iphoto won't read photos from my Canon 5D mk1

[stefos]

Hi, I have taken photos on my Canon 5D mk1 and can view them in camera ok, trying to download through a kingston card reader ( new ) that I know works as other photos have gone through ok onto iphoto, I have also tried to download onto my lightroom 3, on iphoto the photos are black or only part visible, lightroom says it cannot read some of the files,any help would be appreciated,I can't find any info on this.List below of hardware etc

Canon 5D mk1

Kingston 16gb CF cards

Kingston FCR-HS4 card reader

iMac 

Yosemite 10.10.1

iPhoto

Lightroom 3 

Thanks Stefos

[TCampbell]

I'm a bit confused because you're mentioning both iPhoto and Lightroom.  Normally you would use one or the other -- not both.

Are you shooting JPEG or RAW?

iPhoto is intended for use on JPEGs and if you do shoot RAW, iPhoto creates a JPEG from it and then does everything only with the JPEG (as if you shot in JPEG from the start).  iPhoto doesn't destroy the RAW (it leaves it in the Library) but it doesn't use it for adjustment purposes (only the JPEG is adjusted and since JPEG doesn't have the same adjustment latitude as a RAW... there's sort of no point to use RAW with iPhoto.  You lose the advantages of RAW.)   Lightroom will preserve the RAW and retain the full advantages of RAWs adjustment latitude.

When you shoot RAW, the software needs a way to debayer the RAW data into an image.  Apple does that via the Camera RAW updates, but the original 5D has been supported for years (your Mac definitely understands how to debayer an image from an original 5D).  Adobe also provides their own camera RAW support and when they release "new" versions of Lightroom it's not very long before they stop providing updates for older versions of the software.  But again... since you have an original 5D, this wouldn't be an issue.

Also, if you shoot RAW, make sure it's just "RAW" and not any variant (e.g. do not use "sRAW", "mRAW" etc.)  The RAW processing software is usually designed to handle true RAW files only.