Changing the Preview Image of a File (not Thumbnail)

[BruceBanner]

Hi everyone and thanks for having me.

I'm not a user of this program and so am a complete newbie so thought I should post in the Newbie section. I do feel however I have a pretty advanced problem that I am hoping someone here can help me with. Here is the problem;

I have a Pentax K-1 camera. I wish to view on the back of the camera (during the playback feature) a Jpg file that was not originally taken with the camera. The reason is pretty boring, but they are these jpgs created in Illustrator I believe, drawings of couples posing (posing cards). It would be great if on a session with the couple that I could go to my camera, bring up the shot/pose that we will try to go for and then try and get that shot. I could use my phone etc, but sometimes its not on my person (or I don't want it on my person).
I thought this would be easy, but boy was I wrong...

Speaking with the creator of the cards, he was aware this is an issue and is why he simply suggests to take pictures of the cards (on a monitor), but this looks really bad, or print them out and take pictures of them, again not ideal.
Right now I am just fighting to win and somehow figure out a way for my camera to display these non Pentax jpgs, I won't be beaten! 

I have the EXIFGui version installed and have since learned these things;

1) My camera won't seem to display any image if the metadata is gone. I took an image it created, removed the metadata, reinserted card and the image will be black with a message 'Unable to display this image'.

2) When trying to simply drag and drop the (intended) jpg files onto the SD card they will not show unless they have a filename that is at least a follow on filename to the preceeding one, but it still won't show properly (blank with the same error message)

3) Same for folders on SD card, if I create a new (folder) it will not show up, it needs to be a certain folder the camera has created already

4) Copying the metadata from a file taken with the camera to a jpg file that did not originate from the camera does not work, because what happens is the EXIF copy feature seems to give that file the Jpg Preview that it has as well. If image 1 is the source and we're copying the metadata from Image 1 to Image 2 (a different image), then the camera will actually show the preview (pixelated and poor quality as well for some reason) of Image 1 for the Image 2 file (on the camera).

I feel stuck because its as if these Jpg Posing Card files have no Preview, thus even renaming the files and getting them to be reviewable on the camera doesn't work and is just blank. Copying successful EXIF from a healthy jpg to the Posing Cards (and renaming the files of course so the camera can see them) doesn't work because it too shows not the Preview of the actual Jpg file but the Preview of the file the EXIF came too.

I tried importing the jpgs into LR>Exporting them as DNG's, then using EXIFtoolGUI to extract the Previews (makes a Preview folder), which works, but then those files have no metadata so those won't show in the camera, and I do not know how to get them to override their host counterparts.

I'm sure right now it wouldn't matter if the Jpg image itself was just a bright pink 3:2 solid fill, the camera seems to use only the EXIF preview for reviewing it, but it seems nigh impossible to generate these from the Posing Cards and have EXIF it needs to be read by the camera... argh!

I don't even know if I am making sense... perhaps you can understand better from these screen shots.

Below here we can see Lightroom even show the incorrect previews of the Posing Card files during the Import Prompt process. These files are the posing card files that have had their metadata removed and then copied across metadata from a shot taken from my desk with the camera. Note how they all show this image, and its this image that the camera seems to care about during playback review;

https://www.flickr.com/gp/95230640@N04/V64uHS

Once the images have imported properly into LR we can now see them properly as they are and no longer showing that 'preview';

https://www.flickr.com/gp/95230640@N04/6y08oB

So in summary;

The files I want to display on the camera have either dud EXIF info my camera can't read/display, or no Preview sidecar or whatever, and I'm stuck with EXIFtoolGUI as to how I might 'trick' my camera into thinking these are Pentax made files with it's own correct Preview sidecar to go with...

Any ideas anyone?

TIA

BB

[StarGeek]

Check to see if there is a JFIF block in the image.  It used to be that cameras wouldn't read images with a JFIF block in them, though I don't know if that's common anymore.

Also check to see the actual location of the PreviewImage.  If it is part of the Pentax MakerNotes, then it can't be updated.  See the Pentax tags page.

[Alan Clifford]

1.  Display the photo on your computer screen.
2.  Take a photo of the computer screen with your camera.

It will probably look horrible but you only want it to display the poses.

[Phil Harvey]

I'm afraid you are out of luck.  The Pentax K-1 stores the PreviewImage in APP7, which is not currently writable by ExifTool (see here).  Your only option is the picture of the computer screen.  You should be able to get a good image this way by using a high-resolution monitor and slowing the shutter speed to much lower than the refresh rate.

(@StarGeek If it were part of the normal APP1 Exif makernotes then it should have been writable.)

- Phil

[BruceBanner]

1.  Display the photo on your computer screen.
2.  Take a photo of the computer screen with your camera.

It will probably look horrible but you only want it to display the poses.

Yeah that is what the seller recommends, and my attempts did look pretty horrible 

[BruceBanner]

I'm afraid you are out of luck.  The Pentax K-1 stores the PreviewImage in APP7, which is not currently writable by ExifTool (see here).  Your only option is the picture of the computer screen.  You should be able to get a good image this way by using a high-resolution monitor and slowing the shutter speed to much lower than the refresh rate.

(@StarGeek If it were part of the normal APP1 Exif makernotes then it should have been writable.)

- Phil

Dang...

I'll try the slower shutter speed thing as my attempts were pretty poor. I was thinking I might have to just print them our and take pics of them :/