James Stephens

Recently I’ve been taking a look at DxO Optics Pro. I was attracted by the fact that this software is the only product on the market that offers automated correction for optical vignetting, chromatic aberration (both lateral as well as purple fringing), pincushion and barrel distortion. It also reduces noise, corrects for lens softness and acts as a RAW converter too.

DxO has a product called DxO Analyzer which was developed by DxO to conduct performance tests on lenses. From this they were able to reverse engineer corrections for particular lens/body combinations and this is how DxO Optics Pro does its thing.

I came across these reviews of DxO Optics Pro - this one by Michael Reichmann of Luminous Landscape (plus an update to it after RAW support was added), and another by Alain Briot. Both authors sing the praises of DxO’s ability to correct for lens defects (see the first review for some amazing before/after shots) but Michael chooses to stick with Adobe Camera RAW for RAW conversion whereas Alain uses the RAW conversion capabilities of DxO too.

Some thoughts …

1. This is an amazing piece of software in terms of the way it corrects for lens defects but it isn’t cheap at $299. I’d be more inclined to make the jump to purchasing it if they supported the Tamron 17-35mm f/2.8-4 DI LD lens on the Canon EOS 5D body as opposed to just my Canon lenses. I probably need DxO Optics Pro more for the Tamron than anything.
2. Up to now I’ve been using PTlens to correct for pincushion and barrel distortion. PTlens actually does a better job of correcting these defects than Adobe Photoshop CS2, with 4 coefficents versus Photoshop’s 2, and furthermore is automatic. However, DxO Optics Pro takes the correction a step further since whereas the coefficients are calculated at a fixed distance in PTlens for a particular lens/body combination (it is free software after all), in DxO Optics Pro one of four distance ranges is selected to refine the coefficients to a greater level of accuracy than PTlens.
3. The fact that distance data must be provided in order to properly correct for pincushion and barrel distortion does amount to a hindrance to effective batch workflow but this isn’t DxO’s fault; distance information simply isn’t in the EXIF data. I don’t know why my Canon L-series lenses on a Canon EOS 5D body can’t report distance information to the EXIF data but it appears that this is in fact a general problem for other lens/body combinations too.
4. DxO Optics Pro is quite slow to operate. On my Athlon 64 X2 Dual Core 4200+ system with 2GB RAM running Microsoft Windows XP it takes over a minute to perform lens corrections and noise reduction on a RAW file from a Canon EOS 5D. Utilizing corrections for lighting, color and exposure it takes almost twice as long but I find DxO Optics Pro most useful for correcting lens distortion and reducing noise, and prefer to leave other corrections for Adobe Camera RAW.
5. DxO Optics Pro supports output to DNG format but one gripe I have is that the DNG files are saved in linear format (i.e. demosaiced). They end up being around three times larger than either regular DNG files or the original RAW file and this means that I use triple the disk space. I’m waiting for a reply from DxO on why this is.

I recommend trying this software for yourself. You can download a free 21 day demo of DxO Optics Pro v3.5 for a single lens/body combination at http://www.dxo.com.