Looking into Lens Corrections

From time to time, people ask why Olympus or Panasonic lenses are not listed in the Lens Profiles of Lightroom. The confusion is both from us for not seeing the clues and from Adobe for poor user interface / communication of the message to the end user.

What do people mean by Lens Corrections?

Lenses are physical designs and have optical imperfections in creating the image. Designers choose to reduce these imperfections to the minimum but that impacts lens bulk, size, number of elements and cost. Or thinking the other way, lens designers in the digital world, can purposely design imperfect lenses and rely on the camera firmware or computer software to correct them.

The imperfections cover:

• colour fringing (sometimes called Chromatic Aberration)
• optical vignetting falloff (darkening of the image corners)
• curvilinear distortion (straight lines becoming bowed inwards (pincushion) or outwards (barrelling)

Where are the correction parameters stored?

Correction metadata can be stored

• single Lens Correction Profile in separate files one file per lens. Separate files are useful when a user voluntarily carries out the measurements and submits them to the software vendor (e.g. Adobe).
• stored as an "internal" integrated database supplied with the software program
• stored in lens firmware which is then copied by camera body and saved as metadata in the raw file
• stored in lens firmware which is then applied by camera body to the camera JPEG. In which case the SOOC (Straight Out Of The Camera) JPEG does not separately store the parameters, the JPEG is considered the corrected and finished image.

What do software user interfaces look like when they acknowledge the lens identity?

Adobe Lightroom Lens Correction panel in the Develop Module

 Above, you see the Adobe Lightroom Lens Correction panel in the Develop Module. This is what the panel looks like when the lens is recognised by Lightroom. You don't have to take any action. If you click on the Information (i) icon, you will see a dialog stating what the lens model is.

Adobe Lightroom Lens Correction panel in the Develop Module

Above is the Lightroom Lens Correction panel if you explicitly click on the checkbox "Enable Profile Corrections" - presumably, if the lens is already in the internal database, the information it already knows is ignored and you can nominate the individual Lens Profile files that Adobe has supplied or you have created yourself or that you have downloaded using the Adobe Lens Profile Downloader.

Also See: Lens Profile Corrections

Adobe Camera Raw Lens Correction Panel

Similar to Adobe Lightroom's panel design, this is the Adobe Camera Raw Lens Correction panel. Note that this panel is more informative - you do not have to click one more time to display the identification / name of the lens

If you get an .lcp file from a third party, to allow Lightroom and Adobe Camera Raw access to it, put the .lcp file in
C:\Users\yourusername\AppData\Roaming\Adobe\CameraRaw\LensProfiles\1.0\Downloaded

DxO ViewPoint 2 Distortion Correction Panel

Above is the DxO ViewPoint 2 Distortion Correction Panel. Presumably the DxO Optics user interface will be similar. Note that DxO not only identifies the lens, it also identifies which body it is fitted on. This extra information might be used in their corrections.

Corel Aftershot Pro 2 Lens Correction Panel

Above is the Corel Aftershot Pro 2 Lens Correction Panel. It too identifies the camera body and the lens. Clicking "Enable Correction" does not appear to disable Correction, does it enable Correction and not ticking it ignore Correction? Chromatic Aberration and Vignette Correction are not automatically ticked when you tick Enable Correction. 

Raw Therapee Lens Correction Panel

Raw Therapee is a free raw editor. I don't see information about whether it has or knows how to use an internal database. But if you choose to use a Lens Correction Profile, the resulting file selection dialog will refer to Adobe's nest of folders on your computer.

More reading:

• Photography Life article on Lens Corrections in Lightroom
• Julieann Kost's article
• Adobe intro video
• Adobe Help on cameras with built-in lens support (MFT)
• Adobe document on Lens Correction Profiles and folder locations, Mac and Windows
• Creating your own LCP

Notes for next time. Chinese New Year Lion Dances at Glen Waverley

One thing that detracts from my success in achieving the shots I want, is I have a poor memory, fail to write things down after I encounter issues. This means the next year when I attend a similar event, I forget what sunk me the previous time. Here are my notes for this year's Chinese New Year event at Glen Waverley (but it applies to similar Chinese New Year incidents in other locations).

