I work in PS the stacked astrophotography images that coming in Raw 32 bit .tiff and then saved in 16bit when working in PS after the first streching on the stacked image.

When I finish working on the image I use to save it as .tiff not compressed. Usually the image I work can be around 250Mb - 650Mb or even further, 1.2-1.6 Gb. depending the numbers of images stacked etc. I work under windows, my PS version is 2015.5.1.

Several times I found that when I save the image I'm working, the thumbnail show well the pic but almost all the time shows a split image, distorted of the object I was working as you can see in the pic bellow. Also happen that I could not even open again that image. I just always save the work after I flatten all the layers, in the same format .tiff 16 bit. No compresion or layers added. As you can see in the pic bellow, several images where saved while was procesing that image, the .jpg is not the problem, but the .tiff, that some show a properly thumbnail, but other a split image. All the images in the pic I can open in PS, but as I say before, happen that sometimes I can not opened as say memory is out of RAM (In Perfomance is set at 26Gb)

What I'm doing wrong? Are the saved .tiff files afected in some way because the tumbnail is not showing properly the pic?. It depend how big is the file? Can I do a Save As in a layer in the middle of the work showing me that stage only? Is the best way saving the files under .tif or is better in .psd?

Odd thing is, some of the splitted thumbnail images (images are around 277Mb) can be opened in other image software, but others don´t. (GIMP, RawTherapy, ACDC)

enter image description here

1 Answer 1


Bridge cache's thumbnails.... Rebuilding the Bridge cache may correct the issue. (I dislike Bridge and this is one reason why.)

Thumbnails have almost nothing to do with the actual image other than the fact they are created when an image is saved (provided preferences are set to do so). They are a separate embedded secondary image within the file format and often not a direct representation of the file.

Thumbnails can be inaccurate for any number of reasons. They are meant to merely provide a glimpse at the image, not be a 1:1 representation.

Both .tif and .psd formats are compressed formats. PSD may be slightly smaller. Unless you're also working with other applications which require .tif and can not support the .psd format (older QuarkXpress maybe)... I'd save as .psd.

  • Many Thanks Scott for your clarification. I put a pic from Adobe Bridge for show better the issue but is the same under Window 7.8 is the sistem I running on the PC. Regard to save in .psd I read other posts here that is better for files that are big like I usually work in astrop. I'm still worried why sometimes my saving image have the problem that I'm not abble to open it again. Commented May 5, 2020 at 0:56
  • Adobe throws in some proprietary stuff for the tiff format (like transparency and layers). All that is non-standard for tiffs. If you utilize any of that, there's a higher possibility it will be lost in the tiff format compared to the psd format.
    – Scott
    Commented May 5, 2020 at 1:00
  • this may be a bug in the thumbnail generator related to the bit depth(?). I am also thinking of a scenario where some parts of the image (the original instrument raw data images) might have a different pixel aspect and, again, this is being munged by the thumbnail generator.
    – Yorik
    Commented May 25, 2022 at 14:36

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