Pictures taken with my 1D Mark IV show a blue horizontal line at the bottom from ISO 400 onwards.

[numenius]

Pictures taken with my 1D Mark IV show a blue horizontal line at the bottom from ISO 400 onwards. So far nobody has been able tot tell me the cause of this problem. The body is still quite new (15000 pics taken).

[rfdesigner]

Can you post a link to an example please...     Ideally in RAW format..  if we think it's sensor it's best not to muck about with the data.

Edit:   oh..  a picture's appeared..   internet must be slow today

[rfdesigner]

I think you have a dud column/row in the sensor..   seeing the RAW file (.cr2) would be very helpful.  I have a tool that can open it and view as original monchrome (before debayering) which would tell us a lot more.

[numenius]

I tried to upload a RAW file but didn't succeed. Thanks for all the advice and options given. I'll try them out the coming weeks. 

[rfdesigner]

You can drop one on dropbox or any other hosting site (I use dropbox, it works, no other connection)  then post the link

i.e.

https://www.dropbox.com/s/bg1t8ue3av6r0pc/IMG_9685.CR2

[numenius]

https://picasaweb.google.com/103470919743498275798/20140201?authkey=Gv1sRgCMCe_LzY2cih_QE#5975415047...

I hope this RAW picture will help, so far no solutions offered did work.

[ebiggs1]

You did try new CF and SD cards?  If you did, join CPS.  

[numenius]

i did.

[Ed1715]

I sure with I had found this thread a day earlier.  On 01-31-14 I noticed a similar problem with my MK IV.  I eliminated the memory cards as the problem.  I spoke with a Canon representative at CPS and decided to send it in for evaluation/repair.  They'll get a look at it tomorrow.  If it's a sensor issue and needs replacing the dollar amount could be north of $1000.  I certainly would have given these suggestions a try first.  I've included a photo with the green line I noticed.  I've had the camera since it was released and have 53000 shutter actuations.

The line is above the door knobs and traverses the entire photo.

.

[rfdesigner]

Just got back to the site:

If you've got it fixed then great.  Otherwise

Re your raw image you posted

Sadly the image you posted isn't RAW..  it's a JPEG, perhaps a JPEG of a RAW, but that doesn't help sadly, I'm after the .CR2 file..  any old picture from the camera will do, nothing with any 'artisitc worth'.

What I'm trying to do is pixel peep pre-debayering.  most packages don't let you do that (Even DPP doesn't) but one I use can.