Custom lens profile - a guide?

DxO PhotoLab
1

Hi everyone,

I have purchased a lens recently and I noticed that PL does not have a profile for it (Laowa 7.5 mm f/2 auto aperture). Naturally I requested one using the suggestion link on DXO’s web site but I don’t have my hopes very high. The reason is that the lens is from a 3rd party manufacturer for the Micro Four Thirds system and may not be very popular. At the moment PL has a profile for only one other lens by Laowa and my understanding is that it was created years after it was first requested.

Anyway, my question is: in the absence of an “official” DXO profile for this lens, can I build one myself and is there any guide available on how to do that?

Thanks!

2

You could set up a partial preset with adjustments for Chromatic Aberration, Distortion, and Vignetting, although I can’t tell you the best way to configure those settings for an unsupported lens. The fourth component is Lens sharpness, but that feature is not available for an unsupported lens. You would have to use the Unsharp mask as an alternative.

However, often PhotoLab suggests a different lens profile if the specific one for your lens is not available. If they do suggest an alternative to your lens, you can try it, modify it as needed, and then create a partial preset. The advantage is that if an alternative profile is available it will also give you access to the Lens sharpness tool.

Mark

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3

Thus far in my use of DxO PL, the PL application prompts me to load a module (profile) for a lens, and does not do so for an unsupported lens.

(1) How does one get a lens module (profile) from which to start the work?

(2) Once having such a module, how does one modify the module – is this plain ASCII text or does it require a special tool (the equivalent of say, regedit for MS Windows) to make modifications, and if the latter, how does one get the tool? If it is plain ASCII text, how does one get the decode as to what is meant by the various “fields” and what are the “allowed values” or encoding text strings?

(3) Say the module if for lens A but one has lens B – how does one rename the modified module from A to B and then force DxO PL5E to load the module?

4

I think there is no valid “software manipulation” method to use a lens profile A to apply a lens B!
Except in the special case of almost identical lenses, for example a new version of a lens without modifying the optical formula.

The only realistic possibility is to make your own profile as follows, it being understood that this is reasonably possible only for a single focal length lens, and not for a zoom: far too complicated!

  • A pattern must be photographed at a reasonable distance, for example a grid of black lines on a large white sheet of paper (with uniform lighting!).
  • This must be repeated for each of the openings of the diaphragm.

Then in PhotoLab, we open each raw. This step is to be done with the raw taken with the most open diaphragm (f/1.8 for example).

  • We start with the correction of the distortion. Normally (usually) the distortion is constant regardless of the aperture used. So we correct the geometry of the image with the Distortion - Manual / barrel pincushion / fisheye tool as appropriate and the intensity slider.
  • Then we move on to vignetting correction: Vignetting tool - Manual / intensity / medium.
  • Finally it remains to make the correction of sharpness: tool Unsharp Mask - Intensity / radius / Threshold. This step can be done with the raw target (for example if the paper has a pronounced grain), but it can then be refined with a more detailed photo, for example that of a road map or similar. The important point to note is that most often a lens has maximum sharpness in the center, and this sharpness decreases towards the edges/corners. PhotoLab allows you to take this into account with the Edge Offset slider which will accentuate the sharpness going towards the edges.

When all these corrections are made, you can then create a partial preset that you save in the preset editor. This preset will be named for example: “(Brand)_50mm_f1-8”

Once this preset has been saved, open the next raw (taken at f/2 for example) and apply the preset that has just been created. In principle, the distortion correction is the correct one. On the other hand, the other settings are to be repeated, generally by decreasing them. This done, we create a new partial preset that we will name for example “(Brand)_50mm_f2”.

And we start again for each raw corresponding to the other more closed diaphragms…

But it is generally possible to reduce the number of cases very seriously: the vignetting generally decreases fairly quickly and the sharpness improves. This means that we can generally group certain openings. For example, from f/4 or f/5.6 to f/11 the corrections will be identical, so only one preset will be necessary, which could have the name “(Brand)_50mm_f5-6_f11”. This can even be extended to f/16, but the sharpness may need to be adjusted on a case-by-case basis if the diffraction does too much damage.

