SONY a7iv: Uncompressed RAW vs Lossless Comp (L) (M) (S) vs Compressed RAW
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When Sony updated the A7 IV to firmware v1.10, it introduced a new set of RAW format options—giving photographers even more flexibility. But with all these choices—Uncompressed RAW, Lossless Compressed (L, M, S), and Compressed RAW—which one should you actually shoot in?
I recently tested each format side-by-side to help you decide what’s best for your shooting style. Here’s what I found.
The RAW Format Options on the Sony A7 IV
With the latest firmware, the A7 IV now offers five different RAW file types:
Uncompressed RAW
Compressed RAW
Lossless Compressed RAW – Large (L)
Lossless Compressed RAW – Medium (M)
Lossless Compressed RAW – Small (S)
💡 If you don't see these options, check your firmware version. You’ll need to update to 1.10 (and possibly 1.05 first).
File Sizes & Quality Comparison
Here’s a quick breakdown of what each format offers:
Uncompressed RAW 65–70MB Maximum detail, but massive files
Compressed RAW ~35MB Smaller, slightly lossy
Lossless RAW (L) ~35MB Same size as compressed but no image degradation
Lossless RAW (M) ~20MB 12–13MP resolution (4608x3072)
Lossless RAW (S) ~15MB 8MP resolution (3520x2336)
Can You Actually See the Difference?
In my tests, comparing Uncompressed, Compressed, and Lossless Compressed (L) RAWs under identical conditions, the differences were practically invisible—even when zoomed in at 300%. While histograms showed minor differences in data capture, in real-world use, the results looked identical.
So unless you're doing extreme post-processing or archival work, Uncompressed RAW might be overkill.
Burst Shooting Speed
Here’s where things get interesting:
Uncompressed RAW slows your burst rate to around 6–7 FPS
Compressed and Lossless Compressed formats allow for up to 10 FPS
If you shoot action, wildlife, or any high-speed subject matter, those extra frames matter.
What I Personally Use
For 90% of my photography, I’ve settled on Lossless Compressed – Large (L). It gives me the flexibility of RAW editing with smaller file sizes and no quality loss (according to Sony). Occasionally, I’ll switch to Medium (M) when I know I won’t need high resolution or large crops.
I skip Uncompressed RAW entirely now—those files are just too big to justify for my use case.
So, Which RAW Format Should You Choose?
Use Uncompressed RAW if: You need every pixel of detail and file size isn’t a concern.
Use Compressed RAW if: You want smaller files and shoot quickly—but can accept minimal lossy compression.
Use Lossless Compressed (L) if: You want the best balance of size and quality.
Use Medium (M) or Small (S) if: You shoot in volume or don’t need full resolution (e.g., for web or social media).
Final Thoughts
Sony’s flexibility with RAW formats is a gift to hybrid shooters, and with this many options, you can tailor your workflow exactly how you like it.
