[Wolfeye]

This was weird. Only my being happy with the camera and generally unwilling to return it lead me to investigate further. Here's the scenario:

1. Set your K-70 to save as DNG.
2. Take memory card out of camera and insert into a computer
3. Open the .DNG files in Photoshop CS5
4. Save images as JPG to the same folder on the memory card as the .DNG files were located
5. Put card back in camera
6. Review the images. You can't. You get the error message at the top of this thread.
7. Delete the .JPG images from the folder, putting card back in computer
8. Now you can see the .DNG images on your K-70 again.

Weird. I was thinking I had a defective camera for a while there. Odd that the k-70 can't read .JPG files exported from Photoshop, and even odder that it suddenly doesn't even "see" the perfectly fine .DNG files. I'm sure it must prefer displaying .JPG files if they are present.

[Adam]

Here's how I think the camera might be programmed:

If there's a JPEG and a DNG with the same name (i.e. IMGP0001), the camera only shows the JPEG to avoid duplication. If the JPEG then turns out to be corrupt or nonstandard (i.e. edited by photoshop), the camera gives up on that file name and proceeds to the next photo. Rinse repeat until you reach the end of the folder.

So the solution here might be for you to use slightly different filenames (i.e. add a 0 to the end or change the prefix) for your exported JPEGs. Or, simply save those JPEGs to a different folder (the preferred solution). I wouldn't expect the camera to be able to display the photos in any case, though you might get lucky. Regardless, this is a scenario for which the camera isn't designed

[aremmes]

Perhaps it looks for a thumbnail of the image inside the file (see this very detailed explanation), and Photoshop just doesn't embed it.

[BigMackCam]

It's not at all uncommon for cameras to be unable to read JPEG files that they didn't natively create (sometimes they will, sometimes they won't). I've accidentally used an SD card from one brand of camera in another, and during image playback I've had the same kind of issue you report. Worrying when it happens, but once you realise the files are from a different camera - or not even created by a camera - it's less worrisome