Every sensor has a point where the image noise gets too much to make the shot usable. Exactly where that is really comes down to personal tolerance for noise and what the image is being used for.
And most of the time, it’s down to the sensor. Sensors keep getting better and better with new camera models, but the sensor in the camera you have will be stuck in time.
Well, almost. There’s a new generation of RAW image optimization tools that can often pretty dramatically improve the image quality of shots taken with older sensors. They work especially well on images at high ISOs — they tend to the ones that are most degraded, of course. But even on low-ISO, correctly-exposed images, these tools can really help revive old images that are sitting in your archive or ward off the need to spend the big bucks for an imminent upgrade in camera.
The tool I’m focusing on here is DxO’s PureRAW, which is the one that has established an important place in my own workflow for a few years now. (And at the heart of PureRAW is a technology that DxO calls DeepPRIME. I wrote a broader comparison of these tools in my look at the current crop of denoise tools.)
So the purpose of the tests below is to share some examples of what effect PureRAW has on some of my old GR II images, a camera I loved traveling with. Maybe you’re looking to revive your own old GR II images or trying to decide whether it’s really necessary to upgrade to the GR III or GR IV right now. So it’s worth a look to see what can be done with the GR II RAW images with the new generation of RAW optimization tools. Because the results can be pretty dramatic.
So here’s what DxO PureRAW does to Ricoh GR II RAW files, on my own real-world photos, with before/after sliders and 100% crops. And if you’d like an even closer look, you can also download the RAW/DNG files; I have more information on how you can get those at the bottom of the page. I hope these examples are helpful.
First, though, it’s worth being clear that it only works on the GR II’s DNG RAW files, not JPGs. That’s not a limitation of one app — it’s where the gains of this type of technology come from.
Tools like DxO PureRAW and Lightroom’s newer generation of denoise tools work on the sensor data before it has been demosaiced and baked into the pixels, and that’s where these newer machine-learning models have the advantage over the older generation. You can still run the older style of noise reduction on JPEGs and TIFFs (using other apps, not PureRAW), but you’re working with already-cooked data, and the results are a different league. So this is the payoff for deciding to keep all those RAW files from years ago.
You’ll see the most dramatic improvements in high-ISO frames and in shadow detail. That’s where older RAW files degrade most visibly. In many of today’s cameras, ISO 3200 looks fantastic. But in many older digital cameras, ISO 3200 was the bleeding edge and came with pretty heavy noise and graining.
But the improvements aren’t only limited to high ISOs. Even at the camera’s base ISO you can see useful improvements, albeit usually more subtle.
The Ricoh GR II: Sensor and ISO range
A quick look at what we’re working with here.
The GR II has a 16.2-megapixel APS-C CMOS sensor measuring 23.7 × 15.7 mm, recording 4928 × 3264-pixel images; that works out to a pixel pitch of about 4.8 µm. Its base ISO is 100, and the standard sensitivity range runs from ISO 100 to 25600, with no separate extended setting. It came out in 2015, so there are plenty of RAW files from it sitting in archives by now, including my own.
That sensor is better than its age suggests in one respect and ordinary in another. DxOMark measured 13.7 EV of dynamic range at base ISO, which is still a strong number, alongside a low-light ISO score of 1078, which is unremarkable for APS-C. That split is what you see in the files: plenty of shadow detail to pull back at low ISOs, and noise that turns coarse quickly once you’re past ISO 1600. It’s also why there’s so much for denoise to work with here.
The examples below run from ISO 25600 down to ISO 400, highest first, since that’s where the differences are most obvious.
| Sensor | 16.2 MP APS-C CMOS 23.7 × 15.7 mm |
| Resolution | 4928 × 3264 pixels |
| Pixel pitch | ≈ 4.8 µm |
| Base ISO | 100 |
| Native ISO range | 100 – 25600 |
| Extended ISO (low) | none |
| Extended ISO (high) | none |
| ISO in these examples | 25600 – 400 |
One thing worth knowing up front about the Ricoh GR II: Lightroom has no lens profile for it, so Lightroom can’t correct this camera’s vignetting or distortion (it can still remove chromatic aberration). DxO’s optics module can, and does, on the PureRAW side. That matters for the comparisons below — the corners on the PureRAW side get corrections Lightroom has no way to match, so weigh the center crops more heavily — and it’s worth knowing for your own workflow with this camera regardless of PureRAW.
