Leica T performs digital lens correction , a claim by dpreview.com

[imants]

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[earleygallery]

Hi There James

No - they aren't wrong, but perhaps you are misunderstanding.

 

The lens corrections are applied to the JPG files automatically and can't be removed.

 

If you shoot RAW, then the lens corrections are not applied to the data from the sensor - they are a list of instructions to the RAW converter - Lightroom will apply them by default (I'm not sure if you can choose not to apply them in LR - I'm sure someone else will know (I use Aperture)).

 

If you use a different converter which either doesn't apply the lens corrections automatically, or doesn't apply them at all, then they are not applied. As Michael said, these are optcodes which are included in the RAW file (which is a package rather than just the data from the sensor - it also holds exif information etc. etc.). There are other optocdes for dealing with Chromatic aberration etc.

 

Almost all modern zoom lenses are designed to use these corrections (why would you not if it improves the image quality). They aren't a lazy short cut, but an extra opportunity.

 

So - with respect to the T - you can choose to apply them - or not. I actually quite agree with AlanG (I think it was Alan) who said he'd rather not apply them to landscape and some other situations where a bit of distortion isn't noticeable but maximum sharpness is important.

 

But of course, if you have the T and you have a shot where you'd rather not apply the opt codes then you can use a different RAW converter to create a TIFF file which you can use in your normal workflow (let's face it, it's not going to be every shot).

 

All the best

 

Hi Jono,

 

I am not misunderstanding. I know Leica have chosen to apply auto lens correction in their bundled software and - AFAIK - their bundled RAW converter does not allow the user to 'switch off' the lens correction.

 

My point is why are they imposing these corrections and not allowing the user to choose? Why must the user look for another type of RAW converter?

 

It seems that Leica - knowing fully well that most T users will only ever use Jpegs and those that do venture into RAW will be unlikely to look for other software - are trying to impose default correction to mask the otherwise mediocre performance (distortion wise) of the kit lens.

 

Basically, they're not exactly being transparent about it are they? To be kind to them, maybe they just think that the T buyer doesn't want to be confused by such issues!

[mjh]

My point is why are they imposing these corrections and not allowing the user to choose?

Leica isn’t imposing anything. They are writing the opcodes to the DNG file – which is the transparent way to do this as specified in DNG 1.3 and 1.4 – and leave their application to the raw converter. What else could they have done?

[UliWer]

Well, the M (8.9, Typ 240) has a lens-correction by software applied to the DNG-files in camera, if the lenses 6-bit code is detected. Since the M9 you can choose the correction manually from a menue - and you can switch it off.

 

Though I don't know if it would make any sense to switch off the software correction of distortion for a T-lense.

[earleygallery]

Leica isn’t imposing anything. They are writing the opcodes to the DNG file – which is the transparent way to do this as specified in DNG 1.3 and 1.4 – and leave their application to the raw converter. What else could they have done?

 

An option to use the uncorrected file? My Canon has the option to use correction or not in its menu, as well as having the further option of using other software correction myself i.e. for non Canon lenses.

[jaapv]

Yes, but that applies to corrections in the camera, which is not the case here. The corrections are implemented in raw conversion and the camera just includes directions. It would make no sense to cripple the file by leaving information out. The thing that is really needed is an option to switch off the corrections in ACR, to eliminate the need to sidestep to another raw converter.

 

Btw. where does the assumption that future users will not use raw come from? Rather condescending. There are even cellphones offering raw output nowadays.

[xalo]

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...I know Leica have chosen to apply auto lens correction in their bundled software and - AFAIK - their bundled RAW converter does not allow the user to 'switch off' the lens correction.

 

My point is why are they imposing these corrections and not allowing the user to choose? Why must the user look for another type of RAW converter?

...

 

This strategy appears to be exactly the same as the one used in the D-Lux series (4 & 5 at least). Converting in Raw Photo Processor revealed this as a surprise to me. The native vignetting and distortion at the wide end of the D-Lux 5's zoom is impressively strong. I have not seen any review picking this up, though — it goes relatively unnoticed in most cases, but even digitally corrected the images at 24mm equivalent are not totally rectilinear.

 

That said, I guess we're close to the philosophical debate about what a photographic image is in the digital age and what each photographer (and perhaps company) is expecting it to be. To make sure that a photographer can make an informed choice among the options, they must be visible — and accessible.

 

Alexander

[imants]

[quote

Btw. where does the assumption that future users will not use raw come from? Rather condescending. There are even cellphones offering raw output nowadays.

 

Nothing condescending so what cellphone offer raw they also assist in making phone calls.... most people like to take photos not spend time with computers post processing etc.

[mjh]

An option to use the uncorrected file?

