lightroom image quality

[Charliedelta]

I noticed than when I export a photo from lightroom 5 (raw to jpeg) the file size goes from roughly 30mb to roughly 2.5. I know that it is normal, but is it advisable to increase the image quality settings in the export dialog box in order to achieve larger files? I'm thinking about the chance of printing the file...

 

[Benco]

If you set the JPG quality to maximum the file is still quite small as even the highest quality JPGs are still compressed, if you want top quality the use TIFF or another lossless format. Unless you want a huge, top quality print though the top quality JPG is fine.

 

[KmH]

Many print labs will not accept TIFF files for printing, because of the larger file size.
They get 10's of thousands of images uploaded daily and accepting TIFF files would put a huge strain on their storage.

You also need to consider that TIFF files can be 8-bit or 16-bit files. Print labs cannot print 16-bit depth files.

Lightroom's Develop module is not only 16-bit, but it is also uses a color space that has a color gamut larger than printers can print.

Here is a group of tutorials that will provide more detailed information - Tutorials on Color Management & Printing

 

[Charliedelta]

Thanks for the answers. So, just to understand, a professional who has to give a photo to a client would give it to them as a TIFF, a JPEG, or what else? Would he give a different file if the photo were to be printed as a poster or used digitally?

thanks

 

[KmH]

Which file type, bit depth, and color space a photographer provides would depend on how the client will be using the image, and on the terms of the use licensing involved.

 

[Big Mike]

Unless the client specifically asks for something else (and knows what they're doing), then just give them JPEG.

If they are going to be further editing the photo (they would need your permission or transfer of rights), then they may benefit from a TIFF file (or even PSD). But if they are just going to print it, or display on the internet etc, then jpeg is probably OK.

Keep in mind that there are other factors that affect the size of the file. The file type obviously, but that is mainly because JPEG files are designed to compress images. When you save as a JPEG, it strips the unneeded data and compresses the image. This lowers the quality, but usually not so much as to be visible when viewing the image or print.

Further to that, you can set the compression/quality levels. When you export, there is a slider for it. The higher the quality, the less compression and thus the larger the file. The lower the quality (higher compression) the smaller the file size.

But there is also the image size that will affect the size of the file. For example, if you save the image at 5760 x 3840 pixels...then it will be a much bigger file size than if you save it at 1800 x 1200 pixels.
This is where you really need to consider the uses for the image. If someone is going to print it, how large will they need to print it? The more pixels, the easier/better it will be to make larger prints. But if they are just going to view them or post them to the internet (Facebook etc.), then 900 pixels wide is probably large enough.