And a reminder that PureRAW and its competitors only work on RAW files.
The Ricoh GR II: Sensor and ISO range
A quick look at what we’re working with here.
The GR II has a 16.2-megapixel APS-C CMOS sensor measuring 23.7 × 15.7 mm, recording 4928 × 3264-pixel images; that works out to a pixel pitch of about 4.8 µm. Its base ISO is 100, and the standard sensitivity range runs from ISO 100 to 25600, with no separate extended setting. It came out in 2015, so there are plenty of RAW files from it sitting in archives by now, including my own.
The examples below run from ISO 25600 down to ISO 400, highest first, since that’s where the differences are most obvious.
| Sensor | 16.2 MP APS-C CMOS 23.7 × 15.7 mm |
| Resolution | 4928 × 3264 pixels |
| Pixel pitch | ≈ 4.8 µm |
| Base ISO | 100 |
| Native ISO range | 100 – 25600 |
| Extended ISO (low) | none |
| Extended ISO (high) | none |
| ISO in these examples | 25600 – 400 |
One thing worth knowing up front about the Ricoh GR II: Lightroom has no lens profile for it, so Lightroom can’t correct this camera’s vignetting or distortion (it can still remove chromatic aberration). DxO’s optics module can, and does, on the PureRAW side. That matters for the comparisons below — the corners on the PureRAW side get corrections Lightroom has no way to match, so weigh the center crops more heavily — and it’s worth knowing for your own workflow with this camera regardless of PureRAW.
And a reminder that PureRAW and its competitors only work on RAW files.
Results
Shot 1: ISO 25600
Shot 2: ISO 16000
Shot 3: ISO 8000
Shot 4: ISO 3200
Shot 5: ISO 2000
Shot 6: ISO 1600
Shot 7: ISO 800
Shot 8: ISO 400
Verdict
I loved traveling with the GR II, and I took a lot of shots with it. In fact, I still have it, although I’ve mostly been using the GR III instead in recent years. But there are photos I’ve taken with the GR II that I want to keep and improve the image quality from 2015-era standards.
At the very highest ISOs, like 25600, the results are most dramatic. In general, I avoid those highest ISOs, but there are times there’s not a better option because you have to work with the lighting conditions you find.
But it’s still not magic. PureRAW does a really good job of improving the image quality overall, and they look great at social-media-type sizes. But when you view them at 100%, you can end up with waxy smoothing that looks a bit fake. For the tests here, I’m using a standardized suite of settings. If I was processing these for myself, though, I’d normally dial down the Force Details slider on these — I find that that can be problematic at the default 0 on some images that are most afflicted with high-ISO noise.
But it’s in the GR II’s mid-range of ISOs, especially from around ISO 800 to ISO 8000, where the combination can really shine.
Below that, and the results are pretty subtle. Detail is crisper when viewed at 100% — take a look at the ISO 400 shot with lights and scoring in the 100% view of the baseball scoreboards and stands for a good example. But it’s not enough of an improvement, for me, to justify it by itself.
However, if you’re consistently shooting in the ISO 800 to ISO 8000 range, it’s well worth a look.
Other areas where DxO, including PureRAW, are particularly strong aren’t particularly relevant here. There’s not much lens distortion to correct. There’s some lens vignetting, although it’s not particularly stark or egregious. So you don’t really get that much benefit from DxO’s expertise in those areas with this particular camera (because it’s just not needed that much).
You can try it on your own images
I’ve found PureRAW to be very useful in my own workflow and have been a paying customer since version 3 in 2023.
But it’s all well and good to see how it works on a small sample of my images; the real test is what effect it’ll have on your images.
If you want to try it on your own files, DxO offers a free trial of PureRAW. Or, if you want a full RAW editor alternative to Lightroom, the same DeepPRIME engine is built into DxO PhotoLab.
