Lightroom shrinking files on export more then before

[jm68902488]

I have been using lightroom for years and exporting my wedding photos. I am shooting a 24 mega pixel raw file and in years past file  export size was 13-19 mb on average.  Exported my last wedding same way as always and file size down to 9 mb on average.  All export setting are the same.  Quality 100% as always.  File dimensions and resolution the same.  Not sure why the difference?

I made some export presets and didn't know if lightroom has them stuck on its mind.  Exported manually.  No change.  Then deleted all export presets and problem still the same.  File sizes about 1/2 the size they used to me.

Any ideas?

[dj_paige]

File size by itself does not indicate a problem. Some photos can be more compressed than others. As far as I can tell, there is no cause for concern.

[jm68902488]

I checked the pixel dimensions and resolution on the files that are smaller

and the size is correct. I assumed their was more compression going on for

some reason. But as to why the sudden increase in image compression and if

that would affect the quality of the images regarding printing were both

concerns for me and the compression change is very odd. Has lightroom made

any changes to that?

[Per Berntsen]

Image content has a significant effect on the file size of a jpg - large flat or smooth areas compress well (small file size), whereas sharp detail (and noise) is harder to compress (larger file size). Output sharpening (and sharpening done in the Develop module) will also affect file size - the stronger the sharpening, the larger the file size.

So the file size of a jpg is not an indicator of quality, and your images should print fine.

Consider the two images below, both exported at 80 quality from Lightroom. The bottom image has a file size 3.5 times larger than the top one, and the difference is entirely due to image content.

41 kb

146 kb

[richardplondon]

Nice illustration of differently compressible picture content - the sky and the heathland - but it is worth also making the point, that any kind of fine-grained noise or grain - or else the pictorial smoothing of that, also conversely sharpening - can have similar impacts for compressibility TOO.

[dj_paige]

But as to why the sudden increase in image compression and if

that would affect the quality of the images regarding printing were both

concerns for me and the compression change is very odd.  Has lightroom made

any changes to that?

This is a misunderstanding. What has changed is the content of the photos, to photos whose content are more compress-able. The actual compression algorithm hasn't changed, and so the quality of the resulting JPG is exactly what you requested, which is a quality setting of 100.

[Todd Shaner]

jm68902488  wrote

Exported my last wedding same way as always and file size down to 9 mb on average.  All export setting are the same.  Quality 100% as always.  File dimensions and resolution the same.  Not sure why the difference?

There's no need to use LR Quality 100 setting unless you are reediting the exported JPEG files, which is not recommended. A LR Quality setting of 80 will provide the same image quality as illustrated here:

Jeffrey Friedl's Blog » An Analysis of Lightroom JPEG Export Quality Settings

[Joe Foe Toe]

Are you sure you're exporting with bit depth  = 16?  Have you tried recompressing older image to see if results are the same?

[Per Berntsen]

There is no option for 16-bit when exporting jpgs – jpg is 8-bit only.

[Joe Foe Toe]

Per Berntsen, thanks, a big doh on my straw-grasping!

[Heirloom Bob]

I too am experiencing this. A 13 mg RAW file exports with 100% to about a 4.5 mb file.If no loss in quality then maybe that's alright except my stock photo site requires an image of 5mb's or greater.

[Todd Shaner]

What do you mean by "13 mg RAW file?" If you mean the raw file is 13 Megabytes or even 13 Megapixels it's not surprising the 100 Quality JPEG is only 4.5 Megabytes.

I suggest you take the time to read the below article and tell us what specific "stock photo site" you're using. Stating a JPEG file size requirement of 5 Megabytes minimum makes no sense, which you will understand after reviewing the below article.

Jeffrey Friedl's Blog » An Analysis of Lightroom JPEG Export Quality Settings

[elie_dinur]

my stock photo site requires an image of 5mb's or greater.

You should check the stock site to verify if that is 5MB after compression or uncompressed. Many stock agencies  stipulate uncompressed size. Alamy, for instance, requires a minimum of 17 MB uncompressed, which compresses down to a 3 - 5MB jpg. (That is a 6 MP image.)

A 13 Megapixel image produces a 37MB 8 bit uncompressed file. To calculate uncompressed sizes in MB, multiply MP by 2.85 for 8 bits (jpgs) or 5.7 for 16 bits. Or open the jpg in Photoshop and go to Image/Image Size.