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Participant
March 10, 2025
Answered

Lightroom Classic

  • March 10, 2025
  • 2 replies
  • 433 views

Hallo,

ich nutze Lightroom Classic. Die Bilder haben nach Bearbeitung das 2-3 fache der Datengrösse als das Original Bild. Weiss jemand warum das so ist?

 

Danke+Gruss

Correct answer Per Berntsen

The file size of a jpg is determined by three factors.

  • Pixel dimensions
  • Quality setting
  • Image content

Because of the way jpg compression works, image content can have a huge influence on file size.

Images with predominantly flat, smooth, or out of focus areas are easy to compress, and will have a relatively small file size.

Images with lots of sharp, busy detail (or noise) are harder to compress, and will have a relatively large file size.

 

Assuming that you're exporting without resizing –

If your edits include Clarity, Texture, or sharpening, the file size will increase.

If you export at 100 quality, the file size is likely to increase, especially if the original was created with a lower quality setting in the camera.

 

I don't work with jpgs, but as a test I exported an image as jpg at 60 quality, and imported the jpg in LrC. File size 8.5 MB.

I then exported a new jpg at 100 quality from the first jpg (no edits). File size 18,1 MB.

I then exported another jpg at 100 quality from the first jpg with 20 Clarity. File size 25.2 MB.

2 replies

AxelMatt
Community Expert
Community Expert
March 10, 2025

Englisch translation:

Hello

I use Lightroom Classic. After processing, the images have 2-3 times the data size than the original image. Does anyone know why this is so?

 

Thank you+greetings

-----------------------------------------------------------------

 

Without any informations what your doing exactly it's very different to say more.

On which step you're noticed the bigger file size. Lightroom worked non destructive, so the original file would not be changed.

I think you check the file size after you exported a image? So the file size depends on the export settings.

Or you've done the new AI denoising feature in LR. In this case LR create a linear DNG which is at least one to two thirds larger.  On DxO's website I found a good article about linear dng's. What are Linear DNG files? How do you use them? - DxO

 

 

My System: Intel i7-8700K - 64GB RAM - NVidia Geforce RTX 3060 - Windows 11 Pro 25H2 -- LR-Classic 15 - Photoshop 27 - Nik Collection 8 - PureRAW 5 - Topaz Photo
Participant
March 10, 2025

 Hello Axel,

I work with jpeg files, import into LR, do some adjustments (auto, etc.), export the files as jpeg. That‘s all.
Why can the size increase, its the same file.

Regards, Reinhard Honer.
Per Berntsen
Community Expert
Per BerntsenCommunity ExpertCorrect answer
Community Expert
March 10, 2025

The file size of a jpg is determined by three factors.

  • Pixel dimensions
  • Quality setting
  • Image content

Because of the way jpg compression works, image content can have a huge influence on file size.

Images with predominantly flat, smooth, or out of focus areas are easy to compress, and will have a relatively small file size.

Images with lots of sharp, busy detail (or noise) are harder to compress, and will have a relatively large file size.

 

Assuming that you're exporting without resizing –

If your edits include Clarity, Texture, or sharpening, the file size will increase.

If you export at 100 quality, the file size is likely to increase, especially if the original was created with a lower quality setting in the camera.

 

I don't work with jpgs, but as a test I exported an image as jpg at 60 quality, and imported the jpg in LrC. File size 8.5 MB.

I then exported a new jpg at 100 quality from the first jpg (no edits). File size 18,1 MB.

I then exported another jpg at 100 quality from the first jpg with 20 Clarity. File size 25.2 MB.

Per Berntsen
Community Expert
Community Expert
March 10, 2025
quote

I use Lightroom Classic. After processing, the images have 2-3 times the data size than the original image. Does anyone know why this is so?


By @Reinhard3404302975ee

 

Raw files only have one channel, and they are usually compressed, resulting in a small file size.

When you export, a new file is rendered from the raw file. This new file has three channels (RGB), and it can be 8-bit, or 16-bit, which is twice the size of 8-bit. So the increase in file size is perfectly normal.

 

Raw files from my Nikon Z 7 camera are around 50 - 60 MB.

An 8-bit Tiff (or PSD) exported full size without compression will be 130 MB.

Exported in 16-bit without compression it will be 260 MB.