Skip to main content
hemag nova grafik
hemag nova grafik
Inspiring
May 27, 2021
Answered

strange increase in file size

  • May 27, 2021
  • 2 replies
  • 8840 views

i got some files sized approximatly 800x700px, RGB, 300dpi. the info-window in photoshop shos that the file is about 2.5MB. but on the computer the file size suddenly increase to about 35MB. i tried to save it again, merged all layers, saved as jpg, saved as tiff with zip or lzw, restarted but nothing helped. i also reduced resolution from 300 to 230dpi but gained only few MB. how comes? somebody an idea?

heres what info shows:

 

heres the actual file size

 

 

i also attach the file

 

This topic has been closed for replies.
Correct answer TheDigitalDog

The size PS reports isn't all that accurate and if you want to know the actual 'size' the document takes up, the Finder is the way to do so. 

 

Reducing resolution tag from 300 to anything doesn't do anything to alter the 'size'. Reducing the number of pixels (or producing more) of course will. This is just a tag that is used to calculate a possible size (X number of pixels divided by the tag). 

 

Digital images don't have any size other than the space they take up on some storage media. This size varies by many attributes even if the document has the same number of pixels: bit depth, layers, file type and possible compression, color space. It's not worth even considering this size due to so many differences. Digital images therefore should be considered in pixel density. And for this discussion I'm going to limit this to one axis (let's say the long axix) and the image is 1000 pixels. 
 The resolution tag places no role in the 1000 pixel document in this respect: 1000 pixels at 100PPI and 1000 pixels at 100PPI are the same: 1000 pixels. In fact you can take a document that has 1000 pixles with a resolution tag of 100PPI, duplicate it and change the resolution to 1000PPI and the two are identical other than for metadata such as this resolution tag. 

2 replies

T
Test Screen Name
Legend
May 27, 2021

There is, in fact, nothing strange about this. PS does not give you the size on disk. 

    hemag nova grafik
    hemag nova grafikAuthor
    Inspiring
    May 27, 2021

    read answer above, thank you too

    TheDigitalDog
    TheDigitalDogCorrect answer
    Inspiring
    May 27, 2021

    The size PS reports isn't all that accurate and if you want to know the actual 'size' the document takes up, the Finder is the way to do so. 

     

    Reducing resolution tag from 300 to anything doesn't do anything to alter the 'size'. Reducing the number of pixels (or producing more) of course will. This is just a tag that is used to calculate a possible size (X number of pixels divided by the tag). 

     

    Digital images don't have any size other than the space they take up on some storage media. This size varies by many attributes even if the document has the same number of pixels: bit depth, layers, file type and possible compression, color space. It's not worth even considering this size due to so many differences. Digital images therefore should be considered in pixel density. And for this discussion I'm going to limit this to one axis (let's say the long axix) and the image is 1000 pixels. 
     The resolution tag places no role in the 1000 pixel document in this respect: 1000 pixels at 100PPI and 1000 pixels at 100PPI are the same: 1000 pixels. In fact you can take a document that has 1000 pixles with a resolution tag of 100PPI, duplicate it and change the resolution to 1000PPI and the two are identical other than for metadata such as this resolution tag. 

    Author “Color Management for Photographers" & "Photoshop CC Color Management/pluralsight"
      hemag nova grafik
      hemag nova grafikAuthor
      Inspiring
      May 27, 2021

      i am aware of all of this. working with photoshop over 20 years now. i was just a little confused, happens from time to time when you get old 😉 i checked with creating a new file, same size and with 300dpi and it was almost the same size. the actual thing that confused me was - and still is - when i import these pictures (10 of them)  in indesign and make a normal rgb-pdf with 150dpi  it doesnt compress the images. normaly my pdf has about 5 to 10 MB but this one has hundreds of MB. thats why i thought it has to be a problem with the psd in the first place. so i will check the pdf-process then. anyways, thank you dude

      hemag nova grafik
      hemag nova grafikAuthor
      Inspiring
      May 28, 2021

      Consider saving a TIFF with or without compression: how does PS know before you even do so, which size to report? It can't. Consider opening a layered image and then saving it as a JPEG with any number of quality settings, how can PS report the size? It can't really. The bottom line is; ignore what the 'size' is reported in the palette you show. And again, DPI is meaningless! It's simply a metadat tag. 


      i dont get why dpi is meaningless. when i have a 100x100px image with 72dpi, then its lighter than the same image with 300dpi. i am not able to change pixeldensity of it, or am i? i thought pixel density has something to do with screens but not actually with the image itself?

       

      Terms & ConditionsAccessibility statement
      Using the community Terms of use Privacy Cookie preferences Do not sell or share my personal information ad choicesAdChoices