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With DxO Pur­eRAW 6*, DxO now intro­duces the sixth evo­lu­tion­ary stage of its spe­cial­ized AI-dri­ven RAW pre­pro­cess­ing soft­ware. Accord­ing to DxO, this release focus­es on three key inno­va­tions: Deep­PRIME XD3 for Bay­er sen­sors, high­ly effi­cient DNG com­pres­sion, and AI-pow­ered dust spot removal. In addi­tion, spe­cial empha­sis was placed on notice­ably accel­er­at­ing batch processing.

Here are the four main new fea­tures of Ver­sion 6, accord­ing to DxO, in detail:

Theory and practice

All of this sounds very promis­ing in DxO’s press release. How­ev­er, how does the new ver­sion tru­ly com­pare to the pre­vi­ous ver­sion, which was already quite impressive?

Fur­ther­more, Adobe Light­room Clas­sic, the image edit­ing and man­age­ment pro­gram I have been using for sev­er­al years, has already inte­grat­ed a use­ful AI noise reduc­tion fea­ture. What added val­ue does the addi­tion­al devel­op­ment step with Pur­eRAW 6 offer?

That’s why I took a clos­er look at Pur­eRAW 6 from these per­spec­tives. In the fol­low­ing review, I focus only on the new fea­tures in ver­sion 6. I have already described the basic func­tion­al­i­ty of Pur­eRAW in my detailed review of the pre­vi­ous ver­sion, Pur­eRAW 5, and it has not changed significantly.

What does the new DeepPRIME XD3 offer?

For this test, I have cho­sen a pho­to of a majes­tic lion tak­en on New Year’s Day 2022 in the Masai Mara in Kenya. The pho­to was tak­en with the Canon EOS R5, my 400 mm f/2.8 at its widest aper­ture and in low light in the ear­ly morn­ing before sun­rise, so I had to increase the ISO val­ue to 12,800. Here is the edit­ed orig­i­nal, but not yet denoised. I have reduced it to an image width of 2048 pix­els for dis­play purposes:

I then denoised the image using both the “Denoise” AI process inte­grat­ed in Light­room Clas­sic and Pur­eRAW 6 with the new Deep­PRIME XD3 algo­rithm. I used the default set­tings for both pro­grams. In Light­room Clas­sic, the Denoise slid­er was set to 50 in the default settings:

For Pur­eRAW 6, these were the default settings:

To ensure bet­ter com­pa­ra­bil­i­ty, I dis­abled all oth­er cor­rec­tions in Pur­eRAW. The images were then devel­oped using the iden­ti­cal set­tings in Light­room Classic:

cHere is a com­par­i­son of noise reduc­tion using Pur­eRAW 6 with Deep­PRIME XD3 and the AI noise reduc­tion inte­grat­ed into Light­room Clas­sic V 15.2. On the left you can see the result from Light­room Clas­sic, on the right those from Deep­PRIME XD3:

What, you can hard­ly see any dif­fer­ences between the photos?

I actu­al­ly feel the same way about the reduced images. Even the reduced and not yet denoised orig­i­nal still looks quite usable. This is because reduc­tion is already a very effec­tive form of denois­ing. Sev­er­al sen­sor pix­els are com­bined, which par­tial­ly com­pen­sates for the ran­dom­ly dis­trib­uted noise artifacts.