For the door to door lion dances (this year it was 2 pm to 4:30 pm), we had a high dynamic range scene. The sky is super bright courtesy of Melbourne Summer's day. The shaded shop frontage where the lions dance is several stops darker.

Parameter	Used	Result	Preferred	Notes
Metering	Evaluative		Evaluative
ISO	Auto	200	As needed to ensure high shutter speed
Aperture	f/3.5		f/3.5
Shutter Speed	Aperture Priority	1/320 variable	1/500 fixed	Can't use Shutter Priority because Samyang is non electronic lens. Maybe enable Auto ISO for Manual Exposure mode. Fix Shutter Speed at 1/500
Post Processing	Lightroom			Recover highlights severely, use other adjustments
Focus	Focus right slipped		Infinity	Use sticky tape to hold the focus ring stays at infinity. Check position several times during the session

A photo posted by Ananda Sim (@anandasim) on Feb 20, 2016 at 9:21pm PST

Features that you might not know about the Olympus PEN-F

Owners and intending owners of the Olympus PEN-F have mostly read reviews of this camera from review sites, Youtube videos and so on. To "sell" their experience and be known as cognoscenti of cameras, reviewers often take a few features and emphasise their opinion - this is both a good thing (because people want something to read about whether to arouse interest) or a bad thing (arouse disdain).

So we get to know some features very well from this clamour of voices and grasp little of features that people don't mention. Here's a shortlist of features that may have escaped attention.

Note: I come from an E-330,  E-510, E-620, E-PL1, E-PM2 and E-M1 background so only new features will be listed

Silent Mode can shoot at 20 fps in burst mode. Other mechanical shutter modes shoot at 10 fps

See: Amateur Photographer article.

The Spot Metering Mode follows the focus target that is triggered, not the central AF point

See manual, page 109

You can use your thumbs on the LCD to move the AF target around the frame when your eye is to the EVF

See manual, page 105 - the term is called AF Targeting Pad - of course in Custom Menu > Cog A

For non electronically coupled lens, you can name the lens, add focal length, f/no

See manual, page 129 - Custom Menu > Cog K

There are Selfie Assist functions - E-Portrait to smoothen your wrinkles, time delay for the selfie

See manual, page 128, - Custom Menu > Cog K

There is a My Clips facility - short 16 second videos 

See manual, page 70

There is a slow mo movie facility - 120 fps Standard Definition movies played back at 30 fps

See manual, page 73

Face Priority affects not only AF but may affect exposure measurement

This may not be new but worth mentioning - see manual  page 48
When the metering mode is ESP, Face Priority emphasises exposure  of the face.
Even in MF mode, Face Priority emphasises exposure of the face
In a burst, Face Priority only evaluates the first frame of the sequence.

C-AF no worse than other Olympus bodies

There has been a video review where the reviewer went an did a dang thing like fit the huge 300mm f/4 lens to this tiny body and attempted C-AF - result, AF hesitation. Mirrorless bodies still have some way to go to reach the Canon 1D II / 7D prowess with C-AF. Many Olympus users simply use S-AF and in the words of a wise sage: "Half press, observe whether focus has been achieved, if not release and repeat, several times until you get it"

Exposure Compensation has come to Auto ISO on Manual Exposure mode

Many Manual Exposure mode shooters revert to the film era expectation of setting fixed ISO when on Manual Exposure - that means exposure is completely and utterly manual, no shenanigans and that's how it worked in the film days. A bunch of migrators from Nikon DSLR have been crying out for Auto ISO on Manual Exposure and on top of that, changing the Exposure Value Compensation. Prior to the PEN-F, Olympus bodies allowed Auto ISO on Manual Exposure but EV Comp did nothing in that situation. The PEN-F now allows this Nikonish feature.

1. Set the camera to Manual Exposure Mode.
2. Custom Menu > Cog E > ISO Auto > Select ALL instead of P/A/S
3. Ensure that your EVF is not set to S-OVF  (Custom Menu > Cog J > S-OVF)
4. Ensure that Liveview Boost is Off (Custom Menu > Cog D > Live View Boost)
5. Ensure that your EV Compensation dial is not disabled (Custom Menu > Cog B)
6. Set your ISO to Auto (use the Super Control Panel)