Micro 4/3 and LCP


#1

Hi,

I read that LCP is not necessary with Olympus/Panasonic cameras since lens correcting is applied to the photo in the camera before saving as ORF. For this reason, Adobe does not provide any LCP for Micro 4/3. Why is there an option for LCP in RT for Micro 4/3 cameras (lensfun)? It even appears to do something.

Is it recommended to activate lensfun lens correction for these brands/lenses or not?

thanks and regads
b


(Pat David) #2

Do you remember where you read this? I’ve found the images on my E-M5 (original) need it…


#3

It is kind of everywhere, just google for “olympus lcp”

https://www.ephotozine.com/forums/topic/lens-correction-profiles-for-panasonic-and-olympus-in-lightroom-108719

If you install LR or DNG converter, you cannot find an Olympus or Panasonic folder inside the lensprofiles folder.


(Morgan Hardwood) #4

Why is there salt on the table at a high end restaurant?

The option is there for all file formats.

Some cameras perform distortion correction in-camera, most don’t. Those that do, do it on the embedded JPEG, or store the correction parameters as metadata (opcodes or other). The raw data is not touched. No doubt you’ve already read the relevant article in RawPedia, so you know how the JPEG correction applies to the raw, uncorrected data and how it can fail. These tools let you perform the correction in other ways, which may do the job better than the camera did, or at least differently.


(Morgan Hardwood) #5

Look inside the Sigma, Samyang, Rokinon, Bower and Lensbaby folders.


#6

sure, because lens correction cannot be done in the camera for those lenses, there is no data. But it is (allegedly) done with olympus and panasonic (“original”) lenses


#7

My Olympus E-PL5 with Olympus lenses does not correct the ORF file, only the JPG. I use distortion correction in RT all the time.

You can check this yourself: take a wide-angle picture of a close subject, and look at the ORF and the JPG. At least in my case, they are clearly different.


#8

I have read somewhere that the E-PLs do not do lens correction in the ORFs.

I will definitely try what you suggested eventually


#9

I would be surprised if the low-end models don’t cook the ORFs but the high-end models do.


(Alberto) #10

The correction parameters are stored in the file metadata. The raw data are uncorrected. RawTherapee doesn’t know how to read such metadata, so it doesn’t apply those corrections.


(Morgan Hardwood) #11

Wouldn’t be raw if it was cooked.


#12

I agree, but some cameras are alleged to serve RAW files that have been processed. IIRC, some Sony models applied noise reduction before saving the RAW image, for example.


(Flössie) #13

Canons fix stuck pixels even in the raw, FWIW. I can confirm this with my 600D.


#14

LR does it automatically with my OM-D. RT does not do it automatically.

Lensfun works well.
Thanks for the feedback! Nice to know the facts.


#15

The interesting thing is though: the distortions are not visible on the camaera’s display in liveview, as far as I remember
when I was taking the shot, I was looking for the wide-angle distortion and was not sure whether my lens is wide enough or had any distaortions at all

And one more thing: In LR there appears to be no way to undo the correction. there is the option tho correct the correction, but the result is that one part of the photo is cropped, if you try to undo the correction manually


#16

Most, if not all, camera displays tend to show you what the JPG will look like. This is something to be aware of if you shoot raw. For example, the display/histogram may show highlight clipping when the raw will not actually clip (because of a high-contrast setting for example).


(Morgan Hardwood) #17

@betazoid first point:
http://rawpedia.rawtherapee.com/The_Image_Editor_Tab#Eek.21_My_Raw_Photo_Looks_Different_than_the_Camera_JPEG


#18

Micro Four Thirds cameras have a lens correction profile (lcp) saved with the raw file, but not applied to the raw file.

Many software, including some third party software like Adobe PS and LR, apply this lcp automatically when processing the raw file. These images look like the JPEG, which in turn looks like the on-screen live view for all cameras when in live view.

Other raw software ignores the embedded lcp, like DxO and RawTherapee and RPP64. These processed raw files will not look like the live view (or JPEG) seen in the camera.


(Morgan Hardwood) #19

Can you prove that?


#20

I have a lot of m43 experience and can confirm it from experience.

Proof is not something I have sought.