The sit­u­a­tion is dif­fer­ent in the approx. 100% crops. Here is anoth­er small sec­tion from the orig­i­nal image with­out noise reduction:

Here, the strong noise is very clear­ly vis­i­ble, as is to be expect­ed with a high ISO set­ting of 12,800. How do the two AI-based noise reduc­tion meth­ods per­form? Here is a com­par­i­son of Light­room Clas­sic and Deep­PRIME XD3 in the cropped image:

And for com­par­i­son, here is a side-by-side com­par­i­son of Deep­PRIME 3, as pre­vi­ous­ly avail­able in Pur­eRAW 5, with the new Deep­PRIME XD3:

All results are amaz­ing­ly good. Upon clos­er inspec­tion, how­ev­er, Deep­PRIME XD3 shows slight­ly bet­ter results than Deep­PRIME 3 and Light­room AI. Back­ground noise, in par­tic­u­lar, is bet­ter con­trolled, and when mov­ing the com­par­i­son slid­er around, it is notice­able that the Deep­PRIME XD3 image shows slight­ly bet­ter col­or dif­fer­en­ti­a­tion despite iden­ti­cal devel­op­ment para­me­ters. I would esti­mate the gain in noise reduc­tion to be about 1 f-stop.

Size of files

DxO has also imple­ment­ed a new com­pressed DNG for­mat in Pur­eRAW. What this for­mat achieves is tru­ly impres­sive. Here are the sizes of the indi­vid­ual files:

The orig­i­nal file of the lion shown in this arti­cle in Canon .CR3 RAW for­mat is approx­i­mate­ly 63 megabytes in size. In stan­dard mode, Pur­eRAW con­verts it into a huge lin­ear DNG file with 172 megabytes. With the new com­pressed process, how­ev­er, the result­ing DNG file is even sig­nif­i­cant­ly small­er than the orig­i­nal CR3. This is a tru­ly amaz­ing result. Accord­ing to DxO, this is a lossy com­pres­sion, so does the image qual­i­ty suf­fer as a result?

Sur­pris­ing­ly not, as the fol­low­ing com­par­i­son shows. On the left, you can see the stan­dard DNG file, and on the right, the “High Fideli­ty” DNG file:

I real­ly can’t see any dif­fer­ence between the two pictures!

How­ev­er, there is one small caveat to the new format:

Accord­ing to DxO, the for­mat is ful­ly com­pat­i­ble with the DNG spec­i­fi­ca­tions pub­lished by Adobe. It can also be dis­played and edit­ed with­out any prob­lems using Adobe appli­ca­tions and sev­er­al oth­ers that I have tried.

How­ev­er, Win­dows 11 itself can­not cope with this, as can be seen, for exam­ple, in the Explor­er view with large icons:

Instead of an image, which is the case with oth­er RAW for­mats, only a uni­ver­sal place­hold­er is dis­played. Dis­play­ing the image using the Win­dows Pho­to View­er inte­grat­ed in Win­dows 11 also fails:

All that remains is to wait for a Win­dows update.

Sensor spot removal

Anoth­er new fea­ture in Pur­eRAW 6 is inte­grat­ed AI-pow­ered sen­sor spot removal. Light­room Clas­sic ver­sion 15.2 also offers a sim­i­lar fea­ture. Sen­sor spots are caused by tiny dust par­ti­cles on the image sen­sor, but they usu­al­ly only appear at small aper­tures (11 and small­er) and on rea­son­ably homo­ge­neous sur­faces (usu­al­ly in the sky).

cI must admit, how­ev­er, that I rarely have prob­lems with sen­sor spots, as I usu­al­ly work with rel­a­tive­ly large aper­tures and keep my sen­sor metic­u­lous­ly clean. Until now, I have man­u­al­ly removed any sen­sor spots that have occurred using Light­room’s repair brush , which was actu­al­ly rel­a­tive­ly quick and easy to do and could also be applied to sub­se­quent images with­out any problems.

I there­fore had to search through my image archive to find suit­able sam­ple files. I was par­tic­u­lar­ly curi­ous to see how Light­room’s new auto­mat­ic dust removal fea­ture would per­form in com­par­i­son to Pur­eRAW 6, as I had not yet used it before.