That is an option. The metadata required for the correction are present; it is up to the raw converter to use it or not. This isn’t like the corrections applied by the digital M models where the actual image data are modified.

[jonoslack]

Hi Jono,

 

I am not misunderstanding. I know Leica have chosen to apply auto lens correction in their bundled software and - AFAIK - their bundled RAW converter does not allow the user to 'switch off' the lens correction.

 

The "bundled RAW converter" is probably the most used photographic program in the world. Lightroom is an Adobe product, Leica has nothing to do with it's options, so if Adobe choose not to give the option to exclude the lens corrections, you can hardly blame Leica.

 

I would be extremely surprised if there were any modern zoom lenses that do not do this. Gordon Bennett even Hasselblad do it!

 

But go ahead and blame Adobe for not allowing you to turn them off (I know I do!)

[pgk]

For those of you who have seen the film "Chariots of Fire", a quote from Harald Abrahams may be relevant to this thread, said after being lectured on the ways of the amateur and his perceived 'professionalism':

 

"You know, gentlemen, you yearn for victory just as I do, but achieved with the apparent effortlessness of the gods. Yours are the archaic values of the past....."

 

Perhaps a rewrite:

 

"You know, gentlemen, you yearn for the best 'image quality' just as I do, but achieved just with conventional optical design......"

 

Just think what interesting times we live in. Combining absolute optical excellence with software adjustment might just achieve some spectacular results, and here we are with Leica at the start:).

[jaapv]

The "bundled RAW converter" is probably the most used photographic program in the world. Lightroom is an Adobe product, Leica has nothing to do with it's options, so if Adobe choose not to give the option to exclude the lens corrections, you can hardly blame Leica.

 

I would be extremely surprised if there were any modern zoom lenses that do not do this. Gordon Bennett even Hasselblad do it!

 

But go ahead and blame Adobe for not allowing you to turn them off (I know I do!)

 

But, seeing that there is a nag window in place already, it might be possible for Leica to prevail on Adobe to turn this into an option window.

[mjh]

The "bundled RAW converter" is probably the most used photographic program in the world. Lightroom is an Adobe product, Leica has nothing to do with it's options, so if Adobe choose not to give the option to exclude the lens corrections, you can hardly blame Leica.

And btw: While DNG provides the option to include lists of opcodes to indicate how a raw converter might improve an image, there is no option to tell it whether it may, must, or must not use those hints. Adobe thinks it has to but there is nothing in the DNG specs making the application of opcodes mandatory.

[CaptZoom]

Nothing condescending so what cellphone offer raw they also assist in making phone calls....most people like to take photos not spend time with computers post processing etc.

 

 

Yup...that explains Instagram's success.

[rosuna]

A question arising now: Are S lenses designed with software correction in mind just like the T lenses?

 

If the answer is "no", why not? It should allow smaller, cheaper or higher corrected lenses (except for distortion and lateral chroma)...

 

Is the M system the last traditional system out there? (almost pure mechano-optical).

[pico]

[...] it might be possible for Leica to prevail on Adobe to turn this into an option window.

 

Even Apple could not persuade Adobe to update in a timely manner. As Steve Jobs said, "Adobe is lazy."

[CaptZoom]

A question arising now: Are S lenses designed with software correction in mind just like the T lenses?

 

None never checked this?

 

If the answer is "no", why not? It should allow smaller, cheaper or higher corrected lenses (except for distortion and lateral chroma)...

 

Is the M system the last traditional system out there? (almost pure mechano-optical).

 

 

M lenses make use of software correction in-camera on digital M bodies which can then be further corrected in post-processing software such as LR which has Leica lens profiles to make further corrections.

 

Dunno about the S series.

[diogenis]

It appears that every system has these corrections.

And that there is a gold ratio of size of a lens vs these corrections. I would guess the larger the lens the less the need for these filters, but the more the weight/mass then.

M and T are very compact systems and for these lenses to perform like they do is an engineering marvel.

M lenses however are different because they can be used both in an MP and an M so someone can clearly see the differencies. show us the differenceies guys, Jaap can do that easily as he has both cameras

As for MTF graphs these are shown on every M lens.

[rosuna]

M lenses make use of software correction in-camera on digital M bodies which can then be further corrected in post-processing software such as LR which has Leica lens profiles to make further corrections.

 

I know, but the Ms are not lenses designed considering software corrections, because they have to perform well on film too.

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[sandymc]

A question arising now: Are S lenses designed with software correction in mind just like the T lenses?

 

The S DNGs that I have looked at do not have software correction opcodes in the DNG. But (a) I might not have looked at the "right" lens, and ( you could perhaps perform correction on the raw data, although in my view that would be a (very much) less than optimal way of doing things.

 

Sandy