How these examples were made
- Camera: Ricoh GR II (firmware Rev0102, Rev0110)
- Input image format: DNG (the Ricoh GR II’s native RAW format)
- Lenses in this batch: GR LENS
- ISO range: 400–25600
- DxO PureRAW (v. 6.5) — DeepPRIME XD3 (Luminance 40, Force Details 0) · Lens softness: ON · Chromatic aberration, vignetting, distortion: ON · Dust removal: OFF · DNG output (uncompressed)
- Rendering: Adobe Lightroom Classic 15.5, identical develop settings for each before/after pair, with the lens corrections handled by each side’s own engine: Lightroom’s lens profile (distortion + vignetting at default) and chromatic-aberration removal on the Lightroom side, DxO’s on the PureRAW DNG (Lightroom’s lens corrections switched off there so nothing is corrected twice); Lightroom’s sharpening and noise reduction switched off on the DNG (PureRAW already did those); no output sharpening
- Lightroom lens profile: none available for the GR LENS, GR LENS (6 shots) — Lightroom can only remove chromatic aberration on its side, so vignetting and distortion are corrected only on the PureRAW side (see the note in the camera section above)
These are all photos I shot myself, in ordinary shooting conditions, not test-chart frames.
Every before/after pair was rendered from the same file with the same settings; the only variable is whether the file went through PureRAW first.
PureRAW lets you dial each tool up or down. For the purposes here I’m using my standardized settings that amount to sensible defaults rather than chasing extremes: DeepPRIME XD3 noise reduction at its default strength, lens softness, chromatic aberration, vignetting and distortion corrections on, and dust removal off.
I’ve used the same settings for every frame, so the comparisons are apples-to-apples. And to keep it fair on the optics, the Lightroom side has Lightroom’s own lens profile switched on (distortion and vignetting corrections at their defaults) and chromatic aberration removal on in every comparison, so each side has its optics corrected by its own tools — with one wrinkle for this camera: Lightroom has no lens profile for it, so on that side only chromatic aberration could be corrected; more on that in the section on the camera just below. I’ve also tried to include a variety of different ISO settings and scenes.
Why I’ve chosen these settings here
PureRAW does more than noise reduction. Its tools fall into two groups.
The sensor corrections — DeepPRIME’s noise reduction and demosaicing — work on what the sensor recorded.
The optical corrections — lens softness, chromatic aberration, vignetting, and distortion — fix what the lens did to the light on its way in. The sensor corrections are the main event in this post, but I’ve left DxO’s optical corrections on as well. I can’t really think of a good reason not to fix chromatic aberration in every photo (we’re not doing lomography here!), and it’s a setting I always enable by default on my own photos. For my own photos, I am, however, more choosy about when to apply vignetting and distortion fixes, because to my own eye, those optical “flaws” are sometimes positives and something that I want to retain. But for the purposes here of using a standard set of settings to make comparison easier, and because these types of optical profiles and corrections are defining strengths of DxO’s software, I’m applying those fixes in these side-by-side examples.
Lens softness correction is such an integral part of how PureRAW’s output looks that turning it off would misrepresent the tool. And DxO’s optical corrections — built on the enormous body of lens and camera test data that was their original claim to fame — are a genuine strength that separates PureRAW from Lightroom’s built-in tools.
The images above
In the examples above, I’ve included two types of comparisons:
- My edit, upgraded: the before is my finished Lightroom edit, plus Lightroom’s own lens profile (distortion + vignetting at default) and chromatic-aberration removal, switched on for every comparison; the after is the same edit applied to the PureRAW DNG, with Lightroom’s sharpening and noise reduction — and its lens profile and chromatic-aberration removal — switched off on the DNG, because PureRAW has already done those jobs (leaving them on double-processes the file — the most common reason PureRAW output looks over-sharpened). So each side has its optics corrected by its own tools, and everything else is identical on both sides.
- Untouched: both files with no editing at all beyond those lens corrections, at Lightroom’s default settings, so you can see what PureRAW does on its own.
With distortion correction on both sides, each frame is shown as its engine renders it corrected — geometrically the same on both sides, so it doesn’t skew the comparison. On an ultra-wide the correction stretches the corners more than on other lenses, so that’s where any residual difference between the two engines shows up — worth keeping in mind on the corner crops of the 2 ultra-wide frames in this batch.
Colour shift: none worth mentioning. I also check whether PureRAW’s files come back with a different colour balance than the originals (some cameras do). Measured over the central 60% of each pair in linear light at identical Lightroom settings, the Ricoh GR II DNGs stayed within 2% on the red-to-green and blue-to-green ratios (my threshold for “significant” is 4%), so what you see in the sliders is processing, not a colour cast. One exception: Shot at ISO 25600 moved much more (-6% / -47%), which is what heavy colour-noise removal does to the average of a very noisy frame rather than a real cast — you can judge it in that slider yourself.
