tl;dr
- TIFF files offer high quality but can be large in size.
- Compression Options:
- LZW and ZIP: Both are lossless compression methods, preserving image quality.
- Compression reduces file size without quality loss, allowing faster transfers and saving storage space.
- Considerations:
- Compressed TIFF files can be slightly slower to work with due to processing.
- Some older software might not support compressed TIFF files, but this is rare.
- LZW was once patent-protected, but the patent expired in 2003.
- ZIP vs LZW in Practice:
- Images with less detail and fewer tones compress more.
- For 8-bit TIFF files, both LZW and ZIP offer similar compression.
- For 16-bit TIFF files, ZIP is recommended as LZW can increase file size.
- Recommendations:
- Use compression for smaller file sizes without quality degradation.
- For 8-bit TIFFs, both ZIP and LZW are suitable.
- For 16-bit TIFFs, use ZIP compression.
TIFF files are very high quality–much higher quality than most JPEGs–but the trade-off is that they’re big. You do, however, have some options for making them smaller by using compression.
When it comes to TIFF, two main compression options are available–they’re known as LZW or ZIP.
Both ZIP and LZW are lossless compression methods. That means that no data is being lost in the compression, unlike a lossy format like JPG. So neither of them degrades image quality.
You can open and save a TIFF file as many times you like without degrading the image. If you try that with JPG, the image quality will deteriorate more each time.
So you can rest easy: using TIFF compression–and this is true for both LZW and ZIP compression–will not degrade your image quality.
To use or not to use TIFF compression
The reason to use compression, whether it’s ZIP or LZW, is entirely to do with filesize.
TIFF files maintain excellent quality, but the price you pay is that the files are big.
So by applying compression–and, again, this type of compression doesn’t degrade the image quality–you’ll end up with files that are smaller without any loss in quality, which means quicker transfers over networks and you can fit more of them on any given amount of disk or server space.
If you’re a working photographer shooting hundreds or even thousands of images a day, that can add up quickly.
Reasons not to use TIFF compression
There are two main reasons you might not use ZIP or LZW compression.
- Because they require more processing to open and close them, compressed TIFF files can be a little slower to work with. Unless you’re working with ginormous images, that’s rarely much of a problem with the speed of today’s computer processors.
- A second possible reason you might not want to use ZIP or LZW compression has to do with compatibility. It is possible you might run into situations where certain software might not be able to work with compressed TIFF files. But in practice that’s pretty rare these days.
Both formats have been around a long time (LZW for over 30 years and ZIP for over 20), and software developers and hardware manufacturers have had plenty of time to catch up.
There used to be a third reason not to use LZW specifically: the algorithm at its core was protected by patent. But that patent expired in 2003, so that hasn’t been no an issue for software developers to use LZW compression for over two decades.
In practical use, I nearly always use compression on my TIFF files, and it’s exceedingly rare to run into a problem.
ZIP vs LZW TIFF compression: Real-world examples
Compression algorithms are most efficient when they can group a lot of similar data. So images low on detail and with few tones will compress much more than images with lots of detail and lots of different tones.
For some real-world examples, I’ve run each of these four images through the various TIFF compression options. All are exactly the same dimensions and aspect ratio (4200px x 2800px). All have the same amount of embedded metadata (Copyright only). All have the same color profile (sRGB).
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| Image #1 | Image #2 | Image #3 | Image #4 | |
| 8-bit No Compression | 35.3 MB | 35.3 MB | 35.3 MB | 35.3 MB |
| 8-bit LZW | 12.9 MB | 11.5 MB | 22.5 MB | 12.3 MB |
| 8-bit ZIP | 12.6 MB | 11.6 MB | 20.2 MB | 12.0 MB |
| 16-bit No Compression | 70.6 MB | 70.6 MB | 70.6 MB | 70.6 MB |
| 16-bit ZIP | 54.3 MB | 53.6 MB | 61.9 MB | 55.3 MB |
| 16-bit LZW | 87.0 MB | 76.2 MB | 87.5 MB | 70.9 MB |
As you can see, image #2 (the photo of Australia’s Blue Mountains) compresses the most. It has the least detail and the fewest tones. The image that compresses least is image #3 (of the shrine offerings in Luang Prabang). It has the most detail and lots of different tones.
The problem with LZW compression on 16-bit TIFF files
The last compression option, 16-bit LZW compression, is added mostly as a cautionary tale. There’s a reason you don’t have the option to export to that in Lightroom: LZW does not work at all well with 16-bit files and often makes them larger. Which rather defeats the purpose of applying compression algorithms in the first place. So if you’re going to use compression on 16-bit files, stick with ZIP.
The bottom line
So the short answers are:
Should I use TIFF compression?
Almost certainly. It will make smaller files but will not degrade your image quality.
Should I use ZIP or LZW?
For 8-bit TIFF files, there’s not much in it. Both LZW and ZIP will give good results. Use either with confidence.
But for 16-bit TIFF files, it’s clear: use ZIP.
