You need to be cautious about the two programs measuring the same thing. If one measures the file size in megabytes and the other measures the document size in pixel dimensions there can be a large difference. In my case Bridge says a jpeg image is 1.4 meg and photoshop says the document size in pixel dimensions is 16.1 meg.
64.42 MB as shown bridge thumbnail or 17.2 M when opened in photoshop?
Per the example of Curt it seems more logical to have a smaller file size in Bridge then in PS, but you have the other way round.
Can you be more specific in what file and how you open it.
For instance if you have a Raw, or jpg or tiff and open this in PS using ACR it might be you have set ACR to open in a smaller amount of pixels as the original.
MB and M is the same thing right?
regarding Bridge and PS yes. Bridge shows the figure with MB and PS only shows M.
But It still is not clear what you are doing.
I suppose you are using a raw or DNG file from Hasselblad? Can you specify and maybe also look at the pixels of the original and the pixels in the file in PS?
Then use Capture One to alter the settings for the Raw file and export to open it in PS.
Its a long time ago I downloaded a trial version of Capture One but I believe you are able to choose settings for export of the raw file.
Check this first.
What's a "Foiole"?
As the others have said, there are many different size measurements, and they are just that - different, in that they're measuring different things. They are all "correct".
Size in RAM isn't the same as size on disk, and raw file size isn't the same as TIFF file size and that isn't the same as JPEG file size. Even "megabyte" can have two different meanings in computerese (1 million decimal, or 1024 x 1024 bytes). Add to that the potential confustion caused by there being an old photographic defacto "standard" of calling a file size in megabytes per how large an uncompressed 8 bits/channel RGB TIFF would be.
Every one of these measurements has a meaning, and if you want to name them one by one I'm sure as a group on the forum here we can identify exactly what each one is measuring.