Lightroom export file size: why so small? How can I maximize image quality?

[plumleygator]

My image file sizes are much smaller after editing and exporting through Lightroom. Is it impossible to maintain original file size to preserve image quality? Will this smaller file size have negative impact on prints? Any help is appreciated!

[Rob_Cullen]

"the site I need to upload to says file size is too small"

So what File size is required?

And how is the 'site' defining what they mean by "File size"? Are they asking for "Pixel size" or "Megabyte size".

What Camera do you have that is producing files 3936x2624px  (My Nikon NEFs & DNGs are considerably larger! 6016 x 4016px)

how can I make a file larger pixels...?

You can only make "larger" by up-sizing in the export dialog.

You are then asking Lightroom-Classic to 'Re-sample' the image by adding new pixels.

Or, you could use the Menu: Enhance > Super Resolution to double the pixel dimensions, which adds the new pixels by the new 'Artificial Intelligence' features.

[nataliej39733446]

Hi Rob thats very interesting thank you for the detailed reply.

I shoot with the Nikon Z6, in RAW ( its new so maybe my settings are wrong)

Here is a copy of the requirements needed for my photos.

I put these settings into lightroom export but still my files are too small.

thank you for your patience

[Rob_Cullen]

Your camera (if it is the Z6 II) should be producing full-size raw NEF files that are 6016 x 4016 pixels.

I do not understand why you might be getting 3936x2624px NEF (or DNG) images! Are you Cropping the images? Do you have a crop setting in the camera menus? Maybe a DX crop setting?

Anyway your export dialog should look something like this- and you really have no control over the effect of JPG compression.

I used these settings with a 6016 x 4016 px image which resulted in a file that is 3.75 MB-

So what do you mean by "too small"?

A good interactive lesson on JPG compression can be found here-

JPG COMPRESSION EXPLAINED by Jeffrey Friedl

[nataliej39733446]

Thank you. When I say "too small" it is because outside site will not accept them, I don't know what the correct word is.

Now you have started me on another question regarding the nikon Z6II. I dont do any of the following you suggested:

-"I do not understand why you might be getting 3936x2624px NEF (or DNG) images! Are you Cropping the images? Do you have a crop setting in the camera menus? Maybe a DX crop setting?"

- it does take NEF files but lightroom doesnt read that. Lightroom converts to a DNG file.

Camera RAW setting is 3936X2624 10.3M, it doesnt go higher than that.

Thanks for so much advice

[tmickow]

@nataliej39733446  I'm pretty sure that's the max resolution for the Z6 in DX mode.  Are you using a DX lens?  If so, the Z6 is probably auto cropping down to that resolution.

[nataliej39733446]

yes thanks I am using a DX lens, so that makes sense thanks. I didnt realize this meant a DX crop setting.

So from what I understand I am actually doing everything correctly 🙂

Thank you everyone for explaining and clarifying each different stage to me.

I can now confidently tell clients the images are large enough.

[tmickow]

@nataliej39733446 You might want to consider a different lens though.  If it's auto-cropping down to the resolution you mentioned, you're effectively taking your shiny new 24 megapixel camera and limiting it to 10 megapixels of resolution.

[nataliej39733446]

Hi thanks @tmickow  but that isnt the case as images in Lightroom are 25MB it is only once exported out of lightroom that images become 4MB. 

[Rob_Cullen]

OK, I am back and would like to put together some facts-

1) If you shoot with a DX lens your camera files will be 3936x2624 PIXELS.

Your images are already 'limited' in dimensions. They are NOT your full-size sensor size (6014x4014px), so you are starting with a 'smaller' image file!

2) Changing the NEF to the DNG format will NOT change the Pixel size of the files. They remain 3936x2624px.

There is no imperative purpose in converting NEF to DNG. (A 6000x4000 NEF will be a 6000x4000 DNG)

3) Exporting to the JPG format WILL most definitely compress the exported file from 25MB to 4MB (or similar)! 

That is the whole reason for the JPG format to exist- to radically reduce the physical size of image files, and allow many to fit on 5" (64Kb) and 3" (2MB) floppy disks back in the 20th Century!

JPG Compression does NOT reduce the PIXEL dimensions of an image, IF you do not specifiy a 'Resize' in the Export.

4) There is NO reason for you to be Resizing (down-sizing) the exported file by using 3000x2000 pixels in the Export dialog.

DO NOT check the [Resize] box. Then your exported files from the DX lens will be 3936x2624 PIXELS.

5) Read very carefully the words of @dj_paige again in the Correct answer- (my inserts-)

"File size (on disk) is not an indicator of image quality! You are looking at the wrong measure.File size (of the IMAGE) is determined by the number of pixels you have,...."

The physical size of the exported JPG on disk is 99% determined by JPG 'Compression'. You have little control over this.

Did you study the link I gave? JPG COMPRESSION EXPLAINED by Jeffrey Friedl 

6) If you clients want a 'larger' file, export and send them 'TIF' format files. (not JPG). Then they will be 'happy" with the 'Size'  🙂   'TIF' files are NOT compressed (unless forced in the export).

Try this suggestion.

[tmickow]

Sorry @nataliej39733446, but you're either not listening or not understanding what folks are telling you.

The physical size that a file takes up on your disk is not an indicator of the quality or how well it will print.  As others have mentioned, the resolution / number of pixels that make up the image itself is what's important.

