personally, I think it's firmware. If you read through the thread this only happens with this lens, but also specific camera settings.

It only happens in a 20D and AFTER the 2.0.2 firmware upgrade from May, 2005
I shot with this lens prior to the upgrade and this did not happen.

I just posted this ....
Turning ON the ISO expansion ends the "phenomenon."

Quote - How bizarre! This must be an electronic  ... I would take the lens back to Tamron and get it rechipped has to be the easiest option if you want to save space on your card... Or put the lens on ebay maybe somebody would like that feature!! Be interesting to know if the lens does the same on another 20D 

Is it possible to go back to the old firmware and reinstall the newer version... Please remove the lens from your camera before performing this update.

After completing the update, turn the camera off and remove the battery for at least two seconds.

This will cause the camera to recognize the new firmware.

I know that it's possible, but I am not doing all that just for one lens. I can just shoot Canon glass on the 20D and do nothing. I also have a 5D and the lens works fine on that body.

I was just curious if anyone else has seen this before or had similar issues.

The 20D will soon be the matching paperweight to my old Rebel anyway.

I am looking at both the 30D and XTi as a second digital - just haven't decided which one yet.

Quote - Is it possible to go back to the old firmware and reinstall the newer version... Please remove the lens from your camera before performing this update.

After completing the update, turn the camera off and remove the battery for at least two seconds.

This will cause the camera to recognize the new firmware.