Attention: if the opening is present in the exifs, no problem to find the raw to be processed with such or such preset. But if it is not: no contacts on the lens or old lens, it will obviously be necessary to note frame by frame the aperture when shooting!
Well, that sounds complicated… and it kinda is!
But this is THE solution for an unrecognized objective that has no chance of being recognized. For example rare lens, or vintage lens.

The result will obviously not be as good as with a lens supported by DxO, but it does a great service once the investment of time to create the presets is over.

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5

No, you can’t DIY a module (it’s as simple as that)

Checking out this page, I get the impression, that you could work around some of the flaws manually. Take a few shots of a brick wall at different distances and compensate manually, noting the values yo have to use depending on shot distance - if it should matter. Make partial presets for different distance settings (if it matters) and apply it as needed.

6

There now exist fully functional adapters – the functional equivalent of the Nikon FTZ that adapt an internal focus motor Nikon F mount lens (not necessarily made by Nikon) to a Nikon Z body (eg, Z9) – for Canon EF mount (not necessarily made by Canon) to a Z body. If the EF lens has a module in the DxO base (presumably for a Canon body), can PL5E be “forced” to use the correct module with a Nikon Z body that used one of these EF to Z mount adapters? If so, how does one find, install, and “force” the non-F mount DxO lens module to be used? DeepPRIME is superior to High Quality noise reduction, but evidently requires a DxO lens module as well as a DxO supported body “module” or PL5E will NOT allow the user to select DeepPRIME.

7

Not true. Prime and Deep Prime will be applied if the body is supported, regardless of the lens module.

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8

If you modify your Nikon files to make DPL believe they are Canon’s, you can use canon lens modules. As of today, I see no support for Canon lenses on Nikon bodies (e.g. the z7) in DPL’s module database.

9

Is there a way to FORCE PL5E to use a lens module that is not linked to the body in use? This issue will arise again, and not just from myself. There also exist fully functional Sony mirrorless (E mount?) to Nikon Z bodies. In some cases, a lens for a non-Nikon mount that can be adapted WITH FULL AUTOMATION FUNCTIONALITY to a Nikon Z body can have attributes superior to a lens that is either F or Z mount. If such a “forced use” of a module is possible, what files need to be changed?

10

Assuming that a body is supported, which functionalities of PL5E depend upon a lens module? It seems that microcontrast and proper modern sharpening (not unsharp mask, etc.) depend upon the lens module. (Aside: my experience with PL5E after the Z9 was supported was that in some cases only High Quality was available but not PRIME/DeepPRIME if PL5E did not download a lens module. Perhaps this was a software defect.)

11

The lens module only effects distortion, vignetting, chromatic aberration and lens sharpening. not micro contrast or noise reduction.

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12

After playing a bit with Laowa 7.5 mm f/2 I believe correcting the lens distortion is not that big of a deal. The lens is pretty good and does not need much correcting. My bigger issue is sharpness though. Because the lens is not supported I don’t have the Lens Sharpness module available and the resulting images come out really soft. What workaround is there for this specific issue?

13

Hi
I own this lens and have made a preset to correct it.
Indeed, it is clean from the start.
Pascal

0 PARTIEL - Laowa 7.5.preset (672 Bytes)

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14

Thank you, I’ve been playing with similar settings

15

I played a bit with the sharpening settings from your preset: USM (Intensity 200, Radius 0.75, Threshold 2). I Increased the intensity up to 300, played with bigger and smaller radius, moved the threshold down to 0 and up to 4 … I even added some microcontrast and fine contrast… Got better from where I started but not as good as Lightroom. And the frustrating part is that Lightroom does not support his lens either. Its default sharpening (never had to touch any settings there) is so good. See the attached comparison. Lightroom is left and on the right side is DXO PL with the above USM settings.

comp
comp1918×785 316 KB

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