Because you're using a DX lens, your camera is limiting your image resolution to 3,936 x 2,624.  That's because the DX lens was made for cameras with a smaller sensor than your Z6II.  With the proper lens though, the image resolution would be 6,048 x 4,024.  So...

...with your DX lens, you get a 10 megapixel image from your 24 megapixel camera.

...with an FZ or Z lens, you get a 24 megapixel image from your 24 megapixel camera.

You're giving up 14,000,000 pixels by using that DX lens, which is about 58% of your camera's resolution.  That's a huge difference and is what will affect how much you can crop & how large you can print while maintaining the quality you're looking for.

[nataliej39733446]

Thank you yes I am very much listening and trying to understand. I am really appreciative of all the help.

I completly understand

-The physical size that a file takes up on your disk is not an indicator of the quality or how well it will print.  As others have mentioned, the resolution / number of pixels that make up the image itself is what's important.

Its this that I am struggling with

..with your DX lens, you get a 10 megapixel image from your 24 megapixel camera.

...with an FZ or Z lens, you get a 24 megapixel image from your 24 megapixel camera.

As I have shown earlier in Lightroom my images are over 24MB from the DX lens. I do undestand that this is not an indicator of quality or how well it will print. I also understand that with DX lens it is not at full sensor size.

[Rob_Cullen]

MEGABYTES (MB)  and MEGAPIXELS (MP) are NOT the same thing and cannot be compared! Oranges and Apples.

'Megabytes' represent a number of file 'bytes' of data that a file occupies on the surface sectors of a Hard-Drive platter, or storage sites in an SSD drive, or on a USB stick. Hard Drive and 'storage' (volume) statistics are quoted in "Megabytes".

Mega-pixels are the number of  'Photo sensor' receptor sites that record the values of light reaching the camera sensor. A camera with a sensor size of 6000x4000 PIXELS is a 24,000px sensor. ie 24 Mega-Pixels.

So to illustrate I have a DNG (raw) file-

It is 6014x4016   PIXELS in dimensions (from the Camera sensor)

It is 24,152,224 pixels in size (6014x4016 = 24,152,224)  (ie.24.15 MegaPixels)

Lightroom-Classic reports this image file as 'occupying'   28.97 Mega-BYTES,

Windows File Explorer does not agree! (Windows probably split the file over more un-expected disk sectors, thus occupying more disk space than LrC reported/imagined as File-Size.)

In reality Windows File Explorer reports the file size on disk as-  32,746 KB (ie. 32.75 Mega BYTES)

I did Three Exports of this DNG image-  NONE were re-sized in Pixel dimensions. ie. They are ALL 6014x4016 Pixel dimensions, but Note the file sizes on disk!!

DNG = 32.75MB

JPG (0 quality) = 1.384MB

JPG (100 quality) = 21.56MB

a TIF = 141.6MB

A MEGABYTE value is no indication of 'Quality'.!

[Rob_Cullen]

And to be 'fair' -here are screen-clips of the four images at 100% zoom ratio to compare-

1)  DNG Original (Nikon D750 camera. 50mm f1.8 lens 1/1000sec f13 ISO 400)

2) JPG exported at 0 quality-

3) JPG exported at 100 'quality-

4) Exported as TIF

[John26521448jtf2]

This is..all of a subben...happening to me.  I did nothing to any settings.

The customer doesnt know about technical stuff..they do feel shortchanged getting a 3MB file when I took a 25MB file to my camera...and I also feel short changed... I just want the full size file please.  I cant seem to get it back.

[dj_paige]

If you are exporting JPG (you didn't really say that, are you?) then 3MB is reasonable from a 25MB, and this is nothing to be concerned about. JPG is a compression methodology, exported JPG files are supposed to be a lot smaller.

[John26521448jtf2]

yes Im shooting jpeg.

I want the original file size like it has been producing for years until this month. Nobody seems to have an answer. I can find concern about that at least.   My guess is I need to pay money to Adobe to get this function back via upgrade to thier own nothing rent for life plan.

[dj_paige]

This has already been answered here in this thread and elsewhere (see http://regex.info/blog/lightroom-goodies/jpeg-quality)

Having a JPG match the original file size is meaningless, and impossible, since JPG is a compression technology. The image quality of a 3MB JPG is probably indistinguishable from looking at the edited original in Lightroom Classic, which you can confirm with your own eyes.

As far as your claim that "I did nothing to any settings", either your memory about what used to happen is wrong, or you did accidentally make a change to settings, or both.

[Steven350212957h7r]

I had the same problem,
didn't realise when exporting a jpg, there's a "dimensions" pull-down menu under quality
had it set to "small"

[lehib95363884]

Mine nust started doing the same thing in the same session I have been working in! I am combining images in lightroom and now everything i am improting into photoshop from lightroom is coming in at a thumbnail size. I baked in some text that had to be changed so I went back and imported again from lightroom to start over and these are very large raw files straight out of camera that are coming into photoshop as compressed thumbnails now. Its the same exact picture I have imported in the past and i am putting it on a canvas that overlaps the one with baled in text so its not the image size in lightroom that is the problem. Photoshop is doing something to compress images coming into photoshop. This happened the other day with an inage from the web so i just figured it had been a thumbnail i downloaded by accident and moved on but now this is happening in the middle if a time sensitive project where I know for certain that the file soze of the original is not the issue. Reading through this thread is super frustrating because this is not user error. A setting changed on its own or else the software is no longer working correctly.