I found two exam­ples. The first image shows a small sec­tion of a sky that I pho­tographed with an aper­ture of 32. Look­ing close­ly, I can see five sen­sor spots on it:

I then used Pur­eRAW 6 and Light­room Clas­sic to remove noise and dust from the image. In Pur­eRAW 6, I ini­tial­ly left the dust removal pre­set at 20:

cHere is a com­par­i­son of the results from Light­room Clas­sic (also with the default set­tings unchanged) and Pur­eRAW 6.

To be hon­est, I don’t see any effect with Pur­eRAW 6, while Light­Room rec­og­nizes all five spots very well and removes them with­out a trace.

I there­fore tried Pur­eRAW 6 again with a dif­fer­ent image. This time, I increased the sen­si­tiv­i­ty to 50:

Here is the test image I took with an aper­ture of 11. It now shows three slight­ly larg­er sen­sor spots:

By the way, the size of the sen­sor spots changes with the aper­ture set­ting. The small­er the aper­ture, the small­er (and dark­er) the spots appear. In a direct com­par­i­son, Pur­eRAW 6 per­forms slight­ly bet­ter here, but still does­n’t match the results achieved by Light­room Clas­sic. If you look close­ly, the sen­sor spots are still vis­i­ble as shad­ows in Deep­PRIME 6, while Light­room Clas­sic has removed them completely:

On this occa­sion, I had the images processed in Pur­eRAW 6 on my desk­top work­sta­tion. This is a tow­er com­put­er with an AMD Thread­rip­per 2950x 16-core/32-thread proces­sor, 64GB of mem­o­ry, and a Geforce RTX 2080 Ti. Admit­ted­ly, the com­put­er is already more than 6 years old, but it is oth­er­wise quite powerful.

Nev­er­the­less, noise reduc­tion with Deep­Prime XD3 and removal of sen­sor spots took a full 5 min­utes at full graph­ics card load! The cor­re­spond­ing pro­cess­ing in Light­room Clas­sic, on the oth­er hand, took about 20 sec­onds each time.

Any­way, long sto­ry short: if you already have the lat­est ver­sion of Light­room Clas­sic, you don’t need Pur­eRAW 6 for auto­mat­ic sen­sor spot removal!

Speed

The pro­cess­ing speed—especially when batch pro­cess­ing mul­ti­ple files—is also said to have been improved in the sixth ver­sion of Pur­eRAW. To test this, I select­ed a series of pho­tos of a pel­i­can with 20 RAW images from my Canon EOS R5 Mark II. They were tak­en last spring at Duis­burg Zoo. Here is an exam­ple image:

The images are all sim­i­lar to the one above. In total, the 20 .CR3 files from my Canon EOS R5 Mark II used for the test were in total 744MB in size, mean­ing that a sin­gle image was around 37MB.

I then denoised them one after the oth­er using dif­fer­ent set­tings in Pur­eRAW 6 and, for com­par­i­son, also with the pre­vi­ous ver­sion 5. To do this, I again used my lap­top with an Intel i9-11980HK CPU (8 cores, 16 threads), 64GB of main mem­o­ry, and an inte­grat­ed Geforce 3080 RTX with 8GB.

The exact results can be found in the fol­low­ing table:

In fact, Pur­eRAW 6 with the same set­tings as Deep­PRIME 3 in batch mode is now almost 30% faster than its pre­de­ces­sor. The new noise reduc­tion with Deep­PRIME XD3 is appar­ent­ly much more demand­ing, requir­ing more than twice as much time as Deep­PRIME 3.

I am par­tic­u­lar­ly impressed by the high lev­el of com­pres­sion achieved with Pur­eRAW 6 for high-fideli­ty DNG files: in this exam­ple, the DNG files were com­pressed by an incred­i­ble amount of 87%! The result­ing DNG files are even almost three times small­er than the orig­i­nal .CR3 files from my Canon EOS R5 Mark II!

How­ev­er, I must admit that the image I chose is also very well suit­ed for com­pres­sion, as the back­ground is most­ly black.

Resumée

Well, bet­ter is the ene­my of good, as the say­ing goes.

