Strange problem reading tiff files

[starrylandscapestacker]

I am using Affinity Photo 1.4.3 on a late 2015 iMac running Mac OS 10.12.

 

I have written a program that exports pretty simply tiff files. Every app I have tried reads the files my app writes, except Affinity Photo. I have tried Preview, Photoshop, Lightroom, Aperture, Pixelmator, Viveza 2, Safari (I did not know it worked as an image viewer, but it does)).

 

I think maybe Photo is trying to interpret the tiff file as a RAW file. I have attached two screen grabs. One shows the upper left corner of the Photo window with one of the files my app wrote. The other shows the upper left corner of Photo with one of the input files to my app (which was written by lightroom). My app averages stacked images to reduce noise, so I expect the two images to be pretty much the same except for noise.

 

Any suggestions or ideas on what might be going on here? 

[Lee D]

Hi starrylandscapestacker,

 

Welcome to the forums.

 

Would it be possible for you to provide a link such as Dropbox or Google Drive to your files so we can take a look to see if it's something we need to pass over to the developers.

 

Regards

 

Lee

[starrylandscapestacker]

Lee,

 

I was looking for a small sample to send you an discovered something interesting. 12MP files from images originated with a Canon 5D open fine in Photo. 50MP files from  images originated with a Canon 5DS do not. The same binary wrote the files on the same computer a few hours apart. I wonder if there is something about the 50MP images. They are 16-bit so they are pretty big.

 

Can you access this file (402MB)?  https://drive.google.com/file/d/0B9Y1J9zeicGzMGl6TVBSZnlFQ0k/view?usp=sharing

 

Let me know if there is a problem or if I can help in any way.

 

  ralph

[Lee D]

Hi Ralph,

 

Thanks for the file, I can confirm I get the same results when opening that file in both the MAS and the Beta of Photo. It seems to be how the file has been created in the Starry Landscape Stacker app as standard RAW images from a Canon 5DS open fine. The issue has been passed over to our developers to look into the issue. 

 

Regards

 

L

[starrylandscapestacker]

Lee,

 

Thanks for passing the file on.

 

I have done some more testing and I have learned that if I write no metadata into the file then Photo can open it. Strange. There is something in the metadata that confuses Photo (but nothing else), but only when the file has a very large pixel count (50MP, 12MP files are fine). I will slowly start adding metadata back and see if I can figure out which bit of metadata is causing photo to think that a tiff file is a raw file.

 

  ralph

[starrylandscapestacker]

Lee,

 

I have found that if I include either or both of these tiff tags in the metadata Photo assumes that the tiff file is really a RAW file.

 

"Make" = "Canon"

"Model" = "Canon EOS 5DS"

 

If I include just one of these tags, either one, the result is different from when I include both. Now that is weird.

 

Both tags matter and no other tag matters. I copy all the tiff and exif data from the source images so there are a lot of tags. Simply removing these two tags from the tiff data solves the problem.

 

Just for kicks, I tried "Make" = "Nikon" and I got the same result that I got with "Make" = "Canon".

 

 ralph

[RobPNth]

I had exactly the same problem. Removing the "Make:" tag with exiftool fixed the issue.

 

Have your developers figured out what is going on?

 

Thanks,

 

Robert