How PureRAW fits into a real workflow
I’m using these with Lightroom Classic, but PureRAW isn’t limited to only Lightroom-centric workflows. You can use it as a standalone app, and the underlying DeepPRIME technology is also built into DxO’s own full-suite editor app PhotoLab (which is itself well worth a look if you’re after a Lightroom alternative).
In practice, PureRAW is a pre-processing step, not an editor. You can run it as a standalone app (just drop RAW files on it, pick a preset or adjust the settings, and run process) or straight from Lightroom Classic via its plug-in — select the photos, send them to PureRAW, and it hands back the processed versions reimported into Lightroom.
Either way, the output is a new DNG file for each RAW: PureRAW never touches your original. If you’re using Lightroom, the DNG is created next to the original with your existing edits carried across, so you’re not starting over — you just switch to the new file. (TIP: make sure to save any Lightroom develop settings to the file before sending it to PureRAW or the settings won’t be applied to the PureRAW version automatically.)
With this workflow, there are two key considerations to factor in:
- File storage: those DNGs are linear (already demosaiced) files, and they can be considerably larger than the RAWs they came from — the ones in this post average about 2.9× the size of the originals. If you run it across a whole archive, that adds up quickly. So I don’t run it across everything.
- Processing time. DeepPRIME is computationally heavy. So most of the time I’ll only apply it to selected images rather than everything. Running it across dozens or hundreds of images is entirely possible, and I’ll sometimes do that if I have the time, but it takes a while (depending on the speed of your computer) and eats storage space.
What PureRAW doesn’t do
It’s also worth being clear about what this isn’t, because the marketing can blur the lines:
- It doesn’t add resolution. The DNG has exactly the same pixel dimensions as the RAW. It cleans up and sharpens what’s there; it doesn’t upscale. (That’s a separate job for tools like Lightroom’s Super Resolution or Topaz Gigapixel.)
- It doesn’t fix blur. Camera shake, motion blur, and missed focus stay exactly as they were. The “lens softness” correction is a profile-based sharpening for the lens’s known optical softness, not a deblurring tool.
- It doesn’t recover what was never captured. Blown highlights are still blown, and a badly underexposed frame gets cleaner, not correctly exposed — that part is still done in your editor.
A note on the “AI” label
PureRAW and its rivals describe themselves as AI-powered. Which is the marketing buzzword of the day. But it’s worth being precise about what that means here, because “AI” can be a double-edged sword, and the kind of AI we’re talking about here is a different thing from the AI most people now have in mind.
This is more accurately referred to as machine learning. What that means is that DxO trained a model on a very large set of paired examples — noisy sensor data and what the clean version should look like — and the software uses that training to make a better-informed guess about what each pixel really was.
It works from the data in your file and nothing else. It doesn’t invent content, it doesn’t pull in imagery from anywhere else, and it can’t invent a detail out of nothing — where the noise has genuinely destroyed information, you get softness or waxy texture, not made-up content (a good reason to not push those sliders all the way to the right). Push it hard enough on a truly ruined frame and you get mush or waxy textures, not fabrication.
That’s different to how generative AI works. Think ChatGPT or Claude or SeaDance or Nano Banana. That’s a fundamentally different type of technology, one that synthesizes new pixels. And that isn’t what PureRAW uses and isn’t what’s happening in any of the comparisons above. Your photo is still your photo.
You can try it on your own images
I’ve found PureRAW to be very useful in my own workflow and have been a paying customer since version 3 in 2023.
But it’s all well and good to see how it works on a small sample of my images; the real test is what effect it’ll have on your images.
If you want to try it on your own files, DxO offers a free trial of PureRAW. Or, if you want a full RAW editor alternative to Lightroom, the same DeepPRIME engine is built into DxO PhotoLab.
Download the RAW and DNG files
If you want to take an even closer look at the results here, I’ve posted the full-size original RAW files and PureRAW’s DNG output for the examples above for subscribers to my newsletter. The download index is here: RAW file downloads for subscribers. The page is password-protected; the password is in the newsletter’s welcome email.