In fact, the new Deep­PRIME XD3 extracts even more detail from high-ISO images than its pre­de­ces­sor and also than the AI process inte­grat­ed in Light­room Clas­sic. In my com­par­isons, I would esti­mate the improved noise reduc­tion to be about 1 f-stop gain. This means that an ISO 12,800 image denoised with Deep­PRIME XD3 appears to have sim­i­lar noise lev­els to an ISO 6,400 image denoised with the oth­er methods.

How­ev­er, it must be admit­ted that the results achieved by Light­room and the old­er DxO meth­ods are already very good and, in many cas­es, cer­tain­ly more than suf­fi­cient. How­ev­er, the new, more com­plex method also requires more com­put­ing pow­er. On my lap­top with an 8-core Intel CPU and GeForce 3080 RTX graph­ics card, it took me about 10-20 sec­onds to denoise the images shown using Deep­PRIME XD3, while Light­room and Deep­PRIME 3 took rough­ly half that time.

How­ev­er, this may look com­plete­ly dif­fer­ent on oth­er com­put­ers. Basi­cal­ly, AI process­es rely on suf­fi­cient­ly pow­er­ful graph­ics hard­ware. With­out this, and using only the CPU, you will have to wait sev­er­al min­utes for each image.

Whether the new fea­tures in Pur­eRAW 6 are worth upgrad­ing from the pre­vi­ous ver­sion, or whether it is even nec­es­sary to use Pur­eRAW if you already have Light­room Clas­sic, is some­thing every­one must decide for themselves.

Anoth­er aspect to con­sid­er when choos­ing an AI denois­ing pro­gram is its sup­port for dif­fer­ent cam­era mod­els. At DxO, the algo­rithms are specif­i­cal­ly tai­lored to indi­vid­ual cam­era mod­els, which have been care­ful­ly cal­i­brat­ed in the DxO lab­o­ra­to­ries. This ensures that opti­mal results are always achieved. How­ev­er, if you use a cam­era that DxO does not (yet) sup­port, Pur­eRAW 6 will not be able to process the files. It is there­fore impor­tant to check the list of sup­port­ed cam­era mod­els at DxO* before using Pur­eRAW 6. For exam­ple, DJI action cam­eras such as Action 4 to 6 or the Osmo 360 are cur­rent­ly not supported.

Light­room Clas­sic takes a dif­fer­ent approach here. In addi­tion to the pro­pri­etary RAW for­mats of most pop­u­lar cam­eras, it also accepts almost all files in DNG for­mat with­out requir­ing any spe­cial inte­gra­tion. There­fore, Light­room is more like­ly to be able to han­dle DNG files from more exot­ic cameras.

But you can check it out for your­self any­time: just down­load a tri­al ver­sion of Rur­eRAW 6 (right here at DxO*) and try it out with your own pho­tos. DxO is super gen­er­ous and lets you test its pro­grams for 14 days with­out any restrictions.

In any case, I’m glad that Deep­PRIME XD3 allows me to get that lit­tle bit more out of my crit­i­cal high-ISO images - even if I’m sure I’ll only need to do so on rare occasions.

A very wel­come addi­tion is the sig­nif­i­cant­ly more com­pact file for­mat. The gigan­tic files of the pre­vi­ous ver­sions took up a lot of space on the hard dri­ve. I am even con­sid­er­ing con­vert­ing all my future .CR3 files to com­pressed DNG files with Deep­PRIME XD3 in the future to save hard dri­ve space…

I’m not yet real­ly con­vinced by Pur­eRAW 6’s auto­mat­ic dust removal feature.

Prices and availability

DxO Pur­eRAW 6 is avail­able on the DxO web­site for down­load* at the fol­low­ing prices:

• DxO Pur­eRAW 6: 129,99 €
• DxO Pur­eRAW Upgrade from Ver­sion 4 or 5: 79,99 €

*= Affil